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Documentation

Apache HugeGraph Documentation

Apache HugeGraph includes graph database, graph computing, and graph AI components. The HugeGraph core engine manages property graphs, transactions, and real-time queries; Computer and Vermeer run graph algorithms; and HugeGraph-AI provides GraphRAG, graph machine learning, and a Python client.

Quick Navigation by Scenario

I want to…Start here
Run graph queries (OLTP)HugeGraph Server Quickstart
Large-scale graph computing (OLAP)Graph Computing Engine
Build Graph + AI applicationsHugeGraph-AI
Batch import dataHugeGraph Loader
Visualize and manage graphsHubble Web UI

Ecosystem Overview

┌─────────────────────────────────────────────────────────────────┐
│                  Apache HugeGraph Ecosystem                      │
├─────────────────────────────────────────────────────────────────┤
│  ┌─────────────┐  ┌─────────────┐  ┌─────────────────────────┐  │
│  │ HugeGraph   │  │ HugeGraph   │  │ HugeGraph-AI            │  │
│  │ Core Engine │  │ Computer    │  │ (GraphRAG/ML/Python)    │  │
│  │ (OLTP)      │  │ (OLAP)      │  │                         │  │
│  └─────────────┘  └─────────────┘  └─────────────────────────┘  │
│         │               │                    │                   │
│  ┌──────┴───────────────┴────────────────────┴──────────────┐   │
│  │              HugeGraph Toolchain                          │   │
│  │  Hubble (UI) | Loader | Client (Java/Go/Py) | Tools      │   │
│  └───────────────────────────────────────────────────────────┘   │
└─────────────────────────────────────────────────────────────────┘

Core Components

  • HugeGraph Core Engine (OLTP): Exposes REST APIs through HugeGraph Server and supports Gremlin and Cypher queries
  • HugeGraph Toolchain: Includes Java/Go clients, Loader, Hubble, Spark Connector, and Tools; the Python client is maintained in HugeGraph-AI, and a Rust client is under development
  • HugeGraph Computer: Contains the distributed Computer engine and the in-memory Vermeer engine
  • HugeGraph-AI: Includes GraphRAG, graph machine learning, the Python client, and the Vermeer Python client

Deployment Modes

ModeCore ComponentsSuitable ScenariosData Scale
StandaloneServer + RocksDBDevelopment, testing, and small to medium-scale data≤ 2 TB
DistributedServer + PD + Store (HStore)Production, horizontal scaling, and multi-replica deployment≤ 1 PB

See the system introduction and the corresponding quick-start guides for each component’s scope and startup instructions.

1 - Apache HugeGraph Introduction

What Is Apache HugeGraph?

Apache HugeGraph is an easy-to-use, efficient, general-purpose open-source full-stack graph system (GitHub). It covers three major areas: graph databases (OLTP real-time queries), graph computing (OLAP large-scale analysis), and graph AI (GraphRAG and graph machine learning).

HugeGraph supports fast storage and queries for tens of billions of vertices and edges, with strong OLTP performance. Its graph engine is compatible with Apache TinkerPop 3 and supports both Gremlin and Cypher (the OpenCypher standard).

Typical use cases: deep relationship exploration, association analysis, path search, feature extraction, community detection, and knowledge graphs. Application areas: network security, telecom anti-fraud, financial risk control, advertising and recommendations, social networks, and intelligent Q&A.

Ecosystem Overview

┌────────────────────────────────────────────────────────────────────┐
│            Apache HugeGraph - Full-Stack Graph System             │
├──────────────────┬────────────────────┬────────────────────────────┤
│  Graph DB (OLTP) │    Graph Compute   │          Graph AI          │
│  HugeGraph       │  Vermeer (Memory)  │       HugeGraph-AI         │
│  Server          │  Computer (Dist.)  │     GraphRAG / GNN / Py    │
├──────────────────┴────────────────────┴────────────────────────────┤
│                       HugeGraph Toolchain                          │
│ Hubble | Loader | Client (Java/Go/Python; Rust WIP) | Spark | Tools│
└────────────────────────────────────────────────────────────────────┘

HugeGraph Server (OLTP Graph Engine)

HugeGraph Server is the OLTP engine and service entry point for the graph database. It handles property graph modeling, transaction processing, query execution, and API access. Graph data is stored in the configured RocksDB, HStore, or HBase backend.

  • Property graph and schema: Manages VertexLabel, EdgeLabel, PropertyKey, and IndexLabel definitions
  • Query languages: Supports Gremlin (TinkerPop 3) and Cypher (OpenCypher)
  • REST API: Provides endpoints for schemas, graph data, queries, tasks, and operations
  • Indexes and queries: Supports exact, range, and compound-condition queries
  • Storage backends: Versions 1.7.0 through master primarily support RocksDB (standalone), HStore (distributed), and HBase

The main modules include hugegraph-core, the storage backend modules, and hugegraph-api. Core implements the graph model, transactions, and query logic; backend modules connect to specific storage systems; and the API module provides HTTP access. Current REST resource paths include the graph space and graph name, for example:

/graphspaces/{graphspace}/graphs/{graph}

Standalone deployments commonly use RocksDB. Distributed deployments use HStore: PD manages cluster metadata and partition scheduling, while Store persists graph data and replicas. HBase can be used as a separate storage backend.

HugeGraph Toolchain

HugeGraph Toolchain provides clients, data import, visual management, Spark integration, and command-line operations. Together, these tools cover the main stages of a graph application’s lifecycle, from data ingestion to routine management.

ModulePurpose
ClientWraps schema management, graph data reads and writes, Gremlin, and Traverser APIs; supports Java, Python, and Go, with a Rust client under development
LoaderReads data from local files, HDFS, JDBC, Kafka, or another graph, converts it into vertices and edges, and imports it into HugeGraph in batches
HubbleProvides a web management interface for graph connections, schemas, data import, Gremlin queries, and visual results
Spark ConnectorReads and writes HugeGraph data in Spark jobs for offline big-data processing
ToolsProvides command-line operations for deployment, graph management, backup and restore, and Gremlin execution

Graph Computing Engines (OLAP)

The HugeGraph-Computer repository provides two complementary OLAP graph computing engines:

  • Vermeer: Written in Go, it uses a master-worker architecture and primarily performs in-memory computation. It provides REST APIs, gRPC, and a web UI, and is suitable for fast small- and medium-scale graph analysis.
  • Computer: Written in Java, it implements the distributed BSP/Pregel computing model and can run on Kubernetes, YARN, or local processes. It can spill data to disk when memory thresholds are exceeded and is suitable for larger graph computing workloads.

Both engines can read HugeGraph data, but their runtime architectures, resource requirements, configuration, and algorithm interfaces differ.

HugeGraph-AI (Graph + AI)

HugeGraph-AI connects graph technology with large language models and graph machine learning frameworks. The repository uses Python 3.10 or later and manages its workspace with uv. Its main modules are:

  • hugegraph-llm: Provides GraphRAG, knowledge graph construction, natural-language queries, and Text2Gremlin
  • hugegraph-ml: Provides models for node classification, graph classification, graph embeddings, link prediction, and fraud detection
  • hugegraph-python-client: Manages schemas, graph data, and Gremlin queries from Python
  • vermeer-python-client: Calls Vermeer graph computing services from Python

HugeGraph-AI Quick Start

Deployment Modes

ModeCore ComponentsSuitable ScenariosData Scale
Standalone (OLTP)Server + RocksDBDevelopment, testing, and small to medium-scale data≤ 2 TB
Distributed (OLTP)Server + PD + Store (HStore)Production, horizontal scaling, and multi-replica deployment≤ 1 PB

Graph computing is an OLAP workload. Its capacity and resource requirements depend on the selected engine, graph structure, and algorithm, and do not use the OLTP storage capacity figures above.

Where to Start

GoalDocumentation
Start the graph database and run queriesServer Quick Start
Import data in batchesLoader
Manage graphs through a web interfaceHubble
Run graph algorithmsVermeer and Computer
Build GraphRAG or graph machine learning applicationsHugeGraph-AI

Community

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1.1 - Introduction with HugeGraph

Summary

Apache HugeGraph is an easy-to-use, efficient, general-purpose open-source graph database system (Graph Database, GitHub project address), implementing the Apache TinkerPop3 framework and fully compatible with the Gremlin query language, With complete toolchain components, it helps users easily build applications and products based on graph databases. HugeGraph supports fast import of more than 10 billion vertices and edges, and provides millisecond-level relational query capability (OLTP). It also supports large-scale distributed graph computing (OLAP).

Typical application scenarios of HugeGraph include deep relationship exploration, association analysis, path search, feature extraction, data clustering, community detection, knowledge graph, etc., and are applicable to business fields such as network security, telecommunication fraud, financial risk control, advertising recommendation, social network, and intelligence Robots, etc.

Features

HugeGraph supports graph operations in online and offline environments, batch importing of data and efficient complex relationship analysis. It can seamlessly be integrated with big data platforms. HugeGraph supports multi-user parallel operations. Users can enter Gremlin query statements and get graph query results in time. They can also call the HugeGraph API in user programs for graph analysis or queries.

This system has the following features:

  • Ease of use: HugeGraph supports the Gremlin graph query language and a RESTful API, providing common interfaces for graph retrieval, and peripheral tools with complete functions to easily implement various graph-based query and analysis operations.
  • Efficiency: HugeGraph has been deeply optimized in graph storage and graph computing, and provides a variety of batch import tools, which can easily complete the rapid import of tens of billions of data, and achieve millisecond-level response for graph retrieval through optimized queries. Supports simultaneous online real-time operations of thousands of users.
  • Universal: HugeGraph supports the Apache Gremlin standard graph query language and the Property Graph standard graph modeling method, and supports graph-based OLTP and OLAP schemes. Integrate Apache Hadoop and Apache Spark big data platforms.
  • Scalable: supports distributed storage, multiple copies of data, and horizontal expansion, built-in multiple back-end storage engines, and can easily expand the back-end storage engine through plug-ins.
  • Open: HugeGraph code is open source (Apache 2 License), customers can modify and customize independently, and selectively give back to the open-source community.

The functions of this system include but are not limited to:

  • Supports batch import of data from multiple data sources (including local files, HDFS files, MySQL databases, and other data sources), and supports import of multiple file formats (including TXT, CSV, JSON, and other formats)
  • With a visual operation interface, it can be used for operation, analysis, and display diagrams, reducing the threshold for users to use
  • Optimized graph interface: shortest path (Shortest Path), K-step connected subgraph (K-neighbor), K-step to reach the adjacent point (K-out), personalized recommendation algorithm PersonalRank, etc.
  • Implemented based on the Apache TinkerPop3 framework, supports Gremlin graph query language
  • Support attribute graph, attributes can be added to vertices and edges, and support rich attribute types
  • Has independent schema metadata information, has powerful graph modeling capabilities, and facilitates third-party system integration
  • Support multi-vertex ID strategy: support primary key ID, support automatic ID generation, support user-defined string ID, support user-defined digital ID
  • The attributes of edges and vertices can be indexed to support precise query, range query, and full-text search
  • The storage system adopts a plug-in method, supporting RocksDB (standalone/cluster), Cassandra, ScyllaDB, HBase, MySQL, PostgreSQL, Palo and Memory, etc.
  • Integrated with big data systems such as HDFS, Spark/Flink, GraphX, etc., supports BulkLoad operation to import massive data.
  • Supports HA(high availability), multiple data replicas, backup and recovery, monitoring, distributed Trace, etc.

Modules

  • [HugeGraph-Store]: HugeGraph-Store is a distributed storage engine to manage large-scale graph data by integrating storage and computation within a unified system.
  • [HugeGraph-PD]: HugeGraph-PD (Placement Driver) manages metadata and coordinates storage nodes.
  • HugeGraph-Server: HugeGraph-Server is the core part of the HugeGraph project, containing Core, Backend, API and other submodules;
    • Core: Implements the graph engine, connects to the Backend module downwards, and supports the API module upwards;
    • Backend: Implements the storage of graph data to the backend, supports backends including Memory, Cassandra, ScyllaDB, RocksDB, HBase, MySQL and PostgreSQL, users can choose one according to the actual situation;
    • API: Built-in REST Server provides RESTful API to users and is fully compatible with Gremlin queries. (Supports distributed storage and computation pushdown)
  • HugeGraph-Toolchain: (Toolchain)
    • HugeGraph-Client: HugeGraph-Client provides a RESTful API client for connecting to HugeGraph-Server, currently only the Java version is implemented, users of other languages can implement it themselves;
    • HugeGraph-Loader: HugeGraph-Loader is a data import tool based on HugeGraph-Client, which transforms ordinary text data into vertices and edges of the graph and inserts them into the graph database;
    • HugeGraph-Hubble: HugeGraph-Hubble is HugeGraph’s Web visualization management platform, a one-stop visualization analysis platform, the platform covers the whole process from data modeling, to fast data import, to online and offline analysis of data, and unified management of the graph;
    • HugeGraph-Tools: HugeGraph-Tools is HugeGraph’s deployment and management tool, including graph management, backup/recovery, Gremlin execution and other functions.
  • HugeGraph-Computer: HugeGraph-Computer is a distributed graph processing system (OLAP). It is an implementation of Pregel. It can run on clusters such as Kubernetes/Yarn, and supports large-scale graph computing.
  • HugeGraph-AI: HugeGraph-AI is HugeGraph’s independent AI component, providing training and inference functions of graph neural networks, LLM/Graph RAG combination/Python-Client and other related components, continuously updating.

Contact Us

Apache HugeGraph WeChat QR Code{width=“300” height=“94”}

2 - Download Apache HugeGraph (Incubating)

Instructions:

  • It is recommended to use the latest version of the HugeGraph software package. Please select Java11 for the runtime environment.
  • To verify downloads, use the corresponding hash (SHA512), signature, and Project Signature Verification KEYS.
  • Instructions for checking hash (SHA512) and signatures are on the Validate Release page, and you can also refer to ASF official instructions.
  • Note: The version numbers of all components of HugeGraph have been kept consistent, and the version numbers of Maven repositories such as client/loader/hubble/common are the same. You can refer to these for dependency references maven example.

Latest Version 1.7.0

Binary Packages

ServerToolchain
[Binary] [Sign] [SHA512][Binary] [Sign] [SHA512]

Source Packages

Please refer to build from source.

ServerToolchainAIComputer
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Archived Versions

Note: 1.3.0 is the last major version compatible with Java8, please switch to or migrate to Java11 as soon as possible (lower versions of Java have potentially more SEC risks and performance impacts). Starting from version 1.5.0, a Java11 runtime environment is required.

1.5.0

Binary Packages
ServerToolchain
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Source Packages
ServerToolchainAIComputer
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1.3.0

Binary Packages
ServerToolchain
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Source Packages
ServerToolchainAICommon
[Source] [Sign] [SHA512][Source] [Sign] [SHA512][Source] [Sign] [SHA512][Source] [Sign] [SHA512]

1.2.0

Binary Packages
ServerToolchain
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Source Packages
ServerToolchainComputerCommon
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1.0.0

Binary Packages
ServerToolchainComputer
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Source Packages
ServerToolchainComputerCommon
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3 - Quick Start

Choose the quick-start guide for Server, Toolchain, graph computing, or HugeGraph-AI according to your needs. Each component is released independently, so check the runtime requirements and version of the corresponding repository before installation.

3.1 - HugeGraph (OLTP)

🚀 Best practice: Prioritize using DeepWiki intelligent documents

To address the issue of outdated static documents, we provide DeepWiki with real-time updates and more comprehensive content. It is equivalent to an expert with the latest knowledge of the project, which is very suitable for all developers to read and consult before starting the project.

👉 Strongly recommend visiting and having a conversation with: incubator-hugegraph

3.1.1 - HugeGraph Server Quick Start

1 HugeGraph Server Overview

apache/hugegraph is the main repository for the HugeGraph graph database. Its top-level modules include hugegraph-server, hugegraph-pd, and hugegraph-store. This page describes the hugegraph-server module and the service it runs.

The hugegraph-server module contains hugegraph-core, hugegraph-api, hugegraph-dist, and storage adapters. Core implements the property graph model, transactions, and TinkerPop interfaces. API provides the HTTP service and delegates client requests to Core. Graph data is stored in RocksDB (the default standalone backend), HStore (distributed), or HBase.

⚠️ Version note: This page follows HugeGraph 1.7.0 through the master branch and covers only RocksDB, HStore, and HBase. For other legacy backends and their configuration, see the HugeGraph 1.5.x documentation.

Naming: HugeGraph means the overall project or main repository, hugegraph-server is the Server module in that repository, and HugeGraphServer is the Java class for the service process. This page uses “Server service” for a running graph database service.

2 Dependency for Building/Running

2.1 Install Java 11 (JDK 11)

The hugegraph-server module in HugeGraph 1.7.0 is compiled with Java 11. Running and building it from source require Java 11 or later.

Before continuing, run java -version to confirm your JDK version.

Java 8 is no longer supported starting from 1.7.0.

3 Deploy

There are four ways to deploy the Server service:

  • Method 1: Use Docker container (Convenient for Test/Dev)
  • Method 2: Download the binary tarball
  • Method 3: Source code compilation
  • Method 4: One-click deployment

Do not expose Gremlin, Cypher, or other query endpoints directly to the public Internet. In production, enable authentication and authorization, restrict network access, and retain audit logs. See the Security Guide for deployment guidance.

3.1 Use Docker container (Convenient for Test/Dev)

You can refer to the Docker deployment guide.

You can use docker run -itd --name=server -p 8080:8080 -e PASSWORD=xxx hugegraph/hugegraph:1.7.0 to quickly start a Server instance using the RocksDB backend.

Optional:

  1. You can use docker exec -it server bash to enter the container for troubleshooting or other maintenance operations.
  2. You can use docker run -itd --name=server -p 8080:8080 -e PRELOAD="true" hugegraph/hugegraph:1.7.0 to preload a built-in sample graph at startup. You can verify it through the RESTful API. See 5.1.4 for details.
  3. You can use -e PASSWORD=xxx to enable authentication mode and set the admin password. See Config Authentication for details.

If you use Docker Desktop, you can set the options as follows:

Docker Desktop settings for a HugeGraph container

Note: The Docker Compose files use bridge networking (hg-net) and work on Linux and Mac (Docker Desktop). For the 3-node distributed cluster on Mac (Docker Desktop), allocate at least 12 GB of memory (Settings → Resources → Memory). On Linux, Docker uses host memory directly.

If you want a single, unified setup for multiple HugeGraph services, you can use docker compose. Two compose files are available in the docker/ directory:

  • Single-node quickstart (pre-built images): docker/docker-compose.yml
  • Single-node dev build (build from source): docker/docker-compose.dev.yml
cd hugegraph/docker
# Keep the version aligned with the latest release, for example 1.x.0
HUGEGRAPH_VERSION=1.7.0 docker compose up -d

To enable authentication, add PASSWORD=xxx to the service environment in the compose file or pass -e PASSWORD=xxx to docker run.

See docker/README.md for the full setup guide.

Note:

  1. HugeGraph Docker images are provided as a convenient way to start HugeGraph quickly, but they are not official ASF distribution artifacts. You can find more details in the ASF Release Distribution Policy.

  2. We recommend using a release tag (such as 1.7.0 or 1.x.0) for stable deployments. Use the latest tag only if you want the newest features still under development.

3.2 Download the binary tarball

You could download the binary tarball from the download page of the ASF site like this:

# 1.7.0 is a historical release from the incubation period, so its file name still includes "incubating"
wget https://downloads.apache.org/hugegraph/1.7.0/apache-hugegraph-incubating-1.7.0.tar.gz
tar zxf apache-hugegraph-incubating-1.7.0.tar.gz

# (Optional) verify the integrity with SHA512 (recommended)
shasum -a 512 apache-hugegraph-incubating-1.7.0.tar.gz
curl https://downloads.apache.org/hugegraph/1.7.0/apache-hugegraph-incubating-1.7.0.tar.gz.sha512

3.3 Source code compilation

Please ensure that the wget/curl commands are installed before compiling the source code

Download HugeGraph source code in either of the following 2 ways (so as the other HugeGraph repos/modules):

  • download the stable/release version from the ASF site
  • clone the unstable/latest version by GitBox(ASF) or GitHub
# Way 1. download release package from the ASF site
wget https://downloads.apache.org/hugegraph/{version}/apache-hugegraph-incubating-src-{version}.tar.gz
tar zxf *hugegraph*.tar.gz

# (Optional) verify the integrity with SHA512 (recommended)
shasum -a 512 apache-hugegraph-incubating-src-{version}.tar.gz
curl https://downloads.apache.org/hugegraph/{version}/apache-hugegraph-incubating-{version}-src.tar.gz.sha512

# Way2 : clone the latest code by git way (e.g GitHub)
git clone https://github.com/apache/hugegraph.git

Compile and generate tarball

cd *hugegraph
# (Optional) use "-P stage" param if you build failed with the latest code(during pre-release period)
mvn package -DskipTests -ntp

A successful build includes the following line:

[INFO] BUILD SUCCESS

After a successful build, the generated distribution is the *hugegraph-*.tar.gz file in the repository root.

Outdated tools

3.4 One-click deployment (Outdated)

HugeGraph-Tools provides a one-click deployment command that downloads, extracts, configures, and starts the Server service and HugeGraph-Hubble. These tools are included in the HugeGraph-Toolchain distribution.

Of course, you should download the tarball of HugeGraph-Toolchain first.

# download toolchain binary package, it includes loader + tool + hubble
# please check the latest version (e.g. here is 1.7.0)
wget https://downloads.apache.org/hugegraph/1.7.0/apache-hugegraph-toolchain-incubating-1.7.0.tar.gz
tar zxf *hugegraph-*.tar.gz

# enter the tool's package
cd *hugegraph*/*tool*

note: ${version} is the version, The latest version can refer to Download Page, or click the link to download directly from the Download page

The general entry script for HugeGraph-Tools is bin/hugegraph, Users can use the help command to view its usage, here only the commands for one-click deployment are introduced.

bin/hugegraph deploy -v {hugegraph-version} -p {install-path} [-u {download-path-prefix}]

{hugegraph-version} is the Server service and HugeGraphStudio version; see conf/version-mapping.yaml for supported mappings. {install-path} is the installation directory, while {download-path-prefix} optionally overrides the tarball download location. For example, deploy version 0.6 with bin/hugegraph deploy -v 0.6 -p services.

4 Config

If you need to quickly start HugeGraph just for testing, then you only need to modify a few configuration items (see next section). For detailed configuration introduction, please refer to configuration document and introduction to configuration items

5 Startup

5.1 Use a startup script to startup

Startup is divided into “first startup” and “non-first startup”. On the first startup, you need to initialize the backend database before starting the service.

If the service was stopped manually, or needs to be started again for any other reason, you can usually start it directly because the backend database is persistent.

When HugeGraphServer starts, it connects to the backend storage and checks its version information. If the backend has not been initialized, or if it was initialized with an incompatible version (for example, old-version data), HugeGraphServer will fail to start and report an error.

If you need to access HugeGraphServer externally, modify the restserver.url configuration item in rest-server.properties (the default is http://127.0.0.1:8080) and change it to the machine name or IP address.

Since the configuration (hugegraph.properties) and startup steps required by various backends are slightly different, the following will introduce the configuration and startup of each backend one by one.

Note: Configure Server Authentication before starting HugeGraphServer if you need Auth mode (especially for production or public network environments).

5.1.1 Distributed Storage (HStore)

Click to expand/collapse Distributed Storage configuration and startup method

Distributed storage is a new feature introduced after HugeGraph 1.5.0, which implements distributed data storage and computation based on HugeGraph-PD and HugeGraph-Store components.

To use the distributed storage engine, you need to deploy HugeGraph-PD and HugeGraph-Store first. See HugeGraph-PD Quick Start and HugeGraph-Store Quick Start.

After ensuring that both PD and Store services are started, modify the hugegraph.properties configuration of HugeGraph-Server:

backend=hstore
serializer=binary
task.scheduler_type=distributed

# PD service address, multiple PD addresses are separated by commas, configure PD's RPC port
pd.peers=127.0.0.1:8686,127.0.0.1:8687,127.0.0.1:8688
# Simple example (with authentication)
gremlin.graph=org.apache.hugegraph.auth.HugeFactoryAuthProxy

# Specify storage backend hstore
backend=hstore
serializer=binary
store=hugegraph

# Specify the task scheduler (for versions 1.7.0 and earlier, hstore storage is required)
task.scheduler_type=distributed

# pd config
pd.peers=127.0.0.1:8686

Then enable PD discovery in rest-server.properties (required for every HugeGraph-Server node):

usePD=true

# notice: must have this conf in 1.7.0
pd.peers=127.0.0.1:8686,127.0.0.1:8687,127.0.0.1:8688
# If auth is needed
# auth.authenticator=org.apache.hugegraph.auth.StandardAuthenticator

If configuring multiple HugeGraph-Server nodes, you need to modify the rest-server.properties configuration file for each node, for example:

Node 1 (Master node):

usePD=true
restserver.url=http://127.0.0.1:8081
gremlinserver.url=http://127.0.0.1:8181
pd.peers=127.0.0.1:8686

rpc.server_host=127.0.0.1
rpc.server_port=8091

server.id=server-1
server.role=master

Node 2 (Worker node):

usePD=true
restserver.url=http://127.0.0.1:8082
gremlinserver.url=http://127.0.0.1:8182
pd.peers=127.0.0.1:8686

rpc.server_host=127.0.0.1
rpc.server_port=8092

server.id=server-2
server.role=worker

Also, you need to modify the port configuration in gremlin-server.yaml for each node:

Node 1:

host: 127.0.0.1
port: 8181

Node 2:

host: 127.0.0.1
port: 8182

Initialize the database:

cd *hugegraph-${version}
bin/init-store.sh

Start the Server:

bin/start-hugegraph.sh

The startup sequence for using the distributed storage engine is:

  1. Start HugeGraph-PD
  2. Start HugeGraph-Store
  3. Initialize the database (only for the first time)
  4. Start HugeGraph-Server

Verify that the service is started properly:

curl http://localhost:8081/graphs
# Should return: {"graphs":["hugegraph"]}

The sequence to stop the services should be the reverse of the startup sequence:

  1. Stop HugeGraph-Server
  2. Stop HugeGraph-Store
  3. Stop HugeGraph-PD
bin/stop-hugegraph.sh
Docker Distributed Cluster

Run the full distributed cluster (3 PD + 3 Store + 3 Server) with Docker Compose:

cd hugegraph/docker
HUGEGRAPH_VERSION=1.7.0 docker compose -f docker-compose-3pd-3store-3server.yml up -d

Services communicate via container hostnames on the hg-net bridge network. Configuration is injected via environment variables:

# Server configuration
HG_SERVER_BACKEND: hstore
HG_SERVER_PD_PEERS: pd0:8686,pd1:8686,pd2:8686

Verify the cluster:

curl http://localhost:8080/versions
curl http://localhost:8620/v1/stores

To view runtime logs for any container use docker logs <container-name> (e.g. docker logs hg-pd0).

See docker/README.md for the full environment variable reference, port table, and troubleshooting guide.

5.1.2 RocksDB / ToplingDB

Click to expand/collapse RocksDB configuration and startup methods

RocksDB is an embedded database that does not require manual installation and deployment. GCC version >= 4.3.0 (GLIBCXX_3.4.10) is required. If not, GCC needs to be upgraded in advance

Update hugegraph.properties

backend=rocksdb
serializer=binary
rocksdb.data_path=.
rocksdb.wal_path=.

Initialize the database (required on the first startup, or a new configuration was manually added under ‘conf/graphs/’)

cd *hugegraph-${version}
bin/init-store.sh

Start server

bin/start-hugegraph.sh
Starting HugeGraphServer...
Connecting to HugeGraphServer (http://127.0.0.1:8080/graphs)....OK

ToplingDB (Beta): As a high-performance alternative to RocksDB, please refer to the configuration guide: ToplingDB Quick Start

5.1.3 HBase

Click to expand/collapse HBase configuration and startup methods

users need to install HBase by themselves, requiring version 2.0 or above,download link

Update hugegraph.properties

backend=hbase
serializer=hbase

# hbase backend config
hbase.hosts=localhost
hbase.port=2181
# Note: recommend to modify the HBase partition number by the actual/env data amount & RS amount before init store
# it may influence the loading speed a lot
#hbase.enable_partition=true
#hbase.vertex_partitions=10
#hbase.edge_partitions=30

Initialize the database (required on the first startup, or a new configuration was manually added under ‘conf/graphs/’)

cd *hugegraph-${version}
bin/init-store.sh

Start server

bin/start-hugegraph.sh
Starting HugeGraphServer...
Connecting to HugeGraphServer (http://127.0.0.1:8080/graphs)....OK

5.1.4 Create an example graph when startup

Pass the -p true argument when starting the script to enable preload, which creates a sample graph.

bin/start-hugegraph.sh -p true
Starting HugeGraphServer in daemon mode...
Connecting to HugeGraphServer (http://127.0.0.1:8080/graphs)......OK

And use the RESTful API to request HugeGraphServer and get the following result:

> curl "http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices" | gunzip

{"vertices":[{"id":"2:lop","label":"software","type":"vertex","properties":{"name":"lop","lang":"java","price":328}},{"id":"1:josh","label":"person","type":"vertex","properties":{"name":"josh","age":32,"city":"Beijing"}},{"id":"1:marko","label":"person","type":"vertex","properties":{"name":"marko","age":29,"city":"Beijing"}},{"id":"1:peter","label":"person","type":"vertex","properties":{"name":"peter","age":35,"city":"Shanghai"}},{"id":"1:vadas","label":"person","type":"vertex","properties":{"name":"vadas","age":27,"city":"Hongkong"}},{"id":"2:ripple","label":"software","type":"vertex","properties":{"name":"ripple","lang":"java","price":199}}]}

This indicates the successful creation of the sample graph.

5.2 Use Docker to startup

In 3.1 Use Docker container, we introduced how to deploy hugegraph-server with Docker. You can also switch storage backends or preload a sample graph by setting the corresponding parameters.

5.2.1 Create an example graph when starting a server

Set the environment variable PRELOAD=true when starting Docker so that sample data is loaded during startup.

  1. Use docker run

    Use docker run -itd --name=server -p 8080:8080 -e PRELOAD=true hugegraph/hugegraph:1.7.0

  2. Use docker-compose

    Create a docker-compose.yml file like the following and set PRELOAD=true in the environment. example.groovy is a predefined script used to preload sample data. If needed, you can mount a new example.groovy script to change the preload data.

    version: '3'
    services:
      server:
        image: hugegraph/hugegraph:1.7.0
        container_name: server
        environment:
          - PRELOAD=true
          - PASSWORD=xxx
        volumes:
          - /path/to/yourscript:/hugegraph/scripts/example.groovy
        ports:
          - 8080:8080

    Use docker-compose up -d to start the container.

And use the RESTful API to request HugeGraphServer and get the following result:

> curl "http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices" | gunzip

{"vertices":[{"id":"2:lop","label":"software","type":"vertex","properties":{"name":"lop","lang":"java","price":328}},{"id":"1:josh","label":"person","type":"vertex","properties":{"name":"josh","age":32,"city":"Beijing"}},{"id":"1:marko","label":"person","type":"vertex","properties":{"name":"marko","age":29,"city":"Beijing"}},{"id":"1:peter","label":"person","type":"vertex","properties":{"name":"peter","age":35,"city":"Shanghai"}},{"id":"1:vadas","label":"person","type":"vertex","properties":{"name":"vadas","age":27,"city":"Hongkong"}},{"id":"2:ripple","label":"software","type":"vertex","properties":{"name":"ripple","lang":"java","price":199}}]}

This indicates that the sample graph was created successfully.

6. Access server

6.1 Service startup status check

Use jps to see a service process

jps
6475 HugeGraphServer

curl request RESTfulAPI

echo `curl -o /dev/null -s -w %{http_code} "http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices"`

Return 200, which means the server starts normally.

6.2 Request Server

The RESTful API of HugeGraphServer includes various types of resources, typically including graph, schema, gremlin, traverser and task.

  • graph contains verticesedges
  • schema contains vertexlabelspropertykeysedgelabelsindexlabels
  • gremlin contains various Gremlin statements, such as g.v(), which can be executed synchronously or asynchronously
  • traverser contains various advanced queries including shortest paths, intersections, N-step reachable neighbors, etc.
  • task contains query and delete with asynchronous tasks
curl http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices

explanation

  1. Since there are many vertices and edges in the graph, for list-type requests, such as getting all vertices, getting all edges, etc., the server will compress the data and return it, so when use curl, you get a bunch of garbled characters, you can redirect to gunzip for decompression. It is recommended to use the Chrome browser + Restlet plugin to send HTTP requests for testing.

    curl "http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices" | gunzip
  2. The current default configuration of HugeGraphServer can only be accessed locally, and the configuration can be modified so that it can be accessed on other machines.

    vim conf/rest-server.properties
    
    restserver.url=http://0.0.0.0:8080

response body:

{
    "vertices": [
        {
            "id": "2lop",
            "label": "software",
            "type": "vertex",
            "properties": {
                "price": [
                    {
                        "id": "price",
                        "value": 328
                    }
                ],
                "name": [
                    {
                        "id": "name",
                        "value": "lop"
                    }
                ],
                "lang": [
                    {
                        "id": "lang",
                        "value": "java"
                    }
                ]
            }
        },
        {
            "id": "1josh",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": [
                    {
                        "id": "name",
                        "value": "josh"
                    }
                ],
                "age": [
                    {
                        "id": "age",
                        "value": 32
                    }
                ]
            }
        },
        ...
    ]
}

For the detailed API, please refer to RESTful-API

You can also visit localhost:8080/swagger-ui/index.html to check the API.

HugeGraph RESTful API endpoints in Swagger UI

When using Swagger UI to debug the API provided by HugeGraph, if HugeGraph Server turns on authentication mode, you can enter authentication information on the Swagger page.

Authorize button in the HugeGraph Swagger UI

Currently, HugeGraph supports setting authentication information in two forms: Basic and Bearer.

Basic and Bearer credential fields in the Swagger UI authorization dialog

7 Stop Server

cd apache-hugegraph-incubating-1.7.0/apache-hugegraph-server-incubating-1.7.0
bin/stop-hugegraph.sh

8 Debug Server with IntelliJ IDEA

Please refer to Setup Server in IDEA

3.1.2 - HugeGraph-PD Quick Start

1 HugeGraph-PD Overview

HugeGraph-PD (Placement Driver) is the metadata management component of HugeGraph’s distributed version, responsible for managing the distribution of graph data and coordinating storage nodes. It plays a central role in distributed HugeGraph, maintaining cluster status and coordinating HugeGraph-Store storage nodes.

2 Prerequisites

2.1 Requirements

  • Operating System: Linux or macOS (Windows has not been fully tested)
  • Java version: ≥ 11
  • Maven version: ≥ 3.5.0

3 Deployment

There are two ways to deploy the HugeGraph-PD component:

  • Method 1: Download the tar package
  • Method 2: Compile from source

3.1 Download the tar package

Download the latest version of HugeGraph-PD from the Apache HugeGraph official download page:

# 1.7.0 is a historical release from the incubation period, so its file and directory names still include "incubating"
wget https://downloads.apache.org/hugegraph/1.7.0/apache-hugegraph-incubating-1.7.0.tar.gz
tar zxf apache-hugegraph-incubating-1.7.0.tar.gz
cd apache-hugegraph-incubating-1.7.0/apache-hugegraph-pd-incubating-1.7.0

3.2 Compile from source

# 1. Clone the source code
git clone https://github.com/apache/hugegraph.git

# 2. Build the project
cd hugegraph
mvn clean install -DskipTests=true

# 3. After a successful build, the PD directory and complete distribution package are located at
#    hugegraph-pd/apache-hugegraph-pd-{version}
#    target/apache-hugegraph-{version}.tar.gz

3.3 Docker Deployment

The HugeGraph-PD Docker image is available on Docker Hub as hugegraph/pd.

Note: The following steps assume you have already cloned or pulled the HugeGraph main repository locally, or at least have its docker/ directory available.

Use the docker compose setup to deploy the complete 3-node cluster (PD + Store + Server):

cd hugegraph/docker
# Keep the version aligned with the latest release, for example 1.x.0
HUGEGRAPH_VERSION=1.7.0 docker compose -f docker-compose-3pd-3store-3server.yml up -d

To run a single PD node via docker run, configuration is provided via environment variables:

docker run -d \
  -p 8620:8620 \
  -p 8686:8686 \
  -p 8610:8610 \
  -e HG_PD_GRPC_HOST=<your-ip> \
  -e HG_PD_RAFT_ADDRESS=<your-ip>:8610 \
  -e HG_PD_RAFT_PEERS_LIST=<your-ip>:8610 \
  -e HG_PD_INITIAL_STORE_LIST=<store-ip>:8500 \
  -v /path/to/data:/hugegraph-pd/pd_data \
  --name hugegraph-pd \
  hugegraph/pd:1.7.0

Environment variable reference:

VariableRequiredDefaultDescription
HG_PD_GRPC_HOSTYesThis node’s hostname/IP for gRPC (e.g. pd0 in Docker, 192.168.1.10 on bare metal)
HG_PD_RAFT_ADDRESSYesThis node’s Raft address (e.g. pd0:8610)
HG_PD_RAFT_PEERS_LISTYesAll PD peers (e.g. pd0:8610,pd1:8610,pd2:8610)
HG_PD_INITIAL_STORE_LISTYesExpected store gRPC addresses (e.g. store0:8500,store1:8500,store2:8500)
HG_PD_GRPC_PORTNo8686gRPC server port
HG_PD_REST_PORTNo8620REST API port
HG_PD_DATA_PATHNo/hugegraph-pd/pd_dataMetadata storage path
HG_PD_INITIAL_STORE_COUNTNo1Minimum stores required for cluster availability

Note: In Docker bridge networking, use container hostnames (e.g. pd0) for HG_PD_GRPC_HOST and HG_PD_RAFT_ADDRESS instead of IP addresses.

Deprecated aliases: GRPC_HOST, RAFT_ADDRESS, RAFT_PEERS, PD_INITIAL_STORE_LIST still work but log a deprecation warning. Use the HG_PD_* names for new deployments.

To view runtime logs for a running PD container use docker logs <container-name> (e.g. docker logs hg-pd0).

See docker/README.md for the full cluster setup guide.

4 Configuration

The main configuration file for PD is conf/application.yml. Here are the key configuration items:

spring:
  application:
    name: hugegraph-pd

grpc:
  # gRPC port for cluster mode
  port: 8686
  host: 127.0.0.1

server:
  # REST service port
  port: 8620

pd:
  # Storage path
  data-path: ./pd_data
  # Auto-expansion check cycle (seconds)
  patrol-interval: 1800
  # Minimum number of Store nodes required for cluster availability
  initial-store-count: 1
  # Store configuration information, format is IP:gRPC port
  initial-store-list: 127.0.0.1:8500

raft:
  # Cluster mode
  address: 127.0.0.1:8610
  # Raft addresses of all PD nodes in the cluster
  peers-list: 127.0.0.1:8610

store:
  # Store offline time (seconds). After this time, the store is considered permanently unavailable
  max-down-time: 172800
  # Whether to enable store monitoring data storage
  monitor_data_enabled: true
  # Monitoring data interval
  monitor_data_interval: 1 minute
  # Monitoring data retention time
  monitor_data_retention: 1 day
  initial-store-count: 1

partition:
  # Default number of replicas per partition
  default-shard-count: 1
  # Default maximum number of replicas per machine
  store-max-shard-count: 12

For multi-node deployment, you need to modify the port and address configurations for each node to ensure proper communication between nodes.

5 Start and Stop

5.1 Start PD

In the PD installation directory, execute:

./bin/start-hugegraph-pd.sh

The startup script supports a -d flag to control daemon mode:

  • -d true (default): run as a background daemon; the script returns immediately.
  • -d false: run in foreground — the script execs Java, so the container/supervisor process IS Java. Use this when running under Docker or a process supervisor (systemd, supervisord) so crashes are detected and the service is restarted automatically.

After successful startup, you can see logs similar to the following in logs/hugegraph-pd-stdout.log:

YYYY-mm-dd xx:xx:xx [main] [INFO] o.a.h.p.b.HugePDServer - Started HugePDServer in x.xxx seconds (JVM running for x.xxx)

5.2 Stop PD

In the PD installation directory, execute:

./bin/stop-hugegraph-pd.sh

6 Verification

Confirm that the PD service is running properly:

curl http://localhost:8620/actuator/health

If it returns {"status":"UP"}, it indicates that the PD service has been successfully started.

You can also verify Store node status through the PD API:

curl http://localhost:8620/v1/stores

If the response shows state as Up, the corresponding Store node is running normally. The example below shows a single Store node. In a healthy 3-node deployment, the storeId list should contain three IDs, and stateCountMap.Up, numOfService, and numOfNormalService should all be 3.

{
  "message": "OK",
  "data": {
    "stores": [
      {
        "storeId": 8319292642220586694,
        "address": "127.0.0.1:8500",
        "raftAddress": "127.0.0.1:8510",
        "version": "",
        "state": "Up",
        "deployPath": "/Users/{your_user_name}/hugegraph/apache-hugegraph-incubating-1.5.0/apache-hugegraph-store-incubating-1.5.0/lib/hg-store-node-1.5.0.jar",
        "dataPath": "./storage",
        "startTimeStamp": 1754027127969,
        "registedTimeStamp": 1754027127969,
        "lastHeartBeat": 1754027909444,
        "capacity": 494384795648,
        "available": 346535829504,
        "partitionCount": 0,
        "graphSize": 0,
        "keyCount": 0,
        "leaderCount": 0,
        "serviceName": "127.0.0.1:8500-store",
        "serviceVersion": "",
        "serviceCreatedTimeStamp": 1754027127000,
        "partitions": []
      }
    ],
    "stateCountMap": {
      "Up": 1
    },
    "numOfService": 1,
    "numOfNormalService": 1
  },
  "status": 0
}

3.1.3 - HugeGraph-Store Quick Start

1 HugeGraph-Store Overview

HugeGraph-Store is the storage node component of HugeGraph’s distributed version, responsible for actually storing and managing graph data. It works in conjunction with HugeGraph-PD to form HugeGraph’s distributed storage engine, providing high availability and horizontal scalability.

2 Prerequisites

2.1 Requirements

  • Operating System: Linux or macOS (Windows has not been fully tested)
  • Java version: ≥ 11
  • Maven version: ≥ 3.5.0
  • Deploy HugeGraph-PD first for multi-node deployment

3 Deployment

There are two ways to deploy the HugeGraph-Store component:

  • Method 1: Download the tar package
  • Method 2: Compile from source

3.1 Download the tar package

Download the latest version of HugeGraph-Store from the Apache HugeGraph official download page:

# 1.7.0 is a historical release from the incubation period, so its file and directory names still include "incubating"
wget https://downloads.apache.org/hugegraph/1.7.0/apache-hugegraph-incubating-1.7.0.tar.gz
tar zxf apache-hugegraph-incubating-1.7.0.tar.gz
cd apache-hugegraph-incubating-1.7.0/apache-hugegraph-store-incubating-1.7.0

3.2 Compile from source

# 1. Clone the source code
git clone https://github.com/apache/hugegraph.git

# 2. Build the project
cd hugegraph
mvn clean install -DskipTests=true

# 3. After a successful build, the Store directory and complete distribution package are located at
#    hugegraph-store/apache-hugegraph-store-{version}
#    target/apache-hugegraph-{version}.tar.gz

3.3 Docker Deployment

The HugeGraph-Store Docker image is available on Docker Hub as hugegraph/store.

Note: The following steps assume you have already cloned or pulled the HugeGraph main repository locally, or at least have its docker/ directory available.

Use the compose file to deploy the complete 3-node cluster (PD + Store + Server):

cd hugegraph/docker
# Keep the version aligned with the latest release, for example 1.x.0
HUGEGRAPH_VERSION=1.7.0 docker compose -f docker-compose-3pd-3store-3server.yml up -d

To run a single Store node via docker run:

docker run -d \
  -p 8520:8520 \
  -p 8500:8500 \
  -p 8510:8510 \
  -e HG_STORE_PD_ADDRESS=<pd-ip>:8686 \
  -e HG_STORE_GRPC_HOST=<your-ip> \
  -e HG_STORE_RAFT_ADDRESS=<your-ip>:8510 \
  -v /path/to/storage:/hugegraph-store/storage \
  --name hugegraph-store \
  hugegraph/store:1.7.0

Environment variable reference:

VariableRequiredDefaultDescription
HG_STORE_PD_ADDRESSYesPD gRPC addresses (e.g. pd0:8686,pd1:8686,pd2:8686)
HG_STORE_GRPC_HOSTYesThis node’s hostname/IP for gRPC (e.g. store0)
HG_STORE_RAFT_ADDRESSYesThis node’s Raft address (e.g. store0:8510)
HG_STORE_GRPC_PORTNo8500gRPC server port
HG_STORE_REST_PORTNo8520REST API port
HG_STORE_DATA_PATHNo/hugegraph-store/storageData storage path

Note: In Docker bridge networking, use container hostnames (e.g. store0) for HG_STORE_GRPC_HOST instead of IP addresses.

Deprecated aliases: PD_ADDRESS, GRPC_HOST, RAFT_ADDRESS still work but log a deprecation warning. Use the HG_STORE_* names for new deployments.

4 Configuration

The main configuration file for Store is conf/application.yml. Here are the key configuration items:

pdserver:
  # PD service address, multiple PD addresses are separated by commas (configure PD's gRPC port)
  address: 127.0.0.1:8686

grpc:
  # gRPC service address
  host: 127.0.0.1
  port: 8500
  netty-server:
    max-inbound-message-size: 1000MB

raft:
  # raft cache queue size
  disruptorBufferSize: 1024
  address: 127.0.0.1:8510
  max-log-file-size: 600000000000
  # Snapshot generation time interval, in seconds
  snapshotInterval: 1800

server:
  # REST service address
  port: 8520

app:
  # Storage path, supports multiple paths separated by commas
  data-path: ./storage
  #raft-path: ./storage

spring:
  application:
    name: store-node-grpc-server
  profiles:
    active: default
    include: pd

logging:
  config: 'file:./conf/log4j2.xml'
  level:
    root: info

For multi-node deployment, you need to modify the following configurations for each Store node:

  1. grpc.port (RPC port) for each node
  2. raft.address (Raft protocol port) for each node
  3. server.port (REST port) for each node
  4. app.data-path (data storage path) for each node

5 Start and Stop

5.1 Start Store

Ensure that the PD service is already started, then in the Store installation directory, execute:

./bin/start-hugegraph-store.sh

The startup script supports a -d flag to control daemon mode:

  • -d true (default): run as a background daemon; the script returns immediately.
  • -d false: run in foreground — the script execs Java, so the container/supervisor process IS Java. Use this when running under Docker or a process supervisor (systemd, supervisord) so crashes are detected and the service is restarted automatically.

After successful startup, you can see logs similar to the following in logs/hugegraph-store-server.log:

YYYY-mm-dd xx:xx:xx [main] [INFO] o.a.h.s.n.StoreNodeApplication - Started StoreNodeApplication in x.xxx seconds (JVM running for x.xxx)

5.2 Stop Store

In the Store installation directory, execute:

./bin/stop-hugegraph-store.sh

6 Multi-Node Deployment Example

Below is a configuration example for a three-node deployment:

6.1 Three-Node Configuration Reference

  • 3 PD nodes
    • raft ports: 8610, 8611, 8612
    • rpc ports: 8686, 8687, 8688
    • rest ports: 8620, 8621, 8622
  • 3 Store nodes
    • raft ports: 8510, 8511, 8512
    • rpc ports: 8500, 8501, 8502
    • rest ports: 8520, 8521, 8522

6.2 Store Node Configuration

For the three Store nodes, the main configuration differences are as follows:

Node A:

grpc:
  port: 8500
raft:
  address: 127.0.0.1:8510
server:
  port: 8520
app:
  data-path: ./storage-a

Node B:

grpc:
  port: 8501
raft:
  address: 127.0.0.1:8511
server:
  port: 8521
app:
  data-path: ./storage-b

Node C:

grpc:
  port: 8502
raft:
  address: 127.0.0.1:8512
server:
  port: 8522
app:
  data-path: ./storage-c

All nodes should point to the same PD cluster:

pdserver:
  address: 127.0.0.1:8686,127.0.0.1:8687,127.0.0.1:8688

6.3 Docker Distributed Cluster Configuration

The distributed Store cluster definition is included in docker/docker-compose-3pd-3store-3server.yml. Each Store node gets its own hostname and environment variables:

# store0
HG_STORE_PD_ADDRESS: pd0:8686,pd1:8686,pd2:8686
HG_STORE_GRPC_HOST: store0
HG_STORE_GRPC_PORT: "8500"
HG_STORE_REST_PORT: "8520"
HG_STORE_RAFT_ADDRESS: store0:8510
HG_STORE_DATA_PATH: /hugegraph-store/storage

# store1
HG_STORE_PD_ADDRESS: pd0:8686,pd1:8686,pd2:8686
HG_STORE_GRPC_HOST: store1
HG_STORE_RAFT_ADDRESS: store1:8510

# store2
HG_STORE_PD_ADDRESS: pd0:8686,pd1:8686,pd2:8686
HG_STORE_GRPC_HOST: store2
HG_STORE_RAFT_ADDRESS: store2:8510

Store nodes start only after all PD nodes pass healthchecks (/v1/health), enforced via depends_on: condition: service_healthy.

To view runtime logs for a running Store container use docker logs <container-name> (e.g. docker logs hg-store0).

See docker/README.md for the full setup guide.

7 Verify Store Service

Confirm that the Store service is running properly:

curl http://localhost:8520/actuator/health

If it returns {"status":"UP"}, it indicates that the Store service has been successfully started.

You can also check Store node status through the PD API:

curl http://localhost:8620/v1/stores

If Store is configured successfully, the response should include status information for the current node, and state: "Up" means the node is running normally.

The example below shows a single Store node. If all three nodes are configured correctly and running, the storeId list should contain three IDs, and stateCountMap.Up, numOfService, and numOfNormalService should all be 3.

{
  "message": "OK",
  "data": {
    "stores": [
      {
        "storeId": 8319292642220586694,
        "address": "127.0.0.1:8500",
        "raftAddress": "127.0.0.1:8510",
        "version": "",
        "state": "Up",
        "deployPath": "/Users/{your_user_name}/hugegraph/hugegraph-store/apache-hugegraph-store-{version}/lib/hg-store-node-{version}.jar",
        "dataPath": "./storage",
        "startTimeStamp": 1754027127969,
        "registedTimeStamp": 1754027127969,
        "lastHeartBeat": 1754027909444,
        "capacity": 494384795648,
        "available": 346535829504,
        "partitionCount": 0,
        "graphSize": 0,
        "keyCount": 0,
        "leaderCount": 0,
        "serviceName": "127.0.0.1:8500-store",
        "serviceVersion": "",
        "serviceCreatedTimeStamp": 1754027127000,
        "partitions": []
      }
    ],
    "stateCountMap": {
      "Up": 1
    },
    "numOfService": 1,
    "numOfNormalService": 1
  },
  "status": 0
}

3.2 - HugeGraph ToolChain

HugeGraph Toolchain includes the Java and Go clients, Loader, Hubble, Tools, and Spark Connector. See the documents in this section for each module’s features and usage.

Testing Guide: For running toolchain tests locally, please refer to HugeGraph Toolchain Local Testing Guide

DeepWiki provides real-time updated project documentation with more comprehensive and accurate content, suitable for quickly understanding the latest project information.

📖 https://deepwiki.com/apache/hugegraph-toolchain

Source repository: apache/hugegraph-toolchain

3.2.1 - HugeGraph-Hubble Quick Start

1 HugeGraph-Hubble Overview

⚠️ Security notice: As of the 1.7.0 release, Hubble does not provide Auth/Login protection. This feature is planned for the 1.8.0 release. Do not expose Hubble to the public Internet or untrusted networks; restrict access with IP/port allowlists and HTTPS.

Testing Guide: For running HugeGraph-Hubble tests locally, please refer to HugeGraph Toolchain Local Testing Guide

HugeGraph-Hubble is HugeGraph’s web management interface. It manages graph connections and schemas, imports data, runs Gremlin queries, and visualizes query results.

The platform mainly includes the following modules:

Graph Management

Graph Management creates and maintains connections, switches between graphs, and provides access, editing, deletion, and query operations.

Metadata Modeling

Metadata Modeling manages PropertyKeys, VertexLabels, EdgeLabels, and IndexLabels. It provides list and graph views and supports reusing metadata across graphs.

Graph Analysis

Graph Analysis runs Gremlin and path queries and displays results as a graph, table, or JSON. It also keeps execution history and saved statements, and exports query results as JSON.

Task Management

Task Management displays background tasks such as asynchronous Gremlin jobs and index creation or rebuilding.

Data Import

The data import page is intended for small-scale trials. For bulk or production imports, use HugeGraph Loader.

The data import page guides you through creating a task, uploading files, and mapping fields. Multiple import tasks can run in parallel, with resumable uploads and error retries.

2 Deploy

There are three ways to deploy hugegraph-hubble

  • Use Docker (Convenient for Test/Dev)
  • Download the Toolchain binary package
  • Source code compilation

2.1 Use docker (Convenient for Test/Dev)

Special Note: If you are starting hubble with Docker, and hubble and the server are on the same host. When configuring the hostname for the graph on the Hubble web page, please do not directly set it to localhost/127.0.0.1. This will refer to the hubble container internally rather than the host machine, resulting in a connection failure to the server.

If hubble and server is in the same docker network, we recommend using the container_name (in our example, it is server) as the hostname, and 8080 as the port. Or you can use the host IP as the hostname, and the port is configured by the host for the server.

We can use docker run -itd --name=hubble -p 8088:8088 hugegraph/hubble:1.5.0 to quick start hubble.

Alternatively, you can use Docker Compose to start hubble. Additionally, if hubble and the graph is in the same Docker network, you can access the graph using the container name of the graph, eliminating the need for the host machine’s IP address.

Use docker-compose up -ddocker-compose.yml is following:

version: '3'
services:
  server:
    image: hugegraph/hugegraph:1.5.0
    container_name: server
    environment:
      - PASSWORD=xxx
    ports:
      - 8080:8080

  hubble:
    image: hugegraph/hubble:1.5.0
    container_name: hubble
    ports:
      - 8088:8088

Note:

  1. The docker image of hugegraph-hubble is a convenience release to start hugegraph-hubble quickly, but not official distribution artifacts. You can find more details from ASF Release Distribution Policy.

  2. Recommend to use release tag(like 1.5.0) for the stable version. Use latest tag to experience the newest functions in development.

2.2 Download the Toolchain binary package

hubble is in the toolchain project. First, download the binary tar tarball

export VERSION=1.7.0
export ARCHIVE="apache-hugegraph-toolchain-incubating-${VERSION}"
wget "https://downloads.apache.org/hugegraph/${VERSION}/${ARCHIVE}.tar.gz"
tar -xvf "${ARCHIVE}.tar.gz"
cd "${ARCHIVE}/apache-hugegraph-hubble-incubating-${VERSION}"

Run hubble

bin/start-hubble.sh

After startup, open http://<host>:8088. Run bin/stop-hubble.sh to stop the service.

2.3 Source code compilation

Hubble’s build uses frontend-maven-plugin in hugegraph-hubble/hubble-dist/pom.xml to install Node.js 18.20.8 and Yarn 1.22.21, so neither tool needs to be installed beforehand.

Download the toolchain source code.

git clone https://github.com/apache/hugegraph-toolchain.git

Compile hubble. It depends on the loader and client, so you need to build these dependencies in advance during the compilation process (you can skip this step later).

cd hugegraph-toolchain
python -m pip install -r hugegraph-hubble/hubble-dist/assembly/travis/requirements.txt
mvn install -pl hugegraph-client,hugegraph-loader -am -Dmaven.javadoc.skip=true -DskipTests -ntp
cd hugegraph-hubble
mvn -e compile package -Dmaven.javadoc.skip=true -Dmaven.test.skip=true -ntp
cd apache-hugegraph-hubble-*

Run hubble

bin/start-hubble.sh -d

3 Platform Workflows

The module usage process of the platform is as follows:

image

4 Platform Instructions

4.1 Graph Management

4.1.1 Graph creation

Under the graph management module, click [Create graph], and realize the connection of multiple graphs by filling in the graph ID, graph name, host name, port number, username, and password information.

image

Create graph by filling in the content as follows:

image

Special Note: If you are starting hubble with Docker, and hubble and the server are on the same host. When configuring the hostname for the graph on the Hubble web page, please do not directly set it to localhost/127.0.0.1. If hubble and server is in the same docker network, we recommend using the container_name (in our example, it is graph) as the hostname, and 8080 as the port. Or you can use the host IP as the hostname, and the port is configured by the host for the server.

4.1.2 Graph Access

Realize the information access to the graph space. After entering, you can perform operations such as multidimensional query analysis, metadata management, data import, and algorithm analysis of the graph.

image
4.1.3 Graph management
  1. Users can achieve unified management of graphs through overview, search, and information editing and deletion of single graphs.
  2. Search range: You can search for the graph name and ID.
image

4.2 Metadata Modeling (list + graph mode)

4.2.1 Module entry

Left navigation:

image
4.2.2 Property type
4.2.2.1 Create type
  1. Fill in or select the attribute name, data type, and cardinality to complete the creation of the attribute.
  2. Created attributes can be used as attributes of vertex type and edge type.

List mode:

image

Graph mode:

image
4.2.2.2 Reuse
  1. The platform provides the [Reuse] function, which can directly reuse the metadata of other graphs.
  2. Select the graph ID that needs to be reused, and continue to select the attributes that need to be reused. After that, the platform will check whether there is a conflict. After passing, the metadata can be reused.

Select reuse items:

image

Check reuse items:

image
4.2.2.3 Management
  1. You can delete a single item or delete it in batches in the attribute list.
4.2.3 Vertex type
4.2.3.1 Create type
  1. Fill in or select the vertex type name, ID strategy, association attribute, primary key attribute, vertex style, content displayed below the vertex in the query result, and index information: including whether to create a type index, and the specific content of the attribute index, complete the vertex Type creation.

List mode:

image

Graph mode:

image
4.2.3.2 Reuse
  1. The multiplexing of vertex types will reuse the attributes and attribute indexes associated with this type together.
  2. The reuse method is similar to the property reuse, see 3.2.2.2.
4.2.3.3 Administration
  1. Editing operations are available. The vertex style, association type, vertex display content, and attribute index can be edited, and the rest cannot be edited.

  2. You can delete a single item or delete it in batches.

image
4.2.4 Edge Types
4.2.4.1 Create
  1. Fill in or select the edge type name, start point type, end point type, associated attributes, whether to allow multiple connections, edge style, content displayed below the edge in the query result, and index information: including whether to create a type index, and attribute index The specific content, complete the creation of the edge type.

List mode:

image

Graph mode:

image
4.2.4.2 Reuse
  1. The reuse of the edge type will reuse the start point type, end point type, associated attribute and attribute index of this type.
  2. The reuse method is similar to the property reuse, see 3.2.2.2.
4.2.4.3 Administration
  1. Editing operations are available. Edge styles, associated attributes, edge display content, and attribute indexes can be edited, and the rest cannot be edited, the same as the vertex type.
  2. You can delete a single item or delete it in batches.
4.2.5 Index Types

Displays vertex and edge indices for vertex types and edge types.

4.3 Data Import

Note:currently, we recommend to use hugegraph-loader to import data formally. The built-in import of hubble is used for testing and getting started.

The usage process of data import is as follows:

image
4.3.1 Module entrance

Left navigation:

image
4.3.2 Create task
  1. Fill in the task name and remarks (optional) to create an import task.
  2. Multiple import tasks can be created and imported in parallel.
image
4.3.3 Uploading files
  1. Upload the file that needs to be composed. The currently supported format is CSV, which will be updated continuously in the future.
  2. Multiple files can be uploaded at the same time.
image
4.3.4 Setting up data mapping
  1. Set up data mapping for uploaded files, including file settings and type settings

  2. File settings: Check or fill in whether to include the header, separator, encoding format and other settings of the file itself, all set the default values, no need to fill in manually

  3. Type setting:

    1. Vertex map and edge map:

      【Vertex Type】: Select the vertex type, and upload the column data in the file for its ID mapping;

      【Edge Type】: Select the edge type and map the column data of the uploaded file to the ID column of its start point type and end point type;

    2. Mapping settings: upload the column data in the file for the attribute mapping of the selected vertex type. Here, if the attribute name is the same as the header name of the file, the mapping attribute can be automatically matched, and there is no need to manually fill in the selection.

    3. After completing the setting, the setting list will be displayed before proceeding to the next step. It supports the operations of adding, editing and deleting mappings.

Fill in the settings map:

image

Mapping list:

image
4.3.5 Import data

Before importing, you need to fill in the import setting parameters. After filling in, you can start importing data into the gallery.

  1. Import settings
  • The import setting parameter items are as shown in the figure below, all set the default value, no need to fill in manually
image
  1. Import details
  • Click Start Import to start the file import task
  • The import details provide the mapping type, import speed, import progress, time-consuming and the specific status of the current task set for each uploaded file, and can pause, resume, stop and other operations for each task
  • If the import fails, you can view the specific reason
image

4.4 Data Analysis

4.4.1 Module entry

Left navigation:

image
4.4.2 Multi-graphs switching

By switching the entrance on the left, flexibly switch the operation space of multiple graphs

image
4.4.3 Graph Analysis and Processing

HugeGraph supports Gremlin, a graph traversal query language of Apache TinkerPop3. Gremlin is a general graph database query language. By entering Gremlin statements and clicking execute, you can perform query and analysis operations on graph data, and create and delete vertices/edges. vertex/edge attribute modification, etc.

After Gremlin query, below is the graph result display area, which provides 3 kinds of graph result display modes: [Graph Mode], [Table Mode], [Json Mode].

⚠️ SEC Reminder: Hubble allows the direct input and execution of native Gremlin query statements on the web interface, which grants users relatively high operational privileges. Please avoid exposing the Hubble service to public network environments. It is recommended to ensure that the graph database server has enabled the Authentication System (Auth) combined with an IP Whitelist for strict permission control when in use, preventing unauthorized access or malware execution risks.

Support zoom, center, full screen, export and other operations.

【Picture Mode】

image

【Table mode】

image

【Json mode】

image
4.4.4 Data Details

Click the vertex/edge entity to view the data details of the vertex/edge, including vertex/edge type, vertex ID, attribute and corresponding value, expand the information display dimension of the graph, and improve the usability.

4.4.5 Multidimensional Path Query of Graph Results

In addition to the global query, an in-depth customized query and hidden operations can be performed for the vertices in the query result to realize customized mining of graph results.

Right-click a vertex, and the menu entry of the vertex appears, which can be displayed, inquired, hidden, etc.

  • Expand: Click to display the vertices associated with the selected point.
  • Query: By selecting the edge type and edge direction associated with the selected point, and then selecting its attributes and corresponding filtering rules under this condition, a customized path display can be realized.
  • Hide: When clicked, hides the selected point and its associated edges.

Double-clicking a vertex also displays the vertex associated with the selected point.

image
4.4.6 Add vertex/edge
4.4.6.1 Added vertex

In the graph area, two entries can be used to dynamically add vertices, as follows:

  1. Click on the graph area panel, the Add Vertex entry appears
  2. Click the first icon in the action bar in the upper right corner

Complete the addition of vertices by selecting or filling in the vertex type, ID value, and attribute information.

The entry is as follows:

image

Add the vertex content as follows:

image
4.4.6.2 Add edge

Right-click a vertex in the graph result to add the outgoing or incoming edge of that point.

4.4.7 Execute the query of records and favorites
  1. Record each query record at the bottom of the graph area, including: query time, execution type, content, status, time-consuming, as well as [collection] and [load] operations, to achieve a comprehensive record of graph execution, with traces to follow, and Can quickly load and reuse execution content
  2. Provides the function of collecting sentences, which can be used to collect frequently used sentences, which is convenient for fast calling of high-frequency sentences.
image

4.5 Task Management

4.5.1 Module entry

Left navigation:

image
4.5.2 Task Management
  1. Provide unified management and result viewing of asynchronous tasks. There are 4 types of asynchronous tasks, namely:
  • gremlin: Gremlin tasks
  • algorithm: OLAP algorithm task
  • remove_schema: remove metadata
  • rebuild_index: rebuild the index
  1. The list displays the asynchronous task information of the current graph, including task ID, task name, task type, creation time, time-consuming, status, operation, and realizes the management of asynchronous tasks.
  2. Support filtering by task type and status
  3. Support searching for task ID and task name
  4. Asynchronous tasks can be deleted or deleted in batches
image
4.5.3 Gremlin asynchronous tasks
  1. Create a task
  • The data analysis module currently supports two Gremlin operations, Gremlin query and Gremlin task; if the user switches to the Gremlin task, after clicking execute, an asynchronous task will be created in the asynchronous task center;
  1. Task submission
  • After the task is submitted successfully, the graph area returns the submission result and task ID
  1. Mission details
  • Provide [View] entry, you can jump to the task details to view the specific execution of the current task After jumping to the task center, the currently executing task line will be displayed directly
image

Click to view the entry to jump to the task management list, as follows:

image
  1. View the results
  • The results are displayed in the form of JSON
4.5.4 OLAP algorithm tasks

There is no visual OLAP algorithm execution on Hubble. You can call the RESTful API to perform OLAP algorithm tasks, find the corresponding tasks by ID in the task management, and view the progress and results.

4.5.5 Delete metadata, rebuild index
  1. Create a task
  • In the metadata modeling module, when deleting metadata, an asynchronous task for deleting metadata can be created
image
  • When editing an existing vertex/edge type operation, when adding an index, an asynchronous task of creating an index can be created
image
  1. Task details
  • After confirming/saving, you can jump to the task center to view the details of the current task
image

5 Configuration

HugeGraph-Hubble can be configured through the conf/hugegraph-hubble.properties file.

5.1 Server Configuration

Configuration ItemDefault ValueDescription
hubble.host0.0.0.0The address that Hubble service binds to
hubble.port8088The port that Hubble service listens on

5.2 Server and PD

ConfigurationDefaultDescription
pd.enabledfalseWhether to discover services through PD; keep false for a standalone Server
server.direct_urlhttp://127.0.0.1:8080Server address used when pd.enabled=false
pd.peers127.0.0.1:8686PD node address
pd.server127.0.0.1:8620PD service address
route.typeNODE_PORTService routing mode: NODE_PORT, DDS, or BOTH

5.3 Gremlin Query Limits

These settings control query result limits to prevent memory issues:

Configuration ItemDefault ValueDescription
gremlin.suffix_limit250Maximum query suffix length
gremlin.vertex_degree_limit100Maximum vertex degree to display
gremlin.edges_total_limit500Maximum number of edges returned
gremlin.batch_query_ids100ID batch query size

3.2.2 - HugeGraph-Loader Quick Start

1 HugeGraph-Loader Overview

HugeGraph-Loader is the data import component of HugeGraph, which can convert data from various data sources into graph vertices and edges and import them into the graph database in batches.

Currently supported data sources include:

  • Local disk file or directory, supports TEXT, CSV and JSON format files, supports compressed files
  • HDFS file or directory supports compressed files
  • Mainstream relational databases, such as MySQL, PostgreSQL, Oracle, SQL Server

Local disk files and HDFS files support resumable uploads.

It will be explained in detail below.

Note: HugeGraph-Loader requires HugeGraph Server service, please refer to HugeGraph-Server Quick Start to download and start Server

Testing Guide: For running HugeGraph-Loader tests locally, please refer to HugeGraph Toolchain Local Testing Guide

2 Get HugeGraph-Loader

HugeGraph-Loader is available in the following three ways:

  • Use docker image (Convenient for Test/Dev)
  • Download the compiled tarball
  • Clone source code then compile and install

2.1 Use Docker image (Convenient for Test/Dev)

We can deploy the loader service using docker run -itd --name loader hugegraph/loader:1.5.0. For the data that needs to be loaded, it can be copied into the loader container either by mounting -v /path/to/data/file:/loader/file or by using docker cp.

Alternatively, to start the loader using docker-compose, the command is docker-compose up -d. An example of the docker-compose.yml is as follows:

version: '3'

services:
  server:
    image: hugegraph/hugegraph:1.3.0
    container_name: server
    ports:
      - 8080:8080

  loader:
    image: hugegraph/loader:1.3.0
    container_name: loader
    # mount your own data here
    # volumes:
      # - /path/to/data/file:/loader/file

The specific data loading process can be referenced under 4.5 User Docker to load data

Note:

  1. The docker image of hugegraph-loader is a convenience release to start hugegraph-loader quickly, but not official distribution artifacts. You can find more details from ASF Release Distribution Policy.

  2. Recommend to use release tag(like 1.5.0) for the stable version. Use latest tag to experience the newest functions in development.

2.2 Download the compiled archive

Download the latest version of the HugeGraph-Toolchain release package:

export VERSION=1.7.0
export ARCHIVE="apache-hugegraph-toolchain-incubating-${VERSION}"
wget "https://downloads.apache.org/hugegraph/${VERSION}/${ARCHIVE}.tar.gz"
tar zxf "${ARCHIVE}.tar.gz"

2.3 Clone source code to compile and install

Clone the latest version of HugeGraph-Loader source package:

# 1. get from github
git clone https://github.com/apache/hugegraph-toolchain.git

# 2. Download a released source package
export VERSION=1.7.0
export ARCHIVE="apache-hugegraph-toolchain-incubating-${VERSION}"
wget "https://downloads.apache.org/hugegraph/${VERSION}/${ARCHIVE}-src.tar.gz"
How to install OJDBC

Due to the license limitation of the Oracle OJDBC, you need to manually install ojdbc to the local maven repository. Visit the Oracle jdbc downloads page. Select Oracle Database 12c Release 2 (12.2.0.1) drivers, as shown in the following figure.

After opening the link, select “ojdbc8.jar”.

Install ojdbc8 to the local maven repository, enter the directory where ojdbc8.jar is located, and execute the following command.

mvn install:install-file -Dfile=./ojdbc8.jar -DgroupId=com.oracle -DartifactId=ojdbc8 -Dversion=12.2.0.1 -Dpackaging=jar

Compile and generate tar package:

cd hugegraph-toolchain
mvn clean package -pl hugegraph-loader -am -DskipTests -ntp

3 How to use

The basic process of using HugeGraph-Loader is divided into the following steps:

  • Write graph schema
  • Prepare data files
  • Write input source map files
  • Execute command import

3.1 Construct graph schema

This step is the modeling process. Users need to have a clear idea of ​​their existing data and the graph model they want to create, and then write the schema to build the graph model.

For example, if you want to create a graph with two types of vertices and two types of edges, the vertices are “people” and “software”, the edges are “people know people” and “people create software”, and these vertices and edges have some attributes, For example, the vertex “person” has: “name”, “age” and other attributes, “Software” includes: “name”, “sale price” and other attributes; side “knowledge” includes: “date” attribute and so on.

Example graph with person and software vertices connected by knows and created edges

graph model example

After designing the graph model, we can use groovy to write the definition of schema and save it to a file, here named schema.groovy.

// Create some properties
schema.propertyKey("name").asText().ifNotExist().create();
schema.propertyKey("age").asInt().ifNotExist().create();
schema.propertyKey("city").asText().ifNotExist().create();
schema.propertyKey("date").asText().ifNotExist().create();
schema.propertyKey("price").asDouble().ifNotExist().create();

// Create the person vertex type, which has three attributes: name, age, city, and the primary key is name
schema.vertexLabel("person").properties("name", "age", "city").primaryKeys("name").ifNotExist().create();
// Create a software vertex type, which has two properties: name, price, the primary key is name
schema.vertexLabel("software").properties("name", "price").primaryKeys("name").ifNotExist().create();

// Create the knows edge type, which goes from person to person
schema.edgeLabel("knows").sourceLabel("person").targetLabel("person").ifNotExist().create();
// Create the created edge type, which points from person to software
schema.edgeLabel("created").sourceLabel("person").targetLabel("software").ifNotExist().create();

Please refer to the corresponding section in hugegraph-client for the detailed description of the schema.

3.2 Prepare data

The data sources currently supported by HugeGraph-Loader include:

  • local disk file or directory
  • HDFS file or directory
  • Partial relational database
  • Kafka topic
3.2.1 Data source structure
3.2.1.1 Local disk file or directory

The user can specify a local disk file as the data source. If the data is scattered in multiple files, a certain directory is also supported as the data source, but multiple directories are not supported as the data source for the time being.

For example, my data is scattered in multiple files, part-0, part-1 … part-n. To perform the import, it must be ensured that they are placed in one directory. Then in the loader’s mapping file, specify path as the directory.

Supported file formats include:

  • TEXT
  • CSV
  • JSON

TEXT is a text file with custom delimiters, the first line is usually the header, and the name of each column is recorded, and no header line is allowed (specified in the mapping file). Each remaining row represents a record, which will be converted into a vertex/edge; each column of the row corresponds to a field, which will be converted into the id, label or attribute of the vertex/edge;

An example is as follows:

id|name|lang|price|ISBN
1|lop|java|328|ISBN978-7-107-18618-5
2|ripple|java|199|ISBN978-7-100-13678-5

CSV is a TEXT file with commas , as delimiters. When a column value itself contains a comma, the column value needs to be enclosed in double quotes, for example:

marko,29,Beijing
"li,nary",26,"Wu,han"

The JSON file requires that each line is a JSON string, and the format of each line needs to be consistent.

{"source_name": "marko", "target_name": "vadas", "date": "20160110", "weight": 0.5}
{"source_name": "marko", "target_name": "josh", "date": "20130220", "weight": 1.0}
3.2.1.2 HDFS file or directory

Users can also specify HDFS files or directories as data sources, all of the above requirements for local disk files or directories apply here. In addition, since HDFS usually stores compressed files, loader also provides support for compressed files, and local disk file or directory also supports compressed files.

Currently supported compressed file types include: GZIP, BZ2, XZ, LZMA, SNAPPY_RAW, SNAPPY_FRAMED, Z, DEFLATE, LZ4_BLOCK, LZ4_FRAMED, ORC, and PARQUET.

3.2.1.3 Mainstream relational database

The loader also supports some relational databases as data sources, and currently supports MySQL, PostgreSQL, Oracle, and SQL Server.

However, the requirements for the table structure are relatively strict at present. If association query needs to be done during the import process, such a table structure is not allowed. The associated query means: after reading a row of the table, it is found that the value of a certain column cannot be used directly (such as a foreign key), and you need to do another query to determine the true value of the column.

For example, Suppose there are three tables, person, software and created

// person schema
id | name | age | city
// software schema
id | name | lang | price
// created schema
id | p_id | s_id | date

If the id strategy of person or software is specified as PRIMARY_KEY when modeling (schema), choose name as the primary key (note: this is the concept of vertex-label in hugegraph), when importing edge data, the source vertex and target need to be spliced ​​out. For the id of the vertex, you must go to the person/software table with p_id/s_id to find the corresponding name. In the case of the schema that requires additional query, the loader does not support it temporarily. In this case, the following two methods can be used instead:

  1. The id strategy of person and software is still specified as PRIMARY_KEY, but the id column of the person table and software table is used as the primary key attribute of the vertex, so that the id can be generated by directly splicing p_id and s_id with the label of the vertex when importing an edge;
  2. Specify the id policy of person and software as CUSTOMIZE, and then directly use the id column of the person table and the software table as the vertex id, so that p_id and s_id can be used directly when importing edges;

The key point is to make the edge use p_id and s_id directly, don’t check it again.

3.2.2 Prepare vertex and edge data
3.2.2.1 Vertex Data

The vertex data file consists of data line by line. Generally, each line is used as a vertex, and each column is used as a vertex attribute. The following description uses CSV format as an example.

  • person vertex data (the data itself does not contain a header)
Tom,48,Beijing
Jerry,36,Shanghai
  • software vertex data (the data itself contains the header)
name,price
Photoshop,999
Office,388
3.2.2.2 Edge data

The edge data file consists of data line by line. Generally, each line is used as an edge. Some columns are used as the IDs of the source and target vertices, and other columns are used as edge attributes. The following uses JSON format as an example.

  • knows edge data
{"source_name": "Tom", "target_name": "Jerry", "date": "2008-12-12"}
  • created edge data
{"source_name": "Tom", "target_name": "Photoshop"}
{"source_name": "Tom", "target_name": "Office"}
{"source_name": "Jerry", "target_name": "Office"}

3.3 Write data source mapping file

3.3.1 Mapping file overview

The mapping file of the input source is used to describe how to establish the mapping relationship between the input source data and the vertex type/edge type of the graph. It is organized in JSON format and consists of multiple mapping blocks, each of which is responsible for mapping an input source. Mapped to vertices and edges.

Specifically, each mapping block contains an input source and multiple vertex mapping and edge mapping blocks, and the input source block corresponds to the local disk file or directory, HDFS file or directory and relational database are responsible for describing the basic information of the data source, such as where the data is, what format, what is the delimiter, etc. The vertex map/edge map is bound to the input source, which columns of the input source can be selected, which columns are used as ids, which columns are used as attributes, and what attributes are mapped to each column, the values ​​of the columns are mapped to what values ​​of attributes, and so on.

In the simplest terms, each mapping block describes: where is the file to be imported, which type of vertices/edges each line of the file is to be used as which columns of the file need to be imported, and the corresponding vertices/edges of these columns. what properties, etc.

Note: The format of the mapping file before version 0.11.0 and the format after 0.11.0 has changed greatly. For the convenience of expression, the mapping file (format) before 0.11.0 is called version 1.0, and the version after 0.11.0 is version 2.0. And unless otherwise specified, the “map file” refers to version 2.0.

Click to expand/collapse the skeleton of the map file for version 2.0
{
  "version": "2.0",
  "structs": [
    {
      "id": "1",
      "input": {
      },
      "vertices": [
        {},
        {}
      ],
      "edges": [
        {},
        {}
      ]
    }
  ]
}

Two versions of the mapping file are given directly here (the above graph model and data file are described)

Click to expand/collapse the mapping file for version 2.0
{
  "version": "2.0",
  "structs": [
    {
      "id": "1",
      "skip": false,
      "input": {
        "type": "FILE",
        "path": "vertex_person.csv",
        "file_filter": {
          "extensions": [
            "*"
          ]
        },
        "format": "CSV",
        "delimiter": ",",
        "date_format": "yyyy-MM-dd HH:mm:ss",
        "time_zone": "GMT+8",
        "skipped_line": {
          "regex": "(^#|^//).*|"
        },
        "compression": "NONE",
        "header": [
          "name",
          "age",
          "city"
        ],
        "charset": "UTF-8",
        "list_format": {
          "start_symbol": "[",
          "elem_delimiter": "|",
          "end_symbol": "]"
        }
      },
      "vertices": [
        {
          "label": "person",
          "skip": false,
          "id": null,
          "unfold": false,
          "field_mapping": {},
          "value_mapping": {},
          "selected": [],
          "ignored": [],
          "null_values": [
            ""
          ],
          "update_strategies": {}
        }
      ],
      "edges": []
    },
    {
      "id": "2",
      "skip": false,
      "input": {
        "type": "FILE",
        "path": "vertex_software.csv",
        "file_filter": {
          "extensions": [
            "*"
          ]
        },
        "format": "CSV",
        "delimiter": ",",
        "date_format": "yyyy-MM-dd HH:mm:ss",
        "time_zone": "GMT+8",
        "skipped_line": {
          "regex": "(^#|^//).*|"
        },
        "compression": "NONE",
        "header": null,
        "charset": "UTF-8",
        "list_format": {
          "start_symbol": "",
          "elem_delimiter": ",",
          "end_symbol": ""
        }
      },
      "vertices": [
        {
          "label": "software",
          "skip": false,
          "id": null,
          "unfold": false,
          "field_mapping": {},
          "value_mapping": {},
          "selected": [],
          "ignored": [],
          "null_values": [
            ""
          ],
          "update_strategies": {}
        }
      ],
      "edges": []
    },
    {
      "id": "3",
      "skip": false,
      "input": {
        "type": "FILE",
        "path": "edge_knows.json",
        "file_filter": {
          "extensions": [
            "*"
          ]
        },
        "format": "JSON",
        "delimiter": null,
        "date_format": "yyyy-MM-dd HH:mm:ss",
        "time_zone": "GMT+8",
        "skipped_line": {
          "regex": "(^#|^//).*|"
        },
        "compression": "NONE",
        "header": null,
        "charset": "UTF-8",
        "list_format": null
      },
      "vertices": [],
      "edges": [
        {
          "label": "knows",
          "skip": false,
          "source": [
            "source_name"
          ],
          "unfold_source": false,
          "target": [
            "target_name"
          ],
          "unfold_target": false,
          "field_mapping": {
            "source_name": "name",
            "target_name": "name"
          },
          "value_mapping": {},
          "selected": [],
          "ignored": [],
          "null_values": [
            ""
          ],
          "update_strategies": {}
        }
      ]
    },
    {
      "id": "4",
      "skip": false,
      "input": {
        "type": "FILE",
        "path": "edge_created.json",
        "file_filter": {
          "extensions": [
            "*"
          ]
        },
        "format": "JSON",
        "delimiter": null,
        "date_format": "yyyy-MM-dd HH:mm:ss",
        "time_zone": "GMT+8",
        "skipped_line": {
          "regex": "(^#|^//).*|"
        },
        "compression": "NONE",
        "header": null,
        "charset": "UTF-8",
        "list_format": null
      },
      "vertices": [],
      "edges": [
        {
          "label": "created",
          "skip": false,
          "source": [
            "source_name"
          ],
          "unfold_source": false,
          "target": [
            "target_name"
          ],
          "unfold_target": false,
          "field_mapping": {
            "source_name": "name",
            "target_name": "name"
          },
          "value_mapping": {},
          "selected": [],
          "ignored": [],
          "null_values": [
            ""
          ],
          "update_strategies": {}
        }
      ]
    }
  ]
}

Click to expand/collapse the mapping file for version 1.0
{
  "vertices": [
    {
      "label": "person",
      "input": {
        "type": "file",
        "path": "vertex_person.csv",
        "format": "CSV",
        "header": ["name", "age", "city"],
        "charset": "UTF-8"
      }
    },
    {
      "label": "software",
      "input": {
        "type": "file",
        "path": "vertex_software.csv",
        "format": "CSV"
      }
    }
  ],
  "edges": [
    {
      "label": "knows",
      "source": ["source_name"],
      "target": ["target_name"],
      "input": {
        "type": "file",
        "path": "edge_knows.json",
        "format": "JSON"
      },
      "field_mapping": {
        "source_name": "name",
        "target_name": "name"
      }
    },
    {
      "label": "created",
      "source": ["source_name"],
      "target": ["target_name"],
      "input": {
        "type": "file",
        "path": "edge_created.json",
        "format": "JSON"
      },
      "field_mapping": {
        "source_name": "name",
        "target_name": "name"
      }
    }
  ]
}

The 1.0 version of the mapping file is centered on the vertex and edge, and sets the input source; while the 2.0 version is centered on the input source, and sets the vertex and edge mapping. Some input sources (such as a file) can generate both vertices and edges. If you write in the 1.0 format, you need to write an input block in each of the vertex and edge mapping blocks. The two input blocks are exactly the same; and the 2.0 version only needs to write input once. Therefore, compared with version 1.0, version 2.0 can save some repetitive writing of input.

In the bin directory of hugegraph-loader-{version}, there is a script tool mapping-convert.sh that can directly convert the mapping file of version 1.0 to version 2.0. The usage is as follows:

bin/mapping-convert.sh struct.json

A struct-v2.json will be generated in the same directory as struct.json.

3.3.2 Input Source

Input sources are currently divided into five categories: FILE, HDFS, JDBC, KAFKA and GRAPH, which are distinguished by the type node. We call them local file input sources, HDFS input sources, JDBC input sources, KAFKA input sources and GRAPH input source, which are described below.

3.3.2.1 Local file input source
  • id: The id of the input source. This field is used to support some internal functions. It is not required (it will be automatically generated if it is not filled in). It is strongly recommended to write it, which is very helpful for debugging;
  • skip: whether to skip the input source, because the JSON file cannot add comments, if you do not want to import an input source during a certain import, but do not want to delete the configuration of the input source, you can set it to true to skip it, the default is false, not required;
  • input: input source map block, composite structure
    • type: an input source type, file or FILE must be filled;
    • path: the path of the local file or directory, the absolute path or the relative path relative to the mapping file, it is recommended to use the absolute path, required;
    • file_filter: filter files with compound conditions from path, compound structure, currently only supports configuration extensions, represented by child node extensions, the default is “*”, which means to keep all files;
    • format: the format of the local file, the optional values ​​are CSV, TEXT and JSON, which must be uppercase and required;
    • header: the column name of each column of the file, if not specified, the first line of the data file will be used as the header; when the file itself has a header and the header is specified, the first line of the file will be treated as a normal data line; JSON The file does not need to specify a header, optional;
    • delimiter: The column delimiter of the file line, the default is comma "," as the delimiter, the JSON file does not need to be specified, optional;
    • charset: the encoded character set of the file, the default is UTF-8, optional;
    • date_format: custom date format, the default value is yyyy-MM-dd HH:mm:ss, optional; if the date is presented in the form of a timestamp, this item must be written as timestamp (fixed writing);
    • time_zone: Set which time zone the date data is in, the default value is GMT+8, optional;
    • skipped_line: The line to be skipped, compound structure, currently only the regular expression of the line to be skipped can be configured, described by the child node regex, no line is skipped by default, optional;
    • compression: The compression format of the file, the optional values ​​are NONE, GZIP, BZ2, XZ, LZMA, SNAPPY_RAW, SNAPPY_FRAMED, Z, DEFLATE, LZ4_BLOCK, LZ4_FRAMED, ORC and PARQUET, the default is NONE, which means a non-compressed file, optional;
    • list_format: When a column of the file (non-JSON) is a collection structure (the Cardinality of the PropertyKey in the corresponding figure is Set or List), you can use this item to set the start character, separator, and end character of the column, compound structure :
      • start_symbol: The start character of the collection structure column (the default value is [, JSON format currently does not support specification)
      • elem_delimiter: the delimiter of the collection structure column (the default value is |, JSON format currently only supports native , delimiter)
      • end_symbol: the end character of the collection structure column (the default value is ], the JSON format does not currently support specification)
3.3.2.2 HDFS input source

The nodes and meanings of the above local file input source are basically applicable here. Only the different and unique nodes of the HDFS input source are listed below.

  • type: input source type, must fill in hdfs or HDFS, required;
  • path: the path of the HDFS file or directory, it must be the absolute path of HDFS, required;
  • core_site_path: the path of the core-site.xml file of the HDFS cluster, the key point is to specify the address of the NameNode (fs.default.name) and the implementation of the file system (fs.hdfs.impl);
3.3.2.3 JDBC input source

As mentioned above, it supports multiple relational databases, but because their mapping structures are very similar, they are collectively referred to as JDBC input sources, and then use the vendor node to distinguish different databases.

  • type: input source type, must fill in jdbc or JDBC, required;
  • vendor: database type, optional options are [MySQL, PostgreSQL, Oracle, SQLServer], case-insensitive, required;
  • driver: the type of driver used by jdbc, required;
  • url: the url of the database that jdbc wants to connect to, required;
  • database: the name of the database to be connected, required;
  • schema: The name of the schema to be connected, different databases have different requirements, and the details are explained below;
  • table: the name of the table to be connected, at least one of table or custom_sql is required;
  • custom_sql: custom SQL statement, at least one of table or custom_sql is required;
  • username: username to connect to the database, required;
  • password: password for connecting to the database, required;
  • batch_size: The size of one page when obtaining table data by page, the default is 500, optional;

MYSQL

NodeFixed value or common value
vendorMYSQL
drivercom.mysql.cj.jdbc.Driver
urljdbc:mysql://127.0.0.1:3306

schema: nullable, if filled in, it must be the same as the value of database

POSTGRESQL

NodeFixed value or common value
vendorPOSTGRESQL
driverorg.postgresql.Driver
urljdbc:postgresql://127.0.0.1:5432

schema: nullable, default is “public”

ORACLE

NodeFixed value or common value
vendorORACLE
driveroracle.jdbc.driver.OracleDriver
urljdbc:oracle:thin:@127.0.0.1:1521

schema: nullable, the default value is the same as the username

SQLSERVER

NodeFixed value or common value
vendorSQLSERVER
drivercom.microsoft.sqlserver.jdbc.SQLServerDriver
urljdbc:sqlserver://127.0.0.1:1433

schema: required

3.3.2.4 Kafka input source
  • type: input source type, kafka or KAFKA, required;
  • bootstrap_server: set the list of kafka bootstrap servers;
  • topic: the topic to subscribe to;
  • group: group of Kafka consumers;
  • from_beginning: set whether to read from the beginning;
  • format: format of the local file, options are CSV, TEXT and JSON, must be uppercase, required;
  • header: column name of each column of the file, if not specified, the first line of the data file will be used as the header; when the file itself has a header and the header is specified, the first line of the file will be treated as an ordinary data line; JSON files do not need to specify the header, optional;
  • delimiter: delimiter of the file line, default is comma “,” as delimiter, JSON files do not need to specify, optional;
  • charset: encoding charset of the file, default is UTF-8, optional;
  • date_format: customized date format, default value is yyyy-MM-dd HH:mm:ss, optional; if the date is presented in the form of timestamp, this item must be written as timestamp (fixed);
  • extra_date_formats: a customized list of another date formats, empty by default, optional; each item in the list is an alternate date format to the date_format specified date format;
  • time_zone: set which time zone the date data is in, default is GMT+8, optional;
  • skipped_line: the line you want to skip, composite structure, currently can only configure the regular expression of the line to be skipped, described by the child node regex, the default is not to skip any line, optional;
  • early_stop: the record pulled from Kafka broker at a certain time is empty, stop the task, default is false, only for debugging, optional;
3.3.2.5 GRAPH input Source
  • type: Data source type; must be filled in as graph or GRAPH (required);
  • graphspace: Source graphSpace name; default is DEFAULT;
  • graph: Source graph name (required);
  • username: HugeGraph username;
  • password: HugeGraph password;
  • selected_vertices: Filtering rules for vertices to be synchronized;
  • ignored_vertices: Filtering rules for vertices to be ignored;
  • selected_edges: Filtering rules for edges to be synchronized;
  • ignored_edges: Filtering rules for edges to be ignored;
  • pd-peers: HugeGraph-PD node addresses;
  • meta-endpoints: Meta service endpoints of the source cluster;
  • cluster: Source cluster name;
  • batch_size: Batch size for reading data from the source graph; default is 500;
3.3.3 Vertex and Edge Mapping

The nodes of vertex and edge mapping (a key in the JSON file) have a lot of the same parts. The same parts are introduced first, and then the unique nodes of vertex map and edge map are introduced respectively.

Nodes of the same section

  • label: label to which the vertex/edge data to be imported belongs, required;
  • field_mapping: Map the column name of the input source column to the attribute name of the vertex/edge, optional;
  • value_mapping: map the data value of the input source to the attribute value of the vertex/edge, optional;
  • selected: select some columns to insert, other unselected ones are not inserted, cannot exist at the same time as ignored, optional;
  • ignored: ignore some columns so that they do not participate in insertion, cannot exist at the same time as selected, optional;
  • null_values: You can specify some strings to represent null values, such as “NULL”. If the vertex/edge attribute corresponding to this column is also a nullable attribute, the value of this attribute will not be set when constructing the vertex/edge, optional ;
  • update_strategies: If the data needs to be updated in batches in a specific way, you can specify a specific update strategy for each attribute (see below for details), optional;
  • unfold: Whether to unfold the column, each unfolded column will form a row with other columns, which is equivalent to unfolding into multiple rows; for example, the value of a certain column (id column) of the file is [1,2,3], The values ​​of other columns are 18,Beijing. When unfold is set, this row will become 3 rows, namely: 1,18,Beijing, 2,18,Beijing and 3,18, Beijing. Note that this will only expand the column selected as id. Default false, optional;

Update strategy supports 8 types: (requires all uppercase)

  1. Value accumulation: SUM
  2. Take the greater of the two numbers/dates: BIGGER
  3. Take the smaller of two numbers/dates: SMALLER
  4. Set property takes union: UNION
  5. Set attribute intersection: INTERSECTION
  6. List attribute append element: APPEND
  7. List/Set attribute delete element: ELIMINATE
  8. Override an existing property: OVERRIDE

Note: If the newly imported attribute value is empty, the existing old data will be used instead of the empty value. For the effect, please refer to the following example

// The update strategy is specified in the JSON file as follows
{
  "vertices": [
    {
      "label": "person",
      "update_strategies": {
        "age": "SMALLER",
        "set": "UNION"
      },
      "input": {
        "type": "file",
        "path": "vertex_person.txt",
        "format": "TEXT",
        "header": ["name", "age", "set"]
      }
    }
  ]
}

// 1. Write a line of data with the OVERRIDE update strategy (null means empty here)
'a b null null'

// 2. Write another line
'null null c d'

// 3. Finally we can get
'a b c d'   

// If there is no update strategy, you will get
'null null c d'

Note : After adopting the batch update strategy, the number of disk read requests will increase significantly, and the import speed will be several times slower than that of pure write coverage (at this time HDD disk [IOPS](https://en.wikipedia .org/wiki/IOPS) will be the bottleneck, SSD is recommended for speed)

Unique Nodes for Vertex Maps

  • id: Specify a column as the id column of the vertex. When the vertex id policy is CUSTOMIZE, it is required; when the id policy is PRIMARY_KEY, it must be empty;

Unique Nodes for Edge Maps

  • source: Select certain columns of the input source as the id column of source vertex. When the id policy of the source vertex is CUSTOMIZE, a certain column must be specified as the id column of the vertex; when the id policy of the source vertex is When PRIMARY_KEY, one or more columns must be specified for splicing the id of the generated vertex, that is, no matter which id strategy is used, this item is required;
  • target: Specify certain columns as the id columns of target vertex, similar to source, so I won’t repeat them;
  • unfold_source: Whether to unfold the source column of the file, the effect is similar to that in the vertex map, and will not be repeated;
  • unfold_target: Whether to unfold the target column of the file, the effect is similar to that in the vertex mapping, and will not be repeated;

3.4 Execute command import

After preparing the graph model, data file, and input source mapping relationship file, the data file can be imported into the graph database.

The import process is controlled by commands submitted by the user, and the user can control the specific process of execution through different parameters.

3.4.1 Parameter description
ParameterDefault valueRequired or notDescription
-f or --fileYPath to configure script
-g or --graphhugegraphGraph name
--graphspaceDEFAULTGraph space name
-s or --schemaSchema file path; optional when the Schema already exists
-h or --host or -ilocalhostAddress of HugeGraphServer
-p or --port8080Port number of HugeGraphServer
--usernamenullWhen HugeGraphServer enables permission authentication, the username of the current graph
--passwordnullWhen HugeGraphServer enables permission authentication, the password of the current graph
--create-graphfalseWhether to automatically create the graph if it does not exist
--tokennullWhen HugeGraphServer has enabled authorization authentication, the token of the current graph
--protocolhttpProtocol for sending requests to the server, optional http or https
--pd-peersPD service node addresses
--pd-tokenToken for accessing PD service
--meta-endpointsMeta information storage service addresses
--directfalseWhether to directly connect to HugeGraph-Store
--route-typeNODE_PORTRoute selection method (optional values: NODE_PORT / DDS / BOTH)
--clusterhgCluster name
--trust-store-fileWhen the request protocol is https, the client’s certificate file path
--trust-store-passwordWhen the request protocol is https, the client certificate password
--clear-all-datafalseWhether to clear the original data on the server before importing data
--clear-timeout240Timeout for clearing the original data on the server before importing data
--incremental-modefalseWhether to use the breakpoint resume mode; only input sources FILE and HDFS support this mode. Enabling this mode allows starting the import from where the last import stopped
--failure-modefalseWhen failure mode is true, previously failed data will be imported. Generally, the failed data file needs to be manually corrected and edited before re-importing
--batch-insert-threadsCPUsBatch insert thread pool size (CPUs is the number of logical cores available to the current OS)
--single-insert-threads8Size of single insert thread pool
--max-conn4 * CPUsThe maximum number of HTTP connections between HugeClient and HugeGraphServer; it is recommended to adjust this when adjusting threads
--max-conn-per-route2 * CPUsThe maximum number of HTTP connections for each route between HugeClient and HugeGraphServer; it is recommended to adjust this item when adjusting threads
--batch-size500The number of data items in each batch when importing data
--max-parse-errors1The maximum number of data parsing errors allowed (per line); the program exits when this value is reached
--max-insert-errors500The maximum number of data insertion errors allowed (per row); the program exits when this value is reached
--timeout60Timeout (seconds) for insert result return
--shutdown-timeout10Waiting time for multithreading to stop (seconds)
--retry-times3Maximum number of retries after a timeout
--retry-interval10Interval before retry (seconds)
--check-vertexfalseWhether to check if the vertices connected by the edge exist when inserting the edge
--print-progresstrueWhether to print the number of imported items in real time on the console
--dry-runfalseEnable this mode to only parse data without importing; usually used for testing
--help or -helpfalsePrint help information
--parser-threads or --parallel-countmax(2,CPUs/2)Number of parallel read pipelines; --parallel-count is deprecated
--start-file0Start file index for partial loading
--end-file-1End file index for partial loading
--scatter-sourcesfalseScatter multiple sources for I/O optimization
--cdc-flush-interval30000The flush interval for Flink CDC
--cdc-sink-parallelism1The sink parallelism for Flink CDC
--max-read-errors1The maximum number of read error lines before exiting
--max-read-lines-1LThe maximum number of read lines, task stops when reached
--test-modefalseWhether the loader works in test mode
--use-prefilterfalseWhether to filter vertex in advance
--short-idMapping customized ID to shorter ID
--vertex-edge-limit-1LThe maximum number of vertex’s edges
--sink-typetrueSink to different storage type switch
--vertex-partitions64The number of partitions of the HBase vertex table
--edge-partitions64The number of partitions of the HBase edge table
--vertex-table-nameHBase vertex table name
--edge-table-nameHBase edge table name
--hbase-zk-quorumHBase ZooKeeper quorum
--hbase-zk-portHBase ZooKeeper port
--hbase-zk-parentHBase ZooKeeper parent
--restorefalseSet graph mode to RESTORING
--backendhstoreThe backend store type when creating graph if not exists
--serializerbinaryThe serializer type when creating graph if not exists
--scheduler-typedistributedThe task scheduler type when creating graph if not exists
--batch-failure-fallbacktrueWhether to fallback to single insert when batch insert fails
3.4.2 Breakpoint Continuation Mode

Usually, the Loader task takes a long time to execute. If the import interrupt process exits for some reason, and next time you want to continue the import from the interrupted point, this is the scenario of using breakpoint continuation.

The user sets the command line parameter –incremental-mode to true to open the breakpoint resume mode. The key to breakpoint continuation lies in the progress file. When the import process exits, the import progress at the time of exit will be recorded. Recorded in the progress file, the progress file is located in the ${struct} directory, the file name is like load-progress ${date}, ${struct} is the prefix of the mapping file, and ${date} is the start of the import moment. For example, for an import task started at 2019-10-10 12:30:30, the mapping file used is struct-example.json, then the path of the progress file is the same as struct-example.json Sibling struct-example/load-progress 2019-10-10 12:30:30.

Note: The generation of progress files is independent of whether –incremental-mode is turned on or not, and a progress file is generated at the end of each import.

If the data file formats are all legal and the import task is stopped by the user (CTRL + C or kill, kill -9 is not supported), that is to say, if there is no error record, the next import only needs to be set to Continue for the breakpoint.

But if the limit of –max-parse-errors or –max-insert-errors is reached because too much data is invalid or network abnormality is reached, Loader will record these original rows that failed to insert into In the failed file, after the user modifies the data lines in the failed file, set –reload-failure to true to import these “failed files” as input sources (does not affect the normal file import), Of course, if there is still a problem with the modified data line, it will be logged again to the failure file (don’t worry about duplicate lines).

Each vertex map or edge map will generate its own failure file when data insertion fails. The failure file is divided into a parsing failure file (suffix .parse-error) and an insertion failure file (suffix .insert-error). They are stored in the ${struct}/current directory. For example, there is a vertex mapping person, and an edge mapping knows in the mapping file, each of which has some error lines. When the Loader exits, you will see the following files in the ${struct}/current directory:

  • person-b4cd32ab.parse-error: Vertex map person parses wrong data
  • person-b4cd32ab.insert-error: Vertex map person inserts wrong data
  • knows-eb6b2bac.parse-error: edge map knows parses wrong data
  • knows-eb6b2bac.insert-error: edge map knows inserts wrong data

.parse-error and .insert-error do not always exist together. Only lines with parsing errors will have .parse-error files, and only lines with insertion errors will have .insert-error files.

3.4.3 logs directory file description

The log and error data during program execution will be written into the hugegraph-loader.log file.

3.4.4 Execute command

Run bin/hugegraph-loader and pass in parameters

bin/hugegraph-loader -g {GRAPH_NAME} -f ${INPUT_DESC_FILE} -s ${SCHEMA_FILE} -h {HOST} -p {PORT}

4 Complete example

Given below is an example in the example directory of the hugegraph-loader package. (GitHub address)

4.1 Prepare data

Vertex file: example/file/vertex_person.csv

marko,29,Beijing
vadas,27,Hongkong
josh,32,Beijing
peter,35,Shanghai
"li,nary",26,"Wu,han"
tom,null,NULL

Vertex file: example/file/vertex_software.txt

id|name|lang|price|ISBN
1|lop|java|328|ISBN978-7-107-18618-5
2|ripple|java|199|ISBN978-7-100-13678-5

Edge file: example/file/edge_knows.json

{"source_name": "marko", "target_name": "vadas", "date": "20160110", "weight": 0.5}
{"source_name": "marko", "target_name": "josh", "date": "20130220", "weight": 1.0}

Edge file: example/file/edge_created.json

{"aname": "marko", "bname": "lop", "date": "20171210", "weight": 0.4}
{"aname": "josh", "bname": "lop", "date": "20091111", "weight": 0.4}
{"aname": "josh", "bname": "ripple", "date": "20171210", "weight": 1.0}
{"aname": "peter", "bname": "lop", "date": "20170324", "weight": 0.2}

4.2 Write schema

Click to expand/collapse the schema file: example/file/schema.groovy
schema.propertyKey("name").asText().ifNotExist().create();
schema.propertyKey("age").asInt().ifNotExist().create();
schema.propertyKey("city").asText().ifNotExist().create();
schema.propertyKey("weight").asDouble().ifNotExist().create();
schema.propertyKey("lang").asText().ifNotExist().create();
schema.propertyKey("date").asText().ifNotExist().create();
schema.propertyKey("price").asDouble().ifNotExist().create();

schema.vertexLabel("person").properties("name", "age", "city").primaryKeys("name").ifNotExist().create();
schema.vertexLabel("software").properties("name", "lang", "price").primaryKeys("name").ifNotExist().create();

schema.indexLabel("personByAge").onV("person").by("age").range().ifNotExist().create();
schema.indexLabel("personByCity").onV("person").by("city").secondary().ifNotExist().create();
schema.indexLabel("personByAgeAndCity").onV("person").by("age", "city").secondary().ifNotExist().create();
schema.indexLabel("softwareByPrice").onV("software").by("price").range().ifNotExist().create();

schema.edgeLabel("knows").sourceLabel("person").targetLabel("person").properties("date", "weight").ifNotExist().create();
schema.edgeLabel("created").sourceLabel("person").targetLabel("software").properties("date", "weight").ifNotExist().create();

schema.indexLabel("createdByDate").onE("created").by("date").secondary().ifNotExist().create();
schema.indexLabel("createdByWeight").onE("created").by("weight").range().ifNotExist().create();
schema.indexLabel("knowsByWeight").onE("knows").by("weight").range().ifNotExist().create();

4.3 Write the input source mapping file example/file/struct.json

Click to expand/collapse the input source mapping file example/file/struct.json
{
  "vertices": [
    {
      "label": "person",
      "input": {
        "type": "file",
        "path": "example/file/vertex_person.csv",
        "format": "CSV",
        "header": ["name", "age", "city"],
        "charset": "UTF-8",
        "skipped_line": {
          "regex": "(^#|^//).*"
        }
      },
      "null_values": ["NULL", "null", ""]
    },
    {
      "label": "software",
      "input": {
        "type": "file",
        "path": "example/file/vertex_software.txt",
        "format": "TEXT",
        "delimiter": "|",
        "charset": "GBK"
      },
      "id": "id",
      "ignored": ["ISBN"]
    }
  ],
  "edges": [
    {
      "label": "knows",
      "source": ["source_name"],
      "target": ["target_name"],
      "input": {
        "type": "file",
        "path": "example/file/edge_knows.json",
        "format": "JSON",
        "date_format": "yyyyMMdd"
      },
      "field_mapping": {
        "source_name": "name",
        "target_name": "name"
      }
    },
    {
      "label": "created",
      "source": ["source_name"],
      "target": ["target_id"],
      "input": {
        "type": "file",
        "path": "example/file/edge_created.json",
        "format": "JSON",
        "date_format": "yyyy-MM-dd"
      },
      "field_mapping": {
        "source_name": "name"
      }
    }
  ]
}

4.4 Command to import

sh bin/hugegraph-loader.sh -g hugegraph -f example/file/struct.json -s example/file/schema.groovy

After the import is complete, statistics similar to the following will appear:

vertices/edges has been loaded this time : 8/6
--------------------------------------------------
count metrics
     input read success            : 14
     input read failure            : 0
     vertex parse success          : 8
     vertex parse failure          : 0
     vertex insert success         : 8
     vertex insert failure         : 0
     edge parse success            : 6
     edge parse failure            : 0
     edge insert success           : 6
     edge insert failure           : 0

4.5 Use Docker to load data

4.5.1 Use docker exec to load data directly
4.5.1.1 Prepare data

If you just want to try out the loader, you can import the built-in example dataset without needing to prepare additional data yourself.

If using custom data, before importing data with the loader, we need to copy the data into the container.

First, following the steps in 4.1–4.3, we can prepare the data and then use docker cp to copy the prepared data into the loader container.

Suppose we’ve prepared the corresponding dataset following the above steps, stored in the hugegraph-dataset folder with the following file structure:

tree -f hugegraph-dataset/

hugegraph-dataset
├── hugegraph-dataset/edge_created.json
├── hugegraph-dataset/edge_knows.json
├── hugegraph-dataset/schema.groovy
├── hugegraph-dataset/struct.json
├── hugegraph-dataset/vertex_person.csv
└── hugegraph-dataset/vertex_software.txt

Copy the files into the container.

docker cp hugegraph-dataset loader:/loader/dataset
docker exec -it loader ls /loader/dataset

edge_created.json  edge_knows.json  schema.groovy  struct.json  vertex_person.csv  vertex_software.txt
4.5.1.2 Data loading

Taking the built-in example dataset as an example, we can use the following command to load the data.

If you need to import your custom dataset, you need to modify the paths for -f (data script) and -s (schema) configurations.

You can refer to 3.4.1-Parameter description for the rest of the parameters.

docker exec -it loader bin/hugegraph-loader.sh -g hugegraph -f example/file/struct.json -s example/file/schema.groovy -h server -p 8080

If loading a custom dataset, following the previous example, you would use:

docker exec -it loader bin/hugegraph-loader.sh -g hugegraph -f /loader/dataset/struct.json -s /loader/dataset/schema.groovy -h server -p 8080

If loader and server are in the same Docker network, you can specify -h {server_container_name}; otherwise, you need to specify the IP of the server host (in our example, server_container_name is server).

Then we can see the result:

HugeGraphLoader worked in NORMAL MODE
vertices/edges loaded this time : 8/6
--------------------------------------------------
count metrics
    input read success            : 14                  
    input read failure            : 0                   
    vertex parse success          : 8                   
    vertex parse failure          : 0                   
    vertex insert success         : 8                   
    vertex insert failure         : 0                   
    edge parse success            : 6                   
    edge parse failure            : 0                   
    edge insert success           : 6                   
    edge insert failure           : 0                   
--------------------------------------------------
meter metrics
    total time                    : 0.199s              
    read time                     : 0.046s              
    load time                     : 0.153s              
    vertex load time              : 0.077s              
    vertex load rate(vertices/s)  : 103                 
    edge load time                : 0.112s              
    edge load rate(edges/s)       : 53   

You can also use curl or hubble to observe the import result. Here’s an example using curl:

> curl "http://localhost:8080/graphs/hugegraph/graph/vertices" | gunzip
{"vertices":[{"id":1,"label":"software","type":"vertex","properties":{"name":"lop","lang":"java","price":328.0}},{"id":2,"label":"software","type":"vertex","properties":{"name":"ripple","lang":"java","price":199.0}},{"id":"1:tom","label":"person","type":"vertex","properties":{"name":"tom"}},{"id":"1:josh","label":"person","type":"vertex","properties":{"name":"josh","age":32,"city":"Beijing"}},{"id":"1:marko","label":"person","type":"vertex","properties":{"name":"marko","age":29,"city":"Beijing"}},{"id":"1:peter","label":"person","type":"vertex","properties":{"name":"peter","age":35,"city":"Shanghai"}},{"id":"1:vadas","label":"person","type":"vertex","properties":{"name":"vadas","age":27,"city":"Hongkong"}},{"id":"1:li,nary","label":"person","type":"vertex","properties":{"name":"li,nary","age":26,"city":"Wu,han"}}]}

If you want to check the import result of edges, you can use curl "http://localhost:8080/graphs/hugegraph/graph/edges" | gunzip.

4.5.2 Enter the docker container to load data

Besides using docker exec directly for data import, we can also enter the container for data loading. The basic process is similar to 4.5.1.

Enter the container by docker exec -it loader bash and execute the command:

sh bin/hugegraph-loader.sh -g hugegraph -f example/file/struct.json -s example/file/schema.groovy -h server -p 8080

The results of the execution will be similar to those shown in 4.5.1.

4.6 Import data by spark-loader

The current source uses Spark 3.2.2 and Scala 2.12. Other combinations need independent verification.

The parameters of spark-loader are divided into two parts. Note: Because the abbreviations of these two-parameter names have overlapping parts, please use the full name of the parameter. And there is no need to guarantee the order between the two parameters.

Example:

sh bin/hugegraph-spark-loader.sh --master yarn \
--deploy-mode cluster --name spark-hugegraph-loader --file ./hugegraph.json \
--username admin --token admin --host xx.xx.xx.xx --port 8093 \
--graph graph-test --num-executors 6 --executor-cores 16 --executor-memory 15g

3.2.3 - HugeGraph-Tools Quick Start

1 HugeGraph-Tools Overview

HugeGraph-Tools is an automated deployment, management and backup/restore component of HugeGraph.

Testing Guide: For running HugeGraph-Tools tests locally, please refer to HugeGraph Toolchain Local Testing Guide

2 Get HugeGraph-Tools

HugeGraph-Tools is included in the Toolchain distribution. You can download the distribution or build it from source.

  • Download the compiled tarball
  • Clone source code then compile and install

2.1 Download the compiled archive

Download the latest version of the HugeGraph-Toolchain package:

export VERSION=1.7.0
export ARCHIVE="apache-hugegraph-toolchain-incubating-${VERSION}"
wget "https://downloads.apache.org/hugegraph/${VERSION}/${ARCHIVE}.tar.gz"
tar zxf "${ARCHIVE}.tar.gz"

2.2 Clone source code to compile and install

Please ensure that the wget command is installed before compiling the source code

Download the latest version of the HugeGraph-Tools source package:

# 1. get from github
git clone https://github.com/apache/hugegraph-toolchain.git

# 2. Download a released source package
export VERSION=1.7.0
export ARCHIVE="apache-hugegraph-toolchain-incubating-${VERSION}"
wget "https://downloads.apache.org/hugegraph/${VERSION}/${ARCHIVE}-src.tar.gz"

Compile and generate tar package:

cd hugegraph-toolchain
mvn package -pl hugegraph-tools -am -DskipTests -ntp

Generate tar package hugegraph-tools-${version}.tar.gz

3 How to use

3.1 Function overview

After decompression, enter the hugegraph-tools directory, you can use bin/hugegraph or bin/hugegraph help to view the usage information. mainly divided:

  • Graph management type, graph-mode-set, graph-mode-get, graph-list, graph-get, graph-clear, graph-create, graph-clone and graph-drop
  • Asynchronous task management type, task-list, task-get, task-delete, task-cancel and task-clear
  • Gremlin type, gremlin-execute and gremlin-schedule
  • Backup/Restore type, backup, restore, migrate, schedule-backup and dump
  • Authentication data backup/restore type, auth-backup and auth-restore
  • Install deployment type, deploy, clear, start-all and stop-all
Usage: hugegraph [options] [command] [command options]
3.2 [options]-Global Variable

options is a global variable of HugeGraph-Tools, which can be configured in hugegraph-tools/bin/hugegraph, including:

  • –graph,HugeGraph-Tools The name of the graph to operate on, the default value is hugegraph
  • –url,The service address of HugeGraph-Server, the default is http://127.0.0.1:8080
  • –user,When HugeGraph-Server opens authentication, pass username
  • –password,When HugeGraph-Server opens authentication, pass the user’s password
  • –timeout,Timeout when connecting to HugeGraph-Server, the default is 30s
  • –protocol, connection protocol, either http or https; the default is http
  • –trust-store-file,The path of the certificate file, when –url uses https, the truststore file used by HugeGraph-Client, the default is empty, which means using the built-in truststore file conf/hugegraph.truststore of hugegraph-tools
  • –trust-store-password,The password of the certificate file, when –url uses https, the password of the truststore used by HugeGraph-Client, the default is empty, representing the password of the built-in truststore file of hugegraph-tools

The above global variables can also be set through environment variables. One way is to use export on the command line to set temporary environment variables, which are valid until the command line is closed

Global VariableEnvironment VariableExample
–urlHUGEGRAPH_URLexport HUGEGRAPH_URL=http://127.0.0.1:8080
–graphHUGEGRAPH_GRAPHexport HUGEGRAPH_GRAPH=hugegraph
–userHUGEGRAPH_USERNAMEexport HUGEGRAPH_USERNAME=admin
–passwordHUGEGRAPH_PASSWORDexport HUGEGRAPH_PASSWORD=test
–timeoutHUGEGRAPH_TIMEOUTexport HUGEGRAPH_TIMEOUT=30
–trust-store-fileHUGEGRAPH_TRUST_STORE_FILEexport HUGEGRAPH_TRUST_STORE_FILE=/tmp/trust-store
–trust-store-passwordHUGEGRAPH_TRUST_STORE_PASSWORDexport HUGEGRAPH_TRUST_STORE_PASSWORD=xxxx

Another way is to set the environment variable in the bin/hugegraph script:

#!/bin/bash

# Set environment here if needed
#export HUGEGRAPH_URL=
#export HUGEGRAPH_GRAPH=
#export HUGEGRAPH_USERNAME=
#export HUGEGRAPH_PASSWORD=
#export HUGEGRAPH_TIMEOUT=
#export HUGEGRAPH_TRUST_STORE_FILE=
#export HUGEGRAPH_TRUST_STORE_PASSWORD=
3.3 Graph Management Type, graph-mode-set, graph-mode-get, graph-list, graph-get, graph-clear, graph-create, graph-clone and graph-drop
  • graph-mode-set, set graph restore mode
    • –graph-mode or -m, required, specifies the mode to be set, legal values include [NONE, RESTORING, MERGING, LOADING]
  • graph-mode-get, get graph restore mode
  • graph-list, list all graphs in a HugeGraph-Server
  • graph-get, get a graph and its storage backend type
  • graph-clear, clear all schema and data of a graph
    • –confirm-message or -c, required, delete confirmation information, manual input is required, double confirmation to prevent accidental deletion, “I’m sure to delete all data”, including double quotes
  • graph-create, create a new graph with configuration file
    • –name or -n, optional, the name of the new graph, default is hugegraph
    • –file or -f, required, the path to the graph configuration file
  • graph-clone, clone an existing graph
    • –name or -n, optional, the name of the cloned graph, default is hugegraph
    • –clone-graph-name, optional, the name of the source graph to clone from, default is hugegraph
  • graph-drop, drop a graph (different from graph-clear, this completely removes the graph)
    • –confirm-message or -c, required, confirmation message “I’m sure to drop the graph”, including double quotes

When you need to restore the backup graph to a new graph, you need to set the graph mode to RESTORING mode; when you need to merge the backup graph into an existing graph, you need to first set the graph mode to MERGING model.

3.4 Asynchronous task management Type,task-list、task-get and task-delete
  • task-list,List the asynchronous tasks in a graph, which can be filtered according to the status of the tasks
    • –status,Optional, specify the status of the task to view, i.e. filter tasks by status
    • –limit,Optional, specify the number of tasks to be obtained, the default is -1, which means to obtain all eligible tasks
  • task-get,Get detailed information about an asynchronous task
    • –task-id,Required, specifies the ID of the asynchronous task
  • task-delete,Delete information about an asynchronous task
    • –task-id,Required, specifies the ID of the asynchronous task
  • task-cancel,Cancel the execution of an asynchronous task
    • –task-id,ID of the asynchronous task to cancel
  • task-clear,Clean up completed asynchronous tasks
    • –force,Optional. When set, it means to clean up all asynchronous tasks. Unfinished ones are canceled first, and then all asynchronous tasks are cleared. By default, only completed asynchronous tasks are cleaned up
3.5 Gremlin Type,gremlin-execute and gremlin-schedule

⚠️ SEC Reminder: The execution of Gremlin depends on the actual logic of the statements, which may involve scenarios such as large-scale data modification and high-risk system calls with potential implicit hazards. Please use this tool only in secure and trusted network environments. It is imperative to configure and secure HugeGraph-Server with the Authentication System (Auth) and an IP Whitelist to restrict execution requests on the server side. Never hand over the tool or expose the execution entry to unauthorized personnel.

  • gremlin-execute, send Gremlin statements to HugeGraph-Server to execute query or modification operations, execute synchronously, and return results after completion
    • –file or -f, specify the script file to execute, UTF-8 encoding, mutually exclusive with –script
    • –script or -s, specifies the script string to execute, mutually exclusive with –file
    • –aliases or -a, Gremlin alias settings, the format is: key1=value1,key2=value2,…
    • –bindings or -b, Gremlin binding settings, the format is: key1=value1,key2=value2,…
    • –language or -l, the language of the Gremlin script, the default is gremlin-groovy

    –file and –script are mutually exclusive, one of them must be set

  • gremlin-schedule, send Gremlin statements to HugeGraph-Server to perform query or modification operations, asynchronous execution, and return the asynchronous task id immediately after the task is submitted
    • –file or -f, specify the script file to execute, UTF-8 encoding, mutually exclusive with –script
    • –script or -s, specifies the script string to execute, mutually exclusive with –file
    • –bindings or -b, Gremlin binding settings, the format is: key1=value1,key2=value2,…
    • –language or -l, the language of the Gremlin script, the default is gremlin-groovy

    –file and –script are mutually exclusive, one of them must be set

3.6 Backup/Restore Type
  • backup, back up the schema or data in a certain graph out of the HugeGraph system, and store it on the local disk or HDFS in the form of JSON
    • –format, the backup format, optional values include [json, text], the default is json
    • –all-properties, whether to back up all properties of vertices/edges, only valid when –format is text, default false
    • –label, the type of vertices/edges to be backed up, only valid when –format is text, only valid when backing up vertices or edges
    • –properties, properties of vertices/edges to be backed up, separated by commas, only valid when –format is text, valid only when backing up vertices or edges
    • –compress, whether to compress data during backup, the default is true
    • –directory or -d, the directory to store schema or data, the default is ‘./{graphName}’ for local directory, and ‘{fs.default.name}/{graphName}’ for HDFS
    • –huge-types or -t, the data types to be backed up, separated by commas, the optional value is ‘all’ or a combination of one or more [vertex, edge, vertex_label, edge_label, property_key, index_label], ‘all’ Represents all 6 types, namely vertices, edges and all schemas
    • –log or -l, specify the log directory, the default is the current directory
    • –retry, specify the number of failed retries, the default is 3
    • –thread-num or -T, the number of threads to use, default is Math.min(10, Math.max(4, CPUs / 2))
    • –split-size or -s, specifies the size of splitting vertices or edges when backing up, the default is 1048576
    • -D, use the mode of -Dkey=value to specify dynamic parameters, and specify HDFS configuration items when backing up data to HDFS, for example: -Dfs.default.name=hdfs://localhost:9000
  • restore, restore schema or data stored in JSON format to a new graph (RESTORING mode) or merge into an existing graph (MERGING mode)
    • –directory or -d, the directory to store schema or data, the default is ‘./{graphName}’ for local directory, and ‘{fs.default.name}/{graphName}’ for HDFS
    • –clean, whether to delete the directory specified by –directory after the recovery map is completed, the default is false
    • –huge-types or -t, data types to restore, separated by commas, optional value is ‘all’ or a combination of one or more [vertex, edge, vertex_label, edge_label, property_key, index_label], ‘all’ Represents all 6 types, namely vertices, edges and all schemas
    • –log or -l, specify the log directory, the default is the current directory
    • –retry, specify the number of failed retries, the default is 3
    • –thread-num or -T, the number of threads to use, default is Math.min(10, Math.max(4, CPUs / 2))
    • -D, use the mode of -Dkey=value to specify dynamic parameters, which are used to specify HDFS configuration items when restoring graphs from HDFS, for example: -Dfs.default.name=hdfs://localhost:9000

    restore command can be used only if –format is executed as backup for json

  • migrate, migrate the currently connected graph to another HugeGraphServer
    • –target-graph, the name of the target graph, the default is hugegraph
    • –target-url, the HugeGraphServer where the target graph is located, the default is http://127.0.0.1:8081
    • –target-user, the username used to access the target graph
    • –target-password, the password to access the target map
    • –target-timeout, the timeout for accessing the target map
    • –target-trust-store-file, access the truststore file used by the target graph
    • –target-trust-store-password, the password to access the truststore used by the target map
    • –directory or -d, during the migration process, the directory where the schema or data of the source graph is stored. For a local directory, the default is ‘./{graphName}’; for HDFS, the default is ‘{fs.default.name}/ {graphName}’
    • –huge-types or -t, the data types to be migrated, separated by commas, the optional value is ‘all’ or a combination of one or more [vertex, edge, vertex_label, edge_label, property_key, index_label], ‘all’ Represents all 6 types, namely vertices, edges and all schemas
    • –log or -l, specify the log directory, the default is the current directory
    • –retry, specify the number of failed retries, the default is 3
    • –split-size or -s, specify the size of the vertex or edge block when backing up the source graph during the migration process, the default is 1048576
    • -D, use the mode of -Dkey=value to specify dynamic parameters, which are used to specify HDFS configuration items when the data needs to be backed up to HDFS during the migration process, for example: -Dfs.default.name=hdfs://localhost: 9000
    • –graph-mode or -m, the mode to set the target graph when restoring the source graph to the target graph, legal values include [RESTORING, MERGING]
    • –keep-local-data, whether to keep the backup of the source map generated in the process of migrating the map, the default is false, that is, the backup of the source map is not kept after the default migration map ends
  • schedule-backup, periodically back up the graph and keep a certain number of the latest backups (currently only supports local file systems)
    • –directory or -d, required, specifies the directory of the backup data
    • –backup-num, optional, specifies the number of latest backups to save, defaults to 3
    • –interval, an optional item, specifies the backup cycle, the format is the same as the Linux crontab format
  • dump, export all vertices and edges in the graph, using the vertex vertex-edge1 vertex-edge2... JSON format by default. To customize the format, implement a Formatter subclass such as CustomFormatter under hugegraph-tools/src/main/java/org/apache/hugegraph/formatter, then select it when running the command: bin/hugegraph dump -f CustomFormatter
    • –formatter or -f, specify the formatter to use, the default is JsonFormatter
    • –directory or -d, the directory where schema or data is stored, the default is the current directory
    • –log or -l, specify the log directory, the default is the current directory
    • –retry, specify the number of failed retries, the default is 3
    • –split-size or -s, specifies the size of splitting vertices or edges when backing up, the default is 1048576
    • -D, use the mode of -Dkey=value to specify dynamic parameters, and specify HDFS configuration items when backing up data to HDFS, for example: -Dfs.default.name=hdfs://localhost:9000
3.7 Authentication data backup/restore type
  • auth-backup, backup authentication data to a specified directory
    • –types or -t, types of authentication data to back up, separated by commas, optional value is ‘all’ or a combination of one or more [user, group, target, belong, access], ‘all’ represents all 5 types
    • –directory or -d, directory to store backup data, defaults to current directory
    • –log or -l, specify the log directory, the default is the current directory
    • –retry, specify the number of failed retries, the default is 3
    • –thread-num or -T, the number of threads to use, default is Math.min(10, Math.max(4, CPUs / 2))
    • -D, use the mode of -Dkey=value to specify dynamic parameters, and specify HDFS configuration items when backing up data to HDFS, for example: -Dfs.default.name=hdfs://localhost:9000
  • auth-restore, restore authentication data from a specified directory
    • –types or -t, types of authentication data to restore, separated by commas, optional value is ‘all’ or a combination of one or more [user, group, target, belong, access], ‘all’ represents all 5 types
    • –directory or -d, directory where backup data is stored, defaults to current directory
    • –log or -l, specify the log directory, the default is the current directory
    • –retry, specify the number of failed retries, the default is 3
    • –thread-num or -T, the number of threads to use, default is Math.min(10, Math.max(4, CPUs / 2))
    • –strategy, conflict handling strategy, optional values are [stop, ignore], default is stop. stop means stop restoring when encountering conflicts, ignore means ignore conflicts and continue restoring
    • –init-password, initial password to set when restoring users, required when restoring user data
    • -D, use the mode of -Dkey=value to specify dynamic parameters, which are used to specify HDFS configuration items when restoring data from HDFS, for example: -Dfs.default.name=hdfs://localhost:9000
3.8 Install the deployment type
  • deploy, one-click download, install and start HugeGraph-Server and HugeGraph-Studio
    • -v, required, specifies the HugeGraph-Server and HugeGraph-Studio version to install
    • -p, required, specifies the installed HugeGraph-Server and HugeGraph-Studio directories
    • -u, optional, specifies the link to download the HugeGraph-Server and HugeGraph-Studio compressed packages
  • clear, clean up HugeGraph-Server and HugeGraph-Studio directories and tarballs
    • -p, required, specifies the directory of HugeGraph-Server and HugeGraph-Studio to be cleaned
  • start-all, start HugeGraph-Server and HugeGraph-Studio with one click, and start monitoring, automatically pull up the service when the service dies
    • -v, required, specifies the installed HugeGraph-Server and HugeGraph-Studio version to start
    • -p, required, specifies the directory where HugeGraph-Server and HugeGraph-Studio are installed
  • stop-all, close HugeGraph-Server and HugeGraph-Studio with one click

There is an optional parameter -u in the deploy command. When provided, the specified download address will be used instead of the default download address to download the tar package, and the address will be written into the ~/hugegraph-download-url-prefix file; if no address is specified later When -u and ~/hugegraph-download-url-prefix are not specified, the tar package will be downloaded from the address specified by ~/hugegraph-download-url-prefix; if there is neither -u nor ~/hugegraph-download-url-prefix, it will be downloaded from the default download address

3.9 Specific command parameters

The specific parameters of each subcommand are as follows:

Usage: hugegraph [options] [command] [command options]
  Options:
    --graph
      Name of graph
      Default: hugegraph
    --password
      Password of user
    --timeout
      Connection timeout
      Default: 30
    --trust-store-file
      The path of client truststore file used when https protocol is enabled
    --trust-store-password
      The password of the client truststore file used when the https protocol 
      is enabled
    --url
      The URL of HugeGraph-Server
      Default: http://127.0.0.1:8080
    --user
      Name of user
  Commands:
    graph-list      List all graphs
      Usage: graph-list

    graph-get      Get graph info
      Usage: graph-get

    graph-clear      Clear graph schema and data
      Usage: graph-clear [options]
        Options:
        * --confirm-message, -c
            Confirm message of graph clear is "I'm sure to delete all data". 
            (Note: include "")

    graph-mode-set      Set graph mode
      Usage: graph-mode-set [options]
        Options:
        * --graph-mode, -m
            Graph mode, include: [NONE, RESTORING, MERGING]
            Possible Values: [NONE, RESTORING, MERGING, LOADING]

    graph-mode-get      Get graph mode
      Usage: graph-mode-get

    task-list      List tasks
      Usage: task-list [options]
        Options:
          --limit
            Limit number, no limit if not provided
            Default: -1
          --status
            Status of task

    task-get      Get task info
      Usage: task-get [options]
        Options:
        * --task-id
            Task id
            Default: 0

    task-delete      Delete task
      Usage: task-delete [options]
        Options:
        * --task-id
            Task id
            Default: 0

    task-cancel      Cancel task
      Usage: task-cancel [options]
        Options:
        * --task-id
            Task id
            Default: 0

    task-clear      Clear completed tasks
      Usage: task-clear [options]
        Options:
          --force
            Force to clear all tasks, cancel all uncompleted tasks firstly, 
            and delete all completed tasks
            Default: false

    gremlin-execute      Execute Gremlin statements
      Usage: gremlin-execute [options]
        Options:
          --aliases, -a
            Gremlin aliases, valid format is: 'key1=value1,key2=value2...'
            Default: {}
          --bindings, -b
            Gremlin bindings, valid format is: 'key1=value1,key2=value2...'
            Default: {}
          --file, -f
            Gremlin Script file to be executed, UTF-8 encoded, exclusive to 
            --script 
          --language, -l
            Gremlin script language
            Default: gremlin-groovy
          --script, -s
            Gremlin script to be executed, exclusive to --file

    gremlin-schedule      Execute Gremlin statements as asynchronous job
      Usage: gremlin-schedule [options]
        Options:
          --bindings, -b
            Gremlin bindings, valid format is: 'key1=value1,key2=value2...'
            Default: {}
          --file, -f
            Gremlin Script file to be executed, UTF-8 encoded, exclusive to 
            --script 
          --language, -l
            Gremlin script language
            Default: gremlin-groovy
          --script, -s
            Gremlin script to be executed, exclusive to --file

    backup      Backup graph schema/data. If directory is on HDFS, use -D to 
            set HDFS params. For exmaple:
            -Dfs.default.name=hdfs://localhost:9000 
      Usage: backup [options]
        Options:
          --all-properties
            All properties to be backup flag
            Default: false
          --compress
            compress flag
            Default: true
          --directory, -d
            Directory of graph schema/data, default is './{graphname}' in 
            local file system or '{fs.default.name}/{graphname}' in HDFS
          --format
            File format, valid is [json, text]
            Default: json
          --huge-types, -t
            Type of schema/data. Concat with ',' if more than one. 'all' means 
            all vertices, edges and schema, in other words, 'all' equals with 
            'vertex,edge,vertex_label,edge_label,property_key,index_label' 
            Default: [PROPERTY_KEY, VERTEX_LABEL, EDGE_LABEL, INDEX_LABEL, VERTEX, EDGE]
          --label
            Vertex or edge label, only valid when type is vertex or edge
          --log, -l
            Directory of log
            Default: ./logs
          --properties
            Vertex or edge properties to backup, only valid when type is
            vertex or edge
            Default: []
          --retry
            Retry times, default is 3
            Default: 3
          --split-size, -s
            Split size of shard
            Default: 1048576
          -D
            HDFS config parameters
            Syntax: -Dkey=value
            Default: {}

    schedule-backup      Schedule backup task
      Usage: schedule-backup [options]
        Options:
          --backup-num
            The number of latest backups to keep
            Default: 3
        * --directory, -d
            The directory of backups stored
          --interval
            The interval of backup, format is: "a b c d e". 'a' means minute 
            (0 - 59), 'b' means hour (0 - 23), 'c' means day of month (1 - 
            31), 'd' means month (1 - 12), 'e' means day of week (0 - 6) 
            (Sunday=0), "*" means all
            Default: "0 0 * * *"

    dump      Dump graph to files
      Usage: dump [options]
        Options:
          --directory, -d
            Directory of graph schema/data, default is './{graphname}' in 
            local file system or '{fs.default.name}/{graphname}' in HDFS
          --formatter, -f
            Formatter to customize format of vertex/edge
            Default: JsonFormatter
          --log, -l
            Directory of log
            Default: ./logs
          --retry
            Retry times, default is 3
            Default: 3
          --split-size, -s
            Split size of shard
            Default: 1048576
          -D
            HDFS config parameters
            Syntax: -Dkey=value
            Default: {}

    restore      Restore graph schema/data. If directory is on HDFS, use -D to 
            set HDFS params if needed. For 
            exmaple:-Dfs.default.name=hdfs://localhost:9000 
      Usage: restore [options]
        Options:
          --clean
            Whether to remove the directory of graph data after restored
            Default: false
          --directory, -d
            Directory of graph schema/data, default is './{graphname}' in 
            local file system or '{fs.default.name}/{graphname}' in HDFS
          --huge-types, -t
            Type of schema/data. Concat with ',' if more than one. 'all' means 
            all vertices, edges and schema, in other words, 'all' equals with 
            'vertex,edge,vertex_label,edge_label,property_key,index_label' 
            Default: [PROPERTY_KEY, VERTEX_LABEL, EDGE_LABEL, INDEX_LABEL, VERTEX, EDGE]
          --log, -l
            Directory of log
            Default: ./logs
          --retry
            Retry times, default is 3
            Default: 3
          -D
            HDFS config parameters
            Syntax: -Dkey=value
            Default: {}

    migrate      Migrate graph
      Usage: migrate [options]
        Options:
          --directory, -d
            Directory of graph schema/data, default is './{graphname}' in 
            local file system or '{fs.default.name}/{graphname}' in HDFS
          --graph-mode, -m
            Mode used when migrating to target graph, include: [RESTORING, 
            MERGING] 
            Default: RESTORING
            Possible Values: [NONE, RESTORING, MERGING, LOADING]
          --huge-types, -t
            Type of schema/data. Concat with ',' if more than one. 'all' means 
            all vertices, edges and schema, in other words, 'all' equals with 
            'vertex,edge,vertex_label,edge_label,property_key,index_label' 
            Default: [PROPERTY_KEY, VERTEX_LABEL, EDGE_LABEL, INDEX_LABEL, VERTEX, EDGE]
          --keep-local-data
            Whether to keep the local directory of graph data after restored
            Default: false
          --log, -l
            Directory of log
            Default: ./logs
          --retry
            Retry times, default is 3
            Default: 3
          --split-size, -s
            Split size of shard
            Default: 1048576
          --target-graph
            The name of target graph to migrate
            Default: hugegraph
          --target-password
            The password of target graph to migrate
          --target-timeout
            The timeout to connect target graph to migrate
            Default: 0
          --target-trust-store-file
            The trust store file of target graph to migrate
          --target-trust-store-password
            The trust store password of target graph to migrate
          --target-url
            The url of target graph to migrate
            Default: http://127.0.0.1:8081
          --target-user
            The username of target graph to migrate
          -D
            HDFS config parameters
            Syntax: -Dkey=value
            Default: {}

    deploy      Install HugeGraph-Server and HugeGraph-Studio
      Usage: deploy [options]
        Options:
        * -p
            Install path of HugeGraph-Server and HugeGraph-Studio
          -u
            Download url prefix path of HugeGraph-Server and HugeGraph-Studio
        * -v
            Version of HugeGraph-Server and HugeGraph-Studio

    start-all      Start HugeGraph-Server and HugeGraph-Studio
      Usage: start-all [options]
        Options:
        * -p
            Install path of HugeGraph-Server and HugeGraph-Studio
        * -v
            Version of HugeGraph-Server and HugeGraph-Studio

    clear      Clear HugeGraph-Server and HugeGraph-Studio
      Usage: clear [options]
        Options:
        * -p
            Install path of HugeGraph-Server and HugeGraph-Studio

    stop-all      Stop HugeGraph-Server and HugeGraph-Studio
      Usage: stop-all

    help      Print usage
      Usage: help
3.10 Specific command example
1. gremlin statement
# Execute gremlin synchronously
./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph gremlin-execute --script 'g.V().count()'

# Execute gremlin asynchronously
./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph gremlin-schedule --script 'g.V().count()'
2. Show task status
./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph task-list

./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph task-list --limit 5

./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph task-list --status success
3. Set and show graph mode
./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph graph-mode-set -m RESTORING

./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph graph-mode-get

./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph graph-list
4. Cleanup Graph
./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph graph-clear -c "I'm sure to delete all data"
5. Backup Graph
./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph backup -t all --directory ./backup-test
6. Periodic Backup Graph
./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph schedule-backup -d ./backup --interval "*/2 * * * *"
7. Recovery Graph
# set graph mode
./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph graph-mode-set -m RESTORING

# recovery graph
./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph restore -t all --directory ./backup-test

# restore graph mode
./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph graph-mode-set -m NONE
8. Graph Migration
./bin/hugegraph --url http://127.0.0.1:8080 --graph hugegraph migrate --target-url http://127.0.0.1:8090 --target-graph hugegraph

3.2.4 - HugeGraph-Spark-Connector Quick Start

1 HugeGraph-Spark-Connector Overview

HugeGraph-Spark-Connector uses the Spark DataFrame API to write bulk data to HugeGraph. The current implementation provides vertex and edge writers.

2 Environment Requirements

  • Java 8+
  • Maven 3.6+
  • Spark 3.x
  • Scala 2.12

3 Building

3.1 Build without executing tests

git clone https://github.com/apache/hugegraph-toolchain.git
cd hugegraph-toolchain
mvn clean package -pl hugegraph-spark-connector -am -DskipTests -ntp

3.2 Build with default tests

mvn clean package -pl hugegraph-spark-connector -am -ntp

4 Usage

Add the dependency to pom.xml, replacing ${revision} with the release version you use:

<dependency>
    <groupId>org.apache.hugegraph</groupId>
    <artifactId>hugegraph-spark-connector</artifactId>
    <version>${revision}</version>
</dependency>

4.1 Schema Definition Example

If we have a graph, the schema is defined as follows:

schema.propertyKey("name").asText().ifNotExist().create()
schema.propertyKey("age").asInt().ifNotExist().create()
schema.propertyKey("city").asText().ifNotExist().create()
schema.propertyKey("weight").asDouble().ifNotExist().create()
schema.propertyKey("lang").asText().ifNotExist().create()
schema.propertyKey("date").asText().ifNotExist().create()
schema.propertyKey("price").asDouble().ifNotExist().create()

schema.vertexLabel("person")
        .properties("name", "age", "city")
        .useCustomizeStringId()
        .nullableKeys("age", "city")
        .ifNotExist()
        .create()

schema.vertexLabel("software")
        .properties("name", "lang", "price")
        .primaryKeys("name")
        .ifNotExist()
        .create()

schema.edgeLabel("knows")
        .sourceLabel("person")
        .targetLabel("person")
        .properties("date", "weight")
        .ifNotExist()
        .create()

schema.edgeLabel("created")
        .sourceLabel("person")
        .targetLabel("software")
        .properties("date", "weight")
        .ifNotExist()
        .create()

4.2 Vertex Sink (Scala)

val df = sparkSession.createDataFrame(Seq(
  Tuple3("marko", 29, "Beijing"),
  Tuple3("vadas", 27, "HongKong"),
  Tuple3("Josh", 32, "Beijing"),
  Tuple3("peter", 35, "ShangHai"),
  Tuple3("li,nary", 26, "Wu,han"),
  Tuple3("Bob", 18, "HangZhou"),
)) toDF("name", "age", "city")

df.show()

df.write
  .format("org.apache.hugegraph.spark.connector.DataSource")
  .option("host", "127.0.0.1")
  .option("port", "8080")
  .option("graph", "hugegraph")
  .option("data-type", "vertex")
  .option("label", "person")
  .option("id", "name")
  .option("batch-size", 2)
  .mode(SaveMode.Overwrite)
  .save()

4.3 Edge Sink (Scala)

val df = sparkSession.createDataFrame(Seq(
  Tuple4("marko", "vadas", "20160110", 0.5),
  Tuple4("peter", "Josh", "20230801", 1.0),
  Tuple4("peter", "li,nary", "20130220", 2.0)
)).toDF("source", "target", "date", "weight")

df.show()

df.write
  .format("org.apache.hugegraph.spark.connector.DataSource")
  .option("host", "127.0.0.1")
  .option("port", "8080")
  .option("graph", "hugegraph")
  .option("data-type", "edge")
  .option("label", "knows")
  .option("source-name", "source")
  .option("target-name", "target")
  .option("batch-size", 2)
  .mode(SaveMode.Overwrite)
  .save()

5 Configuration Parameters

5.1 Client Configs

Client Configs are used to configure hugegraph-client.

ParameterDefault ValueDescription
hostlocalhostAddress of HugeGraphServer
port8080Port of HugeGraphServer
graphhugegraphGraph name
protocolhttpProtocol for sending requests to the server, optional http or https
usernamenullUsername of the current graph when HugeGraphServer enables permission authentication
tokennullToken of the current graph when HugeGraphServer has enabled authorization authentication
timeout60Timeout (seconds) for inserting results to return
max-connCPUS * 4The maximum number of HTTP connections between HugeClient and HugeGraphServer
max-conn-per-routeCPUS * 2The maximum number of HTTP connections for each route between HugeClient and HugeGraphServer
trust-store-filenullThe client’s certificate file path when the request protocol is https
trust-store-tokennullThe client’s certificate password when the request protocol is https

5.2 Graph Data Configs

Graph Data Configs describe how DataFrame columns map to vertices or edges.

ParameterDefault ValueDescription
data-typeGraph data type, must be vertex or edge
labelLabel to which the vertex/edge data to be imported belongs
idSpecify a column as the id column of the vertex. When the vertex id policy is CUSTOMIZE, it is required; when the id policy is PRIMARY_KEY, it must be empty
source-nameSelect certain columns of the input source as the id column of source vertex. When the id policy of the source vertex is CUSTOMIZE, a certain column must be specified as the id column of the vertex; when the id policy of the source vertex is PRIMARY_KEY, one or more columns must be specified for splicing the id of the generated vertex, that is, no matter which id strategy is used, this item is required
target-nameSpecify certain columns as the id columns of target vertex, similar to source-name
selected-fieldsSelect some columns to insert, other unselected ones are not inserted, cannot exist at the same time as ignored-fields
ignored-fieldsIgnore some columns so that they do not participate in insertion, cannot exist at the same time as selected-fields
batch-size500The number of data items in each batch when importing data

5.3 Common Configs

Common Configs contains some common configurations.

ParameterDefault ValueDescription
delimiter,Separator of source-name, target-name, selected-fields or ignored-fields

6 License

The same as HugeGraph, hugegraph-spark-connector is also licensed under Apache 2.0 License.

3.3 - HugeGraph-AI

hugegraph-ai provides Python clients for HugeGraph, graph machine learning tools, and LLM tools for knowledge graph construction and GraphRAG applications.

Apache License 2.0 · Ask DeepWiki

Modules

  • hugegraph-llm: knowledge graph construction, GraphRAG, and natural-language graph queries.
  • hugegraph-ml: reads graph data from HugeGraph and runs graph learning models.
  • hugegraph-python-client: a Python SDK for managing schemas and graph data and running Gremlin queries.
  • vermeer-python-client: a Python SDK for the Vermeer graph computing service.

The repository uses a uv workspace to manage the LLM and Python client packages. HugeGraph-ML is a path dependency rather than a workspace member.

Requirements

  • HugeGraph-LLM: Python 3.10 or 3.11
  • HugeGraph-ML and the Python clients: Python 3.10 or later
  • uv 0.7 or later
  • HugeGraph Server 1.5 or later

Deploy with Docker Compose

The repository includes a Compose file that starts both HugeGraph Server and the RAG service:

git clone https://github.com/apache/hugegraph-ai.git
cd hugegraph-ai
cp docker/env.template docker/.env
# Edit docker/.env and set PROJECT_PATH to the absolute path of this repository
touch hugegraph-llm/.env
cd docker
docker compose -f docker-compose-network.yml up -d

Default addresses:

  • HugeGraph Server: http://localhost:8080
  • RAG service and Web UI: http://localhost:8001

Start the RAG Service from Source

git clone https://github.com/apache/hugegraph-ai.git
cd hugegraph-ai
uv sync --extra llm
source .venv/bin/activate
cd hugegraph-llm
python -m hugegraph_llm.demo.rag_demo.app

uv sync creates .venv at the repository root. Do not create a separate environment under hugegraph-llm, because doing so can bypass the dependencies locked by the workspace.

Install ML Dependencies

cd hugegraph-ai
uv sync --extra ml
source .venv/bin/activate
cd hugegraph-ml/src

Example scripts are under hugegraph-ml/src/hugegraph_ml/examples/.

Next Steps

3.3.1 - HugeGraph-LLM

HugeGraph-LLM connects graph databases with large language models for knowledge graph construction, GraphRAG, and natural-language graph queries. Its demo service hosts the Gradio UI and FastAPI endpoints in the same process and listens on port 8001 by default.

Requirements

AI-generated project documentation: Ask DeepWiki

  • Python 3.10 or 3.11
  • uv 0.7 or later
  • HugeGraph Server 1.5 or later

Deploy with Docker Compose

Prepare the environment files from the HugeGraph-AI repository root:

git clone https://github.com/apache/hugegraph-ai.git
cd hugegraph-ai
cp docker/env.template docker/.env
# Edit docker/.env and set PROJECT_PATH to the absolute path of this repository
touch hugegraph-llm/.env
cd docker
docker compose -f docker-compose-network.yml up -d
docker compose -f docker-compose-network.yml ps

After startup, HugeGraph Server is available at http://localhost:8080, and the RAG service and Web UI are available at http://localhost:8001.

Start from Source

Install dependencies through the workspace at the repository root:

git clone https://github.com/apache/hugegraph-ai.git
cd hugegraph-ai
uv sync --extra llm
source .venv/bin/activate
cd hugegraph-llm
python -m hugegraph_llm.demo.rag_demo.app

To use a custom address and port:

python -m hugegraph_llm.demo.rag_demo.app \
  --host 127.0.0.1 \
  --port 18001

The service stores model, HugeGraph, and login settings in hugegraph-llm/.env. Prompts are stored separately in hugegraph-llm/src/hugegraph_llm/resources/demo/config_prompt.yaml. The configuration code creates missing files with default values.

Main Capabilities

Build RAG Indexes

The first Web UI tab splits text into a chunk vector index, extracts vertices and edges according to a schema, writes the graph to HugeGraph, and updates the vertex vector index. The schema can be inline JSON or the name of an existing graph. Through the REST API, a graph name requires a matching client_config.graph; inline JSON neither connects to HugeGraph nor accepts client_config.

GraphRAG

The query pipeline can combine direct LLM answers, chunk-vector retrieval, and graph retrieval. Graph retrieval first extracts keywords and matches vertices, then attempts Text2Gremlin. If generation or execution fails, it can fall back to predefined graph traversals. Request parameters control result limits, vector distance thresholds, template counts, and reranking.

Knowledge graph builder

Text2Gremlin

POST /text2gremlin generates Gremlin from natural language, the graph schema, and optional examples. A custom prompt must retain {query}, {schema}, {example}, and {vertices}.

Models and Vector Backends

Chat, information extraction, and Text2Gremlin can independently use an OpenAI-compatible endpoint, Ollama, or LiteLLM. The embedding model is configured separately. FAISS is the default vector index; Milvus or Qdrant are available after installing the optional dependencies:

cd hugegraph-ai
uv sync --package hugegraph-llm --extra vectordb

See the configuration reference and REST API for details.

Development Checks

cd hugegraph-ai
./style/code_format_and_analysis.sh
cd hugegraph-llm
pytest

3.3.2 - HugeGraph-ML

HugeGraph-ML reads graph data from HugeGraph and converts it to DGL graphs for tasks such as node embedding, node classification, and graph classification. Model implementations are under hugegraph-ml/src/hugegraph_ml/models/.

Requirements

  • Python 3.10 or later
  • HugeGraph Server 1.0 or later; 1.5 or later is recommended
  • uv 0.7 or later

Installation

git clone https://github.com/apache/hugegraph-ai.git
cd hugegraph-ai
uv sync --extra ml
source .venv/bin/activate
cd hugegraph-ml/src

HugeGraph-ML is a path dependency of the root project but is not a uv workspace member. Select the ml extra at the repository root instead of creating another lock file in the subdirectory.

Implemented Models

The current README lists these models:

ModelsMain purpose
AGNN, APPNP, ARMA, Cluster-GCN, DAGNN, DeeperGCN, GRAND, JKNetNode classification
BGNN, CARE-GNNFraud detection
BGRL, DGI, GRACERepresentation learning
DiffPoolGraph classification
GATNE, P-GNN, SEALLink prediction or network embedding
C&SCorrection and smoothing of predictions

The source also includes GIN for graph classification and MLPClassifier for downstream classification. The model count changes between versions; use src/hugegraph_ml/models/ as the authoritative list.

DGI Node Embedding Example

First import DGL’s Cora dataset into HugeGraph:

from hugegraph_ml.utils.dgl2hugegraph_utils import import_graph_from_dgl

import_graph_from_dgl("cora")

Read the graph and train DGI:

from hugegraph_ml.data.hugegraph2dgl import HugeGraph2DGL
from hugegraph_ml.models.dgi import DGI
from hugegraph_ml.models.mlp import MLPClassifier
from hugegraph_ml.tasks.node_classify import NodeClassify
from hugegraph_ml.tasks.node_embed import NodeEmbed

hg2d = HugeGraph2DGL()
graph = hg2d.convert_graph(vertex_label="CORA_vertex", edge_label="CORA_edge")

embed_model = DGI(n_in_feats=graph.ndata["feat"].shape[1])
embed_task = NodeEmbed(graph=graph, model=embed_model)
embedded_graph = embed_task.train_and_embed(
    add_self_loop=True, n_epochs=300, patience=30
)

classifier = MLPClassifier(
    n_in_feat=embedded_graph.ndata["feat"].shape[1],
    n_out_feat=embedded_graph.ndata["label"].unique().shape[0],
)
classify_task = NodeClassify(graph=embedded_graph, model=classifier)
classify_task.train(lr=1e-3, n_epochs=400, patience=40)
print(classify_task.evaluate())

The complete script is hugegraph-ml/src/hugegraph_ml/examples/dgi_example.py.

GRAND Node Classification Example

from hugegraph_ml.data.hugegraph2dgl import HugeGraph2DGL
from hugegraph_ml.models.grand import GRAND
from hugegraph_ml.tasks.node_classify import NodeClassify

hg2d = HugeGraph2DGL()
graph = hg2d.convert_graph(vertex_label="CORA_vertex", edge_label="CORA_edge")
model = GRAND(
    n_in_feats=graph.ndata["feat"].shape[1],
    n_out_feats=graph.ndata["label"].unique().shape[0],
)
task = NodeClassify(graph, model)
task.train(lr=1e-2, weight_decay=5e-4, n_epochs=2000, patience=100)
print(task.evaluate())

The complete script is hugegraph-ml/src/hugegraph_ml/examples/grand_example.py.

Troubleshooting

  • Connection failures: check the HugeGraph Server address, port, and credentials.
  • Schema mismatches: the examples use CORA_vertex and CORA_edge; pass the actual labels for your own data.
  • DGL or PyTorch import failures: rerun uv sync --extra ml from the repository root and confirm that Python comes from the root .venv.

3.3.3 - HugeGraph-LLM Workflow

This page explains the processing flow in the HugeGraph-LLM Web UI. See HugeGraph-LLM for startup instructions.

1. Build RAG Indexes

The first tab splits documents into a chunk vector index. It also extracts vertices and edges according to a schema, writes them to HugeGraph, and maintains a vertex vector index.

flowchart TD
    A[Input document] --> B[Split text]
    B --> C[Generate chunk vectors]
    C --> D[Write vector index]
    B --> E[LLM extracts vertices and edges from schema]
    E --> F[Write to HugeGraph]
    F --> G[Update vertex vector index]

Common operations are Import into Vector, Extract Graph Data, Load into GraphDB, and Update Vid Embedding. The page can also inspect or clear chunk indexes, vertex indexes, and graph data. Clearing removes existing data, so first confirm that the current graph and indexes are not still used by other queries.

2. GraphRAG Queries

The second tab can answer directly with the LLM, use only chunk-vector retrieval, use only graph retrieval, or combine graph and vector retrieval.

flowchart TD
    Q[Question] --> V[Query chunk vector index]
    Q --> K[Extract keywords]
    K --> M[Match graph vertices]
    M --> T[Generate and execute Gremlin]
    T -->|Failure| B[Fallback to BFS graph traversal]
    T --> R[Prepare graph results]
    B --> R
    V --> S[Merge and rerank]
    R --> S
    S --> A[Generate answer]

Graph retrieval first matches HugeGraph vertices exactly by keyword and then uses vector similarity if no exact match exists. The matched vertices are passed to Text2Gremlin. If generation or execution fails, the pipeline can fall back to a predefined traversal.

Template Num controls how many examples Text2Gremlin uses. A value less than or equal to zero supplies no templates; a positive value retrieves that many similar examples.

3. Text2Gremlin

The third tab reads the graph schema, retrieves similar natural-language and Gremlin examples, fills the prompt with the question, schema, examples, and matched vertices, then generates Gremlin and optionally executes it.

RAG query scope selector

A custom prompt must contain {query}, {schema}, {example}, and {vertices}. The REST API rejects a request if any placeholder is missing.

4. Graph and Administration Tools

Graph Tools runs graph operations directly. Admin Tools provides functions such as log access. When login is enabled, the UI and APIs require USER_TOKEN; the log endpoint additionally requires a separately configured, secure ADMIN_TOKEN.

Keywords extracted in the RAG UI

5. Prompt Language

Set LANGUAGE=EN or LANGUAGE=CN in hugegraph-llm/.env, then restart the service. This selects the language of built-in prompts; it does not translate input documents and is not a field in the /rag request body.

6. REST Calls

The Web UI and REST API use the same pipeline. For application integration, use /rag, /rag/graph, /graph/extract, and /text2gremlin; see the REST API for request formats.

3.3.4 - Configuration Reference

HugeGraph-LLM reads runtime settings from hugegraph-llm/.env. Prompts are stored separately in hugegraph-llm/src/hugegraph_llm/resources/demo/config_prompt.yaml and are not written to .env.

Create or update the files from configuration-class defaults with:

cd hugegraph-ai/hugegraph-llm
python -m hugegraph_llm.config.generate --update

.env contains keys and passwords. Do not commit it to version control.

Basic Options

SettingDefaultDescription
LANGUAGEENPrompt language: EN or CN
CHAT_LLM_TYPEopenaiAnswer model: openai, litellm, or ollama/local
EXTRACT_LLM_TYPEopenaiInformation extraction model; same choices as above
TEXT2GQL_LLM_TYPEopenaiText2Gremlin model; same choices as above
EMBEDDING_TYPEopenaiEmbedding model; same choices as above, or empty
RERANKER_TYPEemptycohere or siliconflow
KEYWORD_EXTRACT_TYPEllmllm, textrank, or hybrid
WINDOW_SIZE3TextRank window size, from 1 to 10
HYBRID_LLM_WEIGHTS0.5Weight of LLM results in hybrid mode, from 0 to 1

OpenAI-Compatible APIs

Chat, extraction, and Text2Gremlin can use different endpoints, keys, and models.

PurposeAPI baseKeyModelDefault maximum tokens
AnswerOPENAI_CHAT_API_BASEOPENAI_CHAT_API_KEYOPENAI_CHAT_LANGUAGE_MODELOPENAI_CHAT_TOKENS=8192
ExtractionOPENAI_EXTRACT_API_BASEOPENAI_EXTRACT_API_KEYOPENAI_EXTRACT_LANGUAGE_MODELOPENAI_EXTRACT_TOKENS=256
Text2GremlinOPENAI_TEXT2GQL_API_BASEOPENAI_TEXT2GQL_API_KEYOPENAI_TEXT2GQL_LANGUAGE_MODELOPENAI_TEXT2GQL_TOKENS=4096
EmbeddingOPENAI_EMBEDDING_API_BASEOPENAI_EMBEDDING_API_KEYOPENAI_EMBEDDING_MODELNot applicable

The default API base is https://api.openai.com/v1. The default language model for all three tasks is gpt-4.1-mini, and the default embedding model is text-embedding-3-small.

OPENAI_BASE_URL and OPENAI_API_KEY provide general fallback values. Embeddings also support OPENAI_EMBEDDING_BASE_URL and OPENAI_EMBEDDING_API_KEY as fallback values.

LiteLLM

PurposeAPI baseKeyModelDefault maximum tokens
AnswerLITELLM_CHAT_API_BASELITELLM_CHAT_API_KEYLITELLM_CHAT_LANGUAGE_MODELLITELLM_CHAT_TOKENS=8192
ExtractionLITELLM_EXTRACT_API_BASELITELLM_EXTRACT_API_KEYLITELLM_EXTRACT_LANGUAGE_MODELLITELLM_EXTRACT_TOKENS=256
Text2GremlinLITELLM_TEXT2GQL_API_BASELITELLM_TEXT2GQL_API_KEYLITELLM_TEXT2GQL_LANGUAGE_MODELLITELLM_TEXT2GQL_TOKENS=4096
EmbeddingLITELLM_EMBEDDING_API_BASELITELLM_EMBEDDING_API_KEYLITELLM_EMBEDDING_MODELNot applicable

The default language model is openai/gpt-4.1-mini, and the default embedding model is openai/text-embedding-3-small. Model names generally use the provider/model form; supported values depend on the LiteLLM service.

Ollama

PurposeHostPortModel
AnswerOLLAMA_CHAT_HOSTOLLAMA_CHAT_PORTOLLAMA_CHAT_LANGUAGE_MODEL
ExtractionOLLAMA_EXTRACT_HOSTOLLAMA_EXTRACT_PORTOLLAMA_EXTRACT_LANGUAGE_MODEL
Text2GremlinOLLAMA_TEXT2GQL_HOSTOLLAMA_TEXT2GQL_PORTOLLAMA_TEXT2GQL_LANGUAGE_MODEL
EmbeddingOLLAMA_EMBEDDING_HOSTOLLAMA_EMBEDDING_PORTOLLAMA_EMBEDDING_MODEL

The default host is 127.0.0.1 and the default port is 11434. Model names have no defaults; pull the required models in Ollama before use.

Reranking

SettingDefaultDescription
COHERE_BASE_URLhttps://api.cohere.com/v1/rerankCohere rerank endpoint; CO_API_URL is a fallback
RERANKER_API_KEYemptyCohere or SiliconFlow key
RERANKER_MODELemptyModel name supported by the service

HugeGraph Connection and Retrieval Limits

SettingDefaultDescription
GRAPH_URL127.0.0.1:8080HugeGraph address; it is not split into IP and port
GRAPH_NAMEhugegraphGraph name
GRAPH_USERadminUser name
GRAPH_PWDxxxPassword
GRAPH_SPACEemptyGraphSpace name
LIMIT_PROPERTYFalseWhether to limit returned properties; read as a string by the configuration class
MAX_GRAPH_PATH10Maximum graph path length
MAX_GRAPH_ITEMS30Maximum number of graph retrieval items
EDGE_LIMIT_PRE_LABEL8Result limit for each edge label
VECTOR_DIS_THRESHOLD0.9Results beyond this vector-distance threshold are ignored
TOPK_PER_KEYWORD1Candidates per keyword
TOPK_RETURN_RESULTS20Results returned after reranking

External Vector Databases

The default implementation can use local FAISS. After enabling optional dependencies, the following settings are also available:

SettingDefault
QDRANT_HOSTempty
QDRANT_PORT6333
QDRANT_API_KEYempty
MILVUS_HOSTempty
MILVUS_PORT19530
MILVUS_USERempty
MILVUS_PASSWORDempty
cd hugegraph-ai
uv sync --package hugegraph-llm --extra vectordb

Login and Log API

SettingDefaultDescription
ENABLE_LOGINFalseWhether to require a Bearer token; read as a string by the configuration class
USER_TOKEN4321Token for the Web UI and regular APIs
ADMIN_TOKENxxxxAdministrator token used by /logs

/logs returns 403 when ADMIN_TOKEN is empty or still set to xxxx. Replace both the user and administrator tokens in production.

Minimal OpenAI Configuration

LANGUAGE=EN
CHAT_LLM_TYPE=openai
EXTRACT_LLM_TYPE=openai
TEXT2GQL_LLM_TYPE=openai
EMBEDDING_TYPE=openai

OPENAI_API_KEY=your-api-key
OPENAI_BASE_URL=https://api.openai.com/v1
OPENAI_CHAT_LANGUAGE_MODEL=gpt-4.1-mini
OPENAI_EXTRACT_LANGUAGE_MODEL=gpt-4.1-mini
OPENAI_TEXT2GQL_LANGUAGE_MODEL=gpt-4.1-mini
OPENAI_EMBEDDING_MODEL=text-embedding-3-small

GRAPH_URL=127.0.0.1:8080
GRAPH_NAME=hugegraph
GRAPH_USER=admin
GRAPH_PWD=your-password

Configuration Loading

Configuration classes supply code defaults and then apply overrides from .env and the process environment. The Web UI and configuration APIs can update current settings at runtime and write supported fields back to .env. Restart the service after editing .env manually; prompt YAML can be refreshed by the page-loading logic.

Configuration definitions are in:

  • hugegraph-llm/src/hugegraph_llm/config/llm_config.py
  • hugegraph-llm/src/hugegraph_llm/config/hugegraph_config.py
  • hugegraph-llm/src/hugegraph_llm/config/admin_config.py
  • hugegraph-llm/src/hugegraph_llm/config/prompt_config.py

3.3.5 - HugeGraph-LLM REST API

The HugeGraph-LLM demo process serves both the Web UI and REST API. The default address is http://localhost:8001:

cd hugegraph-ai/hugegraph-llm
python -m hugegraph_llm.demo.rag_demo.app \
  --host 127.0.0.1 \
  --port 8001

Authentication

Enable login in .env:

ENABLE_LOGIN=True
USER_TOKEN=replace-with-a-secret

Requests then require a Bearer token:

Authorization: Bearer replace-with-a-secret

RAG

POST /rag

Returns one or more answer types according to the switches. When none is explicitly selected, only graph_only is enabled.

curl -X POST http://localhost:8001/rag \
  -H 'Content-Type: application/json' \
  -d '{
    "query": "Which movies feature Al Pacino?",
    "raw_answer": false,
    "vector_only": false,
    "graph_only": true,
    "graph_vector_answer": false,
    "max_graph_items": 30,
    "topk_return_results": 20,
    "vector_dis_threshold": 0.9,
    "topk_per_keyword": 1,
    "gremlin_tmpl_num": 1,
    "client_config": {
      "url": "127.0.0.1:8080",
      "graph": "hugegraph",
      "user": "admin",
      "pwd": "admin",
      "gs": "DEFAULT"
    }
  }'

The response contains only enabled answer fields:

{
  "query": "Which movies feature Al Pacino?",
  "graph_only": "..."
}

Other optional parameters include graph_ratio, rerank_method (bleu or reranker), near_neighbor_first, custom_priority_info, and three custom prompt fields.

POST /rag/graph

Runs graph retrieval without generating a final natural-language answer:

curl -X POST http://localhost:8001/rag/graph \
  -H 'Content-Type: application/json' \
  -d '{
    "query": "Which movies feature Al Pacino?",
    "get_vertex_only": false,
    "gremlin_tmpl_num": 1,
    "rerank_method": "bleu"
  }'

graph_recall in the response can contain keywords, match_vids, gremlin, graph_result, and vertex_degree_list. Set get_vertex_only=true to return immediately after vertex matching.

Graph Extraction

POST /graph/extract

An inline schema does not connect to HugeGraph:

curl -X POST http://localhost:8001/graph/extract \
  -H 'Content-Type: application/json' \
  -d '{
    "texts": ["Alice works at Acme."],
    "schema": {
      "vertexlabels": [
        {"name": "person", "properties": ["name"]},
        {"name": "company", "properties": ["name"]}
      ],
      "edgelabels": [
        {
          "name": "works_at",
          "source_label": "person",
          "target_label": "company",
          "properties": []
        }
      ]
    },
    "language": "en",
    "split_type": "sentence",
    "include_meta": true
  }'

texts can be a string or an array of strings. language accepts zh or en; split_type accepts document, paragraph, or sentence.

When schema is an existing graph name, also pass client_config, and make client_config.graph match that name:

{
  "texts": "Alice works at Acme.",
  "schema": "hugegraph",
  "client_config": {
    "graph": "hugegraph",
    "user": "admin",
    "pwd": "admin",
    "gs": "DEFAULT"
  }
}

A successful response always contains status, result.vertices, result.edges, warnings, and meta.

Text2Gremlin

POST /text2gremlin

curl -X POST http://localhost:8001/text2gremlin \
  -H 'Content-Type: application/json' \
  -d '{
    "query": "Find all person vertices",
    "example_num": 1,
    "output_types": ["template_gremlin", "template_execution_result"]
  }'

output_types can contain:

  • match_result
  • template_gremlin
  • raw_gremlin
  • template_execution_result
  • raw_execution_result

If omitted, only template_gremlin is returned by default. An empty array lets the implementation return all outputs. A custom gremlin_prompt must contain {query}, {schema}, {example}, and {vertices}.

Runtime Configuration

POST /config/graph

{
  "url": "127.0.0.1:8080",
  "graph": "hugegraph",
  "user": "admin",
  "pwd": "admin",
  "gs": "DEFAULT"
}

POST /config/llm and POST /config/embedding

Both endpoints use the same request model. OpenAI or LiteLLM example:

{
  "llm_type": "openai",
  "api_key": "your-key",
  "api_base": "https://api.openai.com/v1",
  "language_model": "gpt-4.1-mini",
  "max_tokens": "4096"
}

Ollama requests still require the common fields; api_key and api_base can be empty strings:

{
  "llm_type": "ollama/local",
  "api_key": "",
  "api_base": "",
  "language_model": "qwen2.5:7b",
  "host": "127.0.0.1",
  "port": "11434"
}

POST /config/rerank

{
  "reranker_type": "siliconflow",
  "reranker_model": "BAAI/bge-reranker-v2-m3",
  "api_key": "your-key"
}

reranker_type accepts cohere or siliconflow. Cohere also accepts cohere_base_url.

These endpoints change the process’s active configuration and may write values back to .env. client_config in /rag, /rag/graph, and /text2gremlin overrides the HugeGraph connection for one request. The current implementation still changes process-global settings temporarily, so do not issue long-running requests with different connections concurrently.

Logs

POST /logs

This endpoint requires ADMIN_TOKEN in .env to be changed to a secure value. Example request body:

{
  "admin_token": "replace-with-an-admin-secret",
  "log_file": "llm-server.log"
}

log_file must be a file name under logs/ and cannot contain path separators.

3.4 - HugeGraph Computing (OLAP)

The HugeGraph-Computer repository contains two OLAP systems: Computer, a distributed BSP framework implemented in Java, and Vermeer, an in-memory graph computing platform implemented in Go.

DeepWiki provides real-time updated project documentation with more comprehensive and accurate content, suitable for quickly understanding the latest project information.

📖 https://deepwiki.com/apache/hugegraph-computer/

3.4.1 - HugeGraph-Vermeer Quick Start

1. Overview of Vermeer

1.1 Architecture

Vermeer is a high-performance, memory-first graph computing framework written in Go (start once, execute any task), supporting ultra-fast computation of 15+ OLAP graph algorithms (most tasks complete in seconds to minutes), with master and worker roles. Currently, there is only one master (HA can be added), and there can be multiple workers.

The master is responsible for communication, forwarding, and aggregation, with minimal computation and resource usage. Workers are computation nodes used to store graph data and run computation tasks, consuming a large amount of memory and CPU. The grpc and rest modules handle internal communication and external calls, respectively.

The framework’s runtime configuration can be passed via command-line parameters or specified in configuration files located in the config/ directory. The --env parameter can specify which configuration file to use, e.g., --env=master specifies using master.ini. Note that the master needs to specify the listening port, and the worker needs to specify the listening port and the master’s ip:port.

1.2 Running Method

  1. Option 1: Docker Compose (Recommended)

Please ensure that docker-compose.yaml exists in your project root directory. If it doesn’t, here is an example:

services:
  vermeer-master:
    image: hugegraph/vermeer
    container_name: vermeer-master
    volumes:
      - ~/.config:/go/bin/config # Change here to your actual config path
    command: --env=master
    networks:
      vermeer_network:
        ipv4_address: 172.20.0.10 # Assign a static IP for the master

  vermeer-worker:
    image: hugegraph/vermeer
    container_name: vermeer-worker
    volumes:
      - ~/:/go/bin/config # Change here to your actual config path
    command: --env=worker
    networks:
      vermeer_network:
        ipv4_address: 172.20.0.11 # Assign a static IP for the worker

networks:
  vermeer_network:
    driver: bridge
    ipam:
      config:
        - subnet: 172.20.0.0/24 # Define the subnet for your network

Modify docker-compose.yaml

  • Volume: For example, change both instances of ~/:/go/bin/config to /home/user/config:/go/bin/config (or your own configuration directory).
  • Subnet: Modify the subnet IP based on your actual situation. Note that the ports each container needs to access are specified in the config file. Please refer to the contents of the project’s config folder for details.

Build the Image and Start in the Project Directory (or docker build first, then docker-compose up)

# Build the image (in the project root vermeer directory)
docker build -t hugegraph/vermeer .

# Start the services (in the vermeer root directory)
docker-compose up -d
# Or use the new CLI:
# docker compose up -d

View Logs / Stop / Remove

docker-compose logs -f
docker-compose down
  1. Option 2: Start individually via docker run (Manually create network and assign static IP)

Ensure the CONFIG_DIR has proper read/execute permissions for the Docker process.

Build the image:

docker build -t hugegraph/vermeer .

Create a custom bridge network (one-time operation):

docker network create --driver bridge \
  --subnet 172.20.0.0/24 \
  vermeer_network

Run master (adjust CONFIG_DIR to your absolute configuration path, and you can adjust the IP as needed based on your actual situation).

CONFIG_DIR=/home/user/config

docker run -d \
  --name vermeer-master \
  --network vermeer_network --ip 172.20.0.10 \
  -v ${CONFIG_DIR}:/go/bin/config \
  hugegraph/vermeer \
  --env=master

Run worker:

docker run -d \
  --name vermeer-worker \
  --network vermeer_network --ip 172.20.0.11 \
  -v ${CONFIG_DIR}:/go/bin/config \
  hugegraph/vermeer \
  --env=worker

View logs / Stop / Remove:

docker logs -f vermeer-master
docker logs -f vermeer-worker

docker stop vermeer-master vermeer-worker
docker rm vermeer-master vermeer-worker

# Remove the custom network (if needed)
docker network rm vermeer_network
  1. Option 3: Build from Source

Build. You can refer Vermeer Readme.

go build

Enter the directory and input ./vermeer --env=master or ./vermeer --env=worker01.

2. Task Creation REST API

2.1 Introduction

This REST API provides all task creation functions, including reading graph data and various computation functions, offering both asynchronous and synchronous return interfaces. The returned content includes information about the created tasks. The overall process of using Vermeer is to first create a task to read the graph data, and after the graph is read, create a computation task to execute the computation. The graph will not be automatically deleted; multiple computation tasks can be run on one graph without repeated reading. If deletion is needed, the delete graph interface can be used. Task statuses can be divided into graph reading task status and computation task status. Generally, the client only needs to know four statuses: created, in progress, completed, and error. The graph status is the basis for determining whether the graph is available. If the graph is being read or the graph status is erroneous, the graph cannot be used to create computation tasks. The delete graph interface is only available when the graph is in the loaded or error status and has no computation tasks.

Available URLs are as follows:

  • Asynchronous return interface: POST http://master_ip:port/tasks/create returns only whether the task creation is successful, and the task status needs to be actively queried to determine completion.
  • Synchronous return interface: POST http://master_ip:port/tasks/create/sync returns after the task is completed.

2.2 Loading Graph Data

Refer to the Vermeer parameter list document for specific parameters.

Vermeer provides three ways to load data:

  1. Load from Local Files

You can obtain the dataset in advance, such as the Twitter-2010 dataset. Acquisition method: https://snap.stanford.edu/data/twitter-2010.html The first Twitter-2010.text.gz is sufficient.

Request Example:

POST http://localhost:8688/tasks/create
{
 "task_type": "load",
 "graph": "testdb",
 "params": {
  "load.parallel": "50",
  "load.type": "local",
  "load.vertex_files": "{\"localhost\":\"data/twitter-2010.v_[0,99]\"}",
  "load.edge_files": "{\"localhost\":\"data/twitter-2010.e_[0,99]\"}",
  "load.use_out_degree": "1",
  "load.use_outedge": "1"
 }
}
  1. Load from HugeGraph

Request Example:

⚠️ Security Warning: Never store real passwords in configuration files or code. Use environment variables or a secure credential management system instead.

POST http://localhost:8688/tasks/create
{
  "task_type": "load",
  "graph": "testdb",
  "params": {
    "load.parallel": "50",
    "load.type": "hugegraph",
    "load.hg_pd_peers": "[\"<your-hugegraph-ip>:8686\"]",
    "load.hugegraph_name": "DEFAULT/hugegraph2/g",
    "load.hugegraph_username": "admin",
    "load.hugegraph_password": "<your-password-here>",
    "load.use_out_degree": "1",
    "load.use_outedge": "1"
  }
}
  1. Load from HDFS

Request Example:

POST http://localhost:8688/tasks/create
{
  "task_type": "load",
  "graph": "testdb",
  "params": {
    "load.parallel": "50",
    "load.type": "hdfs",
    "load.hdfs_namenode": "name_node1:9000",
    "load.hdfs_conf_path": "/path/to/conf",
    "load.krb_realm": "EXAMPLE.COM",
    "load.krb_name": "user@EXAMPLE.COM",
    "load.krb_keytab_path": "/path/to/keytab",
    "load.krb_conf_path": "/path/to/krb5.conf",
    "load.hdfs_use_krb": "1",
    "load.vertex_files": "/data/graph/vertices",
    "load.edge_files": "/data/graph/edges",
    "load.use_out_degree": "1",
    "load.use_outedge": "1"
  }
}

2.3 Output Computation Results

All Vermeer computation tasks support multiple result output methods, which can be customized: local, hdfs, afs, or hugegraph. Add the corresponding parameters under the params parameter when sending the request to take effect. When output.need_statistics is set to 1, it supports outputting statistical information of the computation results, which will be written in the interface task information. The statistical mode operators currently support “count” and “modularity,” but only for community detection algorithms.

Refer to the Vermeer parameter list document for specific parameters.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "pagerank",
 "compute.parallel": "10",
 "compute.max_step": "10",
 "output.type": "local",
 "output.parallel": "1",
 "output.file_path": "result/pagerank"
  }
}

3. Supported Algorithms

3.1 PageRank

The PageRank algorithm, also known as the web ranking algorithm, is a technique used by search engines to calculate the relevance and importance of web pages (nodes) based on their mutual hyperlinks.

  • If a web page is linked to by many other web pages, it indicates that the web page is relatively important, and its PageRank value will be relatively high.
  • If a web page with a high PageRank value links to other web pages, the PageRank value of the linked web pages will also increase accordingly.

The PageRank algorithm is suitable for scenarios such as web page ranking and identifying key figures in social networks.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "pagerank",
 "compute.parallel":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/pagerank",
 "compute.max_step":"10"
 }
}

3.2 WCC (Weakly Connected Components)

The weakly connected components algorithm calculates all connected subgraphs in an undirected graph and outputs the weakly connected subgraph ID to which each vertex belongs, indicating the connectivity between points and distinguishing different connected communities.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "wcc",
 "compute.parallel":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/wcc",
 "compute.max_step":"10"
 }
}

3.3 LPA (Label Propagation Algorithm)

The label propagation algorithm is a graph clustering algorithm commonly used in social networks to discover potential communities.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "lpa",
 "compute.parallel":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/lpa",
 "compute.max_step":"10"
 }
}

3.4 Degree Centrality

The degree centrality algorithm calculates the degree centrality value of each node in the graph, supporting both undirected and directed graphs. Degree centrality is an important indicator of node importance; the more edges a node has with other nodes, the higher its degree centrality value, and the more important the node is in the graph. In an undirected graph, degree centrality is calculated based on edge information to count the number of times a node appears, resulting in the degree centrality value of the node. In a directed graph, it is based on the direction of the edges, filtering based on input or output-edge information to count the number of times a node appears, resulting in the in-degree or out-degree value of the node. It indicates the importance of each point, with more important points having higher degrees.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "degree",
 "compute.parallel":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/degree",
 "degree.direction":"both"
 }
}

3.5 Closeness Centrality

Closeness centrality is used to calculate the inverse of the shortest distance from a node to all other reachable nodes, accumulating and normalizing the value. Closeness centrality can be used to measure the time it takes for information to be transmitted from the node to other nodes. The larger the closeness centrality of a node, the closer its position in the graph is to the center, suitable for scenarios such as identifying key nodes in social networks.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "closeness_centrality",
 "compute.parallel":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/closeness_centrality",
 "closeness_centrality.sample_rate":"0.01"
 }
}

3.6 Betweenness Centrality

The betweenness centrality algorithm determines the value of a node as a “bridge” node; the larger the value, the more likely it is to be a necessary path between two points in the graph. Typical examples include mutual followers in social networks. It is suitable for measuring the degree of aggregation around a node in a community.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "betweenness_centrality",
 "compute.parallel":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/betweenness_centrality",
 "betweenness_centrality.sample_rate":"0.01"
 }
}

3.7 Triangle Count

The triangle count algorithm calculates the number of triangles passing through each vertex, suitable for calculating the relationships between users and whether the associations form triangles. The more triangles, the higher the degree of association between nodes in the graph, and the tighter the organizational relationship. In social networks, triangles indicate cohesive communities, and identifying triangles helps understand clustering and interconnections among individuals or groups in the network. In financial or transaction networks, the presence of triangles may indicate suspicious or fraudulent activities, and triangle counting can help identify transaction patterns that may require further investigation.

The output result is the Triangle Count corresponding to each vertex, i.e., the number of triangles the vertex is part of.

Note: This algorithm is for undirected graphs and ignores edge directions.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "triangle_count",
 "compute.parallel":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/triangle_count"
 }
}

3.8 K-Core

The K-Core algorithm marks all vertices with a degree of K, suitable for graph pruning and finding the core part of the graph.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "kcore",
 "compute.parallel":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/kcore",
 "kcore.degree_k":"5"
 }
}

3.9 SSSP (Single Source Shortest Path)

The single source the shortest path algorithm calculates the shortest distance from one point to all other points.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "sssp",
 "compute.parallel":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/degree",
 "sssp.source":"tom"
 }
}

3.10 KOUT

Starting from a point, get the k-layer nodes of this point.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "kout",
 "compute.parallel":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/kout",
 "kout.source":"tom",
 "compute.max_step":"6"
 }
}

3.11 Louvain

The Louvain algorithm is a community detection algorithm based on modularity. The basic idea is that nodes in the network try to traverse all neighbor community labels and choose the community label that maximizes the modularity increment. After maximizing modularity, each community is regarded as a new node, and the process is repeated until the modularity no longer increases.

The distributed Louvain algorithm implemented on Vermeer is affected by factors such as node order and parallel computation. Due to the random traversal order of the Louvain algorithm, community compression also has a certain randomness, leading to different results in multiple executions. However, the overall trend will not change significantly.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "louvain",
 "compute.parallel":"10",
 "compute.max_step":"1000",
 "louvain.threshold":"0.0000001",
 "louvain.resolution":"1.0",
 "louvain.step":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/louvain"
  }
 }

3.12 Jaccard Similarity Coefficient

The Jaccard index, also known as the Jaccard similarity coefficient, is used to compare the similarity and diversity between finite sample sets. The larger the Jaccard coefficient value, the higher the similarity of the samples. It is used to calculate the Jaccard similarity coefficient between a given source point and all other points in the graph.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "jaccard",
 "compute.parallel":"10",
 "compute.max_step":"2",
 "jaccard.source":"123",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/jaccard"
 }
}

3.13 Personalized PageRank

The goal of personalized PageRank is to calculate the relevance of all nodes relative to user u. Starting from the node corresponding to user u, at each node, there is a probability of 1-d to stop walking and start again from u, or a probability of d to continue walking, randomly selecting a node from the nodes pointed to by the current node to walk down. It is used to calculate the personalized PageRank score starting from a given starting point, suitable for scenarios such as social recommendations.

Since the calculation requires using out-degree, load.use_out_degree needs to be set to 1 when reading the graph.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "ppr",
 "compute.parallel":"100",
 "compute.max_step":"10",
 "ppr.source":"123",
 "ppr.damping":"0.85",
 "ppr.diff_threshold":"0.00001",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/ppr"
 }
}

3.14 Global Kout

Calculate the k-degree neighbors of all nodes in the graph (excluding themselves and 1~k-1 degree neighbors). Due to the severe memory expansion of the global kout algorithm, k is currently limited to 1 and 2. Additionally, the global kout algorithm supports filtering functions (parameters such as “compute.filter”:“risk_level==1”), and the filtering condition is judged when calculating the k-degree. The final result set includes those that meet the filtering condition. The algorithm’s final output is the number of neighbors that meet the condition.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "kout_all",
 "compute.parallel":"10",
 "output.type":"local",
 "output.parallel":"10",
 "output.file_path":"result/kout",
 "compute.max_step":"2",
 "compute.filter":"risk_level==1"
 }
}

3.15 Clustering Coefficient

The clustering coefficient represents the coefficient of the clustering degree of nodes in a graph. In real networks, especially in specific networks, nodes tend to establish a tightly organized relationship due to relatively high-density connection points. The clustering coefficient algorithm (Cluster Coefficient) is used to calculate the clustering degree of nodes in the graph. This algorithm is for local clustering coefficients. The local clustering coefficient can measure the clustering degree around each node in the graph.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "clustering_coefficient",
 "compute.parallel":"100",
 "compute.max_step":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/cc"
 }
}

3.16 SCC (Strongly Connected Components)

In the mathematical theory of directed graphs, if every vertex of a graph can be reached from any other point in the graph, the graph is said to be strongly connected. The parts of any directed graph that can achieve strong connectivity are called strongly connected components. It indicates the connectivity between points and distinguishes different connected communities.

Request example:

POST http://localhost:8688/tasks/create
{
 "task_type": "compute",
 "graph": "testdb",
 "params": {
 "compute.algorithm": "scc",
 "compute.parallel":"10",
 "output.type":"local",
 "output.parallel":"1",
 "output.file_path":"result/scc",
 "compute.max_step":"200"
 }
}

🚧, further updates and improvements will be made at any time. Suggestions and feedback are welcome.

3.4.2 - HugeGraph-Computer Quick Start

1 HugeGraph-Computer Overview

The HugeGraph-Computer is a distributed graph processing system for HugeGraph (OLAP). It is an implementation of Pregel. It runs on a Kubernetes(K8s) framework.(It focuses on supporting graph data volumes of hundreds of billions to trillions, using disk for sorting and acceleration, which is one of the biggest differences from Vermeer)

Features

  • Support distributed MPP graph computing, and integrates with HugeGraph as graph input/output storage.
  • Based on the BSP (Bulk Synchronous Parallel) model, an algorithm performs computing through multiple parallel iterations; every iteration is a superstep.
  • Auto memory management. The framework will never be OOM(Out of Memory) since it will split some data to disk if it doesn’t have enough memory to hold all the data.
  • The part of edges or the messages of super node can be in memory, so you will never lose it.
  • You can load the data from HDFS or HugeGraph, or any other system.
  • You can output the results to HDFS or HugeGraph, or any other system.
  • Easy to develop a new algorithm. You just need to focus on vertex-only processing just like as in a single server, without worrying about message transfer and memory/storage management.

2 Dependency for Building/Running

2.1 Install Java 11 (JDK 11)

Must use ≥ Java 11 to run Computer, and configure by yourself.

Be sure to execute the java -version command to check the jdk version before reading

3 Get Started

3.1 Run PageRank algorithm locally

To run the algorithm with HugeGraph-Computer, you need to install Java 11 or later versions.

You also need to deploy HugeGraph-Server and Etcd.

There are two ways to get HugeGraph-Computer:

  • Download the compiled tarball
  • Clone source code then compile and package

3.1.1 Download the compiled archive

Download the latest version of the HugeGraph-Computer release package:

wget https://downloads.apache.org/incubator/hugegraph/${version}/apache-hugegraph-computer-incubating-${version}.tar.gz
tar zxvf apache-hugegraph-computer-incubating-${version}.tar.gz -C hugegraph-computer

3.1.2 Clone source code to compile and package

Clone the latest version of HugeGraph-Computer source package:

$ git clone https://github.com/apache/hugegraph-computer.git

Compile and generate tar package:

cd hugegraph-computer
mvn clean package -DskipTests

3.1.3 Start master node

You can use -c parameter specify the configuration file, more computer config please see:Computer Config Options

cd hugegraph-computer
bin/start-computer.sh -d local -r master

3.1.4 Start worker node

bin/start-computer.sh -d local -r worker

3.1.5 Query algorithm results

3.1.5.1 Enable OLAP index query for server

If the OLAP index is not enabled, it needs to be enabled. More reference: modify-graphs-read-mode

PUT http://localhost:8080/graphs/hugegraph/graph_read_mode

"ALL"

3.1.5.2 Query page_rank property value:

curl "http://localhost:8080/graphs/hugegraph/graph/vertices?page&limit=3" | gunzip

3.2 Run PageRank algorithm in Kubernetes

To run an algorithm with HugeGraph-Computer, you need to deploy HugeGraph-Server first

3.2.1 Install HugeGraph-Computer CRD

# Kubernetes version >= v1.16
kubectl apply -f https://raw.githubusercontent.com/apache/hugegraph-computer/master/computer-k8s-operator/manifest/hugegraph-computer-crd.v1.yaml

# Kubernetes version < v1.16
kubectl apply -f https://raw.githubusercontent.com/apache/hugegraph-computer/master/computer-k8s-operator/manifest/hugegraph-computer-crd.v1beta1.yaml

3.2.2 Show CRD

kubectl get crd

NAME                                        CREATED AT
hugegraphcomputerjobs.hugegraph.apache.org   2021-09-16T08:01:08Z

3.2.3 Install hugegraph-computer-operator&etcd-server

kubectl apply -f https://raw.githubusercontent.com/apache/hugegraph-computer/master/computer-k8s-operator/manifest/hugegraph-computer-operator.yaml

3.2.4 Wait for hugegraph-computer-operator&etcd-server deployment to complete

kubectl get pod -n hugegraph-computer-operator-system

NAME                                                              READY   STATUS    RESTARTS   AGE
hugegraph-computer-operator-controller-manager-58c5545949-jqvzl   1/1     Running   0          15h
hugegraph-computer-operator-etcd-28lm67jxk5                       1/1     Running   0          15h

3.2.5 Submit a job

More computer crd please see: Computer CRD

More computer config please see: Computer Config Options

cat <<EOF | kubectl apply --filename -
apiVersion: hugegraph.apache.org/v1
kind: HugeGraphComputerJob
metadata:
  namespace: hugegraph-computer-operator-system
  name: &jobName pagerank-sample
spec:
  jobId: *jobName
  algorithmName: page_rank
  image: hugegraph/hugegraph-computer:latest # algorithm image url
  jarFile: /hugegraph/hugegraph-computer/algorithm/builtin-algorithm.jar # algorithm jar path
  pullPolicy: Always
  workerCpu: "4"
  workerMemory: "4Gi"
  workerInstances: 5
  computerConf:
    job.partitions_count: "20"
    algorithm.params_class: org.apache.hugegraph.computer.algorithm.centrality.pagerank.PageRankParams
    hugegraph.url: http://${hugegraph-server-host}:${hugegraph-server-port} # hugegraph server url
    hugegraph.name: hugegraph # hugegraph graph name
EOF

3.2.6 Show job

kubectl get hcjob/pagerank-sample -n hugegraph-computer-operator-system

NAME               JOBID              JOBSTATUS
pagerank-sample    pagerank-sample    RUNNING

3.2.7 Show log of nodes

# Show the master log
kubectl logs -l component=pagerank-sample-master -n hugegraph-computer-operator-system

# Show the worker log
kubectl logs -l component=pagerank-sample-worker -n hugegraph-computer-operator-system

# Show diagnostic log of a job
# NOTE: diagnostic log exist only when the job fails, and it will only be saved for one hour.
kubectl get event --field-selector reason=ComputerJobFailed --field-selector involvedObject.name=pagerank-sample -n hugegraph-computer-operator-system

3.2.8 Show success event of a job

NOTE: it will only be saved for one hour

kubectl get event --field-selector reason=ComputerJobSucceed --field-selector involvedObject.name=pagerank-sample -n hugegraph-computer-operator-system

3.2.9 Query algorithm results

If the output to Hugegraph-Server is consistent with Locally, if output to HDFS, please check the result file in the directory of /hugegraph-computer/results/{jobId} directory.

4. Built-In algorithms document

4.1 Supported algorithms list:

Centrality Algorithm:
  • PageRank
  • BetweennessCentrality
  • ClosenessCentrality
  • DegreeCentrality
Community Algorithm:
  • ClusteringCoefficient
  • Kcore
  • Lpa
  • TriangleCount
  • Wcc
Path Algorithm:
  • RingsDetection
  • RingsDetectionWithFilter

More algorithms please see: Built-In algorithms

4.2 Algorithm describe

TODO

5 Algorithm development guide

TODO

6 Note

  • If some classes under computer-k8s cannot be found, you need to execute mvn compile in advance to generate corresponding classes.

3.4.3 - HugeGraph-Computer Configuration Reference

Computer Config Options

The defaults in the tables come from ComputerOptions.java in the computer-api module. When the distribution’s conf/computer.properties explicitly overrides an option, the table shows “code default (packaged: actual value)”. At runtime, values in the configuration file take precedence.


1. Basic Configuration

Core job settings for HugeGraph-Computer.

config optiondefault valuedescription
hugegraph.urlhttp://127.0.0.1:8080The HugeGraph server URL to load data and write results back.
hugegraph.namehugegraphThe graph name to load data and write results back.
hugegraph.username"" (empty)The username for HugeGraph authentication (leave empty if authentication is disabled).
hugegraph.password"" (empty)The password for HugeGraph authentication (leave empty if authentication is disabled).
job.idlocal_0001 (packaged: local_001)The job identifier on YARN cluster or K8s cluster.
job.namespace"" (empty)The job namespace used to separate different data sources. This option is managed by the runtime system.
job.workers_count1The number of workers for one graph algorithm job. In K8s, this option is set by the Operator.
job.partitions_count1The number of partitions for computing one graph algorithm job.
job.partitions_thread_nums4The number of threads for partition parallel compute.

2. Algorithm Configuration

Algorithm-specific configuration for computation logic.

config optiondefault valuedescription
algorithm.params_classComputerOptions.Null placeholder classRequired. The class used to pass algorithm parameters before the algorithm runs.
algorithm.result_classComputerOptions.Null placeholder classThe vertex value class used to store computation results.
algorithm.message_classComputerOptions.Null placeholder classThe message class passed while computing a vertex.

3. Input Configuration

Configuration for loading input data from HugeGraph or other sources.

3.1 Input Source

config optiondefault valuedescription
input.source_typehugegraph-serverThe source type to load input data, allowed values: [‘hugegraph-server’, ‘hugegraph-loader’]. The ‘hugegraph-loader’ means use hugegraph-loader to load data from HDFS or file. If using ‘hugegraph-loader’, please configure ‘input.loader_struct_path’ and ‘input.loader_schema_path’.
input.loader_struct_path"" (empty)The structure path for Loader input. It takes effect only when input.source_type=hugegraph-loader.
input.loader_schema_path"" (empty)The schema path for Loader input. It takes effect only when input.source_type=hugegraph-loader.

3.2 Input Splits

config optiondefault valuedescription
input.split_size1048576 (1 MB)The input split size in bytes.
input.split_max_splits10000000The maximum number of input splits.
input.split_page_size500The page size for streamed load input split data.
input.split_fetch_timeout300The timeout in seconds to fetch input splits.

3.3 Input Processing

config optiondefault valuedescription
input.filter_classorg.apache.hugegraph.computer.core.input.filter.DefaultInputFilterThe class to create input-filter object. Input-filter is used to filter vertex edges according to user needs.
input.edge_directionOUTThe direction of edges to load, allowed values: [OUT, IN, BOTH]. When the value is BOTH, edges in both OUT and IN directions will be loaded.
input.edge_freqMULTIPLEThe frequency of edges that can exist between a pair of vertices, allowed values: [SINGLE, SINGLE_PER_LABEL, MULTIPLE]. SINGLE means only one edge can exist between a pair of vertices (identified by sourceId + targetId); SINGLE_PER_LABEL means each edge label can have one edge between a pair of vertices (identified by sourceId + edgeLabel + targetId); MULTIPLE means many edges can exist between a pair of vertices (identified by sourceId + edgeLabel + sortValues + targetId).
input.max_edges_in_one_vertex200The maximum number of adjacent edges allowed to be attached to a vertex. The adjacent edges will be stored and transferred together as a batch unit.

3.4 Input Performance

config optiondefault valuedescription
input.send_thread_nums4The number of threads for parallel sending of vertices or edges.

4. Snapshot & Storage Configuration

HugeGraph-Computer supports snapshot functionality to save vertex/edge partitions to local storage or MinIO object storage, enabling checkpoint recovery or accelerating repeated computations.

4.1 Basic Snapshot Configuration

config optiondefault valuedescription
snapshot.writefalseWhether to write snapshots of input vertex/edge partitions.
snapshot.loadfalseWhether to load from snapshots of vertex/edge partitions.
snapshot.name"" (empty)User-defined snapshot name to distinguish different snapshots.

4.2 MinIO Integration (Optional)

MinIO can be used as a distributed object storage backend for snapshots in K8s deployments.

config optiondefault valuedescription
snapshot.minio_endpoint"" (empty)MinIO service endpoint (e.g., http://minio:9000). Required when using MinIO.
snapshot.minio_access_keyminioadminMinIO access key for authentication.
snapshot.minio_secret_keyminioadminMinIO secret key for authentication.
snapshot.minio_bucket_name"" (empty)MinIO bucket name for storing snapshot data.

Usage Scenarios:

  • Checkpoint Recovery: Resume from snapshots after job failures, avoiding data reloading
  • Repeated Computations: Load data from snapshots when running the same algorithm multiple times
  • A/B Testing: Save multiple snapshot versions of the same dataset to test different algorithm parameters

Example: Local Snapshot (in computer.properties):

snapshot.write=true
snapshot.name=pagerank-snapshot-20260201

Example: MinIO Snapshot (in K8s CRD computerConf):

computerConf:
  snapshot.write: "true"
  snapshot.name: "pagerank-snapshot-v1"
  snapshot.minio_endpoint: "http://minio:9000"
  snapshot.minio_access_key: "my-access-key"
  snapshot.minio_secret_key: "my-secret-key"
  snapshot.minio_bucket_name: "hugegraph-snapshots"

5. Worker & Master Configuration

Configuration for worker and master computation logic.

5.1 Master Configuration

config optiondefault valuedescription
master.computation_classorg.apache.hugegraph.computer.core.master.DefaultMasterComputationMaster-computation is computation that can determine whether to continue to the next superstep. It runs at the end of each superstep on the master.

5.2 Worker Computation

config optiondefault valuedescription
worker.computation_classorg.apache.hugegraph.computer.core.config.NullThe class to create worker-computation object. Worker-computation is used to compute each vertex in each superstep.
worker.combiner_classorg.apache.hugegraph.computer.core.config.NullCombiner can combine messages into one value for a vertex. For example, PageRank algorithm can combine messages of a vertex to a sum value.
worker.partitionerorg.apache.hugegraph.computer.core.graph.partition.HashPartitionerThe partitioner that decides which partition a vertex should be in, and which worker a partition should be in.

5.3 Worker Combiners

config optiondefault valuedescription
worker.vertex_properties_combiner_classorg.apache.hugegraph.computer.core.combiner.OverwritePropertiesCombinerThe combiner can combine several properties of the same vertex into one properties at input step.
worker.edge_properties_combiner_classorg.apache.hugegraph.computer.core.combiner.OverwritePropertiesCombinerThe combiner can combine several properties of the same edge into one properties at input step.

5.4 Worker Buffers

config optiondefault valuedescription
worker.received_buffers_bytes_limit104857600 (100 MB)The limit bytes of buffers of received data. The total size of all buffers can’t exceed this limit. If received buffers reach this limit, they will be merged into a file (spill to disk).
worker.write_buffer_capacity52428800 (50 MB)The initial size of write buffer that used to store vertex or message.
worker.write_buffer_threshold52428800 (50 MB)The threshold of write buffer. Exceeding it will trigger sorting. The write buffer is used to store vertex or message.

5.5 Worker Data & Timeouts

config optiondefault valuedescription
worker.data_dirs[jobs]The directories separated by ‘,’ that received vertices and messages can persist into.
worker.wait_sort_timeout600000 (10 minutes)The max timeout (in ms) for message-handler to wait for sort-thread to sort one batch of buffers.
worker.wait_finish_messages_timeout86400000 (24 hours)The max timeout (in ms) for message-handler to wait for finish-message of all workers.

6. I/O & Output Configuration

Configuration for output computation results.

6.1 Output Class & Result

config optiondefault valuedescription
output.output_classorg.apache.hugegraph.computer.core.output.LogOutputThe class to output the computation result of each vertex. Called after iteration computation.
output.result_namevalueThe value is assigned dynamically by #name() of instance created by WORKER_COMPUTATION_CLASS.
output.result_write_typeOLAP_COMMONThe result write-type to output to HugeGraph, allowed values: [OLAP_COMMON, OLAP_SECONDARY, OLAP_RANGE].

6.2 Output Behavior

config optiondefault valuedescription
output.with_adjacent_edgesfalseWhether to output the adjacent edges of the vertex.
output.with_vertex_propertiesfalseWhether to output the properties of the vertex.
output.with_edge_propertiesfalseWhether to output the properties of the edge.

6.3 Batch Output

config optiondefault valuedescription
output.batch_size500The batch size of output.
output.batch_threads1The number of threads used for batch output.
output.single_threads1The number of threads used for single output.

6.4 HDFS Output

config optiondefault valuedescription
output.hdfs_urlhdfs://127.0.0.1:9000The HDFS URL for output.
output.hdfs_userhadoopThe HDFS user for output.
output.hdfs_path_prefix/hugegraph-computer/resultsThe directory of HDFS output results.
output.hdfs_delimiter, (comma)The delimiter of HDFS output.
output.hdfs_merge_partitionstrueWhether to merge output files of multiple partitions.
output.hdfs_replication3The replication number of HDFS.
output.hdfs_core_site_path"" (empty)The HDFS core site path.
output.hdfs_site_path"" (empty)The HDFS site path.
output.hdfs_kerberos_enablefalseWhether Kerberos authentication is enabled for HDFS.
output.hdfs_kerberos_principal"" (empty)The HDFS principal for Kerberos authentication.
output.hdfs_kerberos_keytab"" (empty)The HDFS keytab file for Kerberos authentication.
output.hdfs_krb5_conf/etc/krb5.confKerberos configuration file path.

6.5 Retry & Timeout

config optiondefault valuedescription
output.retry_times3The retry times when output fails.
output.retry_interval10The retry interval (in seconds) when output fails.
output.thread_pool_shutdown_timeout60The timeout (in seconds) of output thread pool shutdown.

7. Network & Transport Configuration

Configuration for network communication between workers and master.

7.1 Server Configuration

config optiondefault valuedescription
transport.server_host127.0.0.1The hostname or IP that listens for transport data. This option is managed by the runtime system.
transport.server_port0The port that listens for transport data; 0 assigns a random port. This option is managed by the runtime system.
transport.server_threads4The number of transport threads for server.

7.2 Client Configuration

config optiondefault valuedescription
transport.client_threads4The number of transport threads for client.
transport.client_connect_timeout3000The timeout (in ms) of client connect to server.

7.3 Protocol Configuration

config optiondefault valuedescription
transport.provider_classorg.apache.hugegraph.computer.core.network.netty.NettyTransportProviderThe transport provider, currently only supports Netty.
transport.io_modeAUTOThe network IO mode, allowed values: [NIO, EPOLL, AUTO]. AUTO means selecting the appropriate mode automatically.
transport.tcp_keep_alivetrueWhether to enable TCP keep-alive.
transport.transport_epoll_ltfalseWhether to enable EPOLL level-trigger (only effective when io_mode=EPOLL).

7.4 Buffer Configuration

config optiondefault valuedescription
transport.send_buffer_size0The size of socket send-buffer in bytes. 0 means using system default value.
transport.receive_buffer_size0The size of socket receive-buffer in bytes. 0 means using system default value.
transport.write_buffer_high_mark67108864 (64 MB)The high water mark for write buffer in bytes. It will trigger sending unavailable if the number of queued bytes > write_buffer_high_mark.
transport.write_buffer_low_mark33554432 (32 MB)The low water mark for write buffer in bytes. It will trigger sending available if the number of queued bytes < write_buffer_low_mark.

7.5 Flow Control

config optiondefault valuedescription
transport.max_pending_requests8The max number of client unreceived ACKs. It will trigger sending unavailable if the number of unreceived ACKs >= max_pending_requests.
transport.min_pending_requests6The minimum number of client unreceived ACKs. It will trigger sending available if the number of unreceived ACKs < min_pending_requests.
transport.min_ack_interval200The minimum interval (in ms) of server reply ACK.

7.6 Timeouts

config optiondefault valuedescription
transport.close_timeout10000The timeout (in ms) of close server or close client.
transport.sync_request_timeout10000The timeout (in ms) to wait for response after sending sync-request.
transport.finish_session_timeout0The timeout (in ms) to finish session. 0 means using (transport.sync_request_timeout × transport.max_pending_requests).
transport.write_socket_timeout3000The timeout (in ms) to write data to socket buffer.
transport.server_idle_timeout360000 (6 minutes)The max timeout (in ms) of server idle.

7.7 Heartbeat

config optiondefault valuedescription
transport.heartbeat_interval20000 (20 seconds)The minimum interval (in ms) between heartbeats on client side.
transport.max_timeout_heartbeat_count120The maximum times of timeout heartbeat on client side. If the number of timeouts waiting for heartbeat response continuously > max_timeout_heartbeat_count, the channel will be closed from client side.

7.8 Advanced Network Settings

config optiondefault valuedescription
transport.max_syn_backlog511The capacity of SYN queue on server side. 0 means using system default value.
transport.recv_file_modetrueWhether to enable receive buffer-file mode. It will receive buffer and write to file from socket using zero-copy if enabled. Note: Requires OS support for zero-copy (e.g., Linux sendfile/splice).
transport.network_retries3The number of retry attempts for network communication if network is unstable.

8. Storage & Persistence Configuration

Configuration for HGKV (HugeGraph Key-Value) storage engine and value files.

8.1 HGKV Configuration

config optiondefault valuedescription
hgkv.max_file_size2147483648 (2 GB)The max number of bytes in each HGKV file.
hgkv.max_data_block_size65536 (64 KB)The max byte size of HGKV file data block.
hgkv.max_merge_files10The max number of files to merge at one time.
hgkv.temp_file_dir/tmp/hgkvThis folder is used to store temporary files during the file merging process.

8.2 Value File Configuration

config optiondefault valuedescription
valuefile.max_segment_size1073741824 (1 GB)The max number of bytes in each segment of value-file.

9. BSP & Coordination Configuration

Configuration for Bulk Synchronous Parallel (BSP) protocol and etcd coordination.

config optiondefault valuedescription
bsp.etcd_endpointshttp://localhost:2379The etcd endpoints; separate multiple addresses with commas. In K8s deployments, this option is set by the Operator.
bsp.max_super_step10 (packaged: 2)The max super step of the algorithm.
bsp.register_timeout300000 (packaged: 100000)The max timeout (in ms) to wait for master and workers to register.
bsp.wait_workers_timeout86400000 (24 hours)The max timeout (in ms) to wait for workers BSP event.
bsp.wait_master_timeout86400000 (24 hours)The max timeout (in ms) to wait for master BSP event.
bsp.log_interval30000 (30 seconds)The log interval (in ms) to print the log while waiting for BSP event.

10. Performance Tuning Configuration

Configuration for performance optimization.

config optiondefault valuedescription
allocator.max_vertices_per_thread10000Maximum number of vertices per thread processed in each memory allocator.
sort.thread_nums4The number of threads performing internal sorting.

11. System Administration Configuration

The following options are managed by the runtime system and should not be overridden in job configurations.

The following configuration items are automatically managed by the K8s Operator, Driver, or runtime system. Manual modification will cause cluster communication failures or job scheduling errors.

config optionmanaged bydescription
bsp.etcd_endpointsK8s OperatorAutomatically set to operator’s etcd service address
transport.server_hostRuntimeAutomatically set to pod/container hostname
transport.server_portRuntimeAutomatically assigned random port
job.namespaceK8s OperatorAutomatically set to job namespace
job.idK8s OperatorAutomatically set to job ID from CRD
job.workers_countK8s OperatorAutomatically set from CRD workerInstances
rpc.server_hostRuntimeRPC server hostname (system-managed)
rpc.server_portRuntimeRPC server port (system-managed)
rpc.remote_urlRuntimeRPC remote URL (system-managed)

Why These Are Forbidden:

  • BSP/RPC Configuration: Must match the actual deployed etcd/RPC services. Manual overrides break coordination.
  • Job Configuration: Must match K8s CRD specifications. Mismatches cause worker count errors.
  • Transport Configuration: Must use actual pod hostnames/ports. Manual values prevent inter-worker communication.

K8s Operator Config Options

NOTE: Option needs to be converted through environment variable settings, e.g. k8s.internal_etcd_url => INTERNAL_ETCD_URL

config optiondefault valuedescription
k8s.auto_destroy_podtrueWhether to automatically destroy all pods when the job is completed or failed.
k8s.close_reconciler_timeout120The max timeout (in ms) to close reconciler.
k8s.internal_etcd_urlhttp://127.0.0.1:2379The internal etcd URL for operator system.
k8s.max_reconcile_retry3The max retry times of reconcile.
k8s.probe_backlog50The maximum backlog for serving health probes.
k8s.probe_port9892The port that the controller binds to for serving health probes.
k8s.ready_check_internal1000The time interval (ms) of check ready.
k8s.ready_timeout30000The max timeout (in ms) of check ready.
k8s.reconciler_count10The max number of reconciler threads.
k8s.resync_period600000The minimum frequency at which watched resources are reconciled.
k8s.timezoneAsia/ShanghaiThe timezone of computer job and operator.
k8s.watch_namespacehugegraph-computer-systemThe namespace to watch custom resources in. Use ‘*’ to watch all namespaces.

HugeGraph-Computer CRD

CRD: https://github.com/apache/hugegraph-computer/blob/master/computer/computer-k8s-operator/manifest/hugegraph-computer-crd.v1.yaml

specdefault valuedescriptionrequired
algorithmNameThe name of algorithm.true
jobIdThe job id.true
imageThe image of algorithm.true
computerConfThe map of computer config options.true
workerInstancesThe number of worker instances, it will override the ‘job.workers_count’ option.true
pullPolicyAlwaysThe pull-policy of image, detail please refer to: https://kubernetes.io/docs/concepts/containers/images/#image-pull-policyfalse
pullSecretsThe pull-secrets of Image, detail please refer to: https://kubernetes.io/docs/concepts/containers/images/#specifying-imagepullsecrets-on-a-podfalse
masterCpuThe cpu limit of master, the unit can be ’m’ or without unit detail please refer to: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#meaning-of-cpufalse
workerCpuThe cpu limit of worker, the unit can be ’m’ or without unit detail please refer to: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#meaning-of-cpufalse
masterMemoryThe memory limit of master, the unit can be one of Ei、Pi、Ti、Gi、Mi、Ki detail please refer to: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#meaning-of-memoryfalse
workerMemoryThe memory limit of worker, the unit can be one of Ei、Pi、Ti、Gi、Mi、Ki detail please refer to: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#meaning-of-memoryfalse
log4jXmlThe content of log4j.xml for computer job.false
jarFileThe jar path of computer algorithm.false
remoteJarUriThe remote jar uri of computer algorithm, it will overlay algorithm image.false
jvmOptionsThe java startup parameters of computer job.false
envVarsplease refer to: https://kubernetes.io/docs/tasks/inject-data-application/define-interdependent-environment-variables/false
envFromplease refer to: https://kubernetes.io/docs/tasks/inject-data-application/define-environment-variable-container/false
masterCommandbin/start-computer.shThe run command of master, equivalent to ‘Entrypoint’ field of Docker.false
masterArgs["-r master", “-d k8s”]The run args of master, equivalent to ‘Cmd’ field of Docker.false
workerCommandbin/start-computer.shThe run command of worker, equivalent to ‘Entrypoint’ field of Docker.false
workerArgs["-r worker", “-d k8s”]The run args of worker, equivalent to ‘Cmd’ field of Docker.false
volumesPlease refer to: https://kubernetes.io/docs/concepts/storage/volumes/false
volumeMountsPlease refer to: https://kubernetes.io/docs/concepts/storage/volumes/false
secretPathsThe map of k8s-secret name and mount path.false
configMapPathsThe map of k8s-configmap name and mount path.false
podTemplateSpecPlease refer to: https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-template-v1/#PodTemplateSpecfalse
securityContextPlease refer to: https://kubernetes.io/docs/tasks/configure-pod-container/security-context/false

KubeDriver Config Options

config optiondefault valuedescription
k8s.build_image_bash_pathThe path of command used to build image.
k8s.enable_internal_algorithmtrueWhether enable internal algorithm.
k8s.framework_image_urlhugegraph/hugegraph-computer:latestThe image url of computer framework.
k8s.image_repository_passwordThe password for login image repository.
k8s.image_repository_registryThe address for login image repository.
k8s.image_repository_urlhugegraph/hugegraph-computerThe url of image repository.
k8s.image_repository_usernameThe username for login image repository.
k8s.internal_algorithm[pageRank]The name list of all internal algorithm. Note: Algorithm names use camelCase here (e.g., pageRank), but algorithm implementations return underscore_case (e.g., page_rank).
k8s.internal_algorithm_image_urlhugegraph/hugegraph-computer:latestThe image url of internal algorithm.
k8s.jar_file_dir/cache/jars/The directory where the algorithm jar will be uploaded.
k8s.kube_config~/.kube/configThe path of k8s config file.
k8s.log4j_xml_pathThe log4j.xml path for computer job.
k8s.namespacehugegraph-computer-systemThe namespace of hugegraph-computer system.
k8s.pull_secret_names[]The names of pull-secret for pulling image.

3.5 - HugeGraph Client

The Java and Go clients are maintained in the HugeGraph Toolchain repository, while the Python client is maintained in the HugeGraph-AI repository. Their installation methods and APIs differ; see the corresponding pages for details.

3.5.1 - HugeGraph-Java-Client

1 Overview

HugeGraph Java Client translates Java APIs into REST requests to HugeGraph Server. It supports managing schemas and graph data, executing Gremlin queries, and calling Traverser APIs. See the Client API for detailed interfaces; this page shows how to use the client in a Java project.

For other languages, use the Go Client or the Python Client maintained in the HugeGraph-AI repository.

2 What You Need

  • JDK 11 (used by the current CI; the source target remains Java 8)
  • Maven 3.6+

3 How To Use

The basic steps to use HugeGraph-Client are as follows:

  • Build a new Maven project by IDEA or Eclipse
  • Add HugeGraph-Client dependency in a pom file;
  • Create an object to invoke the interface of HugeGraph-Client

See the complete example in the following section for the detail.

4 Complete Example

4.1 Build New Maven Project

Using IDEA or Eclipse to create the project:

4.2 Add Hugegraph-Client Dependency In POM

<dependencies>
    <dependency>
        <groupId>org.apache.hugegraph</groupId>
        <artifactId>hugegraph-client</artifactId>
        <!-- Select a released version from the download page -->
        <version>1.7.0</version>
    </dependency>    
</dependencies>

Development versions of the client and server may differ. Check the corresponding release notes for compatibility before upgrading.

4.3 Example

4.3.1 SingleExample
import java.io.IOException;
import java.util.Iterator;
import java.util.List;

import org.apache.hugegraph.driver.GraphManager;
import org.apache.hugegraph.driver.GremlinManager;
import org.apache.hugegraph.driver.HugeClient;
import org.apache.hugegraph.driver.SchemaManager;
import org.apache.hugegraph.structure.constant.T;
import org.apache.hugegraph.structure.graph.Edge;
import org.apache.hugegraph.structure.graph.Path;
import org.apache.hugegraph.structure.graph.Vertex;
import org.apache.hugegraph.structure.gremlin.Result;
import org.apache.hugegraph.structure.gremlin.ResultSet;

public class SingleExample {

    public static void main(String[] args) throws IOException {
        // If connect failed will throw a exception.
        HugeClient hugeClient = HugeClient.builder("http://localhost:8080",
                                                   "DEFAULT",
                                                   "hugegraph")
                                          .configUser("username", "password")
                                          // This is an example. In a production environment, secure credentials should be used.
                                          .build();

        SchemaManager schema = hugeClient.schema();

        schema.propertyKey("name").asText().ifNotExist().create();
        schema.propertyKey("age").asInt().ifNotExist().create();
        schema.propertyKey("city").asText().ifNotExist().create();
        schema.propertyKey("weight").asDouble().ifNotExist().create();
        schema.propertyKey("lang").asText().ifNotExist().create();
        schema.propertyKey("date").asDate().ifNotExist().create();
        schema.propertyKey("price").asInt().ifNotExist().create();

        schema.vertexLabel("person")
              .properties("name", "age", "city")
              .primaryKeys("name")
              .ifNotExist()
              .create();

        schema.vertexLabel("software")
              .properties("name", "lang", "price")
              .primaryKeys("name")
              .ifNotExist()
              .create();

        schema.indexLabel("personByCity")
              .onV("person")
              .by("city")
              .secondary()
              .ifNotExist()
              .create();

        schema.indexLabel("personByAgeAndCity")
              .onV("person")
              .by("age", "city")
              .secondary()
              .ifNotExist()
              .create();

        schema.indexLabel("softwareByPrice")
              .onV("software")
              .by("price")
              .range()
              .ifNotExist()
              .create();

        schema.edgeLabel("knows")
              .sourceLabel("person")
              .targetLabel("person")
              .properties("date", "weight")
              .ifNotExist()
              .create();

        schema.edgeLabel("created")
              .sourceLabel("person").targetLabel("software")
              .properties("date", "weight")
              .ifNotExist()
              .create();

        schema.indexLabel("createdByDate")
              .onE("created")
              .by("date")
              .secondary()
              .ifNotExist()
              .create();

        schema.indexLabel("createdByWeight")
              .onE("created")
              .by("weight")
              .range()
              .ifNotExist()
              .create();

        schema.indexLabel("knowsByWeight")
              .onE("knows")
              .by("weight")
              .range()
              .ifNotExist()
              .create();

        GraphManager graph = hugeClient.graph();
        Vertex marko = graph.addVertex(T.LABEL, "person", "name", "marko",
                                       "age", 29, "city", "Beijing");
        Vertex vadas = graph.addVertex(T.LABEL, "person", "name", "vadas",
                                       "age", 27, "city", "Hongkong");
        Vertex lop = graph.addVertex(T.LABEL, "software", "name", "lop",
                                     "lang", "java", "price", 328);
        Vertex josh = graph.addVertex(T.LABEL, "person", "name", "josh",
                                      "age", 32, "city", "Beijing");
        Vertex ripple = graph.addVertex(T.LABEL, "software", "name", "ripple",
                                        "lang", "java", "price", 199);
        Vertex peter = graph.addVertex(T.LABEL, "person", "name", "peter",
                                       "age", 35, "city", "Shanghai");

        marko.addEdge("knows", vadas, "date", "2016-01-10", "weight", 0.5);
        marko.addEdge("knows", josh, "date", "2013-02-20", "weight", 1.0);
        marko.addEdge("created", lop, "date", "2017-12-10", "weight", 0.4);
        josh.addEdge("created", lop, "date", "2009-11-11", "weight", 0.4);
        josh.addEdge("created", ripple, "date", "2017-12-10", "weight", 1.0);
        peter.addEdge("created", lop, "date", "2017-03-24", "weight", 0.2);

        GremlinManager gremlin = hugeClient.gremlin();
        System.out.println("==== Path ====");
        ResultSet resultSet = gremlin.gremlin("g.V().outE().path()").execute();
        Iterator<Result> results = resultSet.iterator();
        results.forEachRemaining(result -> {
            System.out.println(result.getObject().getClass());
            Object object = result.getObject();
            if (object instanceof Vertex) {
                System.out.println(((Vertex) object).id());
            } else if (object instanceof Edge) {
                System.out.println(((Edge) object).id());
            } else if (object instanceof Path) {
                List<Object> elements = ((Path) object).objects();
                elements.forEach(element -> {
                    System.out.println(element.getClass());
                    System.out.println(element);
                });
            } else {
                System.out.println(object);
            }
        });

        hugeClient.close();
    }
}
4.3.2 BatchExample
import java.util.ArrayList;
import java.util.List;

import org.apache.hugegraph.driver.GraphManager;
import org.apache.hugegraph.driver.HugeClient;
import org.apache.hugegraph.driver.SchemaManager;
import org.apache.hugegraph.structure.graph.Edge;
import org.apache.hugegraph.structure.graph.Vertex;

public class BatchExample {

    public static void main(String[] args) {
        HugeClient hugeClient = HugeClient.builder("http://localhost:8080",
                                                   "DEFAULT",
                                                   "hugegraph")
                                          .configUser("username", "password")
                                          // This is an example. In a production environment, secure credentials should be used.
                                          .build();

        SchemaManager schema = hugeClient.schema();

        schema.propertyKey("name").asText().ifNotExist().create();
        schema.propertyKey("age").asInt().ifNotExist().create();
        schema.propertyKey("lang").asText().ifNotExist().create();
        schema.propertyKey("date").asDate().ifNotExist().create();
        schema.propertyKey("price").asInt().ifNotExist().create();

        schema.vertexLabel("person")
              .properties("name", "age")
              .primaryKeys("name")
              .ifNotExist()
              .create();

        schema.vertexLabel("person")
              .properties("price")
              .nullableKeys("price")
              .append();

        schema.vertexLabel("software")
              .properties("name", "lang", "price")
              .primaryKeys("name")
              .ifNotExist()
              .create();

        schema.indexLabel("softwareByPrice")
              .onV("software").by("price")
              .range()
              .ifNotExist()
              .create();

        schema.edgeLabel("knows")
              .link("person", "person")
              .properties("date")
              .ifNotExist()
              .create();

        schema.edgeLabel("created")
              .link("person", "software")
              .properties("date")
              .ifNotExist()
              .create();

        schema.indexLabel("createdByDate")
              .onE("created").by("date")
              .secondary()
              .ifNotExist()
              .create();

        // get schema object by name
        System.out.println(schema.getPropertyKey("name"));
        System.out.println(schema.getVertexLabel("person"));
        System.out.println(schema.getEdgeLabel("knows"));
        System.out.println(schema.getIndexLabel("createdByDate"));

        // list all schema objects
        System.out.println(schema.getPropertyKeys());
        System.out.println(schema.getVertexLabels());
        System.out.println(schema.getEdgeLabels());
        System.out.println(schema.getIndexLabels());

        GraphManager graph = hugeClient.graph();

        Vertex marko = new Vertex("person").property("name", "marko")
                                           .property("age", 29);
        Vertex vadas = new Vertex("person").property("name", "vadas")
                                           .property("age", 27);
        Vertex lop = new Vertex("software").property("name", "lop")
                                           .property("lang", "java")
                                           .property("price", 328);
        Vertex josh = new Vertex("person").property("name", "josh")
                                          .property("age", 32);
        Vertex ripple = new Vertex("software").property("name", "ripple")
                                              .property("lang", "java")
                                              .property("price", 199);
        Vertex peter = new Vertex("person").property("name", "peter")
                                           .property("age", 35);

        Edge markoKnowsVadas = new Edge("knows").source(marko).target(vadas)
                                                .property("date", "2016-01-10");
        Edge markoKnowsJosh = new Edge("knows").source(marko).target(josh)
                                               .property("date", "2013-02-20");
        Edge markoCreateLop = new Edge("created").source(marko).target(lop)
                                                 .property("date",
                                                           "2017-12-10");
        Edge joshCreateRipple = new Edge("created").source(josh).target(ripple)
                                                   .property("date",
                                                             "2017-12-10");
        Edge joshCreateLop = new Edge("created").source(josh).target(lop)
                                                .property("date", "2009-11-11");
        Edge peterCreateLop = new Edge("created").source(peter).target(lop)
                                                 .property("date",
                                                           "2017-03-24");

        List<Vertex> vertices = new ArrayList<>();
        vertices.add(marko);
        vertices.add(vadas);
        vertices.add(lop);
        vertices.add(josh);
        vertices.add(ripple);
        vertices.add(peter);

        List<Edge> edges = new ArrayList<>();
        edges.add(markoKnowsVadas);
        edges.add(markoKnowsJosh);
        edges.add(markoCreateLop);
        edges.add(joshCreateRipple);
        edges.add(joshCreateLop);
        edges.add(peterCreateLop);

        vertices = graph.addVertices(vertices);
        vertices.forEach(vertex -> System.out.println(vertex));

        edges = graph.addEdges(edges, false);
        edges.forEach(edge -> System.out.println(edge));

        hugeClient.close();
    }
}

4.4 Run The Example

Before running Example, you need to start the Server. For the startup process, seeHugeGraph-Server Quick Start.

4.5 More Information About Client-API

SeeIntroduce basic API of HugeGraph-Client.

3.5.2 - HugeGraph Python Client Quick Start

hugegraph-python-client is the Python SDK for HugeGraph. It manages schemas, reads and writes graph data, and executes Gremlin queries. HugeGraph-LLM and HugeGraph-ML also use this client.

Requirements

  • Python 3.9 or later
  • An accessible HugeGraph Server
  • uv (recommended) or pip

Installation

The package is currently published on PyPI as hugegraph-python:

uv pip install hugegraph-python
# Alternatively: pip install hugegraph-python

To use the latest repository code, sync the workspace from the root of the HugeGraph-AI repository:

git clone https://github.com/apache/hugegraph-ai.git
cd hugegraph-ai
uv sync
source .venv/bin/activate

Connect and Write Data

from pyhugegraph.client import PyHugeClient

client = PyHugeClient(
    "127.0.0.1:8080",
    graph="hugegraph",
    user="admin",
    pwd="admin",
    graphspace="DEFAULT",
)

schema = client.schema()
schema.propertyKey("name").asText().ifNotExist().create()
schema.propertyKey("birthDate").asText().ifNotExist().create()
schema.vertexLabel("Person").properties("name", "birthDate") \
      .usePrimaryKeyId().primaryKeys("name").ifNotExist().create()
schema.vertexLabel("Movie").properties("name") \
      .usePrimaryKeyId().primaryKeys("name").ifNotExist().create()
schema.edgeLabel("ActedIn").sourceLabel("Person").targetLabel("Movie") \
      .ifNotExist().create()

graph = client.graph()
person = graph.addVertex(
    "Person", {"name": "Al Pacino", "birthDate": "1940-04-25"}
)
movie = graph.addVertex("Movie", {"name": "The Godfather"})
edge = graph.addEdge("ActedIn", person.id, movie.id, {})

print(graph.getVertexById(person.id))
print(graph.getEdgeById(edge.id))
graph.close()

If GraphSpace is disabled in HugeGraph, omit graphspace. When it is enabled, pass the actual space name; the default space is usually DEFAULT.

Common Operations

Query the Schema

schema = client.schema()
print(schema.getPropertyKeys())
print(schema.getVertexLabels())
print(schema.getEdgeLabels())
print(schema.getIndexLabels())

Update and Delete Graph Data

The graph API accepts dictionaries containing object properties:

graph = client.graph()
graph.appendVertex(person.id, {"birthDate": "1940-04-25"})
graph.removeEdgeById(edge.id)
graph.removeVertexById(person.id)
graph.close()

Execute Gremlin

gremlin = client.gremlin()
result = gremlin.exec("g.V().limit(5)")
print(result)

API parameters may change with the HugeGraph REST API version. If an interface is incompatible, first check the REST API documentation for the current server version and the client test cases.

Development Checks

Run formatting and static checks from the root of the HugeGraph-AI repository:

./style/code_format_and_analysis.sh

The source code and tests are under hugegraph-python-client/src/pyhugegraph/ and hugegraph-python-client/src/tests/.

3.5.3 - HugeGraph Go Client Quick Start

HugeGraph Go Client is the Go SDK in the Toolchain repository. It currently provides APIs for version queries, schemas, vertices, edges, and Gremlin.

This module is still under development. Refer to the source code under hugegraph-client-go/api/v1 for the currently available interfaces.

Requirements

  • Go 1.19 or later
  • An accessible HugeGraph Server; examples use http://127.0.0.1:8080

Installation

Run the following command in a Go module project:

go get github.com/apache/hugegraph-toolchain/hugegraph-client-go

Initialize the Client

NewCommonClient requires Host to be an IP address. Leave the username and password empty when authentication is disabled. Current server graph resource paths include a graph space; use DEFAULT for the default space. Leaving GraphSpace empty applies only to older servers that still use the /graphs/{graph} path.

package main

import (
	"fmt"
	"log"

	hugegraph "github.com/apache/hugegraph-toolchain/hugegraph-client-go"
)

func main() {
	client, err := hugegraph.NewCommonClient(hugegraph.Config{
		Host:       "127.0.0.1",
		Port:       8080,
		GraphSpace: "DEFAULT",
		Graph:      "hugegraph",
		Username:   "",
		Password:   "",
	})
	if err != nil {
		log.Fatal(err)
	}

	response, err := client.Version()
	if err != nil {
		log.Fatal(err)
	}
	defer response.Body.Close()

	fmt.Println(response.Versions.Version)
}

The Versions value returned by Version() includes the HugeGraph Server, Core, Gremlin, and REST API versions. The NewDefaultCommonClient() helper in the source connects to the hugegraph graph at 127.0.0.1:8080 with admin/pa authentication. Production code should normally pass an explicit configuration instead.

Available Entry Points

CommonClient currently exposes the following entry points:

Entry pointPurpose
Version()Query the server version
Schema()Query the complete schema
PropertykeyManage property keys
VertexLabelManage vertex labels
EdgeLabelManage edge labels
VertexCreate vertices in single or batch mode and update vertex properties
GremlinExecute Gremlin through GET or POST

For complete usage, see the tests in each API directory, such as version_test.go and vertexlabel_test.go.

4 - HugeGraph-Server Configuration

This section covers HugeGraph-Server configuration files, available options, authentication, and HTTPS settings.

4.1 - Server Startup Guide

1 Overview

The directory for the configuration files is hugegraph-release/conf, and all the configurations related to the service and the graph itself are located in this directory.

The main configuration files include gremlin-server.yaml, rest-server.properties, and hugegraph.properties.

The HugeGraphServer integrates the GremlinServer and RestServer internally, and gremlin-server.yaml and rest-server.properties are used to configure these two servers.

  • GremlinServer: GremlinServer accepts Gremlin requests and invokes the graph engine.
  • RestServer: It provides a RESTful API that, based on different HTTP requests, calls the corresponding Core API. If the user’s request body is a Gremlin statement, it will be forwarded to GremlinServer to perform operations on the graph data.

Now let’s introduce these three configuration files one by one.

2. gremlin-server.yaml

The main structure of gremlin-server.yaml is shown below. Some imports are omitted from this example; refer to the file included in the release package for the complete content.

# host and port of gremlin server, need to be consistent with host and port in rest-server.properties
#host: 127.0.0.1
#port: 8182

# timeout in ms of gremlin query
evaluationTimeout: 30000

channelizer: org.apache.tinkerpop.gremlin.server.channel.WsAndHttpChannelizer
# don't set graph at here, this happens after support for dynamically adding graph
graphs: {
}
scriptEngines: {
  gremlin-groovy: {
    staticImports: [
      org.opencypher.gremlin.process.traversal.CustomPredicates.*',
      org.opencypher.gremlin.traversal.CustomFunctions.*
    ],
    plugins: {
      org.apache.hugegraph.plugin.HugeGraphGremlinPlugin: {},
      org.apache.tinkerpop.gremlin.server.jsr223.GremlinServerGremlinPlugin: {},
      org.apache.tinkerpop.gremlin.jsr223.ImportGremlinPlugin: {
        classImports: [
          java.lang.Math,
          org.apache.hugegraph.backend.id.IdGenerator,
          org.apache.hugegraph.type.define.Directions,
          org.apache.hugegraph.type.define.NodeRole,
          org.apache.hugegraph.traversal.algorithm.CollectionPathsTraverser,
          org.apache.hugegraph.traversal.algorithm.CountTraverser,
          org.apache.hugegraph.traversal.algorithm.CustomizedCrosspointsTraverser,
          org.apache.hugegraph.traversal.algorithm.CustomizePathsTraverser,
          org.apache.hugegraph.traversal.algorithm.FusiformSimilarityTraverser,
          org.apache.hugegraph.traversal.algorithm.HugeTraverser,
          org.apache.hugegraph.traversal.algorithm.JaccardSimilarTraverser,
          org.apache.hugegraph.traversal.algorithm.KneighborTraverser,
          org.apache.hugegraph.traversal.algorithm.KoutTraverser,
          org.apache.hugegraph.traversal.algorithm.MultiNodeShortestPathTraverser,
          org.apache.hugegraph.traversal.algorithm.NeighborRankTraverser,
          org.apache.hugegraph.traversal.algorithm.PathsTraverser,
          org.apache.hugegraph.traversal.algorithm.PersonalRankTraverser,
          org.apache.hugegraph.traversal.algorithm.SameNeighborTraverser,
          org.apache.hugegraph.traversal.algorithm.ShortestPathTraverser,
          org.apache.hugegraph.traversal.algorithm.SingleSourceShortestPathTraverser,
          org.apache.hugegraph.traversal.algorithm.SubGraphTraverser,
          org.apache.hugegraph.traversal.algorithm.TemplatePathsTraverser,
          org.apache.hugegraph.traversal.algorithm.steps.EdgeStep,
          org.apache.hugegraph.traversal.algorithm.steps.RepeatEdgeStep,
          org.apache.hugegraph.traversal.algorithm.steps.WeightedEdgeStep,
          org.apache.hugegraph.traversal.optimize.ConditionP,
          org.apache.hugegraph.traversal.optimize.Text,
          org.apache.hugegraph.traversal.optimize.TraversalUtil,
          org.apache.hugegraph.util.DateUtil,
          org.opencypher.gremlin.traversal.CustomFunctions,
          org.opencypher.gremlin.traversal.CustomPredicate
        ],
        methodImports: [
          java.lang.Math#*,
          org.opencypher.gremlin.traversal.CustomPredicate#*,
          org.opencypher.gremlin.traversal.CustomFunctions#*
        ]
      },
      org.apache.tinkerpop.gremlin.jsr223.ScriptFileGremlinPlugin: {
        files: [scripts/empty-sample.groovy]
      }
    }
  }
}
serializers:
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphBinaryMessageSerializerV1,
      config: {
        serializeResultToString: false,
        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
      }
  }
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0,
      config: {
        serializeResultToString: false,
        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
      }
  }
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV2d0,
      config: {
        serializeResultToString: false,
        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
      }
  }
  - { className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV3d0,
      config: {
        serializeResultToString: false,
        ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
      }
  }
metrics: {
  consoleReporter: {enabled: false, interval: 180000},
  csvReporter: {enabled: false, interval: 180000, fileName: ./metrics/gremlin-server-metrics.csv},
  jmxReporter: {enabled: false},
  slf4jReporter: {enabled: false, interval: 180000},
  gangliaReporter: {enabled: false, interval: 180000, addressingMode: MULTICAST},
  graphiteReporter: {enabled: false, interval: 180000}
}
maxInitialLineLength: 4096
maxHeaderSize: 8192
maxChunkSize: 8192
maxContentLength: 65536
maxAccumulationBufferComponents: 1024
resultIterationBatchSize: 64
writeBufferLowWaterMark: 32768
writeBufferHighWaterMark: 65536
ssl: {
  enabled: false
}

In most cases, you only need to pay attention to channelizer, host, and port. Graphs are not loaded from the Gremlin Server graphs section. Whether local graph configurations are loaded is controlled by graph.load_from_local_config in rest-server.properties.

  • channelizer: The default WsAndHttpChannelizer supports both WebSocket and HTTP. Gremlin Console uses WebSocket, while HugeGraph Client, Loader, and Hubble use HTTP.

By default, the GremlinServer serves at localhost:8182. If you need to modify it, configure the host and port settings.

  • host: The hostname or IP address of the machine where the GremlinServer is deployed. Currently, HugeGraphServer does not support distributed deployment, and GremlinServer is not directly exposed to users.
  • port: The port number of the machine where the GremlinServer is deployed.

Additionally, you need to add the corresponding configuration gremlinserver.url=http://host:port in rest-server.properties.

3. rest-server.properties

The following is an example of the available rest-server.properties options. The current upstream release template does not include graph.load_from_local_config, whose source-code default is false; set it explicitly to true when using local graph configurations under conf/graphs.

# bind url
# could use '0.0.0.0' or specified (real)IP to expose external network access
restserver.url=http://127.0.0.1:8080
#restserver.enable_graphspaces_filter=false
# gremlin server url, need to be consistent with host and port in gremlin-server.yaml
#gremlinserver.url=http://127.0.0.1:8182

graphs=./conf/graphs
graph.load_from_local_config=true

# The maximum thread ratio for batch writing, only take effect if the batch.max_write_threads is 0
batch.max_write_ratio=80
batch.max_write_threads=0

# configuration of arthas
arthas.telnetPort=8562
arthas.httpPort=8561
arthas.ip=127.0.0.1
arthas.disabledCommands=jad

# authentication configs
#auth.authenticator=org.apache.hugegraph.auth.StandardAuthenticator
# for admin password, By default, it is pa and takes effect upon the first startup
#auth.admin_pa=pa
#auth.graph_store=hugegraph

# use pd
# usePD=true

# slow query log
log.slow_query_threshold=1000
# bytes of request body recorded as-is (may contain sensitive literals), 0 to disable
log.slow_query_body_limit=512

# jvm(in-heap) memory usage monitor, set 1 to disable it
memory_monitor.threshold=0.85
memory_monitor.period=2000
  • restserver.url: The URL at which the RestServer provides its services. Modify it according to the actual environment. If you can’t connet to server from other IP address, try to modify it as specific IP; or modify it as http://0.0.0.0 to listen all network interfaces as a convenient solution, but need to take care of the network area that might access.
  • graphs: The directory containing graph configuration files. The default is ./conf/graphs. init-store scans this directory; the Server loads its properties files only when graph.load_from_local_config=true.
  • graph.load_from_local_config: Whether the Server reads local graph configurations at startup. Its default value in the source code is false.

The current upstream template still uses arthas.telnet_port, arthas.http_port, and arthas.disabled_commands, but ServerOptions reads the camelCase names shown in the example above. Custom configurations should use arthas.telnetPort, arthas.httpPort, and arthas.disabledCommands.

The gremlinserver.url configuration option is the URL at which the GremlinServer provides services to the RestServer. By default, it is set to http://localhost:8182. If you need to modify it, it should match the host and port settings in gremlin-server.yaml.

4. hugegraph.properties

hugegraph.properties is a type of file. If the system has multiple graphs, there will be multiple similar files. This file is used to configure parameters related to graph storage and querying. The default content of the file is as follows:

# gremlin entrence to create graph
gremlin.graph=org.apache.hugegraph.HugeFactory

# cache config
#schema.cache_capacity=100000
# vertex-cache default is 1000w, 10min expired
#vertex.cache_capacity=10000000
#vertex.cache_expire=600
# edge-cache default is 100w, 10min expired
#edge.cache_capacity=1000000
#edge.cache_expire=600

# schema illegal name template
#schema.illegal_name_regex=\s+|~.*

# NOTE: since 1.7.0, only hstore, rocksdb, hbase, memory are supported for backend.
# if you want to use Cassandra/MySql/PG... as backend, please use version < 1.7.0
backend=rocksdb
serializer=binary

store=hugegraph

# pd config
#pd.peers=127.0.0.1:8686

# task config
task.schedule_period=10
task.retry=0
task.wait_timeout=10

# if use 'ikanalyzer', need download jar from 'https://github.com/apache/hugegraph-doc/raw/ik_binary/dist/server/ikanalyzer-2012_u6.jar' to lib directory
search.text_analyzer=jieba
search.text_analyzer_mode=INDEX

# rocksdb backend config
#rocksdb.data_path=/path/to/disk
#rocksdb.wal_path=/path/to/disk

# hbase backend config
#hbase.hosts=localhost
#hbase.port=2181
#hbase.znode_parent=/hbase
#hbase.threads_max=64

Pay attention to the following uncommented items:

  • gremlin.graph: The entry point for GremlinServer startup. Users should not modify this item.
  • backend: The storage backend. Version 1.7.0 supports memory, rocksdb, hstore, and hbase.
  • serializer: The serializer used when writing schemas, vertices, and edges to the backend. RocksDB uses binary.
  • store: The storage name used by the graph in the backend.
  • rocksdb.data_path: This item is only meaningful when the backend is set to rocksdb. It specifies the data directory for RocksDB.
  • rocksdb.wal_path: This item is only meaningful when the backend is set to rocksdb. It specifies the log directory for RocksDB.

5. Multi-Graph Configuration

A Server can load multiple graphs, with a separate properties file for each graph. The following example creates a RocksDB graph named hugegraph_rocksdb and an in-memory graph named hugegraph_memory.

[Optional]: Modify rest-server.properties

You can modify the graph profile directory in the graphs option of rest-server.properties. The default configuration is graphs=./conf/graphs, if you want to change it to another directory then adjust the graphs option, e.g. adjust it to graphs=/etc/hugegraph/graphs, example is as follows:

graphs=./conf/graphs
graph.load_from_local_config=true

Under conf/graphs, create hugegraph_memory.properties and hugegraph_rocksdb.properties based on hugegraph.properties.

Configure hugegraph_memory.properties as follows:

backend=memory
serializer=text
store=hugegraph_memory

Configure hugegraph_rocksdb.properties as follows:

backend=rocksdb
serializer=binary

store=hugegraph_rocksdb

Stop the server, execute init-store.sh (to create a new database for the new graph), and restart the server.

$ ./bin/stop-hugegraph.sh
$ ./bin/init-store.sh

Initializing HugeGraph Store...
2023-06-11 14:16:14 [main] [INFO] o.a.h.u.ConfigUtil - Scanning option 'graphs' directory './conf/graphs'
2023-06-11 14:16:14 [main] [INFO] o.a.h.c.InitStore - Init graph with config file: ./conf/graphs/hugegraph_rocksdb.properties
...
2023-06-11 14:16:15 [main] [INFO] o.a.h.StandardHugeGraph - Graph 'hugegraph_rocksdb' has been initialized
2023-06-11 14:16:15 [main] [INFO] o.a.h.c.InitStore - Init graph with config file: ./conf/graphs/hugegraph_memory.properties
...
2023-06-11 14:16:16 [main] [INFO] o.a.h.StandardHugeGraph - Graph 'hugegraph_memory' has been initialized
2023-06-11 14:16:16 [main] [INFO] o.a.h.StandardHugeGraph - Close graph standardhugegraph[hugegraph_rocksdb]
...
2023-06-11 14:16:16 [main] [INFO] o.a.h.HugeFactory - HugeFactory shutdown
2023-06-11 14:16:16 [hugegraph-shutdown] [INFO] o.a.h.HugeFactory - HugeGraph is shutting down
Initialization finished.
$ ./bin/start-hugegraph.sh

Starting HugeGraphServer...
Connecting to HugeGraphServer (http://127.0.0.1:8080/graphspaces/DEFAULT/graphs)...OK
Started [pid 21614]

Check out created graphs:

curl http://127.0.0.1:8080/graphspaces/DEFAULT/graphs

{"graphs":["hugegraph_rocksdb","hugegraph_memory"]}

Get details of a graph:

curl http://127.0.0.1:8080/graphspaces/DEFAULT/graphs/hugegraph_memory

{"name":"hugegraph_memory","backend":"memory"}
curl http://127.0.0.1:8080/graphspaces/DEFAULT/graphs/hugegraph_rocksdb

{"name":"hugegraph_rocksdb","backend":"rocksdb"}

4.2 - Server Complete Configuration Manual

Gremlin Server Config Options

Corresponding configuration file gremlin-server.yaml

config optiondefault valuedescription
host127.0.0.1The host or ip of Gremlin Server.
port8182The listening port of Gremlin Server.
graphs{}Graphs are loaded dynamically by the Server; do not configure them here.
evaluationTimeout30000Gremlin script evaluation timeout in milliseconds.
channelizerorg.apache.tinkerpop.gremlin.server.channel.WsAndHttpChannelizerHandles both WebSocket and HTTP requests.
authenticationNot configuredWhen enabling authentication, configure the authenticator, handler, and path to rest-server.properties.

Rest Server & API Config Options

Corresponding configuration file rest-server.properties

config optiondefault valuedescription
graphs./conf/graphsDirectory containing graph configuration properties files.
graph.load_from_local_configfalseWhether to read the graphs directory when the Server starts; set to true when using local graph configuration.
server.idEmpty stringThe id of rest server, used for license verification.
server.rolemasterThe role of nodes in the cluster, available types are [master, worker, computer]
restserver.urlhttp://127.0.0.1:8080The url for listening of rest server.
ssl.keystore_fileconf/hugegraph-server.keystoreThe path of server keystore file used when https protocol is enabled.
ssl.keystore_passwordhugegraphThe password of the server keystore file used when the https protocol is enabled.
restserver.max_worker_threads2 * CPUsThe maximum worker threads of rest server.
restserver.min_free_memory64The minimum free memory(MB) of rest server, requests will be rejected when the available memory of system is lower than this value.
restserver.request_timeout30The time in seconds within which a request must complete, -1 means no timeout.
restserver.connection_idle_timeout30The time in seconds to keep an inactive connection alive, -1 means no timeout.
restserver.connection_max_requests256The max number of HTTP requests allowed to be processed on one keep-alive connection, -1 means unlimited.
gremlinserver.urlhttp://127.0.0.1:8182The url of gremlin server.
gremlinserver.max_route8The max route number for gremlin server.
gremlinserver.timeout30The timeout in seconds of waiting for gremlin server.
batch.max_edges_per_batch2500The maximum number of edges submitted per batch.
batch.max_vertices_per_batch2500The maximum number of vertices submitted per batch.
batch.max_write_ratio70The maximum thread ratio for batch writing, only take effect if the batch.max_write_threads is 0.
batch.max_write_threads0The maximum threads for batch writing, if the value is 0, the actual value will be set to batch.max_write_ratio * restserver.max_worker_threads.
auth.authenticatorThe class path of authenticator implementation. e.g., org.apache.hugegraph.auth.StandardAuthenticator, or a custom implementation.
auth.graph_storehugegraphThe name of graph used to store authentication information, like users, only for org.apache.hugegraph.auth.StandardAuthenticator.
auth.admin_papaInitial password for the built-in admin user in PD mode. It only applies when the user is first created and must be changed before deployment.
auth.audit_log_rate1000.0The max rate of audit log output per user, default value is 1000 records per second.
auth.cache_capacity10240The max cache capacity of each auth cache item.
auth.cache_expire600The expiration time in seconds of vertex cache.
auth.remote_urlIf the address is empty, it provide auth service, otherwise it is auth client and also provide auth service through rpc forwarding. The remote url can be set to multiple addresses, which are concat by ‘,’.
auth.token_expire86400The expiration time in seconds after token created
auth.token_secretRandomly generated at startupHS256 secret; configure it explicitly if existing tokens must remain valid across restarts.
exception.allow_tracetrueWhether to allow exception trace stack.
memory_monitor.threshold0.85The threshold of JVM(in-heap) memory usage monitoring , 1 means disabling this function.
memory_monitor.period2000The period in ms of JVM(in-heap) memory usage monitoring.
log.slow_query_threshold1000Slow query log threshold in milliseconds, 0 means disabled.
log.slow_query_body_limit512Maximum bytes of a request body recorded in the slow query log, 0 means disabled. The recorded prefix may contain sensitive Gremlin or Cypher literals.

PD/Meta Config Options (Distributed Mode)

Corresponding configuration file rest-server.properties

config optiondefault valuedescription
pd.peers127.0.0.1:8686PD server addresses (comma separated).
meta.endpointshttp://127.0.0.1:2379Meta service endpoints.
usePDfalseWhether to use PD to manage distributed metadata.

Basic Config Options

Basic Config Options and Backend Config Options correspond to configuration files:{graph-name}.properties, such as hugegraph.properties

config optiondefault valuedescription
gremlin.graphorg.apache.hugegraph.HugeFactoryGremlin entrance to create graph.
backendrocksdbThe data store type. For version 1.7.0+: [memory, rocksdb, hstore, hbase]. Note: cassandra, scylladb, mysql, postgresql were removed in 1.7.0 (use <= 1.5.x for legacy backends).
serializerbinaryThe serializer for backend store, available values are [text, binary, cassandra, hbase, mysql].
storehugegraphThe database name like Cassandra Keyspace.
store.connection_detect_interval600The interval in seconds for detecting connections, if the idle time of a connection exceeds this value, detect it and reconnect if needed before using, value 0 means detecting every time.
store.graphgThe graph table name, which store vertex, edge and property.
store.schemamThe schema table name, which store meta data.
store.systemsThe system table name, which store system data.
schema.illegal_name_regex.\s+$|~.The regex specified the illegal format for schema name.
schema.cache_capacity10000The max cache size(items) of schema cache.
vertex.cache_typel2The type of vertex cache, allowed values are [l1, l2].
vertex.cache_capacity10000000The max cache size(items) of vertex cache.
vertex.cache_expire600The expire time in seconds of vertex cache.
vertex.check_customized_id_existfalseWhether to check the vertices exist for those using customized id strategy.
vertex.default_labelvertexThe default vertex label.
vertex.tx_capacity10000The max size(items) of vertices(uncommitted) in transaction.
vertex.check_adjacent_vertex_existfalseWhether to check the adjacent vertices of edges exist.
vertex.lazy_load_adjacent_vertextrueWhether to lazy load adjacent vertices of edges.
vertex.part_edge_commit_size5000Whether to enable the mode to commit part of edges of vertex, enabled if commit size > 0, 0 means disabled.
vertex.encode_primary_key_numbertrueWhether to encode number value of primary key in vertex id.
vertex.remove_left_index_at_overwritefalseWhether remove left index at overwrite.
edge.cache_typel2The type of edge cache, allowed values are [l1, l2].
edge.cache_capacity1000000The max cache size(items) of edge cache.
edge.cache_expire600The expiration time in seconds of edge cache.
edge.tx_capacity10000The max size(items) of edges(uncommitted) in transaction.
query.page_size500The size of each page when querying by paging.
query.batch_size1000The size of each batch when querying by batch.
query.ignore_invalid_datatrueWhether to ignore invalid data of vertex or edge.
query.index_intersect_threshold1000The maximum number of intermediate results to intersect indexes when querying by multiple single index properties.
query.ramtable_edges_capacity20000000The maximum number of edges in ramtable, include OUT and IN edges.
query.ramtable_enablefalseWhether to enable ramtable for query of adjacent edges.
query.ramtable_vertices_capacity10000000The maximum number of vertices in ramtable, generally the largest vertex id is used as capacity.
query.optimize_aggregate_by_indexfalseWhether to optimize aggregate query(like count) by index.
oltp.concurrent_depth10The min depth to enable concurrent oltp algorithm.
oltp.concurrent_threads10Thread number to concurrently execute oltp algorithm.
oltp.collection_typeECThe implementation type of collections used in oltp algorithm.
rate_limit.read0The max rate(times/s) to execute query of vertices/edges.
rate_limit.write0The max rate(items/s) to add/update/delete vertices/edges.
task.wait_timeout10Timeout in seconds for waiting for the task to complete,such as when truncating or clearing the backend.
task.input_size_limit16777216The job input size limit in bytes.
task.result_size_limit16777216The job result size limit in bytes.
task.sync_deletionfalseWhether to delete schema or expired data synchronously.
task.ttl_delete_batch1The batch size used to delete expired data.
computer.config/conf/computer.yamlThe config file path of computer job.
search.text_analyzerikanalyzerChoose a text analyzer for searching the vertex/edge properties, available type are [word, ansj, hanlp, smartcn, jieba, jcseg, mmseg4j, ikanalyzer]. if use ‘ikanalyzer’, need download jar from ‘https://github.com/apache/hugegraph-doc/raw/ik_binary/dist/server/ikanalyzer-2012_u6.jar' to lib directory
search.text_analyzer_modesmartSpecify the mode for the text analyzer, the available mode of analyzer are {word: [MaximumMatching, ReverseMaximumMatching, MinimumMatching, ReverseMinimumMatching, BidirectionalMaximumMatching, BidirectionalMinimumMatching, BidirectionalMaximumMinimumMatching, FullSegmentation, MinimalWordCount, MaxNgramScore, PureEnglish], ansj: [BaseAnalysis, IndexAnalysis, ToAnalysis, NlpAnalysis], hanlp: [standard, nlp, index, nShort, shortest, speed], smartcn: [], jieba: [SEARCH, INDEX], jcseg: [Simple, Complex], mmseg4j: [Simple, Complex, MaxWord], ikanalyzer: [smart, max_word]}.
snowflake.datacenter_id0The datacenter id of snowflake id generator.
snowflake.force_stringfalseWhether to force the snowflake long id to be a string.
snowflake.worker_id0The worker id of snowflake id generator.
raft.modefalseWhether the backend storage works in raft mode.
raft.safe_readfalseWhether to use linearly consistent read.
raft.use_snapshotfalseWhether to use snapshot.
raft.endpoint127.0.0.1:8281The peerid of current raft node.
raft.group_peers127.0.0.1:8281,127.0.0.1:8282,127.0.0.1:8283The peers of current raft group.
raft.path./raft-logThe log path of current raft node.
raft.use_replicator_pipelinetrueWhether to use replicator line, when turned on it multiple logs can be sent in parallel, and the next log doesn’t have to wait for the ack message of the current log to be sent.
raft.election_timeout10000Timeout in milliseconds to launch a round of election.
raft.snapshot_interval3600The interval in seconds to trigger snapshot save.
raft.backend_threadscurrent CPU v-coresThe thread number used to apply task to backend.
raft.read_index_threads8The thread number used to execute reading index.
raft.apply_batch1The apply batch size to trigger disruptor event handler.
raft.queue_size16384The disruptor buffers size for jraft RaftNode, StateMachine and LogManager.
raft.queue_publish_timeout60The timeout in second when publish event into disruptor.
raft.rpc_threads80The rpc threads for jraft RPC layer.
raft.rpc_connect_timeout5000The rpc connect timeout for jraft rpc.
raft.rpc_timeout60000The rpc timeout for jraft rpc.
raft.rpc_buf_low_water_mark10485760The ChannelOutboundBuffer’s low water mark of netty, when buffer size less than this size, the method ChannelOutboundBuffer.isWritable() will return true, it means that low downstream pressure or good network.
raft.rpc_buf_high_water_mark20971520The ChannelOutboundBuffer’s high water mark of netty, only when buffer size exceed this size, the method ChannelOutboundBuffer.isWritable() will return false, it means that the downstream pressure is too great to process the request or network is very congestion, upstream needs to limit rate at this time.
raft.read_strategyReadOnlyLeaseBasedThe linearizability of read strategy.

RocksDB Backend Config Options

config optiondefault valuedescription
backendMust be set to rocksdb.
serializerMust be set to binary.
rocksdb.data_disks[]The optimized disks for storing data of RocksDB. The format of each element: STORE/TABLE: /path/disk.Allowed keys are [g/vertex, g/edge_out, g/edge_in, g/vertex_label_index, g/edge_label_index, g/range_int_index, g/range_float_index, g/range_long_index, g/range_double_index, g/secondary_index, g/search_index, g/shard_index, g/unique_index, g/olap]
rocksdb.data_pathrocksdb-data/dataThe path for storing data of RocksDB.
rocksdb.wal_pathrocksdb-data/walThe path for storing WAL of RocksDB.
rocksdb.option_pathThe YAML file for configuring ToplingDB/RocksDB parameters.
rocksdb.open_httpfalseWhether to start ToplingDB HTTP service. Security: enable only in trusted networks and restrict access (firewall/ACL); the port and document_root are configured in the YAML (http.listening_ports/document_root).
rocksdb.allow_mmap_readsfalseAllow the OS to mmap file for reading sst tables.
rocksdb.allow_mmap_writesfalseAllow the OS to mmap file for writing.
rocksdb.block_cache_capacity8388608The amount of block cache in bytes that will be used by RocksDB, 0 means no block cache.
rocksdb.bloom_filter_bits_per_key-1The bits per key in bloom filter, a good value is 10, which yields a filter with ~ 1% false positive rate, -1 means no bloom filter.
rocksdb.bloom_filter_block_based_modefalseUse block based filter rather than full filter.
rocksdb.bloom_filter_whole_key_filteringtrueTrue if place whole keys in the bloom filter, else place the prefix of keys.
rocksdb.bottommost_compressionNO_COMPRESSIONThe compression algorithm for the bottommost level of RocksDB, allowed values are none/snappy/z/bzip2/lz4/lz4hc/xpress/zstd.
rocksdb.bulkload_modefalseSwitch to the mode to bulk load data into RocksDB.
rocksdb.cache_index_and_filter_blocksfalseIndicating if we’d put index/filter blocks to the block cache.
rocksdb.compaction_styleLEVELSet compaction style for RocksDB: LEVEL/UNIVERSAL/FIFO.
rocksdb.compressionSNAPPY_COMPRESSIONThe compression algorithm for compressing blocks of RocksDB, allowed values are none/snappy/z/bzip2/lz4/lz4hc/xpress/zstd.
rocksdb.compression_per_level[NO_COMPRESSION, NO_COMPRESSION, SNAPPY_COMPRESSION, SNAPPY_COMPRESSION, SNAPPY_COMPRESSION, SNAPPY_COMPRESSION, SNAPPY_COMPRESSION]The compression algorithms for different levels of RocksDB, allowed values are none/snappy/z/bzip2/lz4/lz4hc/xpress/zstd.
rocksdb.delayed_write_rate16777216The rate limit in bytes/s of user write requests when need to slow down if the compaction gets behind.
rocksdb.log_levelINFOThe info log level of RocksDB.
rocksdb.max_background_jobs8Maximum number of concurrent background jobs, including flushes and compactions.
rocksdb.level_compaction_dynamic_level_bytesfalseWhether to enable level_compaction_dynamic_level_bytes, if it’s enabled we give max_bytes_for_level_multiplier a priority against max_bytes_for_level_base, the bytes of base level is dynamic for a more predictable LSM tree, it is useful to limit worse case space amplification. Turning this feature on/off for an existing DB can cause unexpected LSM tree structure so it’s not recommended.
rocksdb.max_bytes_for_level_base536870912The upper-bound of the total size of level-1 files in bytes.
rocksdb.max_bytes_for_level_multiplier10.0The ratio between the total size of level (L+1) files and the total size of level L files for all L.
rocksdb.max_open_files-1The maximum number of open files that can be cached by RocksDB, -1 means no limit.
rocksdb.max_subcompactions4The value represents the maximum number of threads per compaction job.
rocksdb.max_write_buffer_number6The maximum number of write buffers that are built up in memory.
rocksdb.max_write_buffer_number_to_maintain0The total maximum number of write buffers to maintain in memory.
rocksdb.min_write_buffer_number_to_merge2The minimum number of write buffers that will be merged together.
rocksdb.num_levels7Set the number of levels for this database.
rocksdb.optimize_filters_for_hitsfalseThis flag allows us to not store filters for the last level.
rocksdb.optimize_modetrueOptimize for heavy workloads and big datasets.
rocksdb.pin_l0_filter_and_index_blocks_in_cachefalseIndicating if we’d put index/filter blocks to the block cache.
rocksdb.sst_pathThe path for ingesting SST file into RocksDB.
rocksdb.target_file_size_base67108864The target file size for compaction in bytes.
rocksdb.target_file_size_multiplier1The size ratio between a level L file and a level (L+1) file.
rocksdb.use_direct_io_for_flush_and_compactionfalseEnable the OS to use direct read/writes in flush and compaction.
rocksdb.use_direct_readsfalseEnable the OS to use direct I/O for reading sst tables.
rocksdb.write_buffer_size134217728Amount of data in bytes to build up in memory.
rocksdb.max_manifest_file_size104857600The max size of manifest file in bytes.
rocksdb.skip_stats_update_on_db_openfalseWhether to skip statistics update when opening the database, setting this flag true allows us to not update statistics.
rocksdb.max_file_opening_threads16The max number of threads used to open files.
rocksdb.max_total_wal_size0Total size of WAL files in bytes. Once WALs exceed this size, we will start forcing the flush of column families related, 0 means no limit.
rocksdb.db_write_buffer_size0Total size of write buffers in bytes across all column families, 0 means no limit.
rocksdb.delete_obsolete_files_period21600The periodicity in seconds when obsolete files get deleted, 0 means always do full purge.
rocksdb.hard_pending_compaction_bytes_limit274877906944The hard limit to impose on pending compaction in bytes.
rocksdb.level0_file_num_compaction_trigger2Number of files to trigger level-0 compaction.
rocksdb.level0_slowdown_writes_trigger20Soft limit on number of level-0 files for slowing down writes.
rocksdb.level0_stop_writes_trigger36Hard limit on number of level-0 files for stopping writes.
rocksdb.soft_pending_compaction_bytes_limit68719476736The soft limit to impose on pending compaction in bytes.
K8s Config Options (Optional)

Corresponding configuration file rest-server.properties

config optiondefault valuedescription
server.use_k8sfalseWhether to enable K8s multi-tenancy mode.
k8s.namespacehugegraph-computer-systemK8s namespace for compute jobs.
k8s.kubeconfigPath to kubeconfig file.
Arthas Diagnostic Config Options (Optional)

Corresponding configuration file rest-server.properties

config optiondefault valuedescription
arthas.telnetPort8562Arthas telnet port.
arthas.httpPort8561Arthas HTTP port.
arthas.ip0.0.0.0Arthas bind IP.
arthas.disabledCommandsjadDisabled Arthas commands, separated by commas.
HBase Backend Config Options
config optiondefault valuedescription
backendMust be set to hbase.
serializerMust be set to hbase.
hbase.hostslocalhostThe hostnames or ip addresses of HBase zookeeper, separated with commas.
hbase.port2181The port address of HBase zookeeper.
hbase.threads_max64The max threads num of hbase connections.
hbase.znode_parent/hbaseThe znode parent path of HBase zookeeper.
hbase.zk_retry3The recovery retry times of HBase zookeeper.
hbase.aggregation_timeout43200The timeout in seconds of waiting for aggregation.
hbase.kerberos_enablefalseIs Kerberos authentication enabled for HBase.
hbase.kerberos_keytabThe HBase’s key tab file for kerberos authentication.
hbase.kerberos_principalThe HBase’s principal for kerberos authentication.
hbase.krb5_confetc/krb5.confKerberos configuration file, including KDC IP, default realm, etc.
hbase.hbase_site/etc/hbase/conf/hbase-site.xmlThe HBase’s configuration file
hbase.enable_partitiontrueIs pre-split partitions enabled for HBase.
hbase.vertex_partitions10The number of partitions of the HBase vertex table.
hbase.edge_partitions30The number of partitions of the HBase edge table.

≤ 1.5 Version Config (Legacy)

The following backend stores are no longer supported in version 1.7.0+ and are only available in version 1.5.x and earlier:

Cassandra Backend Config Options
config optiondefault valuedescription
backendMust be set to cassandra.
serializerMust be set to cassandra.
cassandra.hostlocalhostThe seeds hostname or ip address of cassandra cluster.
cassandra.port9042The seeds port address of cassandra cluster.
cassandra.connect_timeout5The cassandra driver connect server timeout(seconds).
cassandra.read_timeout20The cassandra driver read from server timeout(seconds).
cassandra.keyspace.strategySimpleStrategyThe replication strategy of keyspace, valid value is SimpleStrategy or NetworkTopologyStrategy.
cassandra.keyspace.replication[3]The keyspace replication factor of SimpleStrategy, like ‘[3]’.Or replicas in each datacenter of NetworkTopologyStrategy, like ‘[dc1:2,dc2:1]’.
cassandra.usernameThe username to use to login to cassandra cluster.
cassandra.passwordThe password corresponding to cassandra.username.
cassandra.compression_typenoneThe compression algorithm of cassandra transport: none/snappy/lz4.
cassandra.jmx_port=71997199The port of JMX API service for cassandra.
cassandra.aggregation_timeout43200The timeout in seconds of waiting for aggregation.
ScyllaDB Backend Config Options
config optiondefault valuedescription
backendMust be set to scylladb.
serializerMust be set to scylladb.

Other options are consistent with the Cassandra backend.

MySQL & PostgreSQL Backend Config Options
config optiondefault valuedescription
backendMust be set to mysql.
serializerMust be set to mysql.
jdbc.drivercom.mysql.jdbc.DriverThe JDBC driver class to connect database.
jdbc.urljdbc:mysql://127.0.0.1:3306The url of database in JDBC format.
jdbc.usernamerootThe username to login database.
jdbc.password******The password corresponding to jdbc.username.
jdbc.ssl_modefalseThe SSL mode of connections with database.
jdbc.reconnect_interval3The interval(seconds) between reconnections when the database connection fails.
jdbc.reconnect_max_times3The reconnect times when the database connection fails.
jdbc.storage_engineInnoDBThe storage engine of backend store database, like InnoDB/MyISAM/RocksDB for MySQL.
jdbc.postgresql.connect_databasetemplate1The database used to connect when init store, drop store or check store exist.
PostgreSQL Backend Config Options
config optiondefault valuedescription
backendMust be set to postgresql.
serializerMust be set to postgresql.

Other options are consistent with the MySQL backend.

The driver and url of the PostgreSQL backend should be set to:

  • jdbc.driver=org.postgresql.Driver
  • jdbc.url=jdbc:postgresql://localhost:5432/

4.3 - Built-in User Authentication and Authorization Configuration and Usage in HugeGraph

Overview

To facilitate authentication usage in different user scenarios, HugeGraph currently provides built-in authorization StandardAuthenticator mode, which supports multi-user authentication and fine-grained access control. It adopts a 4-layer design based on “User-UserGroup-Operation-Resource” to flexibly control user roles and permissions (supports multiple GraphServers).

Some key designs of the StandardAuthenticator mode include:

  • During initialization, a super administrator (admin) user is created. Subsequently, other users can be created by the super administrator. Once newly created users are assigned sufficient permissions, they can create or manage more users.
  • It supports dynamic creation of users, user groups, and resources, as well as dynamic allocation or revocation of permissions.
  • Users can belong to one or multiple user groups. Each user group can have permissions to operate on any number of resources. The types of operations include read, write, delete, execute, and others.
  • “Resource” describes the data in the graph database, such as vertices that meet certain criteria. Each resource consists of three elements: type, label, and properties. There are 18 types in total, with the ability to combine any label and properties. The internal condition of a resource is an AND relationship, while the condition between multiple resources is an OR relationship.

Here is an example to illustrate:

// Scenario: A user only has data read permission for the Beijing area
user(name=xx) -belong-> group(name=xx) -access(read)-> target(graph=graph1, resource={label: person, city: Beijing})

Configure User Authentication

By default, HugeGraph does not enable user authentication, and it needs to be enabled by modifying the configuration file.

Because the flexibility of graph query languages can introduce potential system security risks, do not expose Gremlin, Cypher, or other query endpoints directly to the public network. In production, enable authentication, an IP allowlist, and audit logging, and isolate the Server process with Docker or Kubernetes.

You need to modify the configuration file to enable this feature. HugeGraph provides built-in authentication mode: StandardAuthenticator. This mode supports multi-user authentication and fine-grained permission control. Additionally, developers can implement their own HugeAuthenticator interface to integrate with their existing authentication systems.

HugeGraph uses HTTP Basic Authentication. The value after Basic is the Base64 encoding of username:password. With curl, pass the credentials directly through -u:

curl -u 'admin:<password>' \
  http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/vertexlabels

Warning: Versions of HugeGraph-Server prior to 1.5.0 have a JWT-related security vulnerability in the Auth mode. Users are advised to update to a newer version or manually set the JWT token’s secretKey. It can be set in the rest-server.properties file by setting the auth.token_secret information:

auth.token_secret=XXXX   # should be a 32-chars string, consist of A-Z, a-z and 0-9

You can also generate it with the following command:

RANDOM_STRING=$(head /dev/urandom | tr -dc A-Za-z0-9 | head -c 32)
echo "auth.token_secret=${RANDOM_STRING}" >> rest-server.properties

StandardAuthenticator Mode

The StandardAuthenticator mode supports user authentication and permission control by storing user information in the database backend. This implementation authenticates users based on their names and passwords (encrypted) stored in the database and controls user permissions based on their roles. Below is the specific configuration process (requires service restart):

Configure the authenticator and its rest-server file path in the gremlin-server.yaml configuration file:

authentication: {
  authenticator: org.apache.hugegraph.auth.StandardAuthenticator,
  authenticationHandler: org.apache.hugegraph.auth.WsAndHttpBasicAuthHandler,
  config: {tokens: conf/rest-server.properties}
}

Configure the authenticator and the graph that stores authorization data in rest-server.properties:

auth.authenticator=org.apache.hugegraph.auth.StandardAuthenticator
auth.graph_store=hugegraph
# The initial admin password can be set when the admin user is first created in PD mode
#auth.admin_pa=<your-admin-password>

# Auth Client Config
# If GraphServer and AuthServer are deployed separately, you also need to specify the following configuration. Fill in the IP:RPC port of AuthServer.
# auth.remote_url=127.0.0.1:8899,127.0.0.1:8898,127.0.0.1:8897

In the above configuration, the graph_store option specifies which graph to use for storing user information. If there are multiple graphs, you can choose any of them.

In the hugegraph{n}.properties configuration file, configure the gremlin.graph information:

gremlin.graph=org.apache.hugegraph.auth.HugeFactoryAuthProxy

For authorization API usage, see the Authentication API documentation.

Custom User Authentication System

If you need to support a more flexible user system, you can customize the authenticator for extension. Simply implement the org.apache.hugegraph.auth.HugeAuthenticator interface with your custom authenticator, and then modify the authenticator configuration item in the configuration file to point to your implementation.

Switching authentication mode

When init-store.sh is run for the first time and the admin user does not yet exist, the command prompts for the administrator password. For an initialized persistent backend, init-store.sh adds the system metadata required for authentication without deleting existing graph data.

# stop the hugeGraph firstly
bin/stop-hugegraph.sh

# Initialize authentication system metadata; existing backend data is preserved
bin/init-store.sh

# start hugeGraph again
bin/start-hugegraph.sh

Use docker to enable authentication mode

For versions of the hugegraph/hugegraph image equal to or greater than 1.2.0, you can enable authentication mode while starting the Docker image.

The steps are as follows:

1. Use docker run

To enable authentication mode, add the environment variable PASSWORD=xxx (you can freely set the password) in the docker run command:

docker run -itd -e PASSWORD=xxx --name=server -p 8080:8080 hugegraph/hugegraph:1.7.0

2. Use docker-compose

Use docker-compose and set the environment variable PASSWORD=xxx:

version: '3'
services:
  server:
    image: hugegraph/hugegraph:1.7.0
    container_name: server
    ports:
      - 8080:8080
    environment:
      - PASSWORD=xxx

3. Enter the container to enable authentication mode

Enter the container first:

docker exec -it server bash
# Modify the config quickly, the modified file are save in the conf-bak folder
bin/enable-auth.sh

Then follow Switching authentication mode

4.4 - Configuring HugeGraphServer to Use HTTPS Protocol

Overview

By default, HugeGraphServer uses the HTTP protocol. However, if you have security requirements for your requests, you can configure it to use HTTPS.

Server Configuration

Modify the conf/rest-server.properties configuration file and change the schema part of restserver.url to https.

# Set the protocol to HTTPS
restserver.url=https://127.0.0.1:8080
# Server keystore file path. This default value is automatically effective when using HTTPS, and you can modify it as needed.
ssl.keystore_file=conf/hugegraph-server.keystore
# Server keystore file password. This default value is automatically effective when using HTTPS, and you can modify it as needed.
ssl.keystore_password=******

The server’s conf directory already includes a keystore file named hugegraph-server.keystore, and the password for this file is hugegraph. These are the default values when enabling the HTTPS protocol. Users can generate their own keystore file and password, and then modify the values of ssl.keystore_file and ssl.keystore_password.

Client Configuration

Using HTTPS in HugeGraph-Client

When constructing a HugeClient, pass the HTTPS-related configurations. Here’s an example in Java:

String url = "https://localhost:8080";
String graphName = "hugegraph";
HugeClientBuilder builder = HugeClient.builder(url, graphName);
// Client keystore file path
String trustStoreFilePath = "hugegraph.truststore";
// Client keystore password
String trustStorePassword = "******";
builder.configSSL(trustStoreFilePath, trustStorePassword);
HugeClient hugeClient = builder.build();

Note: Before version 1.9.0, HugeGraph-Client was created directly using the new keyword and did not support the HTTPS protocol. Starting from version 1.9.0, it changed to use the builder pattern and supports configuring the HTTPS protocol.

Using HTTPS in HugeGraph-Loader

When starting an import task, add the following options in the command line:

# HTTPS
--protocol https
# Client certificate file path. When specifying --protocol as https, the default value conf/hugegraph.truststore is automatically used, and you can modify it as needed.
--trust-store-file {file}
# Client certificate file password. When specifying --protocol as https, the default value hugegraph is automatically used, and you can modify it as needed.
--trust-store-password {password}

Under the conf directory of hugegraph-loader, there is already a default client certificate file named hugegraph.truststore, and its password is hugegraph.

Using HTTPS in HugeGraph-Tools

When executing commands, add the following options in the command line:

# Client certificate file path. When using the HTTPS protocol in the URL, the default value conf/hugegraph.truststore is automatically used, and you can modify it as needed.
--trust-store-file {file}
# Client certificate file password. When using the HTTPS protocol in the URL, the default value hugegraph is automatically used, and you can modify it as needed.
--trust-store-password {password}
# When executing migration commands and using the --target-url with the HTTPS protocol, the default value conf/hugegraph.truststore is automatically used, and you can modify it as needed.
--target-trust-store-file {target-file}
# When executing migration commands and using the --target-url with the HTTPS protocol, the default value hugegraph is automatically used, and you can modify it as needed.
--target-trust-store-password {target-password}

Under the conf directory of hugegraph-tools, there is already a default client certificate file named hugegraph.truststore, and its password is hugegraph.

How to Generate Certificate Files

This section provides an example of generating certificates. If the default certificate is sufficient or if you already know how to generate certificates, you can skip this section.

Server

  1. Generate the server’s private key and import it into the server’s keystore file. The server.keystore is for the server’s use and contains its private key.
keytool -genkey -alias serverkey -keyalg RSA -keystore server.keystore

During the process, fill in the description information according to your requirements. The description information for the default certificate is as follows:

First and Last Name: hugegraph
Organizational Unit Name: hugegraph
Organization Name: hugegraph
City or Locality Name: BJ
State or Province Name: BJ
Country Code: CN
  1. Export the server certificate based on the server’s private key.
keytool -export -alias serverkey -keystore server.keystore -file server.crt

server.crt is the server’s certificate.

Client

keytool -import -alias serverkey -file server.crt -keystore client.truststore

client.truststore is for the client’s use and contains the trusted certificate.

4.5 - HugeGraph-Computer Config

Computer Config Options

config optiondefault valuedescription
algorithm.message_classorg.apache.hugegraph.computer.core.config.NullThe class of message passed when compute vertex.
algorithm.params_classorg.apache.hugegraph.computer.core.config.NullThe class used to transfer algorithms’ parameters before algorithm been run.
algorithm.result_classorg.apache.hugegraph.computer.core.config.NullThe class of vertex’s value, the instance is used to store computation result for the vertex.
allocator.max_vertices_per_thread10000Maximum number of vertices per thread processed in each memory allocator
bsp.etcd_endpointshttp://localhost:2379The end points to access etcd.
bsp.log_interval30000The log interval(in ms) to print the log while waiting bsp event.
bsp.max_super_step10The max super step of the algorithm.
bsp.register_timeout300000The max timeout to wait for master and works to register.
bsp.wait_master_timeout86400000The max timeout(in ms) to wait for master bsp event.
bsp.wait_workers_timeout86400000The max timeout to wait for workers bsp event.
hgkv.max_data_block_size65536The max byte size of hgkv-file data block.
hgkv.max_file_size2147483648The max number of bytes in each hgkv-file.
hgkv.max_merge_files10The max number of files to merge at one time.
hgkv.temp_file_dir/tmp/hgkvThis folder is used to store temporary files, temporary files will be generated during the file merging process.
hugegraph.namehugegraphThe graph name to load data and write results back.
hugegraph.urlhttp://127.0.0.1:8080The hugegraph url to load data and write results back.
input.edge_directionOUTThe data of the edge in which direction is loaded, when the value is BOTH, the edges in both OUT and IN direction will be loaded.
input.edge_freqMULTIPLEThe frequency of edges can exist between a pair of vertices, allowed values: [SINGLE, SINGLE_PER_LABEL, MULTIPLE]. SINGLE means that only one edge can exist between a pair of vertices, use sourceId + targetId to identify it; SINGLE_PER_LABEL means that each edge label can exist one edge between a pair of vertices, use sourceId + edgelabel + targetId to identify it; MULTIPLE means that many edge can exist between a pair of vertices, use sourceId + edgelabel + sortValues + targetId to identify it.
input.filter_classorg.apache.hugegraph.computer.core.input.filter.DefaultInputFilterThe class to create input-filter object, input-filter is used to Filter vertex edges according to user needs.
input.loader_schema_pathThe schema path of loader input, only takes effect when the input.source_type=loader is enabled
input.loader_struct_pathThe struct path of loader input, only takes effect when the input.source_type=loader is enabled
input.max_edges_in_one_vertex200The maximum number of adjacent edges allowed to be attached to a vertex, the adjacent edges will be stored and transferred together as a batch unit.
input.source_typehugegraph-serverThe source type to load input data, allowed values: [‘hugegraph-server’, ‘hugegraph-loader’], the ‘hugegraph-loader’ means use hugegraph-loader load data from HDFS or file, if use ‘hugegraph-loader’ load data then please config ‘input.loader_struct_path’ and ‘input.loader_schema_path’.
input.split_fetch_timeout300The timeout in seconds to fetch input splits
input.split_max_splits10000000The maximum number of input splits
input.split_page_size500The page size for streamed load input split data
input.split_size1048576The input split size in bytes
job.idlocal_0001The job id on Yarn cluster or K8s cluster.
job.partitions_count1The partitions count for computing one graph algorithm job.
job.partitions_thread_nums4The number of threads for partition parallel compute.
job.workers_count1The workers count for computing one graph algorithm job.
master.computation_classorg.apache.hugegraph.computer.core.master.DefaultMasterComputationMaster-computation is computation that can determine whether to continue next superstep. It runs at the end of each superstep on master.
output.batch_size500The batch size of output
output.batch_threads1The threads number used to batch output
output.hdfs_core_site_pathThe hdfs core site path.
output.hdfs_delimiter,The delimiter of hdfs output.
output.hdfs_kerberos_enablefalseIs Kerberos authentication enabled for Hdfs.
output.hdfs_kerberos_keytabThe Hdfs’s key tab file for kerberos authentication.
output.hdfs_kerberos_principalThe Hdfs’s principal for kerberos authentication.
output.hdfs_krb5_conf/etc/krb5.confKerberos configuration file.
output.hdfs_merge_partitionstrueWhether merge output files of multiple partitions.
output.hdfs_path_prefix/hugegraph-computer/resultsThe directory of hdfs output result.
output.hdfs_replication3The replication number of hdfs.
output.hdfs_site_pathThe hdfs site path.
output.hdfs_urlhdfs://127.0.0.1:9000The hdfs url of output.
output.hdfs_userhadoopThe hdfs user of output.
output.output_classorg.apache.hugegraph.computer.core.output.LogOutputThe class to output the computation result of each vertex. Be called after iteration computation.
output.result_namevalueThe value is assigned dynamically by #name() of instance created by WORKER_COMPUTATION_CLASS.
output.result_write_typeOLAP_COMMONThe result write-type to output to hugegraph, allowed values are: [OLAP_COMMON, OLAP_SECONDARY, OLAP_RANGE].
output.retry_interval10The retry interval when output failed
output.retry_times3The retry times when output failed
output.single_threads1The threads number used to single output
output.thread_pool_shutdown_timeout60The timeout seconds of output threads pool shutdown
output.with_adjacent_edgesfalseOutput the adjacent edges of the vertex or not
output.with_edge_propertiesfalseOutput the properties of the edge or not
output.with_vertex_propertiesfalseOutput the properties of the vertex or not
sort.thread_nums4The number of threads performing internal sorting.
transport.client_connect_timeout3000The timeout(in ms) of client connect to server.
transport.client_threads4The number of transport threads for client.
transport.close_timeout10000The timeout(in ms) of close server or close client.
transport.finish_session_timeout0The timeout(in ms) to finish session, 0 means using (transport.sync_request_timeout * transport.max_pending_requests).
transport.heartbeat_interval20000The minimum interval(in ms) between heartbeats on client side.
transport.io_modeAUTOThe network IO Mode, either ‘NIO’, ‘EPOLL’, ‘AUTO’, the ‘AUTO’ means selecting the property mode automatically.
transport.max_pending_requests8The max number of client unreceived ack, it will trigger the sending unavailable if the number of unreceived ack >= max_pending_requests.
transport.max_syn_backlog511The capacity of SYN queue on server side, 0 means using system default value.
transport.max_timeout_heartbeat_count120The maximum times of timeout heartbeat on client side, if the number of timeouts waiting for heartbeat response continuously > max_heartbeat_timeouts the channel will be closed from client side.
transport.min_ack_interval200The minimum interval(in ms) of server reply ack.
transport.min_pending_requests6The minimum number of client unreceived ack, it will trigger the sending available if the number of unreceived ack < min_pending_requests.
transport.network_retries3The number of retry attempts for network communication,if network unstable.
transport.provider_classorg.apache.hugegraph.computer.core.network.netty.NettyTransportProviderThe transport provider, currently only supports Netty.
transport.receive_buffer_size0The size of socket receive-buffer in bytes, 0 means using system default value.
transport.recv_file_modetrueWhether enable receive buffer-file mode, it will receive buffer write file from socket by zero-copy if enable.
transport.send_buffer_size0The size of socket send-buffer in bytes, 0 means using system default value.
transport.server_host127.0.0.1The server hostname or ip to listen on to transfer data.
transport.server_idle_timeout360000The max timeout(in ms) of server idle.
transport.server_port0The server port to listen on to transfer data. The system will assign a random port if it’s set to 0.
transport.server_threads4The number of transport threads for server.
transport.sync_request_timeout10000The timeout(in ms) to wait response after sending sync-request.
transport.tcp_keep_alivetrueWhether enable TCP keep-alive.
transport.transport_epoll_ltfalseWhether enable EPOLL level-trigger.
transport.write_buffer_high_mark67108864The high water mark for write buffer in bytes, it will trigger the sending unavailable if the number of queued bytes > write_buffer_high_mark.
transport.write_buffer_low_mark33554432The low water mark for write buffer in bytes, it will trigger the sending available if the number of queued bytes < write_buffer_low_mark.org.apache.hugegraph.config.OptionChecker$$Lambda$97/0x00000008001c8440@776a6d9b
transport.write_socket_timeout3000The timeout(in ms) to write data to socket buffer.
valuefile.max_segment_size1073741824The max number of bytes in each segment of value-file.
worker.combiner_classorg.apache.hugegraph.computer.core.config.NullCombiner can combine messages into one value for a vertex, for example page-rank algorithm can combine messages of a vertex to a sum value.
worker.computation_classorg.apache.hugegraph.computer.core.config.NullThe class to create worker-computation object, worker-computation is used to compute each vertex in each superstep.
worker.data_dirs[jobs]The directories separated by ‘,’ that received vertices and messages can persist into.
worker.edge_properties_combiner_classorg.apache.hugegraph.computer.core.combiner.OverwritePropertiesCombinerThe combiner can combine several properties of the same edge into one properties at inputstep.
worker.partitionerorg.apache.hugegraph.computer.core.graph.partition.HashPartitionerThe partitioner that decides which partition a vertex should be in, and which worker a partition should be in.
worker.received_buffers_bytes_limit104857600The limit bytes of buffers of received data, the total size of all buffers can’t excess this limit. If received buffers reach this limit, they will be merged into a file.
worker.vertex_properties_combiner_classorg.apache.hugegraph.computer.core.combiner.OverwritePropertiesCombinerThe combiner can combine several properties of the same vertex into one properties at inputstep.
worker.wait_finish_messages_timeout86400000The max timeout(in ms) message-handler wait for finish-message of all workers.
worker.wait_sort_timeout600000The max timeout(in ms) message-handler wait for sort-thread to sort one batch of buffers.
worker.write_buffer_capacity52428800The initial size of write buffer that used to store vertex or message.
worker.write_buffer_threshold52428800The threshold of write buffer, exceeding it will trigger sorting, the write buffer is used to store vertex or message.

K8s Operator Config Options

NOTE: Option needs to be converted through environment variable settings, e.g. k8s.internal_etcd_url => INTERNAL_ETCD_URL

config optiondefault valuedescription
k8s.auto_destroy_podtrueWhether to automatically destroy all pods when the job is completed or failed.
k8s.close_reconciler_timeout120The max timeout(in ms) to close reconciler.
k8s.internal_etcd_urlhttp://127.0.0.1:2379The internal etcd url for operator system.
k8s.max_reconcile_retry3The max retry times of reconcile.
k8s.probe_backlog50The maximum backlog for serving health probes.
k8s.probe_port9892The value is the port that the controller bind to for serving health probes.
k8s.ready_check_internal1000The time interval(ms) of check ready.
k8s.ready_timeout30000The max timeout(in ms) of check ready.
k8s.reconciler_count10The max number of reconciler thread.
k8s.resync_period600000The minimum frequency at which watched resources are reconciled.
k8s.timezoneAsia/ShanghaiThe timezone of computer job and operator.
k8s.watch_namespacehugegraph-computer-systemThe value is watch custom resources in the namespace, ignore other namespaces, the ‘*’ means is all namespaces will be watched.

HugeGraph-Computer CRD

CRD: https://github.com/apache/hugegraph-computer/blob/master/computer-k8s-operator/manifest/hugegraph-computer-crd.v1.yaml

specdefault valuedescriptionrequired
algorithmNameThe name of algorithm.true
jobIdThe job id.true
imageThe image of algorithm.true
computerConfThe map of computer config options.true
workerInstancesThe number of worker instances, it will instead the ‘job.workers_count’ option.true
pullPolicyAlwaysThe pull-policy of image, detail please refer to: https://kubernetes.io/docs/concepts/containers/images/#image-pull-policyfalse
pullSecretsThe pull-secrets of Image, detail please refer to: https://kubernetes.io/docs/concepts/containers/images/#specifying-imagepullsecrets-on-a-podfalse
masterCpuThe cpu limit of master, the unit can be ’m’ or without unit detail please refer to:https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#meaning-of-cpufalse
workerCpuThe cpu limit of worker, the unit can be ’m’ or without unit detail please refer to:https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#meaning-of-cpufalse
masterMemoryThe memory limit of master, the unit can be one of Ei、Pi、Ti、Gi、Mi、Ki detail please refer to:https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#meaning-of-memoryfalse
workerMemoryThe memory limit of worker, the unit can be one of Ei、Pi、Ti、Gi、Mi、Ki detail please refer to:https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#meaning-of-memoryfalse
log4jXmlThe content of log4j.xml for computer job.false
jarFileThe jar path of computer algorithm.false
remoteJarUriThe remote jar uri of computer algorithm, it will overlay algorithm image.false
jvmOptionsThe java startup parameters of computer job.false
envVarsplease refer to: https://kubernetes.io/docs/tasks/inject-data-application/define-interdependent-environment-variables/false
envFromplease refer to: https://kubernetes.io/docs/tasks/inject-data-application/define-environment-variable-container/false
masterCommandbin/start-computer.shThe run command of master, equivalent to ‘Entrypoint’ field of Docker.false
masterArgs["-r master", “-d k8s”]The run args of master, equivalent to ‘Cmd’ field of Docker.false
workerCommandbin/start-computer.shThe run command of worker, equivalent to ‘Entrypoint’ field of Docker.false
workerArgs["-r worker", “-d k8s”]The run args of worker, equivalent to ‘Cmd’ field of Docker.false
volumesPlease refer to: https://kubernetes.io/docs/concepts/storage/volumes/false
volumeMountsPlease refer to: https://kubernetes.io/docs/concepts/storage/volumes/false
secretPathsThe map of k8s-secret name and mount path.false
configMapPathsThe map of k8s-configmap name and mount path.false
podTemplateSpecPlease refer to: https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-template-v1/#PodTemplateSpecfalse
securityContextPlease refer to: https://kubernetes.io/docs/tasks/configure-pod-container/security-context/false

KubeDriver Config Options

config optiondefault valuedescription
k8s.build_image_bash_pathThe path of command used to build image.
k8s.enable_internal_algorithmtrueWhether enable internal algorithm.
k8s.framework_image_urlhugegraph/hugegraph-computer:latestThe image url of computer framework.
k8s.image_repository_passwordThe password for login image repository.
k8s.image_repository_registryThe address for login image repository.
k8s.image_repository_urlhugegraph/hugegraph-computerThe url of image repository.
k8s.image_repository_usernameThe username for login image repository.
k8s.internal_algorithm[pageRank]The name list of all internal algorithm.
k8s.internal_algorithm_image_urlhugegraph/hugegraph-computer:latestThe image url of internal algorithm.
k8s.jar_file_dir/cache/jars/The directory where the algorithm jar to upload location.
k8s.kube_config~/.kube/configThe path of k8s config file.
k8s.log4j_xml_pathThe log4j.xml path for computer job.
k8s.namespacehugegraph-computer-systemThe namespace of hugegraph-computer system.
k8s.pull_secret_names[]The names of pull-secret for pulling image.

5 - Clients and APIs

This section covers the REST API, Gremlin Console, and client libraries. The current Server REST API identifies graph resources with both a graph space and a graph name. Refer to each API page and the Server OpenAPI page for the exact paths.

5.1 - HugeGraph RESTful API

⚠️ Version compatibility notes

  • Current graph resource paths begin with /graphspaces/{graphspace}/graphs/{graph}.
  • HugeGraph 1.5.x and earlier use /graphs/{graph}. The request formats of APIs such as graph creation and cloning also differ from the current version.
  • The default graph space is DEFAULT.
  • See the HugeGraph 1.5.x RESTful API documentation for older versions.

After starting Server, open http://localhost:8080/swagger-ui/index.html to view the OpenAPI page for the current version. See the usage example.

5.1.1 - Graphspace API

2.0 Graphspace

HugeGraph implements multi-tenancy through graph spaces, which isolate compute/storage resources per tenant.

Prerequisites

  1. Graphspace currently only works in HStore mode.
  2. In non-HStore mode you can only use the default graphspace DEFAULT; creating/deleting/updating other graphspaces is not supported.
  3. Set usePD=true in rest-server.properties and backend=hstore in hugegraph.properties.
  4. Graphspace enables strict authentication by default (default credential: admin:pa). Change the password immediately to avoid unauthorized access.

2.0.1 Create a graphspace

Method & Url
POST http://localhost:8080/graphspaces
Request Body

Note: CPU/memory and Kubernetes-related capabilities are not publicly available yet.

NameRequiredTypeDefaultRange/NoteDescription
nameYesStringLowercase letters, digits, underscore; must start with a letter; max length 48Graphspace name
descriptionYesStringDescription
cpu_limitYesInt> 0CPU cores for the graphspace
memory_limitYesInt> 0 (GB)Memory quota in GB
storage_limitYesInt> 0Maximum disk usage
compute_cpu_limitNoInt0>= 0Extra HugeGraph-Computer CPU cores; falls back to cpu_limit if unset or 0
compute_memory_limitNoInt0>= 0Extra HugeGraph-Computer memory in GB; falls back to memory_limit if unset or 0
oltp_namespaceYesStringKubernetes namespace for OLTP HugeGraph-Server
olap_namespaceYesStringResources are merged when identical to oltp_namespaceKubernetes namespace for OLAP / HugeGraph-Computer
storage_namespaceYesStringKubernetes namespace for HugeGraph-Store
operator_image_pathNoStringHugeGraph-Computer operator image registry
internal_algorithm_image_urlNoStringHugeGraph-Computer algorithm image registry
max_graph_numberYesInt> 0Maximum number of graphs that can be created inside the graphspace
max_role_numberYesInt> 0Maximum number of roles that can be created inside the graphspace
authNoBooleanfalsetrue / falseWhether to enable authentication for the graphspace
configsNoMapAdditional configuration
{
  "name": "gs1",
  "description": "1st graph space",
  "max_graph_number": 100,
  "cpu_limit": 1000,
  "memory_limit": 8192,
  "storage_limit": 1000000,
  "max_role_number": 10,
  "auth": true,
  "configs": {}
}
Response Status
201
Response Body
{
  "name": "gs1",
  "description": "1st graph space",
  "cpu_limit": 1000,
  "memory_limit": 8192,
  "storage_limit": 1000000,
  "compute_cpu_limit": 0,
  "compute_memory_limit": 0,
  "oltp_namespace": "hugegraph-server",
  "olap_namespace": "hugegraph-server",
  "storage_namespace": "hugegraph-server",
  "operator_image_path": "127.0.0.1/hugegraph-registry/hugegraph-computer-operator:3.1.1",
  "internal_algorithm_image_url": "127.0.0.1/hugegraph-registry/hugegraph-computer-algorithm:3.1.1",
  "max_graph_number": 100,
  "max_role_number": 10,
  "cpu_used": 0,
  "memory_used": 0,
  "storage_used": 0,
  "graph_number_used": 0,
  "role_number_used": 0,
  "auth": true
}

2.0.2 List all graphspaces

Method & Url
GET http://localhost:8080/graphspaces
Response Status
200
Response Body
{
  "graphSpaces": [
    "gs1",
    "DEFAULT"
  ]
}

2.0.3 Get graphspace details

Params

Path parameters

  • graphspace: Graphspace name
Method & Url
GET http://localhost:8080/graphspaces/gs1
Response Status
200
Response Body
{
  "name": "gs1",
  "description": "1st graph space",
  "cpu_limit": 1000,
  "memory_limit": 8192,
  "storage_limit": 1000000,
  "oltp_namespace": "hugegraph-server",
  "olap_namespace": "hugegraph-server",
  "storage_namespace": "hugegraph-server",
  "operator_image_path": "127.0.0.1/hugegraph-registry/hugegraph-computer-operator:3.1.1",
  "internal_algorithm_image_url": "127.0.0.1/hugegraph-registry/hugegraph-computer-algorithm:3.1.1",
  "compute_cpu_limit": 0,
  "compute_memory_limit": 0,
  "max_graph_number": 100,
  "max_role_number": 10,
  "cpu_used": 0,
  "memory_used": 0,
  "storage_used": 0,
  "graph_number_used": 0,
  "role_number_used": 0,
  "auth": true
}

2.0.4 Update a graphspace

auth cannot be changed once a graphspace is created.

Params

Path parameter

  • graphspace: Graphspace name

Request parameters

  • action: Must be "update"
  • update: Container for the actual fields to update (see table below)
NameRequiredTypeRange/NoteDescription
nameYesStringGraphspace name
descriptionYesStringDescription
cpu_limitYesInt> 0CPU cores for OLTP HugeGraph-Server
memory_limitYesInt> 0 (GB)Memory quota (GB) for OLTP HugeGraph-Server
storage_limitYesInt> 0Maximum disk usage
compute_cpu_limitNoInt>= 0Extra HugeGraph-Computer CPU cores; falls back to cpu_limit if unset or 0
compute_memory_limitNoInt>= 0Extra HugeGraph-Computer memory in GB; falls back to memory_limit if unset or 0
oltp_namespaceYesStringKubernetes namespace for OLTP HugeGraph-Server
olap_namespaceYesStringResources are merged when identical to oltp_namespaceKubernetes namespace for OLAP
storage_namespaceYesStringKubernetes namespace for HugeGraph-Store
operator_image_pathNoStringHugeGraph-Computer operator image registry
internal_algorithm_image_urlNoStringHugeGraph-Computer algorithm image registry
max_graph_numberYesInt> 0Maximum number of graphs
max_role_numberYesInt> 0Maximum number of roles
Method & Url
PUT http://localhost:8080/graphspaces/gs1
Request Body
{
  "action": "update",
  "update": {
    "name": "gs1",
    "description": "1st graph space",
    "cpu_limit": 2000,
    "memory_limit": 40960,
    "storage_limit": 2048,
    "oltp_namespace": "hugegraph-server",
    "olap_namespace": "hugegraph-server",
    "operator_image_path": "127.0.0.1/hugegraph-registry/hugegraph-computer-operator:3.1.1",
    "internal_algorithm_image_url": "127.0.0.1/hugegraph-registry/hugegraph-computer-algorithm:3.1.1",
    "max_graph_number": 1000,
    "max_role_number": 100
  }
}
Response Status
200
Response Body
{
  "name": "gs1",
  "description": "1st graph space",
  "cpu_limit": 2000,
  "memory_limit": 40960,
  "storage_limit": 2048,
  "oltp_namespace": "hugegraph-server",
  "olap_namespace": "hugegraph-server",
  "storage_namespace": "hugegraph-server",
  "operator_image_path": "127.0.0.1/hugegraph-registry/hugegraph-computer-operator:3.1.1",
  "internal_algorithm_image_url": "127.0.0.1/hugegraph-registry/hugegraph-computer-algorithm:3.1.1",
  "compute_cpu_limit": 0,
  "compute_memory_limit": 0,
  "max_graph_number": 1000,
  "max_role_number": 100,
  "cpu_used": 0,
  "memory_used": 0,
  "storage_used": 0,
  "graph_number_used": 0,
  "role_number_used": 0,
  "auth": true
}

2.0.5 Delete a graphspace

Params

Path parameter

  • graphspace: Graphspace name
Method & Url
DELETE http://localhost:8080/graphspaces/gs1
Response Status
204

Warning: deleting a graphspace releases all resources that belong to it.

5.1.2 - Schema API

1.1 Schema

HugeGraph provides a single interface to get all Schema information of a graph, including: PropertyKey, VertexLabel, EdgeLabel and IndexLabel.

Method & Url
GET http://localhost:8080/graphspaces/{graphspace}/graphs/{graph_name}/schema

e.g: GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema
Response Status
200
Response Body
{
    "propertykeys": [
        {
            "id": 7,
            "name": "price",
            "data_type": "DOUBLE",
            "cardinality": "SINGLE",
            "aggregate_type": "NONE",
            "write_type": "OLTP",
            "properties": [],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:05.316"
            }
        },
        {
            "id": 6,
            "name": "date",
            "data_type": "TEXT",
            "cardinality": "SINGLE",
            "aggregate_type": "NONE",
            "write_type": "OLTP",
            "properties": [],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:05.309"
            }
        },
        {
            "id": 3,
            "name": "city",
            "data_type": "TEXT",
            "cardinality": "SINGLE",
            "aggregate_type": "NONE",
            "write_type": "OLTP",
            "properties": [],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:05.287"
            }
        },
        {
            "id": 2,
            "name": "age",
            "data_type": "INT",
            "cardinality": "SINGLE",
            "aggregate_type": "NONE",
            "write_type": "OLTP",
            "properties": [],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:05.280"
            }
        },
        {
            "id": 5,
            "name": "lang",
            "data_type": "TEXT",
            "cardinality": "SINGLE",
            "aggregate_type": "NONE",
            "write_type": "OLTP",
            "properties": [],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:05.301"
            }
        },
        {
            "id": 4,
            "name": "weight",
            "data_type": "DOUBLE",
            "cardinality": "SINGLE",
            "aggregate_type": "NONE",
            "write_type": "OLTP",
            "properties": [],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:05.294"
            }
        },
        {
            "id": 1,
            "name": "name",
            "data_type": "TEXT",
            "cardinality": "SINGLE",
            "aggregate_type": "NONE",
            "write_type": "OLTP",
            "properties": [],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:05.250"
            }
        }
    ],
    "vertexlabels": [
        {
            "id": 1,
            "name": "person",
            "id_strategy": "PRIMARY_KEY",
            "primary_keys": [
                "name"
            ],
            "nullable_keys": [
                "age",
                "city"
            ],
            "index_labels": [
                "personByAge",
                "personByCity",
                "personByAgeAndCity"
            ],
            "properties": [
                "name",
                "age",
                "city"
            ],
            "status": "CREATED",
            "ttl": 0,
            "enable_label_index": true,
            "user_data": {
                "~create_time": "2023-05-08 17:49:05.336"
            }
        },
        {
            "id": 2,
            "name": "software",
            "id_strategy": "CUSTOMIZE_NUMBER",
            "primary_keys": [],
            "nullable_keys": [],
            "index_labels": [
                "softwareByPrice"
            ],
            "properties": [
                "name",
                "lang",
                "price"
            ],
            "status": "CREATED",
            "ttl": 0,
            "enable_label_index": true,
            "user_data": {
                "~create_time": "2023-05-08 17:49:05.347"
            }
        }
    ],
    "edgelabels": [
        {
            "id": 1,
            "name": "knows",
            "source_label": "person",
            "target_label": "person",
            "frequency": "SINGLE",
            "sort_keys": [],
            "nullable_keys": [],
            "index_labels": [
                "knowsByWeight"
            ],
            "properties": [
                "weight",
                "date"
            ],
            "status": "CREATED",
            "ttl": 0,
            "enable_label_index": true,
            "user_data": {
                "~create_time": "2023-05-08 17:49:08.437"
            }
        },
        {
            "id": 2,
            "name": "created",
            "source_label": "person",
            "target_label": "software",
            "frequency": "SINGLE",
            "sort_keys": [],
            "nullable_keys": [],
            "index_labels": [
                "createdByDate",
                "createdByWeight"
            ],
            "properties": [
                "weight",
                "date"
            ],
            "status": "CREATED",
            "ttl": 0,
            "enable_label_index": true,
            "user_data": {
                "~create_time": "2023-05-08 17:49:08.446"
            }
        }
    ],
    "indexlabels": [
        {
            "id": 1,
            "name": "personByAge",
            "base_type": "VERTEX_LABEL",
            "base_value": "person",
            "index_type": "RANGE_INT",
            "fields": [
                "age"
            ],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:05.375"
            }
        },
        {
            "id": 2,
            "name": "personByCity",
            "base_type": "VERTEX_LABEL",
            "base_value": "person",
            "index_type": "SECONDARY",
            "fields": [
                "city"
            ],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:06.898"
            }
        },
        {
            "id": 3,
            "name": "personByAgeAndCity",
            "base_type": "VERTEX_LABEL",
            "base_value": "person",
            "index_type": "SECONDARY",
            "fields": [
                "age",
                "city"
            ],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:07.407"
            }
        },
        {
            "id": 4,
            "name": "softwareByPrice",
            "base_type": "VERTEX_LABEL",
            "base_value": "software",
            "index_type": "RANGE_DOUBLE",
            "fields": [
                "price"
            ],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:07.916"
            }
        },
        {
            "id": 5,
            "name": "createdByDate",
            "base_type": "EDGE_LABEL",
            "base_value": "created",
            "index_type": "SECONDARY",
            "fields": [
                "date"
            ],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:08.454"
            }
        },
        {
            "id": 6,
            "name": "createdByWeight",
            "base_type": "EDGE_LABEL",
            "base_value": "created",
            "index_type": "RANGE_DOUBLE",
            "fields": [
                "weight"
            ],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:08.963"
            }
        },
        {
            "id": 7,
            "name": "knowsByWeight",
            "base_type": "EDGE_LABEL",
            "base_value": "knows",
            "index_type": "RANGE_DOUBLE",
            "fields": [
                "weight"
            ],
            "status": "CREATED",
            "user_data": {
                "~create_time": "2023-05-08 17:49:09.473"
            }
        }
    ]
}

5.1.3 - PropertyKey API

1.2 PropertyKey

Params Description:

  • name: The name of the property type, required.
  • data_type: The data type of the property type, including: bool, byte, int, long, float, double, text, blob, date, uuid. The default data type is text (Represent a string type)
  • cardinality: The cardinality of the property type, including: single, list, set. The default cardinality is single.

Request Body Field Description:

  • id: The ID value of the property type.
  • properties: The properties of the property type. For properties, this field is empty.
  • user_data: Setting the common information of the property type, such as setting the value range of the age property from 0 to 100. Currently, no validation is performed on this field, and it is only a reserved entry for future expansion.

1.2.1 Create a PropertyKey

Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/propertykeys
Request Body
{
    "name": "age",
    "data_type": "INT",
    "cardinality": "SINGLE"
}
Response Status
202
Response Body
{
    "property_key": {
        "id": 1,
        "name": "age",
        "data_type": "INT",
        "cardinality": "SINGLE",
        "aggregate_type": "NONE",
        "write_type": "OLTP",
        "properties": [],
        "status": "CREATED",
        "user_data": {
            "~create_time": "2022-05-13 13:47:23.745"
        }
    },
    "task_id": 0
}

1.2.2 Add or Remove userdata for an existing PropertyKey

Params
  • action: Indicates whether the current action is to add or remove userdata. Possible values are append (add) and eliminate (remove).
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/propertykeys/age?action=append
Request Body
{
    "name": "age",
    "user_data": {
        "min": 0,
        "max": 100
    }
}
Response Status
202
Response Body
{
    "property_key": {
        "id": 1,
        "name": "age",
        "data_type": "INT",
        "cardinality": "SINGLE",
        "aggregate_type": "NONE",
        "write_type": "OLTP",
        "properties": [],
        "status": "CREATED",
        "user_data": {
            "min": 0,
            "max": 100,
            "~create_time": "2022-05-13 13:47:23.745"
        }
    },
    "task_id": 0
}

1.2.3 Get all PropertyKeys

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/propertykeys
Response Status
200
Response Body
{
    "propertykeys": [
        {
            "id": 3,
            "name": "city",
            "data_type": "TEXT",
            "cardinality": "SINGLE",
            "properties": [],
            "user_data": {}
        },
        {
            "id": 2,
            "name": "age",
            "data_type": "INT",
            "cardinality": "SINGLE",
            "properties": [],
            "user_data": {}
        },
        {
            "id": 5,
            "name": "lang",
            "data_type": "TEXT",
            "cardinality": "SINGLE",
            "properties": [],
            "user_data": {}
        },
        {
            "id": 4,
            "name": "weight",
            "data_type": "DOUBLE",
            "cardinality": "SINGLE",
            "properties": [],
            "user_data": {}
        },
        {
            "id": 6,
            "name": "date",
            "data_type": "TEXT",
            "cardinality": "SINGLE",
            "properties": [],
            "user_data": {}
        },
        {
            "id": 1,
            "name": "name",
            "data_type": "TEXT",
            "cardinality": "SINGLE",
            "properties": [],
            "user_data": {}
        },
        {
            "id": 7,
            "name": "price",
            "data_type": "INT",
            "cardinality": "SINGLE",
            "properties": [],
            "user_data": {}
        }
    ]
}

1.2.4 Get PropertyKey according to name

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/propertykeys/age

Where age is the name of the PropertyKey to be retrieved.

Response Status
200
Response Body
{
    "id": 1,
    "name": "age",
    "data_type": "INT",
    "cardinality": "SINGLE",
    "aggregate_type": "NONE",
    "write_type": "OLTP",
    "properties": [],
    "status": "CREATED",
    "user_data": {
        "min": 0,
        "max": 100,
        "~create_time": "2022-05-13 13:47:23.745"
    }
}

1.2.5 Delete PropertyKey according to name

Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/propertykeys/age

Where age is the name of the PropertyKey to be deleted.

Response Status
202
Response Body
{
    "task_id" : 0
}

5.1.4 - VertexLabel API

1.3 VertexLabel

Assuming that the PropertyKeys listed in 1.1.3 have already been created.

Params Description:

  • id: The ID value of the vertex type.
  • name: The name of the vertex type, required.
  • id_strategy: The ID strategy for the vertex type, including primary key ID, auto-generated, custom string, custom number, custom UUID. The default strategy is primary key ID.
  • properties: The property types associated with the vertex type.
  • primary_keys: The primary key properties. This field must have a value when the ID strategy is PRIMARY_KEY, and must be empty for other ID strategies.
  • enable_label_index: Whether to enable label indexing. It is disabled by default.
  • index_names: The indexes created for the vertex type. See details in section 3.4.
  • nullable_keys: Nullable properties.
  • user_data: Setting the common information of the vertex type, similar to the property type.

1.3.1 Create a VertexLabel

Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/vertexlabels
Request Body
{
    "name": "person",
    "id_strategy": "DEFAULT",
    "properties": [
        "name",
        "age"
    ],
    "primary_keys": [
        "name"
    ],
    "nullable_keys": [],
    "enable_label_index": true
}
Response Status
201
Response Body
{
    "id": 1,
    "primary_keys": [
        "name"
    ],
    "id_strategy": "PRIMARY_KEY",
    "name": "person2",
    "index_names": [
    ],
    "properties": [
        "name",
        "age"
    ],
    "nullable_keys": [
    ],
    "enable_label_index": true,
    "user_data": {}
}

Starting from version v0.11.2, hugegraph-server supports Time-to-Live (TTL) functionality for vertices. The TTL for vertices is set through VertexLabel. For example, if you want the vertices of type “person” to have a lifespan of one day, you need to set the TTL field to 86400000 (in milliseconds) when creating the “person” VertexLabel.

{
    "name": "person",
    "id_strategy": "DEFAULT",
    "properties": [
        "name",
        "age"
    ],
    "primary_keys": [
        "name"
    ],
    "nullable_keys": [],
    "ttl": 86400000,
    "enable_label_index": true
}

Additionally, if the vertex has a property called “createdTime” and you want to use it as the starting point for calculating the vertex’s lifespan, you can set the ttl_start_time field in the VertexLabel. For example, if the “person” VertexLabel has a property called “createdTime” of type Date, and you want the vertices of type “person” to live for one day starting from the creation time, the Request Body for creating the “person” VertexLabel would be as follows:

{
    "name": "person",
    "id_strategy": "DEFAULT",
    "properties": [
        "name",
        "age",
        "createdTime"
    ],
    "primary_keys": [
        "name"
    ],
    "nullable_keys": [],
    "ttl": 86400000,
    "ttl_start_time": "createdTime",
    "enable_label_index": true
}

1.3.2 Add properties or userdata to an existing VertexLabel, or remove userdata (removing properties is currently not supported)

Params
  • action: Indicates whether the current action is to add or remove. Possible values are append (add) and eliminate (remove).
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/vertexlabels/person?action=append
Request Body
{
    "name": "person",
    "properties": [
        "city"
    ],
    "nullable_keys": ["city"],
    "user_data": {
        "super": "animal"
    }
}
Response Status
200
Response Body
{
    "id": 1,
    "primary_keys": [
        "name"
    ],
    "id_strategy": "PRIMARY_KEY",
    "name": "person",
    "index_names": [
    ],
    "properties": [
        "city",
        "name",
        "age"
    ],
    "nullable_keys": [
        "city"
    ],
    "enable_label_index": true,
    "user_data": {
        "super": "animal"
    }
}

1.3.3 Get all VertexLabels

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/vertexlabels
Response Status
200
Response Body
{
    "vertexlabels": [
        {
            "id": 1,
            "primary_keys": [
                "name"
            ],
            "id_strategy": "PRIMARY_KEY",
            "name": "person",
            "index_names": [
            ],
            "properties": [
                "city",
                "name",
                "age"
            ],
            "nullable_keys": [
                "city"
            ],
            "enable_label_index": true,
            "user_data": {
                "super": "animal"
            }
        },
        {
            "id": 2,
            "primary_keys": [
                "name"
            ],
            "id_strategy": "PRIMARY_KEY",
            "name": "software",
            "index_names": [
            ],
            "properties": [
                "price",
                "name",
                "lang"
            ],
            "nullable_keys": [
                "price"
            ],
            "enable_label_index": false,
            "user_data": {}
        }
    ]
}

1.3.4 Get VertexLabel by name

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/vertexlabels/person
Response Status
200
Response Body
{
    "id": 1,
    "primary_keys": [
        "name"
    ],
    "id_strategy": "PRIMARY_KEY",
    "name": "person",
    "index_names": [
    ],
    "properties": [
        "city",
        "name",
        "age"
    ],
    "nullable_keys": [
        "city"
    ],
    "enable_label_index": true,
    "user_data": {
        "super": "animal"
    }
}

1.3.5 Delete VertexLabel by name

Deleting a VertexLabel will result in the removal of corresponding vertices and related index data. This operation will generate an asynchronous task.

Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/vertexlabels/person
Response Status
202
Response Body
{
    "task_id": 1
}

Note:

You can use GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/1 (where “1” is the task_id) to query the execution status of the asynchronous task. For more information, refer to the Asynchronous Task RESTful API.

5.1.5 - EdgeLabel API

1.4 EdgeLabel

Assuming PropertyKeys from version 1.2.3 and VertexLabels from version 1.3.3 have already been created.

Params Explanation

  • name: Name of the vertex type, required.
  • source_label: Name of the source vertex type, required.
  • target_label: Name of the target vertex type, required.
  • frequency: Whether there can be multiple edges between two points, can have values SINGLE or MULTIPLE, optional (default value: SINGLE).
  • properties: Property types associated with the edge type, optional.
  • sort_keys: Specifies a list of differentiating key properties when multiple associations are allowed.
  • nullable_keys: Nullable properties, optional (default: nullable).
  • enable_label_index: Whether to enable type indexing, disabled by default.

1.4.1 Create an EdgeLabel

Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/edgelabels
Request Body
{
    "name": "created",
    "source_label": "person",
    "target_label": "software",
    "frequency": "SINGLE",
    "properties": [
        "date"
    ],
    "sort_keys": [],
    "nullable_keys": [],
    "enable_label_index": true
}
Response Status
201
Response Body
{
    "id": 1,
    "sort_keys": [
    ],
    "source_label": "person",
    "name": "created",
    "index_names": [
    ],
    "properties": [
        "date"
    ],
    "target_label": "software",
    "frequency": "SINGLE",
    "nullable_keys": [
    ],
    "enable_label_index": true,
    "user_data": {}
}

Starting from version 0.11.2 of hugegraph-server, the TTL (Time to Live) feature for edges is supported. The TTL for edges is set through EdgeLabel. For example, if you want the “knows” type of edge to have a lifespan of one day, you need to set the TTL field to 86400000 when creating the “knows” EdgeLabel, where the unit is milliseconds.

{
    "id": 1,
    "sort_keys": [
    ],
    "source_label": "person",
    "name": "knows",
    "index_names": [
    ],
    "properties": [
        "date",
        "createdTime"
    ],
    "target_label": "person",
    "frequency": "SINGLE",
    "nullable_keys": [
    ],
    "enable_label_index": true,
    "ttl": 86400000,
    "user_data": {}
}

Additionally, when the edge has a property called “createdTime” and you want to use the “createdTime” property as the starting point for calculating the edge’s lifespan, you can set the ttl_start_time field in the EdgeLabel. For example, if the knows EdgeLabel has a property called “createdTime” which is of type Date, and you want the “knows” type of edge to live for one day from the time of creation, the Request Body for creating the knows EdgeLabel would be as follows:

{
    "id": 1,
    "sort_keys": [
    ],
    "source_label": "person",
    "name": "knows",
    "index_names": [
    ],
    "properties": [
        "date",
        "createdTime"
    ],
    "target_label": "person",
    "frequency": "SINGLE",
    "nullable_keys": [
    ],
    "enable_label_index": true,
    "ttl": 86400000,
    "ttl_start_time": "createdTime",
    "user_data": {}
}

1.4.2 Add properties or userdata to an existing EdgeLabel, or remove userdata (removing properties is currently not supported)

Params
  • action: Indicates whether the current action is to add or remove, with values append (add) and eliminate (remove).
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/edgelabels/created?action=append
Request Body
{
    "name": "created",
    "properties": [
        "weight"
    ],
    "nullable_keys": [
        "weight"
    ]
}
Response Status
200
Response Body
{
    "id": 2,
    "sort_keys": [
    ],
    "source_label": "person",
    "name": "created",
    "index_names": [
    ],
    "properties": [
        "date",
        "weight"
    ],
    "target_label": "software",
    "frequency": "SINGLE",
    "nullable_keys": [
        "weight"
    ],
    "enable_label_index": true,
    "user_data": {}
}

1.4.3 Get all EdgeLabels

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/edgelabels
Response Status
200
Response Body
{
    "edgelabels": [
        {
            "id": 1,
            "sort_keys": [
            ],
            "source_label": "person",
            "name": "created",
            "index_names": [
            ],
            "properties": [
                "date",
                "weight"
            ],
            "target_label": "software",
            "frequency": "SINGLE",
            "nullable_keys": [
                "weight"
            ],
            "enable_label_index": true,
            "user_data": {}
        },
        {
            "id": 2,
            "sort_keys": [
            ],
            "source_label": "person",
            "name": "knows",
            "index_names": [
            ],
            "properties": [
                "date",
                "weight"
            ],
            "target_label": "person",
            "frequency": "SINGLE",
            "nullable_keys": [
            ],
            "enable_label_index": false,
            "user_data": {}
        }
    ]
}

1.4.4 Get EdgeLabel by name

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/edgelabels/created
Response Status
200
Response Body
{
    "id": 1,
    "sort_keys": [
    ],
    "source_label": "person",
    "name": "created",
    "index_names": [
    ],
    "properties": [
        "date",
        "city",
        "weight"
    ],
    "target_label": "software",
    "frequency": "SINGLE",
    "nullable_keys": [
        "city",
        "weight"
    ],
    "enable_label_index": true,
    "user_data": {}
}

1.4.5 Delete EdgeLabel by name

Deleting an EdgeLabel will result in the deletion of corresponding edges and related index data. This operation will generate an asynchronous task.

Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/edgelabels/created
Response Status
202
Response Body
{
    "task_id": 1
}

Note:

You can query the execution status of an asynchronous task by using GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/1 (where “1” is the task_id). For more information, refer to the Asynchronous Task RESTful API.

5.1.6 - IndexLabel API

1.5 IndexLabel

Assuming PropertyKeys from version 1.1.3, VertexLabels from version 1.2.3, and EdgeLabels from version 1.3.3 have already been created.

1.5.1 Create an IndexLabel

Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/indexlabels
Request Body
{
    "name": "personByCity",
    "base_type": "VERTEX_LABEL",
    "base_value": "person",
    "index_type": "SECONDARY",
    "fields": [
        "city"
    ]
}
Response Status
202
Response Body
{
    "index_label": {
        "id": 1,
        "base_type": "VERTEX_LABEL",
        "base_value": "person",
        "name": "personByCity",
        "fields": [
            "city"
        ],
        "index_type": "SECONDARY"
    },
    "task_id": 2
}

1.5.2 Get all IndexLabels

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/indexlabels
Response Status
200
Response Body
{
    "indexlabels": [
        {
            "id": 3,
            "base_type": "VERTEX_LABEL",
            "base_value": "software",
            "name": "softwareByPrice",
            "fields": [
                "price"
            ],
            "index_type": "RANGE"
        },
        {
            "id": 4,
            "base_type": "EDGE_LABEL",
            "base_value": "created",
            "name": "createdByDate",
            "fields": [
                "date"
            ],
            "index_type": "SECONDARY"
        },
        {
            "id": 1,
            "base_type": "VERTEX_LABEL",
            "base_value": "person",
            "name": "personByCity",
            "fields": [
                "city"
            ],
            "index_type": "SECONDARY"
        },
        {
            "id": 3,
            "base_type": "VERTEX_LABEL",
            "base_value": "person",
            "name": "personByAgeAndCity",
            "fields": [
                "age",
                "city"
            ],
            "index_type": "SECONDARY"
        }
    ]
}

1.5.3 Get IndexLabel by name

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/indexlabels/personByCity
Response Status
200
Response Body
{
    "id": 1,
    "base_type": "VERTEX_LABEL",
    "base_value": "person",
    "name": "personByCity",
    "fields": [
        "city"
    ],
    "index_type": "SECONDARY"
}

1.5.4 Delete IndexLabel by name

Deleting an IndexLabel will result in the deletion of related index data. This operation will generate an asynchronous task.

Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/schema/indexlabels/personByCity
Response Status
202
Response Body
{
    "task_id": 1
}

Note:

You can query the execution status of an asynchronous task by using GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/1 (where “1” is the task_id). For more information, refer to the Asynchronous Task RESTful API.

5.1.7 - Rebuild API

1.6 Rebuild

1.6.1 Rebuild IndexLabel

Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/jobs/rebuild/indexlabels/personByCity
Response Status
202
Response Body
{
    "task_id": 1
}

Note:

You can get the asynchronous job status by GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/${task_id} (the task_id here should be 1). See More AsyncJob RESTfull API

1.6.2 Rebulid all Indexs of VertexLabel

Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/jobs/rebuild/vertexlabels/person
Response Status
202
Response Body
{
    "task_id": 2
}

Note:

You can get the asynchronous job status by GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/${task_id} (the task_id here should be 2). See More AsyncJob RESTfull API

1.6.3 Rebulid all Indexs of EdgeLabel

Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/jobs/rebuild/edgelabels/created
Response Status
202
Response Body
{
    "task_id": 3
}

Note:

You can get the asynchronous job status by GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/${task_id} (the task_id here should be 3). See More AsyncJob RESTfull API

5.1.8 - Vertex API

2.1 Vertex

In vertex types, the Id strategy determines the type of the vertex Id, with the corresponding relationships as follows:

Id_Strategyid type
AUTOMATICnumber
PRIMARY_KEYstring
CUSTOMIZE_STRINGstring
CUSTOMIZE_NUMBERnumber
CUSTOMIZE_UUIDuuid

For the GET/PUT/DELETE API of a vertex, the id part in the URL should be passed as the id value with type information. This type information is indicated by whether the JSON string is enclosed in quotes, meaning:

  • When the id type is number, the id in the URL is without quotes, for example: xxx/vertices/123456.
  • When the id type is string, the id in the URL is enclosed in quotes, for example: xxx/vertices/"123456".

The next example requires first creating the graph schema from the following groovy script

schema.propertyKey("name").asText().ifNotExist().create();
schema.propertyKey("age").asInt().ifNotExist().create();
schema.propertyKey("city").asText().ifNotExist().create();
schema.propertyKey("weight").asDouble().ifNotExist().create();
schema.propertyKey("lang").asText().ifNotExist().create();
schema.propertyKey("price").asDouble().ifNotExist().create();
schema.propertyKey("hobby").asText().valueList().ifNotExist().create();

schema.vertexLabel("person").properties("name", "age", "city", "weight", "hobby").primaryKeys("name").nullableKeys("age", "city", "weight", "hobby").ifNotExist().create();
schema.vertexLabel("software").properties("name", "lang", "price").primaryKeys("name").nullableKeys("lang", "price").ifNotExist().create();

schema.indexLabel("personByAge").onV("person").by("age").range().ifNotExist().create();

2.1.1 Create a vertex

Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices
Request Body
{
    "label": "person",
    "properties": {
        "name": "marko",
        "age": 29
    }
}
Response Status
201
Response Body
{
    "id": "1:marko",
    "label": "person",
    "type": "vertex",
    "properties": {
        "name": "marko",
        "age": 29
    }
}

2.1.2 Create multiple vertices

Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices/batch
Request Body
[
    {
        "label": "person",
        "properties": {
            "name": "marko",
            "age": 29
        }
    },
    {
        "label": "software",
        "properties": {
            "name": "ripple",
            "lang": "java",
            "price": 199
        }
    }
]
Response Status
201
Response Body
[
    "1:marko",
    "2:ripple"
]

2.1.3 Update vertex properties

Method & Url
PUT http://127.0.0.1:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices/"1:marko"?action=append
Request Body
{
    "label": "person",
    "properties": {
        "age": 30,
        "city": "Beijing"
    }
}

Note: There are three categories for property values: single, set, and list. If it is single, it means adding or updating the property value. If it is set or list, it means appending the property value.

Response Status
200
Response Body
{
    "id": "1:marko",
    "label": "person",
    "type": "vertex",
    "properties": {
        "name": "marko",
        "age": 30,
        "city": "Beijing"
    }
}

2.1.4 Batch Update Vertex Properties

Function Description

Batch update properties of vertices and support various update strategies, including:

  • SUM: Numeric accumulation
  • BIGGER: Take the larger value between two numbers/dates
  • SMALLER: Take the smaller value between two numbers/dates
  • UNION: Take the union of set properties
  • INTERSECTION: Take the intersection of set properties
  • APPEND: Append elements to list properties
  • ELIMINATE: Remove elements from list/set properties
  • OVERRIDE: Override existing properties, if the new property is null, the old property is still used

Assuming the original vertex and properties are:

{
    "vertices": [
        {
            "id": "2:lop",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "lop",
                "lang": "java",
                "price": 328
            }
        },
        {
            "id": "1:josh",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "josh",
                "age": 32,
                "city": "Beijing",
                "weight": 0.1,
                "hobby": [
                    "reading",
                    "football"
                ]
            }
        }
    ]
}

Add vertices with the following command:

curl -H "Content-Type: application/json" -d '[{"label":"person","properties":{"name":"josh","age":32,"city":"Beijing","weight":0.1,"hobby":["reading","football"]}},{"label":"software","properties":{"name":"lop","lang":"java","price":328}}]' http://127.0.0.1:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices/batch
Method & Url
PUT http://127.0.0.1:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices/batch
Request Body
{
    "vertices": [
        {
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "lop",
                "lang": "c++",
                "price": 299
            }
        },
        {
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "josh",
                "city": "Shanghai",
                "weight": 0.2,
                "hobby": [
                    "swimming"
                ]
            }
        }
    ],
    "update_strategies": {
        "price": "BIGGER",
        "age": "OVERRIDE",
        "city": "OVERRIDE",
        "weight": "SUM",
        "hobby": "UNION"
    },
    "create_if_not_exist": true
}
Response Status
200
Response Body
{
    "vertices": [
        {
            "id": "2:lop",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "lop",
                "lang": "c++",
                "price": 328
            }
        },
        {
            "id": "1:josh",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "josh",
                "age": 32,
                "city": "Shanghai",
                "weight": 0.3,
                "hobby": [
                    "reading",
                    "football",
                    "swimming"
                ]
            }
        }
    ]
}

Result Analysis:

  • The lang property does not specify an update strategy and is directly overwritten by the new value, regardless of whether the new value is null.
  • The price property specifies the BIGGER update strategy. The old property value is 328, and the new property value is 299, so the old property value of 328 is retained.
  • The age property specifies the OVERRIDE update strategy, but the new property value does not include age, which is equivalent to age being null. Therefore, the original property value of 32 is still retained.
  • The city property also specifies the OVERRIDE update strategy, and the new property value is not null, so it overrides the old value.
  • The weight property specifies the SUM update strategy. The old property value is 0.1, and the new property value is 0.2. The final value is 0.3.
  • The hobby property (cardinality is Set) specifies the UNION update strategy, so the new value is taken as the union with the old value.

The usage of other update strategies can be inferred in a similar manner and will not be further elaborated.

2.1.5 Delete Vertex Properties

Method & Url
PUT http://127.0.0.1:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices/"1:marko"?action=eliminate
Request Body
{
    "label": "person",
    "properties": {
        "city": "Beijing"
    }
}

Note: Here, the properties (keys and all values) will be directly deleted, regardless of whether the property values are single, set, or list.

Response Status
200
Response Body
{
    "id": "1:marko",
    "label": "person",
    "type": "vertex",
    "properties": {
        "name": "marko",
        "age": 30
    }
}

2.1.6 Get Vertices that Meet the Criteria

Params
  • label: Vertex type
  • properties: Property key-value pairs (precondition: indexes are created for property queries)
  • limit: Maximum number of results
  • page: Page number

All of the above parameters are optional. If the page parameter is provided, the limit parameter must also be provided, and no other parameters are allowed. label, properties, and limit can be combined in any way.

Property key-value pairs consist of the property name and value in JSON format. Multiple property key-value pairs are allowed as query conditions. The property value supports exact matching, range matching, and fuzzy matching. For exact matching, use the format properties={"age":29}, for range matching, use the format properties={"age":"P.gt(29)"}, and for fuzzy matching, use the format properties={"city": "P.textcontains("ChengDu China")}. The following expressions are supported for range matching:

ExpressionExplanation
P.eq(number)Vertices with property value equal to number
P.neq(number)Vertices with property value not equal to number
P.lt(number)Vertices with property value less than number
P.lte(number)Vertices with property value less than or equal to number
P.gt(number)Vertices with property value greater than number
P.gte(number)Vertices with property value greater than or equal to number
P.between(number1,number2)Vertices with property value greater than or equal to number1 and less than number2
P.inside(number1,number2)Vertices with property value greater than number1 and less than number2
P.outside(number1,number2)Vertices with property value less than number1 and greater than number2
P.within(value1,value2,value3,…)Vertices with property value equal to any of the given values

Query all vertices with age 29 and label person

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices?label=person&properties={"age":29}&limit=1
Response Status
200
Response Body
{
    "vertices": [
        {
            "id": "1:marko",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "marko",
                "age": 30
            }
        }
    ]
}

Paginate through all vertices, retrieve the first page (page without parameter value), limited to 3 records

Add vertices with the following command:

curl -H "Content-Type: application/json" -d '[{"label":"person","properties":{"name":"peter","age":29,"city":"Shanghai"}},{"label":"person","properties":{"name":"vadas","age":27,"city":"Hongkong"}}]' http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices/batch
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices?page&limit=3
Response Status
200
Response Body
{
    "vertices": [
        {
            "id": "2:lop",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "lop",
                "lang": "c++",
                "price": 328
            }
        },
        {
            "id": "1:josh",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "josh",
                "age": 32,
                "city": "Shanghai",
                "weight": 0.3,
                "hobby": [
                    "reading",
                    "football",
                    "swimming"
                ]
            }
        },
        {
            "id": "1:marko",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "marko",
                "age": 30
            }
        }
    ],
    "page": "CIYxOnBldGVyAAAAAAAAAAM="
}

The returned body contains information about the page number of the next page, "page": "CIYxOnBldGVyAAAAAAAAAAM". When querying the next page, assign this value to the page parameter.

Paginate and retrieve all vertices, including the next page (passing the page value returned from the previous page), limited to 3 items.

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices?page=CIYxOnBldGVyAAAAAAAAAAM=&limit=3
Response Status
200
Response Body
{
    "vertices": [
        {
            "id": "1:peter",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "peter",
                "age": 29,
                "city": "Shanghai"
            }
        },
        {
            "id": "1:vadas",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "vadas",
                "age": 27,
                "city": "Hongkong"
            }
        },
        {
            "id": "2:ripple",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "ripple",
                "lang": "java",
                "price": 199
            }
        }
    ],
    "page": null
}

At this point, "page": null indicates that there are no more pages available. (Note: When using Cassandra as the backend for performance reasons, if the returned page happens to be the last page, the page value may not be empty. When requesting the next page using that page value, it will return empty data and page = null. The same applies to other similar situations.)

2.1.7 Retrieve Vertex by ID

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices/"1:marko"
Response Status
200
Response Body
{
    "id": "1:marko",
    "label": "person",
    "type": "vertex",
    "properties": {
        "name": "marko",
        "age": 30
    }
}

2.1.8 Delete Vertex by ID

Params
  • label: Vertex type, optional parameter

Delete the vertex based on ID only.

Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices/"1:marko"
Response Status
204

Delete Vertex by Label+ID

When deleting a vertex by specifying both the Label parameter and the ID, it generally offers better performance compared to deleting by ID alone.

Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices/"1:marko"?label=person
Response Status
204

5.1.9 - Edge API

2.2 Edge

The modification of the vertex ID format also affects the ID of the edge, as well as the formats of the source vertex and target vertex IDs.

The EdgeId is formed by concatenating src-vertex-id + direction + label + sort-values + tgt-vertex-id, but the vertex ID types are not distinguished by quotation marks here. Instead, they are distinguished by prefixes:

  • When the ID type is number, the vertex ID in the EdgeId has a prefix L, like “L123456>1»L987654”.
  • When the ID type is string, the vertex ID in the EdgeId has a prefix S, like “S1:peter>1»S2:lop”.

The following example requires creating a graph schema based on the following groovy script:

import org.apache.hugegraph.HugeFactory
import org.apache.tinkerpop.gremlin.structure.T

conf = "conf/graphs/hugegraph.properties"
graph = HugeFactory.open(conf)
schema = graph.schema()

schema.propertyKey("name").asText().ifNotExist().create()
schema.propertyKey("age").asInt().ifNotExist().create()
schema.propertyKey("city").asText().ifNotExist().create()
schema.propertyKey("weight").asDouble().ifNotExist().create()
schema.propertyKey("lang").asText().ifNotExist().create()
schema.propertyKey("date").asText().ifNotExist().create()
schema.propertyKey("price").asInt().ifNotExist().create()

schema.vertexLabel("person").properties("name", "age", "city").primaryKeys("name").ifNotExist().create()
schema.vertexLabel("software").properties("name", "lang", "price").primaryKeys("name").ifNotExist().create()
schema.indexLabel("personByCity").onV("person").by("city").secondary().ifNotExist().create()
schema.indexLabel("personByAgeAndCity").onV("person").by("age", "city").secondary().ifNotExist().create()
schema.indexLabel("softwareByPrice").onV("software").by("price").range().ifNotExist().create()
schema.edgeLabel("knows").sourceLabel("person").targetLabel("person").properties("date", "weight").ifNotExist().create()
schema.edgeLabel("created").sourceLabel("person").targetLabel("software").properties("date", "weight").ifNotExist().create()
schema.indexLabel("createdByDate").onE("created").by("date").secondary().ifNotExist().create()
schema.indexLabel("createdByWeight").onE("created").by("weight").range().ifNotExist().create()
schema.indexLabel("knowsByWeight").onE("knows").by("weight").range().ifNotExist().create()

marko = graph.addVertex(T.label, "person", "name", "marko", "age", 29, "city", "Beijing")
vadas = graph.addVertex(T.label, "person", "name", "vadas", "age", 27, "city", "Hongkong")
lop = graph.addVertex(T.label, "software", "name", "lop", "lang", "java", "price", 328)
josh = graph.addVertex(T.label, "person", "name", "josh", "age", 32, "city", "Beijing")
ripple = graph.addVertex(T.label, "software", "name", "ripple", "lang", "java", "price", 199)
peter = graph.addVertex(T.label, "person", "name", "peter", "age", 35, "city", "Shanghai")

graph.tx().commit()
g = graph.traversal()

2.2.1 Creating an Edge

Params

Path Parameter Description:

  • graph: The graph to operate on

Request Body Description:

  • label: The edge type name (required)
  • outV: The source vertex id (required)
  • inV: The target vertex id (required)
  • outVLabel: The source vertex type (required)
  • inVLabel: The target vertex type (required)
  • properties: The properties associated with the edge. The internal structure of the object is as follows:
    1. name: The property name
    2. value: The property value
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/edges
Request Body
{
    "label": "created",
    "outV": "1:marko",
    "inV": "2:lop",
    "outVLabel": "person",
    "inVLabel": "software",
    "properties": {
        "date": "20171210",
        "weight": 0.4
    }
}
Response Status
201
Response Body
{
    "id": "S1:marko>2>>S2:lop",
    "label": "created",
    "type": "edge",
    "outV": "1:marko",
    "outVLabel": "person",
    "inV": "2:lop",
    "inVLabel": "software",
    "properties": {
        "weight": 0.4,
        "date": "20171210"
    }
}

2.2.2 Creating Multiple Edges

Params

Path Parameter Description:

  • graph: The graph to operate on

Request Parameter Description:

  • check_vertex: Whether to check the existence of vertices (true | false). When set to true, an error will be thrown if the source or target vertices of the edge to be inserted do not exist. Default is true.

Request Body Description:

  • List of edge information
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/edges/batch
Request Body
[
    {
        "label": "knows",
        "outV": "1:marko",
        "inV": "1:vadas",
        "outVLabel": "person",
        "inVLabel": "person",
        "properties": {
            "date": "20160110",
            "weight": 0.5
        }
    },
    {
        "label": "knows",
        "outV": "1:marko",
        "inV": "1:josh",
        "outVLabel": "person",
        "inVLabel": "person",
        "properties": {
            "date": "20130220",
            "weight": 1.0
        }
    }
]
Response Status
201
Response Body
[
    "S1:marko>1>>S1:vadas",
    "S1:marko>1>>S1:josh"
]

2.2.3 Updating Edge Properties

Params

Path Parameter Description:

  • graph: The graph to operate on
  • id: The ID of the edge to be operated on

Request Parameter Description:

  • action: The append action

Request Body Description:

  • Edge information
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/edges/S1:marko>2>>S2:lop?action=append
Request Body
{
    "properties": {
        "weight": 1.0
    }
}

NOTE: There are three categories of property values: single, set, and list. If it is single, it means adding or updating the property value. If it is set or list, it means appending the property value.

Response Status
200
Response Body
{
    "id": "S1:marko>2>>S2:lop",
    "label": "created",
    "type": "edge",
    "outV": "1:marko",
    "outVLabel": "person",
    "inV": "2:lop",
    "inVLabel": "software",
    "properties": {
        "weight": 1.0,
        "date": "20171210"
    }
}

2.2.4 Batch Updating Edge Properties

Params

Path Parameter Description:

  • graph: The graph to operate on

Request Body Description:

  • edges: List of edge information
  • update_strategies: For each property, you can set its update strategy individually, including:
    • SUM: Only supports number type
    • BIGGER/SMALLER: Only supports date/number type
    • UNION/INTERSECTION: Only supports set type
    • APPEND/ELIMINATE: Only supports collection type
    • OVERRIDE
  • check_vertex: Whether to check the existence of vertices (true | false). When set to true, an error will be thrown if the source or target vertices of the edge to be inserted do not exist. Default is true.
  • create_if_not_exist: Currently only supports setting to true
Method & Url
PUT http://127.0.0.1:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/edges/batch
Request Body
{
    "edges": [
        {
            "label": "knows",
            "outV": "1:marko",
            "inV": "1:vadas",
            "outVLabel": "person",
            "inVLabel": "person",
            "properties": {
                "date": "20160111",
                "weight": 1.0
            }
        },
        {
            "label": "knows",
            "outV": "1:marko",
            "inV": "1:josh",
            "outVLabel": "person",
            "inVLabel": "person",
            "properties": {
                "date": "20130221",
                "weight": 0.5
            }
        }
    ],
    "update_strategies": {
        "weight": "SUM",
        "date": "OVERRIDE"
    },
    "check_vertex": false,
    "create_if_not_exist": true
}
Response Status
200
Response Body
{
    "edges": [
        {
            "id": "S1:marko>1>>S1:vadas",
            "label": "knows",
            "type": "edge",
            "outV": "1:marko",
            "outVLabel": "person",
            "inV": "1:vadas",
            "inVLabel": "person",
            "properties": {
                "weight": 1.5,
                "date": "20160111"
            }
        },
        {
            "id": "S1:marko>1>>S1:josh",
            "label": "knows",
            "type": "edge",
            "outV": "1:marko",
            "outVLabel": "person",
            "inV": "1:josh",
            "inVLabel": "person",
            "properties": {
                "weight": 1.5,
                "date": "20130221"
            }
        }
    ]
}

2.2.5 Deleting Edge Properties

Params

Path Parameter Description:

  • graph: The graph to operate on
  • id: The ID of the edge to be operated on

Request Parameter Description:

  • action: The eliminate action

Request Body Description:

  • Edge information
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/edges/S1:marko>2>>S2:lop?action=eliminate
Request Body
{
    "properties": {
        "weight": 1.0
    }
}

NOTE: This will directly delete the properties (removing the key and all values), regardless of whether the property values are single, set, or list.

Response Status
400
Response Body

It is not possible to delete an attribute that is not set as nullable.

{
    "exception": "class java.lang.IllegalArgumentException",
    "message": "Can't remove non-null edge property 'p[weight->1.0]'",
    "cause": ""
}

2.2.6 Fetching Edges that Match the Criteria

Params

Path Parameter:

  • graph: The graph to operate on

Request Parameters:

  • vertex_id: Vertex ID
  • direction: Edge direction (OUT | IN | BOTH), default is BOTH
  • label: Edge label
  • properties: Key-value pairs of properties (requires pre-built indexes for property queries)
  • keep_start_p: Default is false. When set to true, the range matching input expression will not be automatically escaped. For example, properties={"age":"P.gt(0.8)"} will be interpreted as an exact match, i.e., the age property is equal to “P.gt(0.8)”
  • offset: Offset, default is 0
  • limit: Number of queries, default is 100
  • page: Page number

Key-value pairs of properties consist of the property name and value in JSON format. Multiple key-value pairs are allowed as query conditions. Property values support exact matching and range matching. For exact matching, it is in the form properties={"weight":0.8}. For range matching, it is in the form properties={"age":"P.gt(0.8)"}. The expressions supported by range matching are as follows:

ExpressionDescription
P.eq(number)Edges with property value equal to number
P.neq(number)Edges with property value not equal to number
P.lt(number)Edges with property value less than number
P.lte(number)Edges with property value less than or equal to number
P.gt(number)Edges with property value greater than number
P.gte(number)Edges with property value greater than or equal to number
P.between(number1,number2)Edges with property value greater than or equal to number1 and less than number2
P.inside(number1,number2)Edges with property value greater than number1 and less than number2
P.outside(number1,number2)Edges with property value less than number1 and greater than number2
P.within(value1,value2,value3,…)Edges with property value equal to any of the given values
P.textcontains(value)Edges with property value containing the given value (string type)
P.contains(value)Edges with property value containing the given value (collection type)

Edges connected to the vertex person:marko(vertex_id=“1:marko”) with label knows and date property equal to “20160111”

Method & Url
GET http://127.0.0.1:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/edges?vertex_id="1:marko"&label=knows&properties={"date":"P.within(\"20160111\")"}
Response Status
200
Response Body
{
    "edges": [
        {
            "id": "S1:marko>1>>S1:vadas",
            "label": "knows",
            "type": "edge",
            "outV": "1:marko",
            "outVLabel": "person",
            "inV": "1:vadas",
            "inVLabel": "person",
            "properties": {
                "weight": 1.5,
                "date": "20160111"
            }
        }
    ]
}

Paginate and retrieve all edges, get the first page (page without parameter value), limit to 2 entries

Method & Url
GET http://127.0.0.1:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/edges?page&limit=2
Response Status
200
Response Body
{
    "edges": [
        {
            "id": "S1:marko>1>>S1:josh",
            "label": "knows",
            "type": "edge",
            "outV": "1:marko",
            "outVLabel": "person",
            "inV": "1:josh",
            "inVLabel": "person",
            "properties": {
                "weight": 1.5,
                "date": "20130221"
            }
        },
        {
            "id": "S1:marko>1>>S1:vadas",
            "label": "knows",
            "type": "edge",
            "outV": "1:marko",
            "outVLabel": "person",
            "inV": "1:vadas",
            "inVLabel": "person",
            "properties": {
                "weight": 1.5,
                "date": "20160111"
            }
        }
    ],
    "page": "EoYxOm1hcmtvgggCAIQyOmxvcAAAAAAAAAAC"
}

The returned body contains the page number information for the next page, "page": "EoYxOm1hcmtvgggCAIQyOmxvcAAAAAAAAAAC". When querying the next page, assign this value to the page parameter.

Paginate and retrieve all edges, get the next page (include the page value returned from the previous page), limit to 2 entries

Method & Url
GET http://127.0.0.1:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/edges?page=EoYxOm1hcmtvgggCAIQyOmxvcAAAAAAAAAAC&limit=2
Response Status
200
Response Body
{
    "edges": [
        {
            "id": "S1:marko>2>>S2:lop",
            "label": "created",
            "type": "edge",
            "outV": "1:marko",
            "outVLabel": "person",
            "inV": "2:lop",
            "inVLabel": "software",
            "properties": {
                "weight": 1.0,
                "date": "20171210"
            }
        }
    ],
    "page": null
}

When "page": null is returned, it indicates that there are no more pages available.

NOTE: When the backend is Cassandra, for performance considerations, if the returned page happens to be the last page, the page value may not be empty. When requesting the next page data using that page value, it will return empty data and page = null. Similar situations apply for other cases.

2.2.7 Fetching Edge by ID

Params

Path parameter description:

  • graph: The graph to be operated on.
  • id: The ID of the edge to be operated on.
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/edges/S1:marko>2>>S2:lop
Response Status
200
Response Body
{
    "id": "S1:marko>2>>S2:lop",
    "label": "created",
    "type": "edge",
    "outV": "1:marko",
    "outVLabel": "person",
    "inV": "2:lop",
    "inVLabel": "software",
    "properties": {
        "weight": 1.0,
        "date": "20171210"
    }
}

2.2.8 Deleting Edge by ID

Params

Path parameter description:

  • graph: The graph to be operated on.
  • id: The ID of the edge to be operated on.

Request parameter description:

  • label: The label of the edge.

Deleting Edge by ID only

Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/edges/S1:marko>2>>S2:lop
Response Status
204

Deleting Edge by Label + ID

In general, specifying the Label parameter along with the ID to delete an edge will provide better performance compared to deleting by ID only.

Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/edges/S1:marko>1>>S1:vadas?label=knows
Response Status
204

5.1.10 - Traverser API

3.1 Overview of Traverser API

HugeGraphServer provides a RESTful API interface for the HugeGraph graph database. In addition to the basic CRUD operations for vertices and edges, it also offers several traversal methods, which we refer to as the traverser API. These traversal methods implement various complex graph algorithms, making it convenient for users to analyze and explore the graph.

The Traverser API supported by HugeGraph includes:

  • K-out API: It finds neighbors that are exactly N steps away from a given starting vertex. There are two versions:
    • The basic version uses the GET method to find neighbors that are exactly N steps away from a given starting vertex.
    • The advanced version uses the POST method to find neighbors that are exactly N steps away from a given starting vertex. The advanced version differs from the basic version in the following ways:
      • Supports counting the number of neighbors only
      • Supports filtering by edge and vertex properties
      • Supports returning the shortest path to reach the neighbor
  • K-neighbor API: It finds all neighbors that are within N steps of a given starting vertex. There are two versions:
    • The basic version uses the GET method to find all neighbors that are within N steps of a given starting vertex.
    • The advanced version uses the POST method to find all neighbors that are within N steps of a given starting vertex. The advanced version differs from the basic version in the following ways:
      • Supports counting the number of neighbors only
      • Supports filtering by edge and vertex properties
      • Supports returning the shortest path to reach the neighbor
  • Same Neighbors: It queries the common neighbors of two vertices.
  • Jaccard Similarity API: It calculates the Jaccard similarity, which includes two types:
    • One type uses the GET method to calculate the similarity (intersection over union) of neighbors between two vertices.
    • The other type uses the POST method to find the top N vertices with the highest Jaccard similarity to a given starting vertex in the entire graph.
  • Shortest Path API: It finds the shortest path between two vertices.
  • All Shortest Paths: It finds all shortest paths between two vertices.
  • Weighted Shortest Path: It finds the shortest weighted path from a starting vertex to a target vertex.
  • Single Source Shortest Path: It finds the weighted shortest path from a single source vertex to all other vertices.
  • Multi Node Shortest Path: It finds the shortest path between every pair of specified vertices.
  • Paths API: It finds all paths between two vertices. There are two versions:
    • The basic version uses the GET method to find all paths between a given starting vertex and an ending vertex.
    • The advanced version uses the POST method to find all paths that meet certain conditions between a set of starting vertices and a set of ending vertices.

3.2 Detailed Explanation of Traverser API

In the following, we provide a detailed explanation of the Traverser API:

  • Customized Paths API: It traverses all paths that pass through a batch of vertices according to a specific pattern.
  • Template Path API: It specifies a starting point, an ending point, and the path information between them to find matching paths.
  • Crosspoints API: It finds the intersection (common ancestors or common descendants) between two vertices.
  • Customized Crosspoints API: It traverses multiple patterns starting from a batch of vertices and finds the intersections with the vertices reached in the final step.
  • Rings API: It finds the cyclic paths that can be reached from a starting vertex.
  • Rays API: It finds the paths from a starting vertex that reach the boundaries (i.e., paths without cycles).
  • Fusiform Similarity API: It finds the fusiform similar vertices to a given vertex.
  • Vertices API:
    • Batch querying vertices by ID.
    • Getting the partitions of vertices.
    • Querying vertices by partition.
  • Edges API:
    • Batch querying edges by ID.
    • Getting the partitions of edges.
    • Querying edges by partition.

3.2 Detailed Explanation of Traverser API

The usage examples provided in this section are based on the graph presented on the TinkerPop official website:

tinkerpop example graph

The data import program is as follows:

public class Loader {
    public static void main(String[] args) {
        HugeClient client = new HugeClient("http://127.0.0.1:8080", "hugegraph");
        SchemaManager schema = client.schema();
        schema.propertyKey("name").asText().ifNotExist().create();
        schema.propertyKey("age").asInt().ifNotExist().create();
        schema.propertyKey("city").asText().ifNotExist().create();
        schema.propertyKey("weight").asDouble().ifNotExist().create();
        schema.propertyKey("lang").asText().ifNotExist().create();
        schema.propertyKey("date").asText().ifNotExist().create();
        schema.propertyKey("price").asInt().ifNotExist().create();

        schema.vertexLabel("person")
              .properties("name", "age", "city")
              .primaryKeys("name")
              .nullableKeys("age")
              .ifNotExist()
              .create();

        schema.vertexLabel("software")
              .properties("name", "lang", "price")
              .primaryKeys("name")
              .nullableKeys("price")
              .ifNotExist()
              .create();

        schema.indexLabel("personByCity")
              .onV("person")
              .by("city")
              .secondary()
              .ifNotExist()
              .create();

        schema.indexLabel("personByAgeAndCity")
              .onV("person")
              .by("age", "city")
              .secondary()
              .ifNotExist()
              .create();

        schema.indexLabel("softwareByPrice")
              .onV("software")
              .by("price")
              .range()
              .ifNotExist()
              .create();

        schema.edgeLabel("knows")
              .multiTimes()
              .sourceLabel("person")
              .targetLabel("person")
              .properties("date", "weight")
              .sortKeys("date")
              .nullableKeys("weight")
              .ifNotExist()
              .create();

        schema.edgeLabel("created")
              .sourceLabel("person").targetLabel("software")
              .properties("date", "weight")
              .nullableKeys("weight")
              .ifNotExist()
              .create();

        schema.indexLabel("createdByDate")
              .onE("created")
              .by("date")
              .secondary()
              .ifNotExist()
              .create();

        schema.indexLabel("createdByWeight")
              .onE("created")
              .by("weight")
              .range()
              .ifNotExist()
              .create();

        schema.indexLabel("knowsByWeight")
              .onE("knows")
              .by("weight")
              .range()
              .ifNotExist()
              .create();

        GraphManager graph = client.graph();
        Vertex marko = graph.addVertex(T.label, "person", "name", "marko",
                                       "age", 29, "city", "Beijing");
        Vertex vadas = graph.addVertex(T.label, "person", "name", "vadas",
                                       "age", 27, "city", "Hongkong");
        Vertex lop = graph.addVertex(T.label, "software", "name", "lop",
                                     "lang", "java", "price", 328);
        Vertex josh = graph.addVertex(T.label, "person", "name", "josh",
                                      "age", 32, "city", "Beijing");
        Vertex ripple = graph.addVertex(T.label, "software", "name", "ripple",
                                        "lang", "java", "price", 199);
        Vertex peter = graph.addVertex(T.label, "person", "name", "peter",
                                       "age", 35, "city", "Shanghai");

        marko.addEdge("knows", vadas, "date", "20160110", "weight", 0.5);
        marko.addEdge("knows", josh, "date", "20130220", "weight", 1.0);
        marko.addEdge("created", lop, "date", "20171210", "weight", 0.4);
        josh.addEdge("created", lop, "date", "20091111", "weight", 0.4);
        josh.addEdge("created", ripple, "date", "20171210", "weight", 1.0);
        peter.addEdge("created", lop, "date", "20170324", "weight", 0.2);
    }
}

The vertex IDs are:

"2:ripple",
"1:vadas",
"1:peter",
"1:josh",
"1:marko",
"2:lop"

The edge IDs are:

"S1:peter>2>>S2:lop",
"S1:josh>2>>S2:lop",
"S1:josh>2>>S2:ripple",
"S1:marko>1>20130220>S1:josh",
"S1:marko>1>20160110>S1:vadas",
"S1:marko>2>>S2:lop"

3.2.1 K-out API (GET, Basic Version)

3.2.1.1 Functionality Overview

The K-out API allows you to find vertices that are exactly “depth” steps away from a given starting vertex, considering the specified direction, edge type (optional), and depth.

Params
  • source: ID of the starting vertex (required)
  • direction: Direction of traversal from the starting vertex (OUT, IN, BOTH). Optional, default is BOTH.
  • max_depth: Number of steps (required)
  • label: Edge type (optional), represents all edge labels by default
  • nearest: When nearest is set to true, it means the shortest path length from the starting vertex to the result vertices is equal to the depth, and there is no shorter path. When nearest is set to false, it means there is at least one path of length depth from the starting vertex to the result vertices (not necessarily the shortest and may contain cycles). Optional, default is true.
  • max_degree: Maximum number of adjacent edges to traverse per vertex during the query. Optional, default is 10000.
  • capacity: Maximum number of vertices to be visited during the traversal. Optional, default is 10000000.
  • limit: Maximum number of vertices to be returned. Optional, default is 10000000.
3.2.1.2 Usage Example
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/kout?source="1:marko"&max_depth=2
Response Status
200
Response Body
{
    "vertices":[
        "2:ripple",
        "1:peter"
    ]
}
3.2.1.3 Use Cases

Finding vertices that are exactly N steps away in a relationship. Two examples:

  • In a family relationship, finding all grandchildren of a person. The set of vertices that can be reached by person A through two consecutive “son” edges.
  • Discovering potential friends in a social network. For example, finding users who are two degrees of friendship away from the target user, reachable through two consecutive “friend” edges.

3.2.2 K-out API (POST, Advanced Version)

3.2.2.1 Functionality Overview

The K-out API allows you to find vertices that are exactly “depth” steps away from a given starting vertex, considering the specified steps (including direction, edge type, and attribute filtering).

The advanced version differs from the basic version of K-out API in the following aspects:

  • Supports counting the number of neighbors only
  • Supports edge attribute filtering
  • Supports returning the shortest path to the neighbor
Params
  • source: The ID of the starting vertex, required.
  • steps: Steps from the starting point, required, with the following structure:
    • direction: Represents the direction of the edges (OUT, IN, BOTH), default is BOTH.
    • edge_steps: The step set of edges, supporting label and properties filtering for the edge. If edge_steps is empty, the edge is not filtered.
      • label: Edge types.
      • properties: Filter edges based on property values.
    • vertex_steps: The step set of vertices, supporting label and properties filtering for the vertex. If vertex_steps is empty, the vertex is not filtered.
      • label: Vertex types.
      • properties: Filter vertices based on property values.
    • max_degree: Maximum number of adjacent edges to traverse for a single vertex, default is 10000 (Note: Prior to version 0.12, the parameter name was “degree” instead of “max_degree”. Starting from version 0.12, “max_degree” is used uniformly, while still supporting the “degree” syntax for backward compatibility).
    • skip_degree: Sets the minimum number of edges to skip super vertices during the query process. If the number of adjacent edges for a vertex is greater than skip_degree, the vertex is completely skipped. Optional. If enabled, it should satisfy the constraint skip_degree >= max_degree. Default is 0 (not enabled), indicating no skipping of any vertices (Note: Enabling this configuration means that during traversal, an attempt will be made to access skip_degree edges of a vertex, not just max_degree edges. This incurs additional traversal overhead and may have a significant impact on query performance. Please enable it only after understanding the implications).
  • max_depth: Number of steps, required.
  • nearest: When nearest is true, it means the shortest path length from the starting vertex to the result vertex is equal to depth, and there is no shorter path. When nearest is false, it means there is a path of length depth from the starting vertex to the result vertex (not necessarily the shortest and can contain cycles). Optional, default is true.
  • count_only: Boolean value, true indicates only counting the number of results without returning specific results, false indicates returning specific results. Default is false.
  • with_path: When true, it returns the shortest path from the starting vertex to each neighbor. When false, it does not return the shortest path. Optional, default is false.
  • with_edge: Optional parameter, default is false:
    • When true, the result will include complete edge information (all edges in the path):
      • When with_path is true, it returns complete information of all edges in all paths.
      • When with_path is false, no information is returned.
    • When false, it only returns edge IDs.
  • with_vertex: Optional parameter, default is false:
    • When true, the result will include complete vertex information (all vertices in the path):
      • When with_path is true, it returns complete information of all vertices in all paths.
      • When with_path is false, it returns complete information of all neighbors.
    • When false, it only returns vertex IDs.
  • capacity: Maximum number of vertices to visit during traversal. Optional, default is 10000000.
  • limit: Maximum number of vertices to return. Optional, default is 10000000.
  • traverse_mode: Traversal mode. There are two options: “breadth_first_search” and “depth_first_search”, default is “breadth_first_search”.
3.2.2.2 Usage
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/kout
Request Body
{
    "source": "1:marko",
    "steps": {
        "direction": "BOTH",
        "edge_steps": [
            {
                "label": "knows",
                "properties": {
                    "weight": "P.gt(0.1)"
                }
            },
            {
                "label": "created",
                "properties": {
                    "weight": "P.gt(0.1)"
                }
            }
        ],
        "vertex_steps": [
            {
                "label": "person",
                "properties": {
                    "age": "P.lt(32)"
                }
            },
            {
                "label": "software",
                "properties": {}
            }
        ],
        "max_degree": 10000,
        "skip_degree": 100000
    },
    "max_depth": 1,
    "nearest": true,
    "limit": 10000,
    "with_vertex": true,
    "with_path": true,
    "with_edge": true
}
Response Status
200
Response Body
{
    "size": 2,
    "kout": [
        "1:vadas",
        "2:lop"
    ],
    "paths": [
        {
            "objects": [
                "1:marko",
                "2:lop"
            ]
        },
        {
            "objects": [
                "1:marko",
                "1:vadas"
            ]
        }
    ],
    "vertices": [
        {
            "id": "1:marko",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "marko",
                "age": 29,
                "city": "Beijing"
            }
        },
        {
            "id": "1:vadas",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "vadas",
                "age": 27,
                "city": "Hongkong"
            }
        },
        {
            "id": "2:lop",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "lop",
                "lang": "java",
                "price": 328
            }
        }
    ],
    "edges": [
        {
            "id": "S1:marko>1>20160110>S1:vadas",
            "label": "knows",
            "type": "edge",
            "outV": "1:marko",
            "outVLabel": "person",
            "inV": "1:vadas",
            "inVLabel": "person",
            "properties": {
                "weight": 0.5,
                "date": "20160110"
            }
        },
        {
            "id": "S1:marko>2>>S2:lop",
            "label": "created",
            "type": "edge",
            "outV": "1:marko",
            "outVLabel": "person",
            "inV": "2:lop",
            "inVLabel": "software",
            "properties": {
                "weight": 0.4,
                "date": "20171210"
            }
        }
    ]
}
3.2.2.3 Use Cases

Refer to 3.2.1.3.

3.2.3 K-neighbor (GET, Basic Version)

3.2.3.1 Function Introduction

Find all vertices that are reachable within depth steps, including the starting vertex, based on the starting vertex, direction, edge type (optional), and depth.

Equivalent to the union of: starting vertex, K-out(1), K-out(2), …, K-out(max_depth).

Params
  • source: ID of the starting vertex, required.
  • direction: Direction in which the starting vertex’s edges extend (OUT, IN, BOTH). Optional, default is BOTH.
  • max_depth: Number of steps, required.
  • label: Edge type, optional, default represents all edge labels.
  • max_degree: Maximum number of adjacent edges to traverse for a single vertex during the query process. Optional, default is 10000.
  • limit: Maximum number of vertices to return, also represents the maximum number of vertices to visit during traversal. Optional, default is 10000000.
3.2.3.2 Usage
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/kneighbor?source=%221:marko%22&max_depth=2
Response Status
200
Response Body
{
    "vertices":[
        "2:ripple",
        "1:marko",
        "1:josh",
        "1:vadas",
        "1:peter",
        "2:lop"
    ]
}
3.2.3.3 Use Cases

Find all vertices reachable within N steps, for example:

  • In a family relationship, find all descendants within five generations of a person. This can be achieved by traversing five consecutive “parent-child” edges from person A.
  • In a social network, discover friend circles. For example, users who can be reached by 1, 2, or 3 “friend” edges from the target user can form the target user’s friend circle.

3.2.4 K-neighbor API (POST, Advanced Version)

3.2.4.1 Function Introduction

Find all vertices that are reachable within depth steps from the starting vertex, based on the starting vertex, steps (including direction, edge type, and filter properties), and depth.

The difference from the Basic Version of K-neighbor API is that:

  • It supports counting the number of neighbors only.
  • It supports filtering edges based on their properties.
  • It supports returning the shortest path to reach the neighbors.
Params
  • source: Starting vertex ID, required.
  • steps: Steps from the starting point, required, with the following structure:
    • direction: Represents the direction of the edges (OUT, IN, BOTH), default is BOTH.
    • edge_steps: The step set of edges, supporting label and properties filtering for the edge. If edge_steps is empty, the edge is not filtered.
      • label: Edge types.
      • properties: Filter edges based on property values.
    • vertex_steps: The step set of vertices, supporting label and properties filtering for the vertex. If vertex_steps is empty, the vertex is not filtered.
      • label: Vertex types.
      • properties: Filter vertices based on property values.
    • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Default is 10000. (Note: Before version 0.12, the parameter name within the step only supported “degree.” Starting from version 0.12, it is unified as “max_degree” and is backward compatible with the “degree” notation.)
    • skip_degree: Used to set the minimum number of edges to discard super vertices during the query process. When the number of adjacent edges for a vertex exceeds skip_degree, the vertex is completely discarded. This is an optional parameter. If enabled, it should satisfy the constraint skip_degree >= max_degree. Default is 0 (not enabled), which means no vertices are skipped. (Note: When this configuration is enabled, the traversal will attempt to access skip_degree edges for each vertex, not just max_degree edges. This incurs additional traversal overhead and may significantly impact query performance. Please make sure to understand this before enabling.)
  • max_depth: Number of steps, required.
  • count_only: Boolean value. If true, only the count of results is returned without the actual results. If false, the specific results are returned. Default is false.
  • with_path: If true, the shortest path from the starting point to each neighbor is returned. If false, the shortest path from the starting point to each neighbor is not returned. This is an optional parameter. Default is false.
  • with_edge: Optional parameter, default is false:
    • When true, the result will include complete edge information (all edges in the path):
      • When with_path is true, it returns complete information of all edges in all paths.
      • When with_path is false, no information is returned.
    • When false, it only returns edge IDs.
  • with_vertex: Optional parameter, default is false:
    • When true, the result will include complete vertex information (all vertices in the path):
      • When with_path is true, it returns complete information of all vertices in all paths.
      • When with_path is false, it returns complete information of all neighbors.
    • When false, it only returns vertex IDs.
  • limit: Maximum number of vertices to be returned. Also, the maximum number of vertices visited during the traversal process. This is an optional parameter. Default is 10000000.
3.2.4.2 Usage Method
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/kneighbor
Request Body
{
    "source": "1:marko",
    "steps": {
        "direction": "BOTH",
        "edge_steps": [
            {
                "label": "knows",
                "properties": {
                    "weight": "P.gt(0.1)"
                }
            },
            {
                "label": "created",
                "properties": {
                    "weight": "P.gt(0.1)"
                }
            }
        ],
        "vertex_steps": [
            {
                "label": "person",
                "properties": {
                    "age": "P.lt(32)"
                }
            },
            {
                "label": "software",
                "properties": {}
            }
        ],
        "max_degree": 10000,
        "skip_degree": 100000
    },
    "max_depth": 1,
    "nearest": true,
    "limit": 10000,
    "with_vertex": true,
    "with_path": true,
    "with_edge": true
}
Response Status
200
Response Body
{
    "size": 4,
    "kneighbor": [
        "1:josh",
        "2:lop",
        "1:peter",
        "2:ripple"
    ],
    "paths": [
        {
            "objects": [
                "1:marko",
                "2:lop"
            ]
        },
        {
            "objects": [
                "1:marko",
                "2:lop",
                "1:peter"
            ]
        },
        {
            "objects": [
                "1:marko",
                "1:josh"
            ]
        },
        {
            "objects": [
                "1:marko",
                "1:josh",
                "2:ripple"
            ]
        }
    ],
    "vertices": [
        {
            "id": "2:ripple",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "ripple",
                "lang": "java",
                "price": 199
            }
        },
        {
            "id": "1:marko",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "marko",
                "age": 29,
                "city": "Beijing"
            }
        },
        {
            "id": "1:josh",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "josh",
                "age": 32,
                "city": "Beijing"
            }
        },
        {
            "id": "1:peter",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "peter",
                "age": 35,
                "city": "Shanghai"
            }
        },
        {
            "id": "2:lop",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "lop",
                "lang": "java",
                "price": 328
            }
        }
    ],
    "edges": [
        {
            "id": "S1:josh>2>>S2:ripple",
            "label": "created",
            "type": "edge",
            "outV": "1:josh",
            "outVLabel": "person",
            "inV": "2:ripple",
            "inVLabel": "software",
            "properties": {
                "weight": 1.0,
                "date": "20171210"
            }
        },
        {
            "id": "S1:marko>2>>S2:lop",
            "label": "created",
            "type": "edge",
            "outV": "1:marko",
            "outVLabel": "person",
            "inV": "2:lop",
            "inVLabel": "software",
            "properties": {
                "weight": 0.4,
                "date": "20171210"
            }
        },
        {
            "id": "S1:marko>1>20130220>S1:josh",
            "label": "knows",
            "type": "edge",
            "outV": "1:marko",
            "outVLabel": "person",
            "inV": "1:josh",
            "inVLabel": "person",
            "properties": {
                "weight": 1.0,
                "date": "20130220"
            }
        },
        {
            "id": "S1:peter>2>>S2:lop",
            "label": "created",
            "type": "edge",
            "outV": "1:peter",
            "outVLabel": "person",
            "inV": "2:lop",
            "inVLabel": "software",
            "properties": {
                "weight": 0.2,
                "date": "20170324"
            }
        }
    ]
}
3.2.4.3 Use Cases

See 3.2.3.3

3.2.5 Same Neighbors

3.2.5.1 Function Introduction

Retrieve the common neighbors of two vertices.

Params
  • vertex: ID of one vertex, required.
  • other: ID of another vertex, required.
  • direction: Direction in which the vertex expands outward (OUT, IN, BOTH). Optional, default is BOTH.
  • label: Edge type. Optional, default represents all edge labels.
  • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Optional, default is 10000.
  • limit: Maximum number of common neighbors to be returned. Optional, default is 10000000.
3.2.5.2 Usage Method
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/sameneighbors?vertex=%221:marko%22&other=%221:josh%22
Response Status
200
Response Body
{
    "same_neighbors":[
        "2:lop"
    ]
}
3.2.5.3 Use Cases

Find the common neighbors of two vertices:

  • In a social network, find the common followers or users both users are following.

3.2.6 Jaccard Similarity (GET)

3.2.6.1 Function Introduction

Compute the Jaccard similarity between two vertices (the intersection of the neighbors of the two vertices divided by the union of the neighbors of the two vertices).

Params
  • vertex: ID of one vertex, required.
  • other: ID of another vertex, required.
  • direction: Direction in which the vertex expands outward (OUT, IN, BOTH). Optional, default is BOTH.
  • label: Edge type. Optional, default represents all edge labels.
  • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Optional, default is 10000.
3.2.6.2 Usage Method
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/jaccardsimilarity?vertex="1:marko"&other="1:josh"
Response Status
200
Response Body
{
    "jaccard_similarity": 0.2
}
3.2.6.3 Use Cases

Used to evaluate the similarity or closeness between two vertices.

3.2.7 Jaccard Similarity (POST)

3.2.7.1 Function Introduction

Compute the N vertices with the highest Jaccard similarity to a specified vertex.

The Jaccard similarity is calculated as the intersection of the neighbors of the two vertices divided by the union of the neighbors of the two vertices.

Params
  • vertex: ID of a vertex, required.
  • Steps from the starting point, required. The structure is as follows:
    • direction: Direction of the edges (OUT, IN, BOTH). Optional, default is BOTH.
    • labels: List of edge types.
    • properties: Filter edges based on property values.
    • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Default is 10000. (Note: Prior to version 0.12, the parameter name inside “step” was “degree”. Starting from version 0.12, it is unified as “max_degree” and still compatible with “degree” notation.)
    • skip_degree: Used to set the minimum number of edges to skip super vertices during the query process. If the number of adjacent edges for a vertex is greater than skip_degree, the vertex is completely skipped. Optional, default is 0 (not enabled), which means no skipping. (Note: When this configuration is enabled, the traversal will attempt to access skip_degree edges of a vertex, not just max_degree edges. This incurs additional traversal overhead and may have a significant impact on query performance. Please enable it after understanding and confirming.)
  • top: Return the top N vertices with the highest Jaccard similarity for a starting vertex. Optional, default is 100.
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional, default is 10000000.
3.2.7.2 Usage Method
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/jaccardsimilarity
Request Body
{
  "vertex": "1:marko",
  "step": {
    "direction": "BOTH",
    "labels": [],
    "max_degree": 10000,
    "skip_degree": 100000
  },
  "top": 3
}
Response Status
200
Response Body
{
    "2:ripple": 0.3333333333333333,
    "1:peter": 0.3333333333333333,
    "1:josh": 0.2
}
3.2.7.3 Use Cases

Used to find the vertices in the graph that have the highest similarity to a specified vertex.

3.2.8 Shortest Path

3.2.8.1 Function Introduction

Find the shortest path between a starting vertex and a target vertex based on the direction, edge type (optional), and maximum depth.

Params
  • source: ID of the starting vertex, required.
  • target: ID of the target vertex, required.
  • direction: Direction in which the starting vertex expands (OUT, IN, BOTH). Optional, default is BOTH.
  • max_depth: Maximum number of steps, required.
  • label: Edge type, optional. Default represents all edge labels.
  • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Optional, default is 10000.
  • skip_degree: Used to set the minimum number of edges to skip super vertices during the query process. If the number of adjacent edges for a vertex is greater than skip_degree, the vertex is completely skipped. Optional, default is 0 (not enabled), which means no skipping. (Note: When this configuration is enabled, the traversal will attempt to access skip_degree edges of a vertex, not just max_degree edges. This incurs additional traversal overhead and may have a significant impact on query performance. Please enable it after understanding and confirming.)
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional, default is 10000000.
3.2.8.2 Usage Method
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/shortestpath?source="1:marko"&target="2:ripple"&max_depth=3
Response Status
200
Response Body
{
    "path":[
        "1:marko",
        "1:josh",
        "2:ripple"
    ]
}
3.2.8.3 Use Cases

Used to find the shortest path between two vertices, for example:

  • In a social network, finding the shortest path between two users, representing the closest friend relationship chain.
  • In a device association network, finding the shortest association relationship between two devices.

3.2.9 All Shortest Paths

3.2.9.1 Function Introduction

Find all shortest paths between a starting vertex and a target vertex based on the direction, edge type (optional), and maximum depth.

Params
  • source: ID of the starting vertex, required.
  • target: ID of the target vertex, required.
  • direction: Direction in which the starting vertex expands (OUT, IN, BOTH). Optional, default is BOTH.
  • max_depth: Maximum number of steps, required.
  • label: Edge type, optional. Default represents all edge labels.
  • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Optional, default is 10000.
  • skip_degree: Used to set the minimum number of edges to skip super vertices during the query process. If the number of adjacent edges for a vertex is greater than skip_degree, the vertex is completely skipped. Optional, default is 0 (not enabled), which means no skipping. (Note: When this configuration is enabled, the traversal will attempt to access skip_degree edges of a vertex, not just max_degree edges. This incurs additional traversal overhead and may have a significant impact on query performance. Please enable it after understanding and confirming.)
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional, default is 10000000.
3.2.9.2 Usage Method
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/allshortestpaths?source="A"&target="Z"&max_depth=10
Response Status
200
Response Body
{
    "paths":[
        {
            "objects": [
                "A",
                "B",
                "C",
                "Z"
            ]
        },
        {
            "objects": [
                "A",
                "M",
                "N",
                "Z"
            ]
        }
    ]
}
3.2.9.3 Use Cases

Used to find all shortest paths between two vertices, for example:

  • In a social network, finding all shortest paths between two users, representing all the closest friend relationship chains.
  • In a device association network, finding all shortest association relationships between two devices.

3.2.10 Weighted Shortest Path

3.2.10.1 Function Introduction

Find a weighted shortest path between a starting vertex and a target vertex based on the direction, edge type (optional), maximum depth, and edge weight property.

Params
  • source: ID of the starting vertex, required.
  • target: ID of the target vertex, required.
  • direction: Direction in which the starting vertex expands (OUT, IN, BOTH). Optional, default is BOTH.
  • label: Edge type, optional. Default represents all edge labels.
  • weight: Edge weight property, required. It must be a numeric property.
  • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Optional, default is 10000.
  • skip_degree: Used to set the minimum number of edges to skip super vertices during the query process. If the number of adjacent edges for a vertex is greater than skip_degree, the vertex is completely skipped. Optional, default is 0 (not enabled), which means no skipping. (Note: When this configuration is enabled, the traversal will attempt to access skip_degree edges of a vertex, not just max_degree edges. This incurs additional traversal overhead and may have a significant impact on query performance. Please enable it after understanding and confirming.)
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional, default is 10000000.
  • with_vertex: true to include complete vertex information (all vertices in the path) in the result, false to only return vertex IDs. Optional, default is false.
3.2.10.2 Usage Method
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/weightedshortestpath?source="1:marko"&target="2:ripple"&weight="weight"&with_vertex=true
Response Status
200
Response Body
{
    "path": {
        "weight": 2.0,
        "vertices": [
            "1:marko",
            "1:josh",
            "2:ripple"
        ]
    },
    "vertices": [
        {
            "id": "1:marko",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "marko",
                "age": 29,
                "city": "Beijing"
            }
        },
        {
            "id": "1:josh",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "josh",
                "age": 32,
                "city": "Beijing"
            }
        },
        {
            "id": "2:ripple",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "ripple",
                "lang": "java",
                "price": 199
            }
        }
    ]
}
3.2.10.3 Use Cases

Used to find the weighted shortest path between two vertices, for example:

  • In a transportation network, finding the transportation method that requires the least cost from city A to city B.

3.2.11 Single Source Shortest Path

3.2.11.1 Function Introduction

Starting from a vertex, find the shortest paths from that vertex to other vertices in the graph (optional with weight).

Params
  • source: ID of the starting vertex, required.
  • direction: Direction in which the starting vertex expands (OUT, IN, BOTH). Optional, default is BOTH.
  • label: Edge type, optional. Default represents all edge labels.
  • weight: Edge weight property, optional. It must be a numeric property. If not provided or the edges don’t have this property, the weight is considered as 1.0.
  • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Optional, default is 10000.
  • skip_degree: Used to set the minimum number of edges to skip super vertices during the query process. If the number of adjacent edges for a vertex is greater than skip_degree, the vertex is completely skipped. Optional, default is 0 (not enabled), which means no skipping. (Note: When this configuration is enabled, the traversal will attempt to access skip_degree edges of a vertex, not just max_degree edges. This incurs additional traversal overhead and may have a significant impact on query performance. Please enable it after understanding and confirming.)
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional, default is 10000000.
  • limit: Number of target vertices to be queried and the number of shortest paths to be returned. Optional, default is 10.
  • with_vertex: true to include complete vertex information (all vertices in the path) in the result, false to only return vertex IDs. Optional, default is false.
3.2.11.2 Usage Method
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/singlesourceshortestpath?source="1:marko"&with_vertex=true
Response Status
200
Response Body
{
    "paths": {
        "2:ripple": {
            "weight": 2.0,
            "vertices": [
                "1:marko",
                "1:josh",
                "2:ripple"
            ]
        },
        "1:josh": {
            "weight": 1.0,
            "vertices": [
                "1:marko",
                "1:josh"
            ]
        },
        "1:vadas": {
            "weight": 1.0,
            "vertices": [
                "1:marko",
                "1:vadas"
            ]
        },
        "1:peter": {
            "weight": 2.0,
            "vertices": [
                "1:marko",
                "2:lop",
                "1:peter"
            ]
        },
        "2:lop": {
            "weight": 1.0,
            "vertices": [
                "1:marko",
                "2:lop"
            ]
        }
    },
    "vertices": [
        {
            "id": "2:ripple",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "ripple",
                "lang": "java",
                "price": 199
            }
        },
        {
            "id": "1:marko",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "marko",
                "age": 29,
                "city": "Beijing"
            }
        },
        {
            "id": "1:josh",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "josh",
                "age": 32,
                "city": "Beijing"
            }
        },
        {
            "id": "1:vadas",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "vadas",
                "age": 27,
                "city": "Hongkong"
            }
        },
        {
            "id": "1:peter",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "peter",
                "age": 35,
                "city": "Shanghai"
            }
        },
        {
            "id": "2:lop",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "lop",
                "lang": "java",
                "price": 328
            }
        }
    ]
}
3.2.11.3 Use Cases

Used to find the weighted shortest path from one vertex to other vertices, for example:

  • Finding the shortest travel time by bus from Beijing to all other cities in the country.

3.2.12 Multi Node Shortest Path

3.2.12.1 Function Introduction

Finds the shortest paths between pairs of specified vertices.

Params
  • vertices: Defines the starting vertices, required. It can be specified in the following ways:
    • ids: Provide a list of vertex IDs as starting vertices.
    • label and properties: If no IDs are specified, use the combined conditions of label and properties to query the starting vertices.
      • label: Vertex type.
      • properties: Query the starting vertices based on property values.

      Note: Property values in properties can be a list, indicating that the value of the key can be any value in the list.

  • step: Represents the path from the starting vertices to the destination vertices, required. The structure of the step is as follows:
    • direction: Represents the direction of the edges (OUT, IN, BOTH). Default is BOTH.
    • labels: List of edge types.
    • properties: Filters the edges based on property values.
    • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Default is 10000. (Note: Before version 0.12, the step only supported “degree” as the parameter name. Starting from version 0.12, “max_degree” is used uniformly, and “degree” is still supported for backward compatibility.)
    • skip_degree: Used to set the minimum number of edges to skip super vertices during the query process. If the number of adjacent edges for a vertex is greater than skip_degree, the vertex is completely skipped. Optional, default is 0 (not enabled), which means no skipping. (Note: When this configuration is enabled, the traversal will attempt to access skip_degree edges of a vertex, not just max_degree edges. This incurs additional traversal overhead and may have a significant impact on query performance. Please enable it after understanding and confirming.)
  • max_depth: Number of steps, required.
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional, default is 10000000.
  • with_vertex: true to include complete vertex information (all vertices in the path) in the result, false to only return vertex IDs. Optional, default is false.
3.2.12.2 Usage Method
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/multinodeshortestpath
Request Body
{
    "vertices": {
        "ids": ["382:marko", "382:josh", "382:vadas", "382:peter", "383:lop", "383:ripple"]
    },
    "step": {
        "direction": "BOTH",
        "properties": {
        }
    },
    "max_depth": 10,
    "capacity": 100000000,
    "with_vertex": true
}
Response Status
200
Response Body
{
    "paths": [
        {
            "objects": [
                "382:peter",
                "383:lop"
            ]
        },
        {
            "objects": [
                "382:peter",
                "383:lop",
                "382:marko"
            ]
        },
        {
            "objects": [
                "382:peter",
                "383:lop",
                "382:josh"
            ]
        },
        {
            "objects": [
                "382:peter",
                "383:lop",
                "382:marko",
                "382:vadas"
            ]
        },
        {
            "objects": [
                "383:lop",
                "382:marko"
            ]
        },
        {
            "objects": [
                "383:lop",
                "382:josh"
            ]
        },
        {
            "objects": [
                "383:lop",
                "382:marko",
                "382:vadas"
            ]
        },
        {
            "objects": [
                "382:peter",
                "383:lop",
                "382:josh",
                "383:ripple"
            ]
        },
        {
            "objects": [
                "382:marko",
                "382:josh"
            ]
        },
        {
            "objects": [
                "383:lop",
                "382:josh",
                "383:ripple"
            ]
        },
        {
            "objects": [
                "382:marko",
                "382:vadas"
            ]
        },
        {
            "objects": [
                "382:marko",
                "382:josh",
                "383:ripple"
            ]
        },
        {
            "objects": [
                "382:josh",
                "383:ripple"
            ]
        },
        {
            "objects": [
                "382:josh",
                "382:marko",
                "382:vadas"
            ]
        },
        {
            "objects": [
                "382:vadas",
                "382:marko",
                "382:josh",
                "383:ripple"
            ]
        }
    ],
    "vertices": [
        {
            "id": "382:peter",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "peter",
                "age": 29,
                "city": "Shanghai"
            }
        },
        {
            "id": "383:lop",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "lop",
                "lang": "java",
                "price": 328
            }
        },
        {
            "id": "382:marko",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "marko",
                "age": 29,
                "city": "Beijing"
            }
        },
        {
            "id": "382:josh",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "josh",
                "age": 32,
                "city": "Beijing"
            }
        },
        {
            "id": "382:vadas",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "vadas",
                "age": 27,
                "city": "Hongkong"
            }
        },
        {
            "id": "383:ripple",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "ripple",
                "lang": "java",
                "price": 199
            }
        }
    ]
}
3.2.12.3 Use Cases

Used to find the shortest paths between multiple vertices, for example:

  • Finding the shortest paths between multiple companies and their legal representatives.

3.2.13 Paths (GET, Basic Version)

3.2.13.1 Function Introduction

Finds all paths based on conditions such as the starting vertex, destination vertex, direction, edge types (optional), and maximum depth.

Params
  • source: ID of the starting vertex, required.
  • target: ID of the destination vertex, required.
  • direction: Direction in which the starting vertex expands (OUT, IN, BOTH). Optional, default is BOTH.
  • label: Edge type. Optional, default represents all edge labels.
  • max_depth: Number of steps, required.
  • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Optional, default is 10000.
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional, default is 10000000.
  • limit: Maximum number of paths to be returned. Optional, default is 10.
3.2.13.2 Usage Method
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/paths?source="1:marko"&target="1:josh"&max_depth=5
Response Status
200
Response Body
{
    "paths":[
        {
            "objects":[
                "1:marko",
                "1:josh"
            ]
        },
        {
            "objects":[
                "1:marko",
                "2:lop",
                "1:josh"
            ]
        }
    ]
}
3.2.13.3 Use Cases

Used to find all paths between two vertices, for example:

  • In a social network, finding all possible relationship paths between two users.
  • In a device association network, finding all associated paths between two devices.

3.2.14 Paths (POST, Advanced Version)

3.2.14.1 Function Introduction

Finds all paths based on conditions such as the starting vertex, destination vertex, steps (step), and maximum depth.

Params
  • sources: Defines the starting vertices, required. The specification methods include:
    • ids: Provide the starting vertices through a list of vertex IDs.
    • label and properties: If no IDs are specified, use the label and properties as combined conditions to query the starting vertices.
      • label: Vertex type.
      • properties: Query the starting vertices based on the values of their properties.

      Note: The property values in properties can be a list, indicating that any value corresponding to the key is acceptable.

  • targets: Defines the destination vertices, required. The specification methods include:
    • ids: Provide the destination vertices through a list of vertex IDs.
    • label and properties: If no IDs are specified, use the label and properties as combined conditions to query the destination vertices.
      • label: Vertex type.
      • properties: Query the destination vertices based on the values of their properties.

      Note: The property values in properties can be a list, indicating that any value corresponding to the key is acceptable.

  • step: Represents the path from the starting vertex to the destination vertex, required. The structure of Step is as follows:
    • direction: Represents the direction of edges (OUT, IN, BOTH). The default is BOTH.
    • labels: List of edge types.
    • properties: Filters edges based on property values.
    • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Default is 10000. (Note: Prior to version 0.12, step only supported degree as a parameter name. Starting from version 0.12, max_degree is used uniformly and degree writing is backward compatible.)
    • skip_degree: Used to set the minimum number of edges to be discarded for super vertices during the query process. When the number of adjacent edges for a vertex is greater than skip_degree, the vertex is completely discarded. Optional, if enabled, it must satisfy the constraint skip_degree >= max_degree. Default is 0 (not enabled), which means no points are skipped. (Note: When this configuration is enabled, the traversal will attempt to visit skip_degree edges of a vertex, not just max_degree edges. This incurs additional traversal overhead and may have a significant impact on query performance. Please make sure to understand before enabling it.)
  • max_depth: Number of steps, required.
  • nearest: When nearest is true, it means the shortest path length from the starting vertex to the result vertex is depth, and there is no shorter path. When nearest is false, it means there is a path of length depth from the starting vertex to the result vertex (not necessarily the shortest path and can have cycles). Optional, default is true.
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional, default is 10000000.
  • limit: Maximum number of paths to be returned. Optional, default is 10.
  • with_vertex: When true, the results include complete vertex information (all vertices in the path). When false, only the vertex IDs are returned. Optional, default is false.
3.2.14.2 Usage Method
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/paths
Request Body
{
"sources": {
  "ids": ["1:marko"]
},
"targets": {
  "ids": ["1:peter"]
},
"step": {
"direction": "BOTH",
  "properties": {
    "weight": "P.gt(0.01)"
  }
},
"max_depth": 10,
"capacity": 100000000,
"limit": 10000000,
"with_vertex": false
}
Response Status
200
Response Body
{
    "paths": [
        {
            "objects": [
                "1:marko",
                "1:josh",
                "2:lop",
                "1:peter"
            ]
        },
        {
            "objects": [
                "1:marko",
                "2:lop",
                "1:peter"
            ]
        }
    ]
}
3.2.14.3 Use Cases

Used to find all paths between two vertices, for example:

  • In a social network, finding all possible relationship paths between two users.
  • In a device association network, finding all associated paths between two devices.

3.2.15 Customized Paths

3.2.15.1 Function Introduction

Finds all paths that meet the specified conditions based on a batch of starting vertices, edge rules (including direction, edge types, and property filters), and maximum depth.

Params
  • sources: Defines the starting vertices, required. The specification methods include:
    • ids: Provide the starting vertices through a list of vertex IDs.
    • label and properties: If no IDs are specified, use the label and properties as combined conditions to query the starting vertices.
      • label: Vertex type.
      • properties: Query the starting vertices based on the values of their properties.

      Note: The property values in properties can be a list, indicating that any value corresponding to the key is acceptable.

  • steps: Represents the path rules traversed from the starting vertices and is a list of Steps. Required. The structure of each Step is as follows:
    • direction: Represents the direction of edges (OUT, IN, BOTH). The default is BOTH.
    • labels: List of edge types.
    • properties: Filters edges based on property values.
    • weight_by: Calculates the weight of edges based on the specified property. It is effective when sort_by is not NONE and is mutually exclusive with default_weight.
    • default_weight: The default weight to be used when there is no property to calculate the weight of edges. It is effective when sort_by is not NONE and is mutually exclusive with weight_by.
    • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Default is 10000. (Note: Prior to version 0.12, step only supported degree as a parameter name. Starting from version 0.12, max_degree is used uniformly and degree writing is backward compatible.)
    • sample: Used when sampling is needed for the edges that meet the conditions of a specific step. -1 means no sampling, and the default is to sample 100 edges.
  • sort_by: Sorts the paths based on their weights. Optional, default is NONE:
    • NONE: No sorting, default value.
    • INCR: Sorts in ascending order based on path weights.
    • DECR: Sorts in descending order based on path weights.
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional, default is 10000000.
  • limit: Maximum number of paths to be returned. Optional, default is 10.
  • with_vertex: When true, the results include complete vertex information (all vertices in the path). When false, only the vertex IDs are returned. Optional, default is false.
3.2.15.2 Usage Method
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/customizedpaths
Request Body
{
    "sources":{
        "ids":[

        ],
        "label":"person",
        "properties":{
            "name":"marko"
        }
    },
    "steps":[
        {
            "direction":"OUT",
            "labels":[
                "knows"
            ],
            "weight_by":"weight",
            "max_degree":-1
        },
        {
            "direction":"OUT",
            "labels":[
                "created"
            ],
            "default_weight":8,
            "max_degree":-1,
            "sample":1
        }
    ],
    "sort_by":"INCR",
    "with_vertex":true,
    "capacity":-1,
    "limit":-1
}
Response Status
200
Response Body
{
    "paths":[
        {
            "objects":[
                "1:marko",
                "1:josh",
                "2:lop"
            ],
            "weights":[
                1,
                8
            ]
        }
    ],
    "vertices":[
        {
            "id":"1:marko",
            "label":"person",
            "type":"vertex",
            "properties":{
                "city":[
                    {
                        "id":"1:marko>city",
                        "value":"Beijing"
                    }
                ],
                "name":[
                    {
                        "id":"1:marko>name",
                        "value":"marko"
                    }
                ],
                "age":[
                    {
                        "id":"1:marko>age",
                        "value":29
                    }
                ]
            }
        },
        {
            "id":"1:josh",
            "label":"person",
            "type":"vertex",
            "properties":{
                "city":[
                    {
                        "id":"1:josh>city",
                        "value":"Beijing"
                    }
                ],
                "name":[
                    {
                        "id":"1:josh>name",
                        "value":"josh"
                    }
                ],
                "age":[
                    {
                        "id":"1:josh>age",
                        "value":32
                    }
                ]
            }
        },
        {
            "id":"2:lop",
            "label":"software",
            "type":"vertex",
            "properties":{
                "price":[
                    {
                        "id":"2:lop>price",
                        "value":328
                    }
                ],
                "name":[
                    {
                        "id":"2:lop>name",
                        "value":"lop"
                    }
                ],
                "lang":[
                    {
                        "id":"2:lop>lang",
                        "value":"java"
                    }
                ]
            }
        }
    ]
}
3.2.15.3 Use Cases

Suitable for finding various complex sets of paths, for example:

  • In a social network, finding the paths from users who have watched movies directed by Zhang Yimou to the influencers they follow (Zhang Yimou —> Movie —> User —> Influencer).
  • In a risk control network, finding the paths from multiple high-risk users to the friends of their direct relatives (High-risk user —> Direct relative —> Friend).

3.2.16 Template Paths

3.2.16.1 Function Introduction

Finds all paths that meet the specified conditions based on a batch of starting vertices, edge rules (including direction, edge types, and property filters), and maximum depth.

Params
  • sources: Defines the starting vertices, required. The specification methods include:
    • ids: Provide the starting vertices through a list of vertex IDs.
    • label and properties: If no IDs are specified, use the label and properties as combined conditions to query the starting vertices.
      • label: Vertex type.
      • properties: Query the starting vertices based on the values of their properties.

      Note: The property values in properties can be a list, indicating that any value corresponding to the key is acceptable.

  • targets: Defines the ending vertices, required. The specification methods include:
    • ids: Provide the ending vertices through a list of vertex IDs.
    • label and properties: If no IDs are specified, use the label and properties as combined conditions to query the ending vertices.
      • label: Vertex type.
      • properties: Query the ending vertices based on the values of their properties.

      Note: The property values in properties can be a list, indicating that any value corresponding to the key is acceptable.

  • steps: Represents the path rules traversed from the starting vertices and is a list of Steps. Required. The structure of each Step is as follows:
    • direction: Represents the direction of edges (OUT, IN, BOTH). The default is BOTH.
    • labels: List of edge types.
    • properties: Filters edges based on property values.
    • max_times: The number of times the current step can be repeated. When set to N, it means the starting vertices can pass through the current step 1-N times.
    • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Default is 10000. (Note: Prior to version 0.12, step only supported degree as a parameter name. Starting from version 0.12, max_degree is used uniformly and degree writing is backward compatible.)
    • skip_degree: Used to set the minimum number of edges to discard super vertices during the query process. When the number of adjacent edges of a vertex is greater than skip_degree, the vertex is completely discarded. Optional. If enabled, it must satisfy the skip_degree >= max_degree constraint. Default is 0 (not enabled), which means no points are skipped. (Note: After enabling this configuration, traversing will attempt to access a vertex’s skip_degree edges, not just max_degree edges. This incurs additional traversal overhead and may have a significant impact on query performance. Please ensure understanding before enabling.)
  • with_ring: Boolean value, true to include cycles; false to exclude cycles. Default is false.
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional, default is 10000000.
  • limit: Maximum number of paths to be returned. Optional, default is 10.
  • with_vertex: When true, the results include complete vertex information (all vertices in the path). When false, only the vertex IDs are returned. Optional, default is

false.

3.2.16.2 Usage Method
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/templatepaths
Request Body
{
  "sources": {
    "ids": [],
    "label": "person",
    "properties": {
      "name": "vadas"
    }
  },
  "targets": {
    "ids": [],
    "label": "software",
    "properties": {
      "name": "ripple"
    }
  },
  "steps": [
    {
      "direction": "IN",
      "labels": ["knows"],
      "properties": {
      },
      "max_degree": 10000,
      "skip_degree": 100000
    },
    {
      "direction": "OUT",
      "labels": ["created"],
      "properties": {
      },
      "max_degree": 10000,
      "skip_degree": 100000
    },
    {
      "direction": "IN",
      "labels": ["created"],
      "properties": {
      },
      "max_degree": 10000,
      "skip_degree": 100000
    },
    {
      "direction": "OUT",
      "labels": ["created"],
      "properties": {
      },
      "max_degree": 10000,
      "skip_degree": 100000
    }
  ],
  "capacity": 10000,
  "limit": 10,
  "with_vertex": true
}
Response Status
200
Response Body
{
    "paths": [
        {
            "objects": [
                "1:vadas",
                "1:marko",
                "2:lop",
                "1:josh",
                "2:ripple"
            ]
        }
    ],
    "vertices": [
        {
            "id": "2:ripple",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "ripple",
                "lang": "java",
                "price": 199
            }
        },
        {
            "id": "1:marko",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "marko",
                "age": 29,
                "city": "Beijing"
            }
        },
        {
            "id": "1:josh",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "josh",
                "age": 32,
                "city": "Beijing"
            }
        },
        {
            "id": "1:vadas",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "vadas",
                "age": 27,
                "city": "Hongkong"
            }
        },
        {
            "id": "2:lop",
            "label": "software",
            "type": "vertex",
            "properties": {
                "name": "lop",
                "lang": "java",
                "price": 328
            }
        }
    ]
}
3.2.16.3 Use Cases

Suitable for finding various complex template paths, such as personA -(Friend)-> personB -(Classmate)-> personC, where the “Friend” and “Classmate” edges can have a maximum depth of 3 and 4 layers, respectively.

3.2.17 Crosspoints

3.2.17.1 Function Introduction

Finds the intersection points based on the specified conditions, including starting vertices, destination vertices, direction, edge types (optional), and maximum depth.

Params
  • source: ID of the starting vertex, required.
  • target: ID of the destination vertex, required.
  • direction: The direction from the starting vertex to the destination vertex. The reverse direction is used from the destination vertex to the starting vertex. When set to BOTH, the direction is not considered (OUT, IN, BOTH). Optional, default is BOTH.
  • label: Edge type, optional. Default represents all edge labels.
  • max_depth: Number of steps, required.
  • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Optional, default is 10000.
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional, default is 10000000.
  • limit: Maximum number of intersection points to be returned. Optional, default is 10.
3.2.17.2 Usage Method
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/crosspoints?source="2:lop"&target="2:ripple"&max_depth=5&direction=IN
Response Status
200
Response Body
{
    "crosspoints":[
        {
            "crosspoint":"1:josh",
            "objects":[
                "2:lop",
                "1:josh",
                "2:ripple"
            ]
        }
    ]
}
3.2.17.3 Use Cases

Used to find the intersection points and their paths between two vertices, such as:

  • In a social network, finding the topics or influencers that two users have in common.
  • In a family relationship, finding common ancestors.

3.2.18 Customized Crosspoints

3.2.18.1 Function Introduction

Finds the intersection of destination vertices that satisfy the specified conditions, including starting vertices, multiple edge rules (including direction, edge type, and property filters), and maximum depth.

Params
  • sources: Defines the starting vertices, required. The specified options include:

    • ids: Provides a list of vertex IDs as starting vertices.
    • label and properties: If no IDs are specified, uses the combined conditions of label and properties to query the starting vertices.
      • label: Type of the vertex.
      • properties: Queries the starting vertices based on property values.

      Note: Property values in properties can be a list, indicating that the value of the key can be any item in the list.

  • path_patterns: Represents the path rules to be followed from the starting vertices. It is a list of rules. Required. Each rule is a PathPattern.

    • Each PathPattern consists of a list of steps, where each step has the following structure:
      • direction: Indicates the direction of the edge (OUT, IN, BOTH). Default is BOTH.
      • labels: List of edge types.
      • properties: Filters the edges based on property values.
      • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Default is 10000.
      • skip_degree: Sets the minimum number of edges to discard super vertices during the query process. If the number of adjacent edges for a vertex is greater than skip_degree, the vertex is completely discarded. Optional. If enabled, it must satisfy the constraint skip_degree >= max_degree. Default is 0 (not enabled), which means no vertices are skipped. Note: When this configuration is enabled, the traversal process will attempt to visit skip_degree edges of a vertex, not just max_degree edges. This incurs additional traversal overhead and may significantly impact query performance. Please make sure you understand it before enabling.
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional. Default is 10000000.

  • limit: Maximum number of paths to be returned. Optional. Default is 10.

  • with_path: When set to true, returns the paths where the intersection points are located. When set to false, does not return the paths. Optional. Default is false.

  • with_vertex: Optional. Default is false.

    • When set to true, the result includes complete vertex information (all vertices in the paths):
      • When with_path is true, it returns complete information of all vertices in the paths.
      • When with_path is false, it returns complete information of all intersection points.
    • When set to false, only the vertex IDs are returned.
3.2.18.2 Usage Method
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/customizedcrosspoints
Request Body
{
    "sources":{
        "ids":[
            "2:lop",
            "2:ripple"
        ]
    },
    "path_patterns":[
        {
            "steps":[
                {
                    "direction":"IN",
                    "labels":[
                        "created"
                    ],
                    "max_degree":-1
                }
            ]
        }
    ],
    "with_path":true,
    "with_vertex":true,
    "capacity":-1,
    "limit":-1
}
Response Status
200
Response Body
{
    "crosspoints":[
        "1:josh"
    ],
    "paths":[
        {
            "objects":[
                "2:ripple",
                "1:josh"
            ]
        },
        {
            "objects":[
                "2:lop",
                "1:josh"
            ]
        }
    ],
    "vertices":[
        {
            "id":"2:ripple",
            "label":"software",
            "type":"vertex",
            "properties":{
                "price":[
                    {
                        "id":"2:ripple>price",
                        "value":199
                    }
                ],
                "name":[
                    {
                        "id":"2:ripple>name",
                        "value":"ripple"
                    }
                ],
                "lang":[
                    {
                        "id":"2:ripple>lang",
                        "value":"java"
                    }
                ]
            }
        },
        {
            "id":"1:josh",
            "label":"person",
            "type":"vertex",
            "properties":{
                "city":[
                    {
                        "id":"1:josh>city",
                        "value":"Beijing"
                    }
                ],
                "name":[
                    {
                        "id":"1:josh>name",
                        "value":"josh"
                    }
                ],
                "age":[
                    {
                        "id":"1:josh>age",
                        "value":32
                    }
                ]
            }
        },
        {
            "id":"2:lop",
            "label":"software",
            "type":"vertex",
            "properties":{
                "price":[
                    {
                        "id":"2:lop>price",
                        "value":328
                    }
                ],
                "name":[
                    {
                        "id":"2:lop>name",
                        "value":"lop"
                    }
                ],
                "lang":[
                    {
                        "id":"2:lop>lang",
                        "value":"java"
                    }
                ]
            }
        }
    ]
}
3.2.18.3 Use Cases

Used to query a group of vertices that have intersections at the destination through multiple paths. For example:

  • In a product knowledge graph, multiple models of smartphones, learning devices, and gaming devices belong to the top-level category of electronic devices through different lower-level category paths.

3.2.19 Rings

3.2.19.1 Function Introduction

Finds reachable cycles based on the specified conditions, including starting vertices, direction, edge types (optional), and maximum depth.

For example: 1 -> 25 -> 775 -> 14690 -> 25, where the cycle is 25 -> 775 -> 14690 -> 25.

Params
  • source: Starting vertex ID, required.
  • direction: Direction of edges emitted from the starting vertex (OUT, IN, BOTH). Optional. Default is BOTH.
  • label: Edge type. Optional. Default represents all edge labels.
  • max_depth: Number of steps. Required.
  • source_in_ring: Whether the starting point is included in the cycle. Optional. Default is true.
  • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Optional. Default is 10000.
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional. Default is 10000000.
  • limit: Maximum number of reachable cycles to be returned. Optional. Default is 10.
3.2.19.2 Usage Method
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/rings?source="1:marko"&max_depth=2
Response Status
200
Response Body
{
    "rings":[
        {
            "objects":[
                "1:marko",
                "1:josh",
                "1:marko"
            ]
        },
        {
            "objects":[
                "1:marko",
                "1:vadas",
                "1:marko"
            ]
        },
        {
            "objects":[
                "1:marko",
                "2:lop",
                "1:marko"
            ]
        }
    ]
}
3.2.19.3 Use Cases

Used to query cycles reachable from the starting vertex, for example:

  • In a risk control project, querying individuals or devices involved in a circular guarantee that a user is connected to.
  • In a device network, discovering devices that have circular references around a specific device.

3.2.20 Rays

3.2.20.1 Function Introduction

Finds paths that diverge from the starting vertex and reach boundary vertices based on the specified conditions, including starting vertices, direction, edge types (optional), and maximum depth.

For example: 1 -> 25 -> 775 -> 14690 -> 2289 -> 18379, where 18379 is the boundary vertex, meaning there are no edges emitted from 18379.

Params
  • source: Starting vertex ID, required.
  • direction: Direction of edges emitted from the starting vertex (OUT, IN, BOTH). Optional. Default is BOTH.
  • label: Edge type. Optional. Default represents all edge labels.
  • max_depth: Number of steps. Required.
  • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Optional. Default is 10000.
  • capacity: Maximum number of vertices to be visited during the traversal process. Optional. Default is 10000000.
  • limit: Maximum number of non-cycle paths to be returned. Optional. Default is 10.
3.2.20.2 Usage Method
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/traversers/rays?source="1:marko"&max_depth=2&direction=OUT
Response Status
200
Response Body
{
    "rays":[
        {
            "objects":[
                "1:marko",
                "1:vadas"
            ]
        },
        {
            "objects":[
                "1:marko",
                "2:lop"
            ]
        },
        {
            "objects":[
                "1:marko",
                "1:josh",
                "2:ripple"
            ]
        },
        {
            "objects":[
                "1:marko",
                "1:josh",
                "2:lop"
            ]
        }
    ]
}
3.2.20.3 Use Cases

Used to find paths from the starting vertex to boundary vertices based on a specific relationship, for example:

  • In a family relationship, finding paths from a person to all descendants who do not have children.
  • In a device network, discovering paths from a specific device to terminal devices.

3.2.21 Fusiform Similarity

3.2.21.1 Function Introduction

Queries a batch of “fusiform similar vertices” based on specified conditions. When two vertices share a certain relationship with many common vertices, they are considered “fusiform similar vertices.” For example, if “Reader A” has read 100 books, readers who have read 80 or more of these 100 books can be defined as “fusiform similar vertices” of “Reader A.”

Params
  • sources: Starting vertices, required. Specify using:

    • ids: Provide a list of vertex IDs as starting vertices.
    • label and properties: If ids are not specified, use the combined conditions of label and properties to query the starting vertices.
      • label: Vertex type.
      • properties: Query the starting vertices based on the values of their properties.

      Note: Property values in properties can be a list, indicating that the value of the key can be any value in the list.

  • label: Edge type. Optional. Default represents all edge labels.

  • direction: Direction in which the starting vertex diverges (OUT, IN, BOTH). Optional. Default is BOTH.

  • min_neighbors: Minimum number of neighbors. If the number of neighbors is less than this threshold, the starting vertex is not considered a “fusiform similar vertex.” For example, if you want to find “fusiform similar vertices” of books read by “Reader A,” and min_neighbors is set to 100, it means that “Reader A” must have read at least 100 books to have “fusiform similar vertices.” Required.

  • alpha: Similarity, representing the proportion of common neighbors between the starting vertex and “fusiform similar vertices” to all neighbors of the starting vertex. Required.

  • min_similars: Minimum number of “fusiform similar vertices.” Only when the number of “fusiform similar vertices” of the starting vertex is greater than or equal to this value, the starting vertex and its “fusiform similar vertices” will be returned. Optional. Default is 1.

  • top: Returns the top highest similarity “fusiform similar vertices” of a starting vertex. Required. 0 means all.

  • group_property: Used together with min_groups. Returns the starting vertex and its “fusiform similar vertices” only if there are at least min_groups different values for a certain attribute of the starting vertex and its “fusiform similar vertices.” For example, when recommending “out-of-town” book buddies for “Reader A,” set group_property to the “city” attribute of readers and min_group to at least 2. Optional. If not specified, no filtering based on attributes is needed.

  • min_groups: Used together with group_property. Only meaningful when group_property is set.

  • max_degree: Maximum number of adjacent edges to traverse for each vertex during the query process. Optional. Default is 10000.

  • capacity: Maximum number of vertices to be visited during the traversal process. Optional. Default is 10000000.

  • limit: Maximum number of results to be returned (one starting vertex and its “fusiform similar vertices” count as one result). Optional. Default is 10.

  • with_intermediary: Whether to return the starting vertex and the intermediate vertices that are commonly related to the “fusiform

similar vertices.” Default is false.

  • with_vertex: Optional. Default is false.
    • true: Returns complete vertex information in the results.
    • false: Only returns vertex IDs.
3.2.21.2 Usage Method
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/traversers/fusiformsimilarity
Request Body
{
    "sources":{
        "ids":[],
        "label": "person",
        "properties": {
            "name":"p1"
        }
    },
    "label":"read",
    "direction":"OUT",
    "min_neighbors":8,
    "alpha":0.75,
    "min_similars":1,
    "top":0,
    "group_property":"city",
    "min_group":2,
    "max_degree": 10000,
    "capacity": -1,
    "limit": -1,
    "with_intermediary": false,
    "with_vertex":true
}
Response Status
200
Response Body
{
    "similars": {
        "3:p1": [
            {
                "id": "3:p2",
                "score": 0.8888888888888888,
                "intermediaries": [
                ]
            },
            {
                "id": "3:p3",
                "score": 0.7777777777777778,
                "intermediaries": [
                ]
            }
        ]
    },
    "vertices": [
        {
            "id": "3:p1",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "p1",
                "city": "Beijing"
            }
        },
        {
            "id": "3:p2",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "p2",
                "city": "Shanghai"
            }
        },
        {
            "id": "3:p3",
            "label": "person",
            "type": "vertex",
            "properties": {
                "name": "p3",
                "city": "Beijing"
            }
        }
    ]
}
3.2.21.3 Use Cases

Used to query vertices that have high similarity with a group of vertices. For example:

  • Readers with similar book lists to a specific reader.
  • Players who play similar games to a specific player.

3.2.22 Vertices

3.2.22.1 Batch Query Vertices by Vertex IDs
Params
  • ids: List of vertex IDs to be queried.
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/traversers/vertices?ids="1:marko"&ids="2:lop"
Response Status
200
Response Body
{
    "vertices":[
        {
            "id":"1:marko",
            "label":"person",
            "type":"vertex",
            "properties":{
                "city":[
                    {
                        "id":"1:marko>city",
                        "value":"Beijing"
                    }
                ],
                "name":[
                    {
                        "id":"1:marko>name",
                        "value":"marko"
                    }
                ],
                "age":[
                    {
                        "id":"1:marko>age",
                        "value":29
                    }
                ]
            }
        },
        {
            "id":"2:lop",
            "label":"software",
            "type":"vertex",
            "properties":{
                "price":[
                    {
                        "id":"2:lop>price",
                        "value":328
                    }
                ],
                "name":[
                    {
                        "id":"2:lop>name",
                        "value":"lop"
                    }
                ],
                "lang":[
                    {
                        "id":"2:lop>lang",
                        "value":"java"
                    }
                ]
            }
        }
    ]
}
3.2.22.2 Get Vertex Shard Information

Obtain vertex shard information by specifying the shard size split_size (can be used in conjunction with Scan in 3.2.21.3 to retrieve vertices).

Params
  • split_size: Shard size, required.
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/traversers/vertices/shards?split_size=67108864
Response Status
200
Response Body
{
    "shards":[
        {
            "start": "0",
            "end": "2165893",
            "length": 0
        },
        {
            "start": "2165893",
            "end": "4331786",
            "length": 0
        },
        {
            "start": "4331786",
            "end": "6497679",
            "length": 0
        },
        {
            "start": "6497679",
            "end": "8663572",
            "length": 0
        },
        ......
    ]
}
3.2.22.3 Batch Retrieve Vertices Based on Shard Information

Retrieve vertices in batches based on the specified shard information (refer to 3.2.21.2 Shard for obtaining shard information).

Params
  • start: Shard start position, required.
  • end: Shard end position, required.
  • page: Page position for pagination, optional. Default is null, no pagination. When page is “”, it represents the first page of pagination starting from the position indicated by start.
  • page_limit: The upper limit of the number of vertices per page when retrieving vertices with pagination, optional. Default is 100000.
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/traversers/vertices/scan?start=0&end=4294967295
Response Status
200
Response Body
{
    "vertices":[
        {
            "id":"2:ripple",
            "label":"software",
            "type":"vertex",
            "properties":{
                "price":[
                    {
                        "id":"2:ripple>price",
                        "value":199
                    }
                ],
                "name":[
                    {
                        "id":"2:ripple>name",
                        "value":"ripple"
                    }
                ],
                "lang":[
                    {
                        "id":"2:ripple>lang",
                        "value":"java"
                    }
                ]
            }
        },
        {
            "id":"1:vadas",
            "label":"person",
            "type":"vertex",
            "properties":{
                "city":[
                    {
                        "id":"1:vadas>city",
                        "value":"Hongkong"
                    }
                ],
                "name":[
                    {
                        "id":"1:vadas>name",
                        "value":"vadas"
                    }
                ],
                "age":[
                    {
                        "id":"1:vadas>age",
                        "value":27
                    }
                ]
            }
        },
        {
            "id":"1:peter",
            "label":"person",
            "type":"vertex",
            "properties":{
                "city":[
                    {
                        "id":"1:peter>city",
                        "value":"Shanghai"
                    }
                ],
                "name":[
                    {
                        "id":"1:peter>name",
                        "value":"peter"
                    }
                ],
                "age":[
                    {
                        "id":"1:peter>age",
                        "value":35
                    }
                ]
            }
        },
        {
            "id":"1:josh",
            "label":"person",
            "type":"vertex",
            "properties":{
                "city":[
                    {
                        "id":"1:josh>city",
                        "value":"Beijing"
                    }
                ],
                "name":[
                    {
                        "id":"1:josh>name",
                        "value":"josh"
                    }
                ],
                "age":[
                    {
                        "id":"1:josh>age",
                        "value":32
                    }
                ]
            }
        },
        {
            "id":"1:marko",
            "label":"person",
            "type":"vertex",
            "properties":{
                "city":[
                    {
                        "id":"1:marko>city",
                        "value":"Beijing"
                    }
                ],
                "name":[
                    {
                        "id":"1:marko>name",
                        "value":"marko"
                    }
                ],
                "age":[
                    {
                        "id":"1:marko>age",
                        "value":29
                    }
                ]
            }
        },
        {
            "id":"2:lop",
            "label":"software",
            "type":"vertex",
            "properties":{
                "price":[
                    {
                        "id":"2:lop>price",
                        "value":328
                    }
                ],
                "name":[
                    {
                        "id":"2:lop>name",
                        "value":"lop"
                    }
                ],
                "lang":[
                    {
                        "id":"2:lop>lang",
                        "value":"java"
                    }
                ]
            }
        }
    ]
}
3.2.22.4 Use Cases
  • Querying vertices by ID list, which can be used for batch vertex queries. For example, after querying multiple paths in a path search, you can further query all vertex properties of a specific path.
  • Retrieving shards and querying vertices by shard, which can be used to traverse all vertices.

3.2.23 Edges

3.2.23.1 Batch Retrieve Edges Based on Edge IDs
Params
  • ids: List of edge IDs to be queried.
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/traversers/edges?ids="S1:josh>1>>S2:lop"&ids="S1:josh>1>>S2:ripple"
Response Status
200
Response Body
{
    "edges": [
        {
            "id": "S1:josh>1>>S2:lop",
            "label": "created",
            "type": "edge",
            "inVLabel": "software",
            "outVLabel": "person",
            "inV": "2:lop",
            "outV": "1:josh",
            "properties": {
                "date": "20091111",
                "weight": 0.4
            }
        },
        {
            "id": "S1:josh>1>>S2:ripple",
            "label": "created",
            "type": "edge",
            "inVLabel": "software",
            "outVLabel": "person",
            "inV": "2:ripple",
            "outV": "1:josh",
            "properties": {
                "date": "20171210",
                "weight": 1
            }
        }
    ]
}
3.2.23.2 Retrieve Edge Shard Information

Retrieve shard information for edges by specifying the shard size (split_size). This can be used in conjunction with the Scan operation described in section 3.2.22.3 to retrieve edges.

Params
  • split_size: Shard size, required field.
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/traversers/edges/shards?split_size=4294967295
Response Status
200
Response Body
{
    "shards":[
        {
            "start": "0",
            "end": "1073741823",
            "length": 0
        },
        {
            "start": "1073741823",
            "end": "2147483646",
            "length": 0
        },
        {
            "start": "2147483646",
            "end": "3221225469",
            "length": 0
        },
        {
            "start": "3221225469",
            "end": "4294967292",
            "length": 0
        },
        {
            "start": "4294967292",
            "end": "4294967295",
            "length": 0
        }
    ]
}
3.2.23.3 Batch Retrieve Edges Based on Shard Information

Batch retrieve edges by specifying shard information (refer to section 3.2.22.2 for shard retrieval).

Params
  • start: Shard starting position, required field.
  • end: Shard ending position, required field.
  • page: Page position for pagination, optional field. Default is null, which means no pagination. When page is empty, it indicates the first page of pagination starting from the position indicated by start.
  • page_limit: Upper limit of the number of edges per page for paginated retrieval, optional field. Default is 100000.
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/traversers/edges/scan?start=0&end=3221225469
Response Status
200
Response Body
{
    "edges":[
        {
            "id":"S1:peter>2>>S2:lop",
            "label":"created",
            "type":"edge",
            "inVLabel":"software",
            "outVLabel":"person",
            "inV":"2:lop",
            "outV":"1:peter",
            "properties":{
                "weight":0.2,
                "date":"20170324"
            }
        },
        {
            "id":"S1:josh>2>>S2:lop",
            "label":"created",
            "type":"edge",
            "inVLabel":"software",
            "outVLabel":"person",
            "inV":"2:lop",
            "outV":"1:josh",
            "properties":{
                "weight":0.4,
                "date":"20091111"
            }
        },
        {
            "id":"S1:josh>2>>S2:ripple",
            "label":"created",
            "type":"edge",
            "inVLabel":"software",
            "outVLabel":"person",
            "inV":"2:ripple",
            "outV":"1:josh",
            "properties":{
                "weight":1,
                "date":"20171210"
            }
        },
        {
            "id":"S1:marko>1>20130220>S1:josh",
            "label":"knows",
            "type":"edge",
            "inVLabel":"person",
            "outVLabel":"person",
            "inV":"1:josh",
            "outV":"1:marko",
            "properties":{
                "weight":1,
                "date":"20130220"
            }
        },
        {
            "id":"S1:marko>1>20160110>S1:vadas",
            "label":"knows",
            "type":"edge",
            "inVLabel":"person",
            "outVLabel":"person",
            "inV":"1:vadas",
            "outV":"1:marko",
            "properties":{
                "weight":0.5,
                "date":"20160110"
            }
        },
        {
            "id":"S1:marko>2>>S2:lop",
            "label":"created",
            "type":"edge",
            "inVLabel":"software",
            "outVLabel":"person",
            "inV":"2:lop",
            "outV":"1:marko",
            "properties":{
                "weight":0.4,
                "date":"20171210"
            }
        }
    ]
}
3.2.23.4 Use Cases
  • Querying edges based on ID list, suitable for batch retrieval of edges.
  • Retrieving shard information and querying edges based on shards, useful for traversing all edges.

5.1.11 - Rank API

4.1 Rank API overview

Not only the Graph iteration (traverser) method, HugeGraph-Server also provide Rank API for recommendation purpose. You can use it to recommend some vertexes much closer to a vertex.

4.2 Details of Rank API

4.2.1 Personal Rank API

A typical scenario for Personal Rank algorithm is in recommendation application. According to the out edges of a vertex, recommend some other vertices that having the same or similar edges.

Here is a use case: According to someone’s reading habit or reading history, we can recommend some books he may be interested or some book pal.

For Example:

  1. Suppose we have a vertex, Person type, and named tom.He like 5 books a,b,c,d,e. If we want to recommend some book pal and books for tom, an easier idea is let’s check whoever also liked these books (common hobby based).
  2. Now, we need someone else, like neo, he like three books b,d,f. And Jay, he like 4 books c,d,e,g, and Lee, he also like 4 books a,d,e,f.
  3. For we don’t need to recommend books tom already read, the recommend-list should only contain the books Tom’s book pal already read but tom haven’t read yet. Such as book “f” and “g”, and with priority f > g.
  4. Now, we recompute Tom’s personal rank value, we will get a sorted TopN book pal or book recommend-list. (Choose OTHER_LABEL,for Only Book purpose)
4.2.1.0 Data Preparation

The case above is simple. Here we also provide a public test dataset MovieLens for use case. You should download the dataset. The load it into HugeGraph with HugeGraph-Loader. To make it simple, we ignore all properties data of user and move. only field id is enough. we also ignore the value of edge rating.

The metadata for input file and mapping file as follows:

////////////////////////////////////////////////////////////
// UserID::Gender::Age::Occupation::Zip-code
// MovieID::Title::Genres
// UserID::MovieID::Rating::Timestamp
////////////////////////////////////////////////////////////

// Define schema
schema.propertyKey("id").asInt().ifNotExist().create();
schema.propertyKey("rate").asInt().ifNotExist().create();

schema.vertexLabel("user")
      .properties("id")
      .primaryKeys("id")
      .ifNotExist()
      .create();
schema.vertexLabel("movie")
      .properties("id")
      .primaryKeys("id")
      .ifNotExist()
      .create();

schema.edgeLabel("rating")
      .sourceLabel("user")
      .targetLabel("movie")
      .properties("rate")
      .ifNotExist()
      .create();
{
  "vertices": [
    {
      "label": "user",
      "input": {
        "type": "file",
        "path": "users.dat",
        "format": "TEXT",
        "delimiter": "::",
        "header": ["UserID", "Gender", "Age", "Occupation", "Zip-code"]
      },
      "ignored": ["Gender", "Age", "Occupation", "Zip-code"],
      "mapping": {
          "UserID": "id"
      }
    },
    {
      "label": "movie",
      "input": {
        "type": "file",
        "path": "movies.dat",
        "format": "TEXT",
        "delimiter": "::",
        "header": ["MovieID", "Title", "Genres"]
      },
      "ignored": ["Title", "Genres"],
      "mapping": {
          "MovieID": "id"
      }
    }
  ],
  "edges": [
    {
      "label": "rating",
      "source": ["UserID"],
      "target": ["MovieID"],
      "input": {
        "type": "file",
        "path": "ratings.dat",
        "format": "TEXT",
        "delimiter": "::",
        "header": ["UserID", "MovieID", "Rating", "Timestamp"]
      },
      "ignored": ["Timestamp"],
      "mapping": {
          "UserID": "id",
          "MovieID": "id",
          "Rating": "rate"
      }
    }
  ]
}

Note: modify the input.path to your local path.

4.2.1.1 Function Introduction

suitable for bipartite graph, will return all vertex or a list of its correlation which related to all source vertex.

Bipartite Graph is a special model in Graph Theory, as well as a special flow in network. The strongest feature is, it split all vertex in graph into two sets. The vertex in the set is not connected. However,the vertex in two sets may connect with each other.

Suppose we have one bipartite graph based on user and things. A random walk based PersonalRank algorithm should be likes this:

  1. Choose a user u as start vertex, let’s set the initial weight to be 1.0 . Go from Vu with probability alpha to a neighbor vertex, and (1-alpha) to stay.
  2. If we decide to go outside, we would like to choose an edge, such as rating, to find a common judge.
    1. Then choose the neighbors of current vertex randomly with uniform distribution, and reset the weights with uniform distribution.
    2. Compensate the source vertex’s weight with (1 - alpha)
    3. Repeat step 2;
  3. Convergence after reaching a certain number of steps or precision, then we got a recommend-list.
Params

Required:

  • source: the id of source vertex
  • label: edge label go from the source vertex, should connect two different type of vertex

Optional:

  • alpha: the probability of going out for one vertex in each iteration,similar to the alpha of PageRank,required, value range is (0, 1], default 0.85.
  • max_degree: in query process, the max iteration number of adjacency edge for a vertex, default 10000
  • max_depth: iteration number,range [2, 50], default 5
  • with_label:result filter,default BOTH_LABEL,optional list as follows:
    • SAME_LABEL:Only keep vertex which has the same type as source vertex
    • OTHER_LABEL:Only keep vertex which has different type as source vertex (the another part in bipartite graph)
    • BOTH_LABEL:Keep both type vertex
  • limit: max return vertex number,default 100
  • max_diff: accuracy for convergence, default 0.0001 (will implement soon)
  • sorted: whether sort the result by rank or not, true for descending sort, false for none, default true
4.2.1.2 Usage
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/traversers/personalrank
Request Body
{
    "source": "1:1",
    "label": "rating",
    "alpha": 0.6,
    "max_depth": 15,
    "with_label": "OTHER_LABEL",
    "sorted": true,
    "limit": 10
}
Response Status
200
Response Body
{
    "2:2858": 0.0005014026017816927,
    "2:1196": 0.0004336708357653617,
    "2:1210": 0.0004128083140214213,
    "2:593": 0.00038117341069881513,
    "2:480": 0.00037005373269728036,
    "2:1198": 0.000366641614652057,
    "2:2396": 0.0003622362410538888,
    "2:2571": 0.0003593312457300953,
    "2:589": 0.00035922123055598566,
    "2:110": 0.0003466135844390885
}
4.2.1.3 Suitable Scenario

In a bipartite graph build by two different type of vertex, recommend other most related vertex to one vertex. for example:

  • Reading recommendation: find out the books should be recommended to someone first, It is also possible to recommend book pal with the highest common preferences at the same time (just like: WeChat “your friend also read xx " function)
  • Social recommendation: find out other Poster who interested in same topics, or other News/Messages you may be interested with (Such as : “Hot News” function in Weibo)
  • Commodity recommendation: according to someone’s shopping habit,find out a commodity list should recommend first, some online salesman may also be good (Such as : “You May Like” function in TaoBao)

4.2.2 Neighbor Rank API

4.2.2.0 Data Preparation
public class Loader {
    public static void main(String[] args) {
        HugeClient client = new HugeClient("http://127.0.0.1:8080", "hugegraph");
        SchemaManager schema = client.schema();

        schema.propertyKey("name").asText().ifNotExist().create();

        schema.vertexLabel("person")
              .properties("name")
              .useCustomizeStringId()
              .ifNotExist()
              .create();

        schema.vertexLabel("movie")
              .properties("name")
              .useCustomizeStringId()
              .ifNotExist()
              .create();

        schema.edgeLabel("follow")
              .sourceLabel("person")
              .targetLabel("person")
              .ifNotExist()
              .create();

        schema.edgeLabel("like")
              .sourceLabel("person")
              .targetLabel("movie")
              .ifNotExist()
              .create();

        schema.edgeLabel("directedBy")
              .sourceLabel("movie")
              .targetLabel("person")
              .ifNotExist()
              .create();

        GraphManager graph = client.graph();

        Vertex O = graph.addVertex(T.label, "person", T.id, "O", "name", "O");

        Vertex A = graph.addVertex(T.label, "person", T.id, "A", "name", "A");
        Vertex B = graph.addVertex(T.label, "person", T.id, "B", "name", "B");
        Vertex C = graph.addVertex(T.label, "person", T.id, "C", "name", "C");
        Vertex D = graph.addVertex(T.label, "person", T.id, "D", "name", "D");

        Vertex E = graph.addVertex(T.label, "movie", T.id, "E", "name", "E");
        Vertex F = graph.addVertex(T.label, "movie", T.id, "F", "name", "F");
        Vertex G = graph.addVertex(T.label, "movie", T.id, "G", "name", "G");
        Vertex H = graph.addVertex(T.label, "movie", T.id, "H", "name", "H");
        Vertex I = graph.addVertex(T.label, "movie", T.id, "I", "name", "I");
        Vertex J = graph.addVertex(T.label, "movie", T.id, "J", "name", "J");

        Vertex K = graph.addVertex(T.label, "person", T.id, "K", "name", "K");
        Vertex L = graph.addVertex(T.label, "person", T.id, "L", "name", "L");
        Vertex M = graph.addVertex(T.label, "person", T.id, "M", "name", "M");

        O.addEdge("follow", A);
        O.addEdge("follow", B);
        O.addEdge("follow", C);
        D.addEdge("follow", O);

        A.addEdge("follow", B);
        A.addEdge("like", E);
        A.addEdge("like", F);

        B.addEdge("like", G);
        B.addEdge("like", H);

        C.addEdge("like", I);
        C.addEdge("like", J);

        E.addEdge("directedBy", K);
        F.addEdge("directedBy", B);
        F.addEdge("directedBy", L);

        G.addEdge("directedBy", M);
    }
}
4.2.2.1 Function Introduction

In a general graph structure,find the first N vertices of each layer with the highest correlation with a given starting point and their relevance.

In graph words: to go out from the starting point, get the probability of going to each vertex of each layer.

Params
  • source: id of source vertex,required
  • alpha:the probability of going out for one vertex in each iteration,similar to the alpha of PageRank,required, value range is (0, 1]
  • steps: a path rule for source vertex visited,it’s a list of Step,each Step map to a layout in result,required.The structure of each Step as follows:
    • direction:the direction of edge(OUT, IN, BOTH), BOTH for default.
    • labels:a list of edge types, will union all edge types
    • max_degree:in query process, the max iteration number of adjacency edge for a vertex, default 10000 (Note: before v0.12 step only support degree as parameter name, from v0.12, use max_degree, compatible with degree)
    • top: retains only the top N results with the highest weight in each layer of the results, default 100, max 1000
  • capacity: the maximum number of vertexes visited during the traversal, optional, default 10000000
4.2.2.2 Usage
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/traversers/neighborrank
Request Body
{
    "source":"O",
    "steps":[
        {
            "direction":"OUT",
            "labels":[
                "follow"
            ],
            "max_degree":-1,
            "top":100
        },
        {
            "direction":"OUT",
            "labels":[
                "follow",
                "like"
            ],
            "max_degree":-1,
            "top":100
        },
        {
            "direction":"OUT",
            "labels":[
                "directedBy"
            ],
            "max_degree":-1,
            "top":100
        }
    ],
    "alpha":0.9,
    "capacity":-1
}
Response Status
200
Response Body
{
    "ranks": [
        {
            "O": 1
        },
        {
            "B": 0.4305,
            "A": 0.3,
            "C": 0.3
        },
        {
            "G": 0.17550000000000002,
            "H": 0.17550000000000002,
            "I": 0.135,
            "J": 0.135,
            "E": 0.09000000000000001,
            "F": 0.09000000000000001
        },
        {
            "M": 0.15795,
            "K": 0.08100000000000002,
            "L": 0.04050000000000001
        }
    ]
}
4.2.2.3 Suitable Scenario

Find the vertices in different layers for a given start point that should be most recommended

  • For example, in the four-layered structure of the audience, friends, movies, and directors, according to the movies that a certain audience’s friends like, recommend movies for that audience, or recommend directors for those movies based on who made them.

5.1.12 - Variable API

5.1 Variables

Variables can be used to store data about the entire graph. The data is accessed and stored in the form of key-value pairs.

5.1.1 Creating or Updating a Key-Value Pair

Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/variables/name
Request Body
{
  "data": "tom"
}
Response Status
200
Response Body
{
    "name": "tom"
}

5.1.2 Listing all key-value pairs

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/variables
Response Status
200
Response Body
{
    "name": "tom"
}

5.1.3 Listing a specific key-value pair

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/variables/name
Response Status
200
Response Body
{
    "name": "tom"
}

5.1.4 Deleting a specific key-value pair

Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/variables/name
Response Status
204

5.1.13 - Graphs API

6.1 Graphs

Important Reminder: Since HugeGraph 1.7.0, dynamic graph creation must enable authentication mode. For non-authentication mode, please refer to Graph Configuration File to statically create graphs through configuration files.

6.1.1 List all graphs in the graphspace

Params

Path parameters

  • graphspace: Graphspace name
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs
Response Status
200
Response Body
{
  "graphs": [
    "hugegraph",
    "hugegraph1"
  ]
}

6.1.2 Get details of the graph

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph
Response Status
200
Response Body
{
  "name": "hugegraph",
  "backend": "rocksdb"
}

6.1.3 Clear all data of a graph, include: schema, vertex, edge and index, This operation requires administrator privileges

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name

Query parameters

Since emptying the graph is a dangerous operation, we have added parameters for confirmation to the API to avoid false calls by users:

  • confirm_message: default by I'm sure to delete all data
Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/clear?confirm_message=I%27m+sure+to+delete+all+data
Response Status
204

6.1.4 Clone graph, this operation requires administrator privileges

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Name of the new graph to create

Query parameters

  • clone_graph_name: name of an existed graph. To clone from an existing graph, the user can choose to transfer the configuration file, which will replace the configuration in the existing graph
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph_clone?clone_graph_name=hugegraph
Request Body [Optional]

Clone a non-auth mode graph (set Content-Type: application/json)

{
  "gremlin.graph": "org.apache.hugegraph.HugeFactory",
  "backend": "rocksdb",
  "serializer": "binary",
  "store": "hugegraph",
  "rocksdb.data_path": "./rks-data-xx",
  "rocksdb.wal_path": "./rks-data-xx"
}

Note:

  1. The data/wal_path can’t be the same as the existing graph (use separate directories)
  2. Replace “gremlin.graph=org.apache.hugegraph.auth.HugeFactoryAuthProxy” to enable auth mode
Response Status
200
Response Body
{
  "name": "hugegraph_clone",
  "backend": "rocksdb"
}

6.1.5 Create graph, this operation requires administrator privileges

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph2
Request Body

Create a non-auth graph (set Content-Type: application/json)

{
  "gremlin.graph": "org.apache.hugegraph.HugeFactory",
  "backend": "rocksdb",
  "serializer": "binary",
  "store": "hugegraph2",
  "rocksdb.data_path": "./rks-data-xx",
  "rocksdb.wal_path": "./rks-data-xx"
}

Note:

  1. The data/wal_path can’t be the same as the existing graph (use separate directories)
  2. Replace “gremlin.graph=org.apache.hugegraph.auth.HugeFactoryAuthProxy” to enable auth mode
Response Status
200
Response Body
{
  "name": "hugegraph2",
  "backend": "rocksdb"
}

6.1.6 Delete graph and its data

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name

Query parameters

Since deleting a graph is a dangerous operation, we have added parameters for confirmation to the API to avoid false calls by users:

  • confirm_message: default by I'm sure to drop the graph
Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph_clone?confirm_message=I%27m%20sure%20to%20drop%20the%20graph
Response Status
204

Note: For HugeGraph 1.5.0 and earlier versions, if you need to create or drop a graph, please still use the legacy text/plain (properties) style request body instead of JSON.

6.2 Conf

6.2.1 Get configuration for a graph, This operation requires administrator privileges

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/conf
Response Status
200
Response Body
# gremlin entrence to create graph
gremlin.graph=org.apache.hugegraph.HugeFactory
# cache config
#schema.cache_capacity=1048576
#graph.cache_capacity=10485760
#graph.cache_expire=600

# schema illegal name template
#schema.illegal_name_regex=\s+|~.*

#vertex.default_label=vertex

backend=rocksdb
serializer=binary

store=hugegraph
...=

6.3 Mode

Allowed graph mode values are: NONE, RESTORING, MERGING, LOADING

  • None mode is regular mode
    • Not allowed to create schema with specified id
    • Not support creating vertex with id for AUTOMATIC id strategy
  • LOADING mode used to load data via hugegraph-loader.
    • When adding vertices / edges, it is not checked whether the required attributes are passed in

Restore has two different modes: Restoring and Merging

  • Restoring mode is used to restore schema and graph data to a new graph.
    • Support create schema with specified id
    • Support create vertex with id for AUTOMATIC id strategy
  • Merging mode is used to merge schema and graph data to an existing graph.
    • Not allowed to create schema with specified id
    • Support create vertex with id for AUTOMATIC id strategy

Under normal circumstances, the graph mode is None. When you need to restore the graph, you need to temporarily modify the graph mode to Restoring or Merging as needed. When you complete the restore, change the graph mode to None.

6.3.1 Get graph mode

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/mode
Response Status
200
Response Body
{
  "mode": "NONE"
}

Allowed graph mode values are: NONE, RESTORING, MERGING

6.3.2 Modify graph mode. This operation requires administrator privileges

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/mode
Request Body
"RESTORING"

Allowed graph mode values are: NONE, RESTORING, MERGING

Response Status
200
Response Body
{
  "mode": "RESTORING"
}

6.3.3 Get graph’s read mode

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph_read_mode
Response Status
200
Response Body
{
  "graph_read_mode": "ALL"
}

6.3.4 Modify graph’s read mode. This operation requires administrator privileges

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph_read_mode
Request Body
"OLTP_ONLY"

Allowed read mode values are: ALL, OLTP_ONLY, OLAP_ONLY

Response Status
200
Response Body
{
  "graph_read_mode": "OLTP_ONLY"
}

6.4 Snapshot

6.4.1 Create a snapshot

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/snapshot_create
Response Status
200
Response Body
{
  "hugegraph": "snapshot_created"
}

6.4.2 Resume a snapshot

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/snapshot_resume
Response Status
200
Response Body
{
  "hugegraph": "snapshot_resumed"
}

6.5 Compact

6.5.1 Manually compact graph, This operation requires administrator privileges

Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/compact
Response Status
200
Response Body
{
  "nodes": 1,
  "cluster_id": "local",
  "servers": {
    "local": "OK"
  }
}

5.1.14 - Task API

7.1 Task

7.1.1 List all async tasks in graph

Params
  • status: the status of asyncTasks
  • limit: the max number of tasks to return
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks?status=success
Response Status
200
Response Body
{
	"tasks": [{
		"task_name": "hugegraph.traversal().V()",
		"task_progress": 0,
		"task_create": 1532943976585,
		"task_status": "success",
		"task_update": 1532943976736,
		"task_result": "0",
		"task_retries": 0,
		"id": 2,
		"task_type": "gremlin",
		"task_callable": "org.apache.hugegraph.api.job.GremlinAPI$GremlinJob",
		"task_input": "{\"gremlin\":\"hugegraph.traversal().V()\",\"bindings\":{},\"language\":\"gremlin-groovy\",\"aliases\":{\"hugegraph\":\"graph\"}}"
	}]
}

7.1.2 View the details of an async task

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/2
Response Status
200
Response Body
{
	"task_name": "hugegraph.traversal().V()",
	"task_progress": 0,
	"task_create": 1532943976585,
	"task_status": "success",
	"task_update": 1532943976736,
	"task_result": "0",
	"task_retries": 0,
	"id": 2,
	"task_type": "gremlin",
	"task_callable": "org.apache.hugegraph.api.job.GremlinAPI$GremlinJob",
	"task_input": "{\"gremlin\":\"hugegraph.traversal().V()\",\"bindings\":{},\"language\":\"gremlin-groovy\",\"aliases\":{\"hugegraph\":\"graph\"}}"
}

7.1.3 Delete task information of an async task,won’t delete the task itself

Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/2
Response Status
204

7.1.4 Cancel an async task, the task should be able to be canceled

If you already created an async task via Gremlin API as follows:

"for (int i = 0; i < 10; i++) {" +
    "hugegraph.addVertex(T.label, 'man');" +
    "hugegraph.tx().commit();" +
    "try {" +
        "sleep(1000);" +
    "} catch (InterruptedException e) {" +
        "break;" +
    "}" +
"}"
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/2?action=cancel

cancel it in 10s. if more than 10s, the task may already be finished, then can’t be cancelled.

Response Status
202
Response Body
{
    "cancelled": true
}

At this point, the number of vertices whose label is man must be less than 10.

5.1.15 - Gremlin API

8.1 Gremlin

8.1.1 Sending a gremlin statement (GET) to HugeGraphServer for synchronous execution

Params
  • gremlin: The gremlin statement to be sent to HugeGraphServer for execution
  • bindings: Used to bind parameters. Key is a string, and the value is the bound value (can only be a string or number). This functionality is similar to MySQL’s Prepared Statement and is used to speed up statement execution.
  • language: The language type of the sent statement. Default is gremlin-groovy.
  • aliases: Adds aliases for existing variables in the graph space.

Querying vertices

Method & Url
GET http://127.0.0.1:8080/gremlin?gremlin=hugegraph.traversal().V('1:marko')
Response Status
200
Response Body
{
	"requestId": "c6ef47a8-b634-4b07-9d38-6b3b69a3a556",
	"status": {
		"message": "",
		"code": 200,
		"attributes": {}
	},
	"result": {
		"data": [{
			"id": "1:marko",
			"label": "person",
			"type": "vertex",
			"properties": {
				"city": [{
					"id": "1:marko>city",
					"value": "Beijing"
				}],
				"name": [{
					"id": "1:marko>name",
					"value": "marko"
				}],
				"age": [{
					"id": "1:marko>age",
					"value": 29
				}]
			}
		}],
		"meta": {}
	}
}

8.1.2 Sending a gremlin statement (POST) to HugeGraphServer for synchronous execution

Method & Url
POST http://localhost:8080/gremlin

Querying vertices

Request Body
{
	"gremlin": "hugegraph.traversal().V('1:marko')",
	"bindings": {},
	"language": "gremlin-groovy",
	"aliases": {}
}
Response Status
200
Response Body
{
	"requestId": "c6ef47a8-b634-4b07-9d38-6b3b69a3a556",
	"status": {
		"message": "",
		"code": 200,
		"attributes": {}
	},
	"result": {
		"data": [{
			"id": "1:marko",
			"label": "person",
			"type": "vertex",
			"properties": {
				"city": [{
					"id": "1:marko>city",
					"value": "Beijing"
				}],
				"name": [{
					"id": "1:marko>name",
					"value": "marko"
				}],
				"age": [{
					"id": "1:marko>age",
					"value": 29
				}]
			}
		}],
		"meta": {}
	}
}

Note:

Here we directly use the graph object (hugegraph), first retrieve its traversal iterator (traversal()), and then retrieve the vertices. Instead of writing graph.traversal().V() or g.V(), you can use aliases to operate on the graph and traversal iterator. In this case, hugegraph is a native variable, and __g_hugegraph is an additional variable added by HugeGraphServer. Each graph will have a corresponding traversal iterator object in this format (__g_${graph}).

The structure of the response body is different from the RESTful API structure of other vertices or edges. Users may need to parse it manually.

Querying edges

Request Body
{
	"gremlin": "g.E('S1:marko>2>>S2:lop')",
	"bindings": {},
	"language": "gremlin-groovy",
	"aliases": {
		"graph": "hugegraph", 
		"g": "__g_hugegraph"
	}
}
Response Status
200
Response Body
{
	"requestId": "3f117cd4-eedc-4e08-a106-ee01d7bb8249",
	"status": {
		"message": "",
		"code": 200,
		"attributes": {}
	},
	"result": {
		"data": [{
			"id": "S1:marko>2>>S2:lop",
			"label": "created",
			"type": "edge",
			"inVLabel": "software",
			"outVLabel": "person",
			"inV": "2:lop",
			"outV": "1:marko",
			"properties": {
				"weight": 0.4,
				"date": "20171210"
			}
		}],
		"meta": {}
	}
}

8.1.3 Sending a gremlin statement (POST) to HugeGraphServer for asynchronous execution

Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/jobs/gremlin

Querying vertices

Request Body
{
	"gremlin": "g.V('1:marko')",
	"bindings": {},
	"language": "gremlin-groovy",
	"aliases": {}
}

Note:

Asynchronous execution of Gremlin statements does not currently support aliases. You can use graph to represent the graph you want to operate on, or directly use the name of the graph, such as hugegraph. Additionally, g represents the traversal, which is equivalent to graph.traversal() or hugegraph.traversal().

Response Status
201
Response Body
{
	"task_id": 1
}

Note:

You can query the execution status of an asynchronous task by using GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/1 (where “1” is the task_id). For more information, refer to the Asynchronous Task RESTful API.

Querying edges

Request Body
{
	"gremlin": "g.E('S1:marko>2>>S2:lop')",
	"bindings": {},
	"language": "gremlin-groovy",
	"aliases": {}
}
Response Status
201
Response Body
{
	"task_id": 2
}

Note:

You can query the execution status of an asynchronous task by using GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/tasks/2 (where “2” is the task_id). For more information, refer to the Asynchronous Task RESTful API.

5.1.16 - Cypher API

9.1 Cypher

9.1.1 Sending a cypher statement (GET) to HugeGraphServer for synchronous execution

Method & Url
GET /graphspaces/{graphspace}/graphs/{graph}/cypher?cypher={cypher}
Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name

Query parameters

  • cypher: Cypher statement
Example
GET http://localhost:8080/graphspaces/DEFAULT/graphs/hugecypher1/cypher?cypher=match(n:person) return n.name as name order by n.name limit 1
Response Status
200
Response Body
{
    "requestId": "766b9f48-2f10-40d9-951a-3027d0748ab7",
    "status": {
        "message": "",
        "code": 200,
        "attributes": {
        }
    },
    "result": {
        "data": [
            {
                "name": "hello"
            }
        ],
        "meta": {
        }
    }
}

9.1.2 Sending a cypher statement (POST) to HugeGraphServer for synchronous execution

Method & Url
POST /graphspaces/{graphspace}/graphs/{graph}/cypher
Params

Path parameters

  • graphspace: Graphspace name
  • graph: Graph name
Body

{cypher}

  • cypher: Cypher statement

Note:

It is not in JSON format, but a plain text Cypher statement.

Example
POST http://localhost:8080/graphspaces/DEFAULT/graphs/hugecypher1/cypher
Request Body
match(n:person) return n.name as name order by n.name limit 1
Response Status
200
Response Body
{
    "requestId": "f096bee0-e249-498f-b5a3-ea684fc84f57",
    "status": {
        "message": "",
        "code": 200,
        "attributes": {
        }
    },
    "result": {
        "data": [
            {
                "name": "hello"
            }
        ],
        "meta": {
        }
    }
}

5.1.17 - Authentication API

10.1 User Authentication and Access Control

To enable authentication and related configurations, please refer to the Authentication Configuration documentation.

Overview of User Authentication and Access Control:

HugeGraph supports multi-user authentication and fine-grained access control. It adopts a 4-tier design based on “User-User Group-Operation-Resource” to flexibly control user roles and permissions. Resources describe data in the graph database, such as vertices that meet certain conditions. Each resource consists of three elements: type, label, and properties. There are a total of 18 types and combinations of any label and properties to form resources. The internal condition of a resource is an “AND” relationship, while the condition between multiple resources is an “OR” relationship. Users can belong to one or more user groups, and each user group can have permissions for any number of resources. The types of operations include read, write, delete, execute, etc. HugeGraph supports dynamically creating users, user groups, and resources, and supports dynamically assigning or revoking permissions. During the initialization of the database, a super administrator user is created, and subsequently, various role users can be created by the super administrator. If a newly created user is assigned sufficient permissions, they can create or manage more users.

Example:

user(name=boss) -belong-> group(name=all) -access(read)-> target(graph=graph1, resource={label: person, city: Beijing})
Description: User ‘boss’ has read permission for people in the ‘graph1’ graph from Beijing.

Interface Description:

The user authentication and access control interface includes 5 categories: UserAPI, GroupAPI, TargetAPI, BelongAPI, AccessAPI. Note Before 1.5.0, the format of ids such as group/target was similar to -69:grant. After 1.7.0, the id and name were consistent. Such as admin HugeGraph 1.5 x RESTful API

10.2 User (User) API

The user interface includes APIs for creating users, deleting users, modifying users, and querying user-related information.

10.2.1 Create User

Params
  • user_name: User name
  • user_password: User password
  • user_phone: User phone number
  • user_email: User email

Both user_name and user_password are required.

Request Body
{
    "user_name": "boss",
    "user_password": "******",
    "user_phone": "182****9088",
    "user_email": "123@xx.com"
}
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/auth/users
Response Status
201 
Response Body

In the response message, the password is encrypted as ciphertext.

{
    "user_password": "******",
    "user_email": "123@xx.com",
    "user_update": "2020-11-17 14:31:07.833",
    "user_name": "boss",
    "user_creator": "admin",
    "user_phone": "182****9088",
    "id": "boss",
    "user_create": "2020-11-17 14:31:07.833"
}

10.2.2 Delete User

Params
  • id: User ID to be deleted
Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/auth/users/test
Response Status
204
Response Body
1

10.2.3 Modify User

Params
  • id: User ID to be modified
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/auth/users/test
Request Body

Modify user_name, user_password, and user_phone.

{
    "user_name": "test",
    "user_password": "******",
    "user_phone": "183****9266"
}
Response Status
200
Response Body

The returned result is the entire user object including the modified content.

{
    "user_password": "******",
    "user_update": "2020-11-12 10:29:30.455",
    "user_name": "test",
    "user_creator": "admin",
    "user_phone": "183****9266",
    "id": "test",
    "user_create": "2020-11-12 10:27:13.601"
}

10.2.4 Query User List

Params
  • limit: Upper limit of the number of results returned
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/auth/users
Response Status
200
Response Body
{
    "users": [
        {
            "user_password": "******",
            "user_update": "2020-11-11 11:41:12.254",
            "user_name": "admin",
            "user_creator": "system",
            "id": "admin",
            "user_create": "2020-11-11 11:41:12.254"
        }
    ]
}

10.2.5 Query a User

Params
  • id: User ID to be queried
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/auth/users/admin
Response Status
200
Response Body
{
    "users": [
        {
            "user_password": "******",
            "user_update": "2020-11-11 11:41:12.254",
            "user_name": "admin",
            "user_creator": "system",
            "id": "admin",
            "user_create": "2020-11-11 11:41:12.254"
        }
    ]
}

10.2.6 Query Roles of a User

Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/auth/users/boss/role
Response Status
200
Response Body
{
    "roles": {
        "hugegraph": {
            "READ": [
                {
                    "type": "ALL",
                    "label": "*",
                    "properties": null
                }
            ]
        }
    }
}

10.3 Group (Group) API

Groups grant corresponding resource permissions, and users are assigned to different groups, thereby having different resource permissions. The group interface includes APIs for creating groups, deleting groups, modifying groups, and querying group-related information.

10.3.1 Create Group

Params
  • group_name: Group name
  • group_description: Group description
Request Body
{
    "group_name": "all",
    "group_description": "group can do anything"
}
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/auth/groups
Response Status
201 
Response Body
{
    "group_creator": "admin",
    "group_name": "all",
    "group_create": "2020-11-11 15:46:08.791",
    "group_update": "2020-11-11 15:46:08.791",
    "id": "-69:all",
    "group_description": "group can do anything"
}

10.3.2 Delete Group

Params
  • id: Group ID to be deleted
Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/auth/groups/-69:grant
Response Status
204
Response Body
1

10.3.3 Modify Group

Params
  • id: Group ID to be modified
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/auth/groups/-69:grant
Request Body

Modify group_description

{
    "group_name": "grant",
    "group_description": "grant"
}
Response Status
200
Response Body

The returned result is the entire group object including the modified content.

{
    "group_creator": "admin",
    "group_name": "grant",
    "group_create": "2020-11-12 09:50:58.458",
    "group_update": "2020-11-12 09:57:58.155",
    "id": "-69:grant",
    "group_description": "grant"
}

10.3.4 Query Group List

Params
  • limit: Upper limit of the number of results returned
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/auth/groups
Response Status
200
Response Body
{
    "groups": [
        {
            "group_creator": "admin",
            "group_name": "all",
            "group_create": "2020-11-11 15:46:08.791",
            "group_update": "2020-11-11 15:46:08.791",
            "id": "-69:all",
            "group_description": "group can do anything"
        }
    ]
}

10.3.5 Query a Specific Group

Params
  • id: Group ID to be queried
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/auth/groups/-69:all
Response Status
200
Response Body
{
    "group_creator": "admin",
    "group_name": "all",
    "group_create": "2020-11-11 15:46:08.791",
    "group_update": "2020-11-11 15:46:08.791",
    "id": "-69:all",
    "group_description": "group can do anything"
}

10.4 Resource (Target) API

Resources describe data in the graph database, such as vertices that meet certain criteria. Each resource includes three elements: type, label, and properties. There are 18 types in total, and the combination of any label and any properties forms a resource. The internal conditions of a resource are based on the AND relationship, while the conditions between multiple resources are based on the OR relationship.
The resource API includes creating, deleting, modifying, and querying resources.

10.4.1 Create Resource

Params
  • target_name: Name of the resource
  • target_graph: Graph of the resource
  • target_url: URL of the resource
  • target_resources: Resource definitions (list)

target_resources can include multiple target_resource, stored in the form of a list.
Each target_resource contains:

  • type: Optional value: VERTEX, EDGE, etc. Can be filled with ALL, indicating it can be a vertex or edge.
  • label: Optional value: name of a vertex or edge type. Can be filled with *, indicating any type.
  • properties: Map type, can contain multiple key-value pairs of properties. Must match all property values. Property values can support conditional ranges (e.g., age: P.gte(18)). If properties are null, it means any property is allowed. If both the property name and value are ‘*’, it also means any property is allowed.

For example, a specific resource: “target_resources”: [{“type”:“VERTEX”,“label”:“person”,“properties”:{“city”:“Beijing”,“age”:“P.gte(20)”}}]
The resource definition means: a vertex of type ‘person’ with the city property set to ‘Beijing’ and the age property greater than or equal to 20.

Request Body
{
    "target_name": "all",
    "target_graph": "hugegraph",
    "target_url": "127.0.0.1:8080",
    "target_resources": [
        {
            "type": "ALL"
        }
    ]
}
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/auth/targets
Response Status
201 
Response Body
{
    "target_creator": "admin",
    "target_name": "all",
    "target_url": "127.0.0.1:8080",
    "target_graph": "hugegraph",
    "target_create": "2020-11-11 15:32:01.192",
    "target_resources": [
        {
            "type": "ALL",
            "label": "*",
            "properties": null
        }
    ],
    "id": "-77:all",
    "target_update": "2020-11-11 15:32:01.192"
}

10.4.2 Delete Resource

Params
  • id: Resource Id to be deleted
Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/auth/targets/-77:gremlin
Response Status
204
Response Body
1

10.4.3 Modify Resource

Params
  • id: Resource Id to be modified
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/auth/targets/-77:gremlin
Request Body

Modify the ’type’ in the resource definition.

{
    "target_name": "gremlin",
    "target_graph": "hugegraph",
    "target_url": "127.0.0.1:8080",
    "target_resources": [
        {
            "type": "NONE"
        }
    ]
}
Response Status
200
Response Body

The response contains the entire target group object, including the modified content.

{
    "target_creator": "admin",
    "target_name": "gremlin",
    "target_url": "127.0.0.1:8080",
    "target_graph": "hugegraph",
    "target_create": "2020-11-12 09:34:13.848",
    "target_resources": [
        {
            "type": "NONE",
            "label": "*",
            "properties": null
        }
    ],
    "id": "-77:gremlin",
    "target_update": "2020-11-12 09:37:12.780"
}

10.4.4 Query Resource List

Params
  • limit: Upper limit of the number of returned results.
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/auth/targets
Response Status
200
Response Body
{
    "targets": [
        {
            "target_creator": "admin",
            "target_name": "all",
            "target_url": "127.0.0.1:8080",
            "target_graph": "hugegraph",
            "target_create": "2020-11-11 15:32:01.192",
            "target_resources": [
                {
                    "type": "ALL",
                    "label": "*",
                    "properties": null
                }
            ],
            "id": "-77:all",
            "target_update": "2020-11-11 15:32:01.192"
        },
        {
            "target_creator": "admin",
            "target_name": "grant",
            "target_url": "127.0.0.1:8080",
            "target_graph": "hugegraph",
            "target_create": "2020-11-11 15:43:24.841",
            "target_resources": [
                {
                    "type": "GRANT",
                    "label": "*",
                    "properties": null
                }
            ],
            "id": "-77:grant",
            "target_update": "2020-11-11 15:43:24.841"
        }
    ]
}

10.4.5 Query a Specific Resource

Params
  • id: Id of the resource to query
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/auth/targets/-77:grant
Response Status
200
Response Body
{
    "target_creator": "admin",
    "target_name": "grant",
    "target_url": "127.0.0.1:8080",
    "target_graph": "hugegraph",
    "target_create": "2020-11-11 15:43:24.841",
    "target_resources": [
        {
            "type": "GRANT",
            "label": "*",
            "properties": null
        }
    ],
    "id": "-77:grant",
    "target_update": "2020-11-11 15:43:24.841"
}

10.5 Association of Roles (Belong) API

The association between users and user groups allows a user to be associated with one or more user groups. User groups have permissions for related resources, and the permissions for different user groups can be understood as different roles. In other words, users are associated with roles.
The API for associating roles includes creating, deleting, modifying, and querying the association of roles for users.

10.5.1 Create an Association of Roles for a User

Params
  • user: User ID
  • group: User group ID
  • belong_description: Description
Request Body
{
    "user": "boss",
    "group": "-69:all"
}
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/auth/belongs
Response Status
201 
Response Body
{
    "belong_create": "2020-11-11 16:19:35.422",
    "belong_creator": "admin",
    "belong_update": "2020-11-11 16:19:35.422",
    "id": "Sboss>-82>>S-69:all",
    "user": "boss",
    "group": "-69:all"
}

10.5.2 Delete an Association of Roles

Params
  • id: ID of the association of roles to delete
Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/auth/belongs/Sboss>-82>>S-69:grant
Response Status
204
Response Body
1

10.5.3 Modify an Association of Roles

An association of roles can only be modified for its description. The user and group properties cannot be modified. If you need to modify an association of roles, you need to delete the existing association and create a new one.

Params
  • id: ID of the association of roles to modify
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/auth/belongs/Sboss>-82>>S-69:grant
Request Body

Modify the belong_description field

{
    "belong_description": "update test"
}
Response Status
200
Response Body

The response includes the modified content as well as the entire association of roles object

{
    "belong_description": "update test",
    "belong_create": "2020-11-12 10:40:21.720",
    "belong_creator": "admin",
    "belong_update": "2020-11-12 10:42:47.265",
    "id": "Sboss>-82>>S-69:grant",
    "user": "boss",
    "group": "-69:grant"
}

10.5.4 Query List of Associations of Roles

Params
  • limit: Upper limit on the number of results to return
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/auth/belongs
Response Status
200
Response Body
{
    "belongs": [
        {
            "belong_create": "2020-11-11 16:19:35.422",
            "belong_creator": "admin",
            "belong_update": "2020-11-11 16:19:35.422",
            "id": "Sboss>-82>>S-69:all",
            "user": "boss",
            "group": "-69:all"
        }
    ]
}

10.5.5 View a Specific Association of Roles

Params
  • id: The id of the association of roles to be queried
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/auth/belongs/Sboss>-82>>S-69:all
Response Status
200
Response Body
{
    "belong_create": "2020-11-11 16:19:35.422",
    "belong_creator": "admin",
    "belong_update": "2020-11-11 16:19:35.422",
    "id": "Sboss>-82>>S-69:all",
    "user": "boss",
    "group": "-69:all"
}

10.6 Authorization (Access) API

Grant permissions to user groups for resources, including operations such as READ, WRITE, DELETE, EXECUTE, etc. The authorization API includes: creating, deleting, modifying, and querying permissions.

10.6.1 Create Authorization (Granting permissions to user groups for resources)

Params
  • group: Group ID
  • target: Resource ID
  • access_permission: Permission grant
  • access_description: Authorization description

Access permissions:

  • READ: Read operations, including all queries such as querying the schema, retrieving vertices/edges, aggregating vertex and edge counts (VERTEX_AGGR/EDGE_AGGR), and reading the graph’s status (STATUS), variables (VAR), tasks (TASK), etc.
  • WRITE: Write operations, including creating and updating operations, such as adding property keys to the schema or adding/updating properties of vertices.
  • DELETE: Delete operations, including deleting metadata, vertices, or edges.
  • EXECUTE: Execute operations, including executing Gremlin queries, executing tasks, and executing metadata functions.
Request Body
{
    "group": "-69:all",
    "target": "-77:all",
    "access_permission": "READ"
}
Method & Url
POST http://localhost:8080/graphspaces/DEFAULT/auth/accesses
Response Status
201 
Response Body
{
    "access_permission": "READ",
    "access_create": "2020-11-11 15:54:54.008",
    "id": "S-69:all>-88>11>S-77:all",
    "access_update": "2020-11-11 15:54:54.008",
    "access_creator": "admin",
  "group": "-69:all",
  "target": "-77:all"
}

10.6.2 Delete Authorization

Params
  • id: The ID of the authorization to be deleted
Method & Url
DELETE http://localhost:8080/graphspaces/DEFAULT/auth/accesses/S-69:all>-88>12>S-77:all
Response Status
204
Response Body
1

10.6.3 Modify Authorization

Authorization can only be modified for its description. User group, resource, and permission cannot be modified. If you need to modify the authorization relationship, delete the original authorization and create a new one.

Params
  • id: The ID of the authorization to be modified
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/auth/accesses/S-69:all>-88>12>S-77:all
Request Body

Modify access_description

{
  "access_description": "test"
}
Response Status
200
Response Body

The response includes the modified content as well as the entire authorization object.

{
  "access_description": "test",
  "access_permission": "WRITE",
  "access_create": "2020-11-12 10:12:03.074",
  "id": "S-69:all>-88>12>S-77:all",
  "access_update": "2020-11-12 10:16:18.637",
  "access_creator": "admin",
  "group": "-69:all",
  "target": "-77:all"
}

10.6.4 Query Authorization List

Params
  • limit: The maximum number of results to return
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/auth/accesses
Response Status
200
Response Body
{
  "accesses": [
    {
      "access_permission": "READ",
      "access_create": "2020-11-11 15:54:54.008",
      "id": "S-69:all>-88>11>S-77:all",
      "access_update": "2020-11-11 15:54:54.008",
      "access_creator": "admin",
      "group": "-69:all",
      "target": "-77:all"
    }
  ]
}

10.6.5 Query a Specific Authorization

Params
  • id: The ID of the authorization to be queried
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/auth/accesses/S-69:all>-88>11>S-77:all
Response Status
200
Response Body
{
  "access_permission": "READ",
  "access_create": "2020-11-11 15:54:54.008",
  "id": "S-69:all>-88>11>S-77:all",
  "access_update": "2020-11-11 15:54:54.008",
  "access_creator": "admin",
    "group": "-69:all",
    "target": "-77:all"
}

10.7 Graphspace Manager (Manager) API

Note: Before using the following APIs, you need to create a graphspace first. For example, create a graphspace named gs1 via the Graphspace API. The examples below assume that gs1 already exists.

  1. The graphspace manager API is used to grant/revoke manager roles for users at the graphspace level, and to query the roles of the current user or other users in a graphspace. Supported role types include SPACE, SPACE_MEMBER, and ADMIN.

10.7.1 Check whether the current login user has a specific role

Params
  • type: Role type to check, optional
Method & Url
GET http://localhost:8080/graphspaces/gs1/auth/managers/check?type=WRITE
Response Status
200
Response Body
"true"

The API returns the string true or false indicating whether the current user has the given role.

10.7.2 List graphspace managers

Params
  • type: Role type, optional, used to filter by role
Method & Url
GET http://localhost:8080/graphspaces/gs1/auth/managers?type=SPACE
Response Status
200
Response Body
{
  "managers": [
    {
      "user": "admin",
      "type": "SPACE",
      "create_time": "2024-01-10 09:30:00"
    }
  ]
}

10.7.3 Grant/create a graphspace manager

  • The following example grants user boss the SPACE_MEMBER role in graphspace gs1.
Request Body
{
  "user": "boss",
  "type": "SPACE_MEMBER"
}
Method & Url
POST http://localhost:8080/graphspaces/gs1/auth/managers
Response Status
201
Response Body
{
  "user": "boss",
  "type": "SPACE_MEMBER",
  "manager_creator": "admin",
  "manager_create": "2024-01-10 09:45:12"
}

10.7.4 Revoke graphspace manager privileges

  • The following example revokes the SPACE_MEMBER role of user boss in graphspace gs1.
Params
  • user: User ID to revoke
  • type: Role type to revoke
Method & Url
DELETE http://localhost:8080/graphspaces/gs1/auth/managers?user=boss&type=SPACE_MEMBER
Response Status
204
Response Body
1

10.7.5 Query roles of a specific user in a graphspace

Params
  • user: User ID
Method & Url
GET http://localhost:8080/graphspaces/gs1/auth/managers/role?user=boss
Response Status
200
Response Body
{
  "roles": {
    "boss": [
      "READ",
      "SPACE_MEMBER"
    ]
  }
}

5.1.18 - Metrics API

HugeGraph provides a metrics interface for obtaining monitoring information, such as statistics on each Gremlin execution time, cache size, etc. The metrics interface includes the following categories: basic metrics, statistical metrics, system metrics, and backend storage metrics.

1. Basic Metrics

1.1 Get All Basic Metrics

Params
  • type: If the passed value is json, it is returned in json format, otherwise it is returned in Promethaus format.
1.1.1 Method & Url
http://localhost:8080/metrics/?type=json
Response Status
200
Response Body
{
  "gauges": {
    "org.apache.hugegraph.backend.cache.Cache.edge-hugegraph.capacity": {
      "value": 1000000
    },
    "org.apache.hugegraph.backend.cache.Cache.edge-hugegraph.expire": {
      "value": 600000
    },
    "org.apache.hugegraph.backend.cache.Cache.edge-hugegraph.hits": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.edge-hugegraph.miss": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.edge-hugegraph.size": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.instances": {
      "value": 7
    },
    "org.apache.hugegraph.backend.cache.Cache.schema-id-hugegraph.capacity": {
      "value": 10000
    },
    "org.apache.hugegraph.backend.cache.Cache.schema-id-hugegraph.expire": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.schema-id-hugegraph.hits": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.schema-id-hugegraph.miss": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.schema-id-hugegraph.size": {
      "value": 17
    },
    "org.apache.hugegraph.backend.cache.Cache.schema-name-hugegraph.capacity": {
      "value": 10000
    },
    "org.apache.hugegraph.backend.cache.Cache.schema-name-hugegraph.expire": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.schema-name-hugegraph.hits": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.schema-name-hugegraph.miss": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.schema-name-hugegraph.size": {
      "value": 17
    },
    "org.apache.hugegraph.backend.cache.Cache.token-hugegraph.capacity": {
      "value": 10240
    },
    "org.apache.hugegraph.backend.cache.Cache.token-hugegraph.expire": {
      "value": 600000
    },
    "org.apache.hugegraph.backend.cache.Cache.token-hugegraph.hits": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.token-hugegraph.miss": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.token-hugegraph.size": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.users-hugegraph.capacity": {
      "value": 10240
    },
    "org.apache.hugegraph.backend.cache.Cache.users-hugegraph.expire": {
      "value": 600000
    },
    "org.apache.hugegraph.backend.cache.Cache.users-hugegraph.hits": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.users-hugegraph.miss": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.users-hugegraph.size": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.users_pwd-hugegraph.capacity": {
      "value": 10240
    },
    "org.apache.hugegraph.backend.cache.Cache.users_pwd-hugegraph.expire": {
      "value": 600000
    },
    "org.apache.hugegraph.backend.cache.Cache.users_pwd-hugegraph.hits": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.users_pwd-hugegraph.miss": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.users_pwd-hugegraph.size": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.vertex-hugegraph.capacity": {
      "value": 10000000
    },
    "org.apache.hugegraph.backend.cache.Cache.vertex-hugegraph.expire": {
      "value": 600000
    },
    "org.apache.hugegraph.backend.cache.Cache.vertex-hugegraph.hits": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.vertex-hugegraph.miss": {
      "value": 0
    },
    "org.apache.hugegraph.backend.cache.Cache.vertex-hugegraph.size": {
      "value": 0
    },
    "org.apache.hugegraph.server.RestServer.max-write-threads": {
      "value": 0
    },
    "org.apache.hugegraph.task.TaskManager.pending-tasks": {
      "value": 0
    },
    "org.apache.hugegraph.task.TaskManager.workers": {
      "value": 4
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.average-load-penalty": {
      "value": 922769200
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.estimated-size": {
      "value": 2
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.eviction-count": {
      "value": 0
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.eviction-weight": {
      "value": 0
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.hit-count": {
      "value": 0
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.hit-rate": {
      "value": 0
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.load-count": {
      "value": 2
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.load-failure-count": {
      "value": 0
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.load-failure-rate": {
      "value": 0
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.load-success-count": {
      "value": 2
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.long-run-compilation-count": {
      "value": 0
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.miss-count": {
      "value": 2
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.miss-rate": {
      "value": 1
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.request-count": {
      "value": 2
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.total-load-time": {
      "value": 1845538400
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.sessions": {
      "value": 0
    }
  },
  "counters": {
    "favicon.ico/GET/FAILED_COUNTER": {
      "count": 1
    },
    "favicon.ico/GET/TOTAL_COUNTER": {
      "count": 1
    },
    "metrics/POST/FAILED_COUNTER": {
      "count": 1
    },
    "metrics/POST/TOTAL_COUNTER": {
      "count": 1
    },
    "metrics/backend/GET/SUCCESS_COUNTER": {
      "count": 2
    },
    "metrics/backend/GET/TOTAL_COUNTER": {
      "count": 2
    },
    "metrics/gauges/GET/SUCCESS_COUNTER": {
      "count": 1
    },
    "metrics/gauges/GET/TOTAL_COUNTER": {
      "count": 1
    },
    "metrics/system/GET/SUCCESS_COUNTER": {
      "count": 2
    },
    "metrics/system/GET/TOTAL_COUNTER": {
      "count": 2
    },
    "system/GET/FAILED_COUNTER": {
      "count": 1
    },
    "system/GET/TOTAL_COUNTER": {
      "count": 1
    }
  },
  "histograms": {
    "favicon.ico/GET/RESPONSE_TIME_HISTOGRAM": {
      "count": 1,
      "min": 1,
      "mean": 1,
      "max": 1,
      "stddev": 0,
      "p50": 1,
      "p75": 1,
      "p95": 1,
      "p98": 1,
      "p99": 1,
      "p999": 1
    },
    "metrics/POST/RESPONSE_TIME_HISTOGRAM": {
      "count": 1,
      "min": 21,
      "mean": 21,
      "max": 21,
      "stddev": 0,
      "p50": 21,
      "p75": 21,
      "p95": 21,
      "p98": 21,
      "p99": 21,
      "p999": 21
    },
    "metrics/backend/GET/RESPONSE_TIME_HISTOGRAM": {
      "count": 2,
      "min": 6,
      "mean": 12.6852124529148,
      "max": 20,
      "stddev": 6.992918475157571,
      "p50": 6,
      "p75": 20,
      "p95": 20,
      "p98": 20,
      "p99": 20,
      "p999": 20
    },
    "metrics/gauges/GET/RESPONSE_TIME_HISTOGRAM": {
      "count": 1,
      "min": 7,
      "mean": 7,
      "max": 7,
      "stddev": 0,
      "p50": 7,
      "p75": 7,
      "p95": 7,
      "p98": 7,
      "p99": 7,
      "p999": 7
    },
    "metrics/system/GET/RESPONSE_TIME_HISTOGRAM": {
      "count": 2,
      "min": 0,
      "mean": 8.942674506664073,
      "max": 40,
      "stddev": 16.665399873223066,
      "p50": 0,
      "p75": 0,
      "p95": 40,
      "p98": 40,
      "p99": 40,
      "p999": 40
    },
    "system/GET/RESPONSE_TIME_HISTOGRAM": {
      "count": 1,
      "min": 2,
      "mean": 2,
      "max": 2,
      "stddev": 0,
      "p50": 2,
      "p75": 2,
      "p95": 2,
      "p98": 2,
      "p99": 2,
      "p999": 2
    }
  },
  "meters": {
    "org.apache.hugegraph.api.API.commit-succeed": {
      "count": 0,
      "mean_rate": 0,
      "m15_rate": 0,
      "m5_rate": 0,
      "m1_rate": 0,
      "rate_unit": "events/second"
    },
    "org.apache.hugegraph.api.API.expected-error": {
      "count": 0,
      "mean_rate": 0,
      "m15_rate": 0,
      "m5_rate": 0,
      "m1_rate": 0,
      "rate_unit": "events/second"
    },
    "org.apache.hugegraph.api.API.illegal-arg": {
      "count": 0,
      "mean_rate": 0,
      "m15_rate": 0,
      "m5_rate": 0,
      "m1_rate": 0,
      "rate_unit": "events/second"
    },
    "org.apache.hugegraph.api.API.unknown-error": {
      "count": 0,
      "mean_rate": 0,
      "m15_rate": 0,
      "m5_rate": 0,
      "m1_rate": 0,
      "rate_unit": "events/second"
    },
    "org.apache.tinkerpop.gremlin.server.GremlinServer.errors": {
      "count": 0,
      "mean_rate": 0,
      "m15_rate": 0,
      "m5_rate": 0,
      "m1_rate": 0,
      "rate_unit": "events/second"
    }
  },
  "timers": {
    "org.apache.hugegraph.api.auth.AccessAPI.create": {
      "count": 0,
      "min": 0,
      "mean": 0,
      "max": 0,
      "stddev": 0,
      "p50": 0,
      "p75": 0,
      "p95": 0,
      "p98": 0,
      "p99": 0,
      "p999": 0,
      "duration_unit": "milliseconds",
      "mean_rate": 0,
      "m15_rate": 0,
      "m5_rate": 0,
      "m1_rate": 0,
      "rate_unit": "calls/second"
    },
    "org.apache.hugegraph.api.auth.AccessAPI.delete": {
      "count": 0,
      "min": 0,
      "mean": 0,
      "max": 0,
      "stddev": 0,
      "p50": 0,
      "p75": 0,
      "p95": 0,
      "p98": 0,
      "p99": 0,
      "p999": 0,
      "duration_unit": "milliseconds",
      "mean_rate": 0,
      "m15_rate": 0,
      "m5_rate": 0,
      "m1_rate": 0,
      "rate_unit": "calls/second"
    },
    "org.apache.hugegraph.api.auth.AccessAPI.get": {
      "count": 0,
      "min": 0,
      "mean": 0,
      "max": 0,
      "stddev": 0,
      "p50": 0,
      "p75": 0,
      "p95": 0,
      "p98": 0,
      "p99": 0,
      "p999": 0,
      "duration_unit": "milliseconds",
      "mean_rate": 0,
      "m15_rate": 0,
      "m5_rate": 0,
      "m1_rate": 0,
      "rate_unit": "calls/second"
    },
    "org.apache.hugegraph.api.auth.AccessAPI.list": {
      "count": 0,
      "min": 0,
      "mean": 0,
      "max": 0,
      "stddev": 0,
      "p50": 0,
      "p75": 0,
      "p95": 0,
      "p98": 0,
      "p99": 0,
      "p999": 0,
      "duration_unit": "milliseconds",
      "mean_rate": 0,
      "m15_rate": 0,
      "m5_rate": 0,
      "m1_rate": 0,
      "rate_unit": "calls/second"
    },
    ...
  }
}
1.1.2 Method & Url
http://localhost:8080/metrics/
Response Status
200
Response Body
# HELP hugegraph_info
# TYPE hugegraph_info untyped
hugegraph_info{version="0.69",
} 1.0
# HELP org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_capacity
# TYPE org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_capacity gauge
org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_capacity 1000000
# HELP org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_expire
# TYPE org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_expire gauge
org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_expire 600000
# HELP org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_hits
# TYPE org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_hits gauge
org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_hits 0
# HELP org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_miss
# TYPE org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_miss gauge
org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_miss 0
# HELP org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_size
# TYPE org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_size gauge
org_apache_hugegraph_backend_cache_Cache_edge_hugegraph_size 0
# HELP org_apache_hugegraph_backend_cache_Cache_instances
# TYPE org_apache_hugegraph_backend_cache_Cache_instances gauge
org_apache_hugegraph_backend_cache_Cache_instances 7
# HELP org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_capacity
# TYPE org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_capacity gauge
org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_capacity 10000
# HELP org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_expire
# TYPE org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_expire gauge
org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_expire 0
# HELP org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_hits
# TYPE org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_hits gauge
org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_hits 0
# HELP org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_miss
# TYPE org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_miss gauge
org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_miss 0
# HELP org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_size
# TYPE org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_size gauge
org_apache_hugegraph_backend_cache_Cache_schema_id_hugegraph_size 17
# HELP org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_capacity
# TYPE org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_capacity gauge
org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_capacity 10000
# HELP org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_expire
# TYPE org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_expire gauge
org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_expire 0
# HELP org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_hits
# TYPE org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_hits gauge
org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_hits 0
# HELP org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_miss
# TYPE org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_miss gauge
org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_miss 0
# HELP org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_size
# TYPE org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_size gauge
org_apache_hugegraph_backend_cache_Cache_schema_name_hugegraph_size 17
...

1.2 Get Gauges Metrics

Method & Url
http://localhost:8080/metrics/gauges
Response Status
200
Response Body
{
  "org.apache.hugegraph.backend.cache.Cache.edge-hugegraph.capacity": {
    "value": 1000000
  },
  "org.apache.hugegraph.backend.cache.Cache.edge-hugegraph.expire": {
    "value": 600000
  },
  "org.apache.hugegraph.backend.cache.Cache.edge-hugegraph.hits": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.edge-hugegraph.miss": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.edge-hugegraph.size": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.instances": {
    "value": 7
  },
  "org.apache.hugegraph.backend.cache.Cache.schema-id-hugegraph.capacity": {
    "value": 10000
  },
  "org.apache.hugegraph.backend.cache.Cache.schema-id-hugegraph.expire": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.schema-id-hugegraph.hits": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.schema-id-hugegraph.miss": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.schema-id-hugegraph.size": {
    "value": 17
  },
  "org.apache.hugegraph.backend.cache.Cache.schema-name-hugegraph.capacity": {
    "value": 10000
  },
  "org.apache.hugegraph.backend.cache.Cache.schema-name-hugegraph.expire": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.schema-name-hugegraph.hits": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.schema-name-hugegraph.miss": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.schema-name-hugegraph.size": {
    "value": 17
  },
  "org.apache.hugegraph.backend.cache.Cache.token-hugegraph.capacity": {
    "value": 10240
  },
  "org.apache.hugegraph.backend.cache.Cache.token-hugegraph.expire": {
    "value": 600000
  },
  "org.apache.hugegraph.backend.cache.Cache.token-hugegraph.hits": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.token-hugegraph.miss": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.token-hugegraph.size": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.users-hugegraph.capacity": {
    "value": 10240
  },
  "org.apache.hugegraph.backend.cache.Cache.users-hugegraph.expire": {
    "value": 600000
  },
  "org.apache.hugegraph.backend.cache.Cache.users-hugegraph.hits": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.users-hugegraph.miss": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.users-hugegraph.size": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.users_pwd-hugegraph.capacity": {
    "value": 10240
  },
  "org.apache.hugegraph.backend.cache.Cache.users_pwd-hugegraph.expire": {
    "value": 600000
  },
  "org.apache.hugegraph.backend.cache.Cache.users_pwd-hugegraph.hits": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.users_pwd-hugegraph.miss": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.users_pwd-hugegraph.size": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.vertex-hugegraph.capacity": {
    "value": 10000000
  },
  "org.apache.hugegraph.backend.cache.Cache.vertex-hugegraph.expire": {
    "value": 600000
  },
  "org.apache.hugegraph.backend.cache.Cache.vertex-hugegraph.hits": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.vertex-hugegraph.miss": {
    "value": 0
  },
  "org.apache.hugegraph.backend.cache.Cache.vertex-hugegraph.size": {
    "value": 0
  },
  "org.apache.hugegraph.server.RestServer.max-write-threads": {
    "value": 0
  },
  "org.apache.hugegraph.task.TaskManager.pending-tasks": {
    "value": 0
  },
  "org.apache.hugegraph.task.TaskManager.workers": {
    "value": 4
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.average-load-penalty": {
    "value": 9.227692E8
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.estimated-size": {
    "value": 2
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.eviction-count": {
    "value": 0
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.eviction-weight": {
    "value": 0
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.hit-count": {
    "value": 0
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.hit-rate": {
    "value": 0.0
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.load-count": {
    "value": 2
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.load-failure-count": {
    "value": 0
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.load-failure-rate": {
    "value": 0.0
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.load-success-count": {
    "value": 2
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.long-run-compilation-count": {
    "value": 0
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.miss-count": {
    "value": 2
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.miss-rate": {
    "value": 1.0
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.request-count": {
    "value": 2
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.gremlin-groovy.sessionless.class-cache.total-load-time": {
    "value": 1845538400
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.sessions": {
    "value": 0
  }
}

1.3 Get Counters Metrics

Method & Url
GET http://localhost:8080/metrics/counters
Response Status
200
Response Body
{
  "favicon.ico/GET/FAILED_COUNTER": {
    "count": 1
  },
  "favicon.ico/GET/TOTAL_COUNTER": {
    "count": 1
  },
  "metrics//GET/SUCCESS_COUNTER": {
    "count": 2
  },
  "metrics//GET/TOTAL_COUNTER": {
    "count": 2
  },
  "metrics/POST/FAILED_COUNTER": {
    "count": 1
  },
  "metrics/POST/TOTAL_COUNTER": {
    "count": 1
  },
  "metrics/backend/GET/SUCCESS_COUNTER": {
    "count": 2
  },
  "metrics/backend/GET/TOTAL_COUNTER": {
    "count": 2
  },
  "metrics/gauges/GET/SUCCESS_COUNTER": {
    "count": 1
  },
  "metrics/gauges/GET/TOTAL_COUNTER": {
    "count": 1
  },
  "metrics/statistics/GET/SUCCESS_COUNTER": {
    "count": 2
  },
  "metrics/statistics/GET/TOTAL_COUNTER": {
    "count": 2
  },
  "metrics/system/GET/SUCCESS_COUNTER": {
    "count": 2
  },
  "metrics/system/GET/TOTAL_COUNTER": {
    "count": 2
  },
  "metrics/timers/GET/SUCCESS_COUNTER": {
    "count": 1
  },
  "metrics/timers/GET/TOTAL_COUNTER": {
    "count": 1
  },
  "system/GET/FAILED_COUNTER": {
    "count": 1
  },
  "system/GET/TOTAL_COUNTER": {
    "count": 1
  }
}

1.4 Get Histograms Metrics

Method & Url
GET http://localhost:8080/metrics/gauges
Response Status
200
Response Body
{
  "favicon.ico/GET/RESPONSE_TIME_HISTOGRAM": {
    "count": 1,
    "min": 1,
    "mean": 1.0,
    "max": 1,
    "stddev": 0.0,
    "p50": 1.0,
    "p75": 1.0,
    "p95": 1.0,
    "p98": 1.0,
    "p99": 1.0,
    "p999": 1.0
  },
  "metrics//GET/RESPONSE_TIME_HISTOGRAM": {
    "count": 2,
    "min": 10,
    "mean": 10.0,
    "max": 10,
    "stddev": 0.0,
    "p50": 10.0,
    "p75": 10.0,
    "p95": 10.0,
    "p98": 10.0,
    "p99": 10.0,
    "p999": 10.0
  },
  "metrics/POST/RESPONSE_TIME_HISTOGRAM": {
    "count": 1,
    "min": 21,
    "mean": 21.0,
    "max": 21,
    "stddev": 0.0,
    "p50": 21.0,
    "p75": 21.0,
    "p95": 21.0,
    "p98": 21.0,
    "p99": 21.0,
    "p999": 21.0
  },
  "metrics/backend/GET/RESPONSE_TIME_HISTOGRAM": {
    "count": 2,
    "min": 6,
    "mean": 12.6852124529148,
    "max": 20,
    "stddev": 6.992918475157571,
    "p50": 6.0,
    "p75": 20.0,
    "p95": 20.0,
    "p98": 20.0,
    "p99": 20.0,
    "p999": 20.0
  },
  "metrics/gauges/GET/RESPONSE_TIME_HISTOGRAM": {
    "count": 1,
    "min": 7,
    "mean": 7.0,
    "max": 7,
    "stddev": 0.0,
    "p50": 7.0,
    "p75": 7.0,
    "p95": 7.0,
    "p98": 7.0,
    "p99": 7.0,
    "p999": 7.0
  },
  "metrics/statistics/GET/RESPONSE_TIME_HISTOGRAM": {
    "count": 2,
    "min": 1,
    "mean": 1.4551211076264199,
    "max": 2,
    "stddev": 0.49798181193626,
    "p50": 1.0,
    "p75": 2.0,
    "p95": 2.0,
    "p98": 2.0,
    "p99": 2.0,
    "p999": 2.0
  },
  "metrics/system/GET/RESPONSE_TIME_HISTOGRAM": {
    "count": 2,
    "min": 0,
    "mean": 8.942674506664073,
    "max": 40,
    "stddev": 16.665399873223066,
    "p50": 0.0,
    "p75": 0.0,
    "p95": 40.0,
    "p98": 40.0,
    "p99": 40.0,
    "p999": 40.0
  },
  "metrics/timers/GET/RESPONSE_TIME_HISTOGRAM": {
    "count": 1,
    "min": 3,
    "mean": 3.0,
    "max": 3,
    "stddev": 0.0,
    "p50": 3.0,
    "p75": 3.0,
    "p95": 3.0,
    "p98": 3.0,
    "p99": 3.0,
    "p999": 3.0
  },
  "system/GET/RESPONSE_TIME_HISTOGRAM": {
    "count": 1,
    "min": 2,
    "mean": 2.0,
    "max": 2,
    "stddev": 0.0,
    "p50": 2.0,
    "p75": 2.0,
    "p95": 2.0,
    "p98": 2.0,
    "p99": 2.0,
    "p999": 2.0
  }
}

1.5 Get Meters Metrics

Method & Url
GET http://localhost:8080/metrics/meters
Response Status
200
Response Body
{
  "org.apache.hugegraph.api.API.commit-succeed": {
    "count": 0,
    "mean_rate": 0.0,
    "m15_rate": 0.0,
    "m5_rate": 0.0,
    "m1_rate": 0.0,
    "rate_unit": "events/second"
  },
  "org.apache.hugegraph.api.API.expected-error": {
    "count": 0,
    "mean_rate": 0.0,
    "m15_rate": 0.0,
    "m5_rate": 0.0,
    "m1_rate": 0.0,
    "rate_unit": "events/second"
  },
  "org.apache.hugegraph.api.API.illegal-arg": {
    "count": 0,
    "mean_rate": 0.0,
    "m15_rate": 0.0,
    "m5_rate": 0.0,
    "m1_rate": 0.0,
    "rate_unit": "events/second"
  },
  "org.apache.hugegraph.api.API.unknown-error": {
    "count": 0,
    "mean_rate": 0.0,
    "m15_rate": 0.0,
    "m5_rate": 0.0,
    "m1_rate": 0.0,
    "rate_unit": "events/second"
  },
  "org.apache.tinkerpop.gremlin.server.GremlinServer.errors": {
    "count": 0,
    "mean_rate": 0.0,
    "m15_rate": 0.0,
    "m5_rate": 0.0,
    "m1_rate": 0.0,
    "rate_unit": "events/second"
  }
}

1.6 Get Timers Metrics

Method & Url
GET http://localhost:8080/metrics/timers
Response Status
200
Response Body
{
  "org.apache.hugegraph.api.auth.AccessAPI.create": {
    "count": 0,
    "min": 0.0,
    "mean": 0.0,
    "max": 0.0,
    "stddev": 0.0,
    "p50": 0.0,
    "p75": 0.0,
    "p95": 0.0,
    "p98": 0.0,
    "p99": 0.0,
    "p999": 0.0,
    "duration_unit": "milliseconds",
    "mean_rate": 0.0,
    "m15_rate": 0.0,
    "m5_rate": 0.0,
    "m1_rate": 0.0,
    "rate_unit": "calls/second"
  },
  "org.apache.hugegraph.api.auth.AccessAPI.delete": {
    "count": 0,
    "min": 0.0,
    "mean": 0.0,
    "max": 0.0,
    "stddev": 0.0,
    "p50": 0.0,
    "p75": 0.0,
    "p95": 0.0,
    "p98": 0.0,
    "p99": 0.0,
    "p999": 0.0,
    "duration_unit": "milliseconds",
    "mean_rate": 0.0,
    "m15_rate": 0.0,
    "m5_rate": 0.0,
    "m1_rate": 0.0,
    "rate_unit": "calls/second"
  },
  ...
}

2.Statistical Metrics

Params
  • type: If the passed value is JSON, it is returned in JSON format, otherwise it is returned in Promethaus format.
2.1 Method & Url
GET http://localhost:8080/metrics/statistics
Response Status
# HELP hugegraph_info
# TYPE hugegraph_info untyped
hugegraph_info{version="0.69",
} 1.0
# HELP metrics_POST
# TYPE metrics_POST gauge
metrics_POST{name=FAILED_REQUEST,} 1
metrics_POST{name=MEAN_RESPONSE_TIME,} 21.0
metrics_POST{
name=MAX_RESPONSE_TIME,
} 21
metrics_POST{name=SUCCESS_REQUEST,
} 0
metrics_POST{
name=TOTAL_REQUEST,
} 1
# HELP metrics_backend_GET
# TYPE metrics_backend_GET gauge
metrics_backend_GET{name=FAILED_REQUEST,
} 0
metrics_backend_GET{
name=MEAN_RESPONSE_TIME,
} 12.6852124529148
metrics_backend_GET{
name=MAX_RESPONSE_TIME,
} 20
metrics_backend_GET{
name=SUCCESS_REQUEST,
} 2
metrics_backend_GET{name=TOTAL_REQUEST,} 2
# HELP system_GET
# TYPE system_GET gauge
system_GET{name=FAILED_REQUEST,} 1
system_GET{name=MEAN_RESPONSE_TIME,} 2.0
system_GET{name=MAX_RESPONSE_TIME,} 2
system_GET{
name=SUCCESS_REQUEST,
} 0
system_GET{name=TOTAL_REQUEST,
} 1
# HELP metrics_gauges_GET
# TYPE metrics_gauges_GET gauge
metrics_gauges_GET{name=FAILED_REQUEST,} 0
metrics_gauges_GET{name=MEAN_RESPONSE_TIME,
} 7.0
metrics_gauges_GET{
name=MAX_RESPONSE_TIME,
} 7
metrics_gauges_GET{
name=SUCCESS_REQUEST,
} 1
metrics_gauges_GET{
name=TOTAL_REQUEST,
} 1
# HELP favicon.ico_GET
# TYPE favicon.ico_GET gauge
favicon.ico_GET{name=FAILED_REQUEST,
} 1
favicon.ico_GET{
name=MEAN_RESPONSE_TIME,
} 1.0
favicon.ico_GET{name=MAX_RESPONSE_TIME,} 1
favicon.ico_GET{name=SUCCESS_REQUEST,} 0
favicon.ico_GET{
name=TOTAL_REQUEST,
} 1
# HELP metrics__GET
# TYPE metrics__GET gauge
metrics__GET{name=FAILED_REQUEST,} 0
metrics__GET{name=MEAN_RESPONSE_TIME,} 10.0
metrics__GET{name=MAX_RESPONSE_TIME,
} 10
metrics__GET{
name=SUCCESS_REQUEST,
} 2
metrics__GET{
name=TOTAL_REQUEST,
} 2
# HELP metrics_system_GET
# TYPE metrics_system_GET gauge
metrics_system_GET{name=FAILED_REQUEST,} 0
metrics_system_GET{name=MEAN_RESPONSE_TIME,
} 8.942674506664073
metrics_system_GET{
name=MAX_RESPONSE_TIME,
} 40
metrics_system_GET{name=SUCCESS_REQUEST,} 2
metrics_system_GET{name=TOTAL_REQUEST,
} 2
Response Body
200
2.2 Method & Url
GET http://localhost:8080/metrics/statistics?type=json
Response Status
200
Response Body
{
  "metrics/POST": {
    "FAILED_REQUEST": 1,
    "MEAN_RESPONSE_TIME": 21,
    "MAX_RESPONSE_TIME": 21,
    "SUCCESS_REQUEST": 0,
    "TOTAL_REQUEST": 1
  },
  "metrics/backend/GET": {
    "FAILED_REQUEST": 0,
    "MEAN_RESPONSE_TIME": 12.6852124529148,
    "MAX_RESPONSE_TIME": 20,
    "SUCCESS_REQUEST": 2,
    "TOTAL_REQUEST": 2
  },
  "system/GET": {
    "FAILED_REQUEST": 1,
    "MEAN_RESPONSE_TIME": 2,
    "MAX_RESPONSE_TIME": 2,
    "SUCCESS_REQUEST": 0,
    "TOTAL_REQUEST": 1
  },
  "metrics/gauges/GET": {
    "FAILED_REQUEST": 0,
    "MEAN_RESPONSE_TIME": 7,
    "MAX_RESPONSE_TIME": 7,
    "SUCCESS_REQUEST": 1,
    "TOTAL_REQUEST": 1
  },
  "favicon.ico/GET": {
    "FAILED_REQUEST": 1,
    "MEAN_RESPONSE_TIME": 1,
    "MAX_RESPONSE_TIME": 1,
    "SUCCESS_REQUEST": 0,
    "TOTAL_REQUEST": 1
  },
  "metrics//GET": {
    "FAILED_REQUEST": 0,
    "MEAN_RESPONSE_TIME": 10,
    "MAX_RESPONSE_TIME": 10,
    "SUCCESS_REQUEST": 2,
    "TOTAL_REQUEST": 2
  },
  "metrics/system/GET": {
    "FAILED_REQUEST": 0,
    "MEAN_RESPONSE_TIME": 8.942674506664073,
    "MAX_RESPONSE_TIME": 40,
    "SUCCESS_REQUEST": 2,
    "TOTAL_REQUEST": 2
  }
}

3.System Metrics

System metrics mainly return the machine metrics, such as memory, threads, and other information.

Method & Url
GET http://localhost:8080/metrics/system
Response Status
200
Response Body
{
  "basic": {
    "mem": 1010,
    "mem_total": 911,
    "mem_used": 239,
    "mem_free": 671,
    "mem_unit": "MB",
    "processors": 20,
    "uptime": 137503,
    "systemload_average": -1.0
  },
  "heap": {
    "committed": 911,
    "init": 254,
    "used": 239,
    "max": 3596
  },
  "nonheap": {
    "committed": 98,
    "init": 2,
    "used": 95,
    "max": 0
  },
  "thread": {
    "peak": 82,
    "daemon": 34,
    "total_started": 108,
    "count": 82
  },
  "class_loading": {
    "count": 11495,
    "loaded": 11495,
    "unloaded": 0
  },
  "garbage_collector": {
    "ps_scavenge_count": 16,
    "ps_scavenge_time": 155,
    "ps_marksweep_count": 3,
    "ps_marksweep_time": 494,
    "time_unit": "ms"
  }
}

4.Backend Metrics

HugeGraph supports multiple backend storage, with backend metrics including memory, disk, and other information.

Method & Url
GET http://localhost:8080/metrics/backend
Response Status
200
Response Body
{
  "hugegraph": {
    "backend": "rocksdb",
    "nodes": 1,
    "cluster_id": "local",
    "servers": {
      "local": {
        "mem_unit": "MB",
        "disk_unit": "GB",
        "mem_used": 0.1,
        "mem_used_readable": "103.53 KB",
        "disk_usage": 0.03,
        "disk_usage_readable": "29.03 KB",
        "block_cache_usage": 0.00359344482421875,
        "block_cache_pinned_usage": 0.00359344482421875,
        "block_cache_capacity": 304.0,
        "estimate_table_readers_mem": 0.019697189331054688,
        "size_all_mem_tables": 0.07421875,
        "cur_size_all_mem_tables": 0.07421875,
        "estimate_live_data_size": 5.536526441574097E-5,
        "total_sst_files_size": 5.536526441574097E-5,
        "live_sst_files_size": 5.536526441574097E-5,
        "estimate_pending_compaction_bytes": 0.0,
        "estimate_num_keys": 0,
        "num_entries_active_mem_table": 0,
        "num_entries_imm_mem_tables": 0,
        "num_deletes_active_mem_table": 0,
        "num_deletes_imm_mem_tables": 0,
        "num_running_flushes": 0,
        "mem_table_flush_pending": 0,
        "num_running_compactions": 0,
        "compaction_pending": 0,
        "num_immutable_mem_table": 0,
        "num_snapshots": 0,
        "oldest_snapshot_time": 0,
        "num_live_versions": 38,
        "current_super_version_number": 38
      }
    }
  }
}

5.1.19 - Other API

11.1 Other

11.1.1 View Version Information of HugeGraph

Method & Url
GET http://localhost:8080/versions
Response Status
200
Response Body
{
    "versions": {
        "version": "v1",
        "core": "1.7.0",
        "gremlin": "3.5.1",
        "api": "0.71.0.0"
    }
}

5.2 - HugeGraph Java Client

The code in this document is written in java, but its style is very similar to gremlin(groovy). The user only needs to replace the variable declaration in the code with def or remove it directly, You can convert java code into groovy; in addition, each line of statement can be without a semicolon at the end, groovy considers a line to be a statement. The gremlin(groovy) written by the user in HugeGraph-Studio can refer to the java code in this document, and some examples will be given below.

1 HugeGraph-Client

HugeGraph-Client is the general entry for operating graph. Users must first create a HugeGraph-Client object and establish a connection (pseudo connection) with HugeGraph-Server before they can obtain the operation entry objects of schema, graph and gremlin.

HugeGraph-Client connects to an existing graph on the server. Its builder accepts a GraphSpace; the two-argument builder, or an empty GraphSpace value, uses DEFAULT.

// HugeGraphServer address: "http://localhost:8080"
// Graph Name: "hugegraph"
HugeClient hugeClient = HugeClient.builder("http://localhost:8080", "hugegraph")
                                //.builder("http://localhost:8080", "graphSpaceName", "hugegraph")
                                  .configTimeout(20) // 20s timeout
                                  .configUser("**", "**") // enable auth 
                                  .build();

If the above process of creating HugeClient fails, an exception will be thrown, and the user needs to use try-catch. If successful, continue to get schema, graph and gremlin manager.

When operating through gremlin in HugeGraph-Hubble(or HugeGraph-Studio), HugeClient is not required and can be ignored.

2 Schema

2.1 SchemaManager

SchemaManager is used to manage four kinds of schema in HugeGraph, namely PropertyKey (property type), VertexLabel (vertex type), EdgeLabel (edge type) and IndexLabel (index label). A SchemaManager object can be created for schema information definition.

The user can obtain the SchemaManager object using the following methods:

SchemaManager schema = hugeClient.schema()

Create a schema object via gremlin in HugeGraph-Hubble:

schema = graph.schema()

The definition process of the 4 kinds of schema is described below.

2.2 PropertyKey

2.2.1 Interface and parameter introduction

PropertyKey is used to standardize the property constraints of vertices and edges, and properties of properties are not currently supported.

The constraint information that PropertyKey allows to define includes: name, datatype, cardinality, and userdata, which are introduced one by one below.

  • name: The name of the property, used to distinguish different PropertyKeys, PropertyKeys with the same name are not allowed.
interfaceparammust set
propertyKey(String name)namey
  • datatype: property value type, you must select an explicit setting from the following table that conforms to the specific business scenario:
interfaceJava Class
asText()String
asInt()Integer
asDate()Date
asUuid()UUID
asBoolean()Boolean
asByte()Byte
asBlob()Byte[]
asDouble()Double
asFloat()Float
asLong()Long
  • cardinality: Whether the property value is single-valued or multivalued, in the case of multivalued, it is divided into allowing-duplicate values and not-allowing-duplicate values. This item is single by default. If necessary, you can select a setting from the following table:
interfacecardinalitydescription
valueSingle()singlesingle value
valueList()listmulti-values that allow duplicate value
valueSet()setmulti-values that not allow duplicate value
  • userdata: Users can add some constraints or additional information by themselves, and then check whether the incoming properties satisfy the constraints, or extract additional information when necessary:
interfacedescription
userdata(String key, Object value)The same key, the latter will cover the former
2.2.2 Create PropertyKey
schema.propertyKey("name").asText().valueSet().ifNotExist().create()

The syntax of creating the above PropertyKey object through gremlin in HugeGraph-Hubble is exactly the same. If the user does not define the schema variable, it should be written like this:

graph.schema().propertyKey("name").asText().valueSet().ifNotExist().create()

In the following examples, the syntax of gremlin and java is exactly the same, so we won’t repeat them.

  • ifNotExist(): Add a judgment mechanism for create, if the current PropertyKey already exists, it will not be created, otherwise the property will be created. If no ifNotExist() is added, an exception will be thrown if a property-key with the same name already exists. The same as below, and will not be repeated there.
2.2.3 Delete PropertyKey
schema.propertyKey("name").remove()
2.2.4 Query PropertyKey
// Get PropertyKey
schema.getPropertyKey("name")

// Get attributes of PropertyKey
schema.getPropertyKey("name").cardinality()
schema.getPropertyKey("name").dataType()
schema.getPropertyKey("name").name()
schema.getPropertyKey("name").userdata()

2.3 VertexLabel

2.3.1 Interface and parameter introduction

VertexLabel is used to define the vertex type and describe the constraint information of the vertex.

The constraint information that VertexLabel allows to define include: name, idStrategy, properties, primaryKeys and nullableKeys, which are introduced one by one below.

  • name: The name of the VertexLabel, used to distinguish different VertexLabels, VertexLabels with the same name are not allowed.
interfaceparammust set
vertexLabel(String name)namey
  • idStrategy: Each VertexLabel can choose its own ID strategy. There are currently three strategies to choose from, namely Automatic (automatically generated), Customize (user input) and PrimaryKey (primary attribute key). Among them, Automatic uses the Snowflake algorithm to generate ID, Customize requires the user to pass in the ID of string or number type, and PrimaryKey allows the user to select several properties of VertexLabel as the basis for differentiation. HugeGraph will be spliced and generated ID according to the value of the primary properties. idStrategy uses Automatic by default, but if the user does not explicitly set idStrategy and calls the primaryKeys(…) method to set the primary property, then idStrategy will automatically use PrimaryKey.
interfaceidStrategydescription
useAutomaticIdAUTOMATICgenerate id automatically by Snowflake algorithm
useCustomizeStringIdCUSTOMIZE_STRINGpassed id by user, must be string type
useCustomizeNumberIdCUSTOMIZE_NUMBERpassed id by user, must be number type
usePrimaryKeyIdPRIMARY_KEYchoose some important prop as primary key to splice id
  • properties: define the properties of the vertex, the incoming parameter is the name of the PropertyKey.
interfacedescription
properties(String… properties)allow to pass multi properties
  • primaryKeys: When the user selects the ID strategy of PrimaryKey, several primary properties need to be selected from the properties of VertexLabel as the basis for differentiation;
interfacedescription
primaryKeys(String… keys)allow to choose multi prop as primaryKeys

Note that the selection of the ID strategy and the setting of primaryKeys have some mutual constraints, which cannot be called at will. The constraints are shown in the following table:

useAutomaticIduseCustomizeStringIduseCustomizeNumberIdusePrimaryKeyId
unset primaryKeysAUTOMATICCUSTOMIZE_STRINGCUSTOMIZE_NUMBERERROR
set primaryKeysERRORERRORERRORPRIMARY_KEY
  • nullableKeys: For properties set by the properties(…) method, all of them are non-nullable by default, that is, the property must be assigned a value when creating a vertex, which may impose too strict integrity requirements on user data. In order to avoid such strong constraints, the user can set some properties to be nullable through this method, so that the properties can be unassigned when adding vertices.
interfacedescription
nullableKeys(String… properties)allow to pass multi props

Note: primaryKeys and nullableKeys cannot intersect, because a property cannot be both primary and nullable.

  • enableLabelIndex: The user can specify whether to create an index for the label. If you don’t create it, you can’t globally search for the vertices and edges of the specified label. If you create it, you can search globally, like g.V().hasLabel('person'), g.E().has('label', 'person') query, but the performance will be slower when inserting data, and it will take up more storage space. This defaults to true.
interfacedescription
enableLabelIndex(boolean enable)Whether to create a label index
  • userdata: Users can add some constraints or additional information by themselves, and then check whether the incoming properties meet the constraints, or extract additional information when necessary.
interfacedescription
userdata(String key, Object value)The same key, the latter will cover the former
2.3.2 Create VertexLabel
// Use Automatic Id strategy
schema.vertexLabel("person").properties("name", "age").ifNotExist().create();
schema.vertexLabel("person").useAutomaticId().properties("name", "age").ifNotExist().create();

// Use Customize_String Id strategy
schema.vertexLabel("person").useCustomizeStringId().properties("name", "age").ifNotExist().create();
// Use Customize_Number Id strategy
schema.vertexLabel("person").useCustomizeNumberId().properties("name", "age").ifNotExist().create();

// Use PrimaryKey Id strategy
schema.vertexLabel("person").properties("name", "age").primaryKeys("name").ifNotExist().create();
schema.vertexLabel("person").usePrimaryKeyId().properties("name", "age").primaryKeys("name").ifNotExist().create();
2.3.3 Update VertexLabel

VertexLabel can append constraints, but only properties and nullableKeys, and the appended properties must also be added to the nullableKeys collection.

schema.vertexLabel("person").properties("price").nullableKeys("price").append();
2.3.4 Delete VertexLabel
schema.vertexLabel("person").remove();
2.3.5 Query VertexLabel
// Get VertexLabel
schema.getVertexLabel("name")

// Get attributes of VertexLabel
schema.getVertexLabel("person").idStrategy()
schema.getVertexLabel("person").primaryKeys()
schema.getVertexLabel("person").name()
schema.getVertexLabel("person").properties()
schema.getVertexLabel("person").nullableKeys()
schema.getVertexLabel("person").userdata()

2.4 EdgeLabel

2.4.1 Interface and parameter introduction

EdgeLabel is used to define the edge type and describe the constraint information of the edge.

The constraint information that EdgeLabel allows to define include: name, sourceLabel, targetLabel, frequency, properties, sortKeys and nullableKeys, which are introduced one by one below.

  • name: The name of the EdgeLabel, used to distinguish different EdgeLabels, EdgeLabels with the same name are not allowed.
interfaceparammust set
edgeLabel(String name)namey
  • sourceLabel: The name of the source vertex type of the edge link, only one is allowed;

  • targetLabel: The name of the target vertex type of the edge link, only one is allowed;

interfaceparammust set
sourceLabel(String label)labely
targetLabel(String label)labely
  • frequency: Indicating the number of times a relationship occurs between two specific vertices, which can be single (single) or multiple (frequency), the default is single.
interfacefrequencydescription
singleTime()singlea relationship can only occur once
multiTimes()multiplea relationship can occur many times
  • properties: Define the properties of the edge.
interfacedescription
properties(String… properties)allow to pass multi props
  • sortKeys: When the frequency of EdgeLabel is multiple, some properties are needed to distinguish the multiple relationships, so sortKeys (sorted keys) is introduced;
interfacedescription
sortKeys(String… keys)allow to choose multi prop as sortKeys
  • nullableKeys: Consistent with the concept of nullableKeys in vertices.

Note: sortKeys and nullableKeys also cannot intersect.

  • enableLabelIndex: It is consistent with the concept of enableLabelIndex in the vertex.

  • userdata: Users can add some constraints or additional information by themselves, and then check whether the incoming properties meet the constraints, or extract additional information when necessary.

interfacedescription
userdata(String key, Object value)The same key, the latter will cover the former
2.4.2 Create EdgeLabel
schema.edgeLabel("knows").link("person", "person").properties("date").ifNotExist().create();
schema.edgeLabel("created").multiTimes().link("person", "software").properties("date").sortKeys("date").ifNotExist().create();
2.4.3 Update EdgeLabel
schema.edgeLabel("knows").properties("price").nullableKeys("price").append();
2.4.4 Delete EdgeLabel
schema.edgeLabel("knows").remove();
2.4.5 Query EdgeLabel
// Get EdgeLabel
schema.getEdgeLabel("knows")

// Get attributes of EdgeLabel
schema.getEdgeLabel("knows").frequency()
schema.getEdgeLabel("knows").sourceLabel()
schema.getEdgeLabel("knows").targetLabel()
schema.getEdgeLabel("knows").sortKeys()
schema.getEdgeLabel("knows").name()
schema.getEdgeLabel("knows").properties()
schema.getEdgeLabel("knows").nullableKeys()
schema.getEdgeLabel("knows").userdata()

2.5 IndexLabel

2.5.1 Interface and parameter introduction

IndexLabel is used to define the index type and describe the constraint information of the index, mainly for the convenience of query.

The constraint information that IndexLabel allows to define include: name, baseType, baseValue, indexFields, indexType, which are introduced one by one below.

  • name: The name of the IndexLabel, used to distinguish different IndexLabels, IndexLabels with the same name are not allowed.
interfaceparammust set
indexLabel(String name)namey
  • baseType: Indicates whether to index VertexLabel or EdgeLabel, used in conjunction with the baseValue below.

  • baseValue: Specifies the name of the VertexLabel or EdgeLabel to be indexed.

interfaceparamdescription
onV(String baseValue)baseValuebuild index for VertexLabel: ‘baseValue’
onE(String baseValue)baseValuebuild index for EdgeLabel: ‘baseValue’
  • indexFields: on which fields to index, it can be a joint index for multiple columns.
interfaceparamdescription
by(String… fields)filesallow to build index for multi fields for secondary index
  • indexType: There are currently five types of indexes established, namely Secondary, Range, Search, Shard and Unique.
    • Secondary Index supports exact matching secondary index, allow to build joint index, joint index supports index prefix search
      • Single Property Secondary Index, support equality query, for example: the secondary index of the city property of the person vertex, you can use g.V().has("city", "Beijing") to query all the vertices with “city attribute value is Beijing”
      • Joint Secondary Index, supports prefix query and equality query, such as: joint index of city and street properties of person vertex, you can use g.V().has("city", "Beijing").has('street', 'Zhongguancun street ') to query all vertices of “city property value is Beijing and street property value is ZhongGuanCun”, or g.V().has("city", "Beijing") to query all vertices of “city property value is Beijing”.

      The query of Secondary Index is based on the query condition of “yes” or “equal”, and does not support “partial matching”.

    • Range Index supports for range queries of numeric types
      • Must be a single number or date attribute, for example: the range index of the age property of the person vertex, you can use g.V().has("age", P.gt(18)) to query the vertices with “age property value greater than 18” . In addition to P.gt(), also supports P.gte(), P.lte(), P.lt(), P.eq(), P.between() , P.inside() and P.outside() etc.
    • Search Index supports full-text search
      • It must be a single text property, such as: full-text index of the address property of the person vertex, you can use g.V().has("address", Text.contains('building') to query all vertices whose “address property contains a ‘building’”

      The query of the Search Index is based on the query condition of “is” or “contains”.

    • Shard Index supports prefix matching + numeric range query
      • The shard index of N properties supports range queries with equal prefixes. For example, the shard index of the city and age properties of the person vertex can use g.V().has("city", "Beijing").has ("age", P.between(18, 30))Query “city property is Beijing and all vertices whose age is greater than or equal to 18 and less than 30”.
      • When all N properties are text properties in a Shard Index, it is equivalent to Secondary Index.
      • When there is only one single number or date property in a Shard Index, it is equivalent to the Range Index.

      Shard Index can have any number or date property, but at most one range search condition can be provided when querying, and the prefix properties of the Shard Search conditions must be “equals”.

    • Unique Index supports properties uniqueness constraints, that is, the value of properties can be limited to not repeat, and joint indexing is allowed, but querying is not supported now
      • The unique index of single or multiple properties cannot be used for query, only the value of the property can be limited, and an error will be reported when there is a duplicate value.
interfaceindexTypedescription
secondary()Secondarysupport prefix search
range()Rangesupport range(numeric or date type) search
search()Searchsupport full text search
shard()Shardsupport prefix + range(numeric or date type) search
unique()Uniquesupport unique props value, not support search
2.5.2 Create IndexLabel
schema.indexLabel("personByAge").onV("person").by("age").range().ifNotExist().create();
schema.indexLabel("createdByDate").onE("created").by("date").secondary().ifNotExist().create();
schema.indexLabel("personByLived").onE("person").by("lived").search().ifNotExist().create();
schema.indexLabel("personByCityAndAge").onV("person").by("city", "age").shard().ifNotExist().create();
schema.indexLabel("personById").onV("person").by("id").unique().ifNotExist().create();
2.5.3 Delete IndexLabel
schema.indexLabel("personByAge").remove()
2.5.4 Query IndexLabel
// Get IndexLabel
schema.getIndexLabel("personByAge")

// Get attributes of IndexLabel
schema.getIndexLabel("personByAge").baseType()
schema.getIndexLabel("personByAge").baseValue()
schema.getIndexLabel("personByAge").indexFields()
schema.getIndexLabel("personByAge").indexType()
schema.getIndexLabel("personByAge").name()

3 Graph

3.1 Vertex

Vertices are the most basic elements of a graph, and there can be many vertices in a graph. Here is an example of adding vertices:

Vertex marko = graph.addVertex(T.label, "person", "name", "marko", "age", 29);
Vertex lop = graph.addVertex(T.label, "software", "name", "lop", "lang", "java", "price", 328);
  • The key to adding vertices is the vertex properties. The number of parameters of the vertex adding function must be an even number and satisfy the order of key1 -> val1, key2 -> val2 ..., and the order between key-value pairs is free .
  • The parameter must contain a special key-value pair, namely T.label -> "val", which is used to define the category of the vertex, so that the program can obtain the schema definition of the VertexLabel from the cache or backend, and then do subsequent constraint checks. The label in the example is defined as person.
  • If the vertex type’s ID policy is AUTOMATIC, users are not allowed to pass in id key-value pairs.
  • If the ID policy of the vertex type is CUSTOMIZE_STRING, the user needs to pass in the value of the id of the String type. The key-value pair is like: "T.id", "123456".
  • If the ID policy of the vertex type is CUSTOMIZE_NUMBER, the user needs to pass in the value of the id of the Number type. The key-value pair is like: "T.id", 123456.
  • If the ID policy of the vertex type is PRIMARY_KEY, the parameters must also contain the name and value of the properties corresponding to the primaryKeys, if not set an exception will be thrown. For example, the primaryKeys of person is name, in the example, the value of name is set to marko.
  • For properties that are not nullableKeys, a value must be assigned.
  • The remaining parameters are the settings of other properties of the vertex, but they are not required.
  • After calling the addVertex method, the vertices are inserted into the backend storage system immediately.

3.2 Edge

After added vertices, edges are also needed to form a complete graph. Here is an example of adding edges:

Edge knows1 = marko.addEdge("knows", vadas, "city", "Beijing");
  • The function addEdge() of the (source) vertex is to add an edge(relationship) between itself and another vertex. The first parameter of the function is the label of the edge, and the second parameter is the target vertex. The position and order of these two parameters are fixed. The subsequent parameters are the order of key1 -> val1, key2 -> val2 ..., set the properties of the edge, and the key-value pair order is free.
  • The source and target vertices must conform to the definitions of source-label and target label in EdgeLabel, and cannot be added arbitrarily.
  • For properties that are not nullableKeys, a value must be assigned.

Note: When frequency is multiple, the value of the property type corresponding to sortKeys must be set.

4 GraphSpace

The client can manage multiple GraphSpaces in one physical deployment, and each GraphSpace can contain multiple graphs. When no GraphSpace is specified, it uses DEFAULT.

4.1 Create GraphSpace

GraphSpaceManager spaceManager = hugeClient.graphSpace();

// Define GraphSpace configuration
GraphSpace graphSpace = new GraphSpace();
graphSpace.setName("myGraphSpace");
graphSpace.setDescription("Business data graph space");
graphSpace.setMaxGraphNumber(10);  // Maximum number of graphs
graphSpace.setMaxRoleNumber(100);  // Maximum number of roles

// Create GraphSpace
spaceManager.createGraphSpace(graphSpace);

4.2 GraphSpace Interface Summary

CategoryInterfaceDescription
Manager - QuerylistGraphSpace()Get all GraphSpace names
listProfile() / listProfile(String prefix)Get GraphSpace profiles
getGraphSpace(String name)Get the specified GraphSpace
getDefault()Get the default GraphSpace
Manager - Create/UpdatecreateGraphSpace(GraphSpace)Create a GraphSpace
updateGraphSpace(GraphSpace)Update configuration
setDefault(String name)Set the default GraphSpace
Manager - DeletedeleteGraphSpace(String name)Delete the specified GraphSpace
GraphSpace - PropertiesgetName() / getDescription()Get name / description
getGraphNumber()Get the number of graphs
GraphSpace - ConfigurationsetDescription(String)Set description
setMaxGraphNumber(int)Set the maximum number of graphs

5 Simple Example

Simple examples can reference HugeGraph-Client

5.3 - Gremlin-Console

Gremlin-Console is an interactive client developed by TinkerPop. Users can use this client to perform various operations on Graph. There are two main usage modes:

  • Stand-alone offline mode
  • Client/Server mode

Note: Gremlin-Console is only for users to quickly get started and experience, it is not recommended for use in production environments.

1 Stand-alone offline mode

Since the lib directory already contains the HugeCore jar package, and HugeGraph-Server has been registered in the Console as a plug-in, the users can write a groovy script directly to call the code of HugeGraph-Core, and then hand it over to the parsing engine in Gremlin-Console for execution. As a result, the users can operate the graph without starting the Server.

Here is an example, first modify the hugegraph.properties configuration to use the Memory backend (using other backends may encounter some initialization issues):

backend=memory
serializer=text

Then enter the following command:

> ./bin/gremlin-console.sh -- -i scripts/example.groovy

         \,,,/
         (o o)
-----oOOo-(3)-oOOo-----
plugin activated: HugeGraph
plugin activated: tinkerpop.server
plugin activated: tinkerpop.utilities
plugin activated: tinkerpop.tinkergraph
main dict load finished, time elapsed 644 ms
model load finished, time elapsed 35 ms.
>>>> query all vertices: size=6
>>>> query all edges: size=6
gremlin> 

The -- here will be parsed by getopts as the last option, allowing the subsequent options to be passed to Gremlin-Console for processing. -i represents Execute the specified script and leave the console open on completion. For more options, you can refer to the source code of Gremlin-Console.

example.groovy is an example script under the scripts directory. This script inserts some data and queries the number of vertices and edges in the graph at the end.

You can continue to enter Gremlin statements to operate on the graph:

gremlin> g.V()
==>v[2:lop]
==>v[1:josh]
==>v[1:marko]
==>v[1:peter]
==>v[1:vadas]
==>v[2:ripple]
gremlin> g.E()
==>e[S1:josh>2>>S2:lop][1:josh-created->2:lop]
==>e[S1:josh>2>>S2:ripple][1:josh-created->2:ripple]
==>e[S1:marko>1>>S1:josh][1:marko-knows->1:josh]
==>e[S1:marko>1>>S1:vadas][1:marko-knows->1:vadas]
==>e[S1:marko>2>>S2:lop][1:marko-created->2:lop]
==>e[S1:peter>2>>S2:lop][1:peter-created->2:lop]
gremlin> 

For more Gremlin statements, please refer to Tinkerpop Official Website

2 Client/Server mode

Gremlin Console connects to HugeGraph Server through WebSocket. The default configuration uses WsAndHttpChannelizer, which handles both WebSocket and HTTP requests, so there is no need to switch the Channelizer.

# vim conf/gremlin-server.yaml
# ......
channelizer: org.apache.tinkerpop.gremlin.server.channel.WsAndHttpChannelizer
# ......

Confirm that host and port match the settings in remote.yaml, and then follow the steps to start HugeGraph Server.

Then enter Gremlin-Console:

> ./bin/gremlin-console.sh

         \,,,/
         (o o)
-----oOOo-(3)-oOOo-----
plugin activated: HugeGraph
plugin activated: tinkerpop.server
plugin activated: tinkerpop.utilities
plugin activated: tinkerpop.tinkergraph

To connect to the server, you need to specify the connection parameters in the configuration file, and there is a default remote.yaml file in the conf directory

# cat conf/remote.yaml
hosts: [localhost]
port: 8182
serializer: {
  className: org.apache.tinkerpop.gremlin.driver.ser.GraphSONMessageSerializerV1d0,
  config: {
    serializeResultToString: false,
    ioRegistries: [org.apache.hugegraph.io.HugeGraphIoRegistry]
  }
}
gremlin> :remote connect tinkerpop.server conf/remote.yaml
==>Configured localhost/127.0.0.1:8182

After a successful connection, if the sample graph example.groovy is imported during the startup of HugeGraph-Server, you can directly perform queries in the console.

gremlin> :> hugegraph.traversal().V()
==>[id:2:lop,label:software,type:vertex,properties:[name:lop,lang:java,price:328]]
==>[id:1:josh,label:person,type:vertex,properties:[name:josh,age:32,city:Beijing]]
==>[id:1:marko,label:person,type:vertex,properties:[name:marko,age:29,city:Beijing]]
==>[id:1:peter,label:person,type:vertex,properties:[name:peter,age:35,city:Shanghai]]
==>[id:1:vadas,label:person,type:vertex,properties:[name:vadas,age:27,city:Hongkong]]
==>[id:2:ripple,label:software,type:vertex,properties:[name:ripple,lang:java,price:199]]

NOTE: In Client/Server mode, all operations related to the Server should be prefixed with :> . If not added, it indicates local console operations.

You can also put multiple statements in a single string variable and send them to the Server at once:

gremlin> script = """
......1> graph = hugegraph;
......2> g = graph.traversal();
......3> g.V().toList().size();
......4> """
==>
graph = hugegraph;
g = graph.traversal();
g.V().toList().size();

gremlin> :> @script
==>6
gremlin> 

For more information on the use of Gremlin-Console, please refer to Tinkerpop Official Website

6 - GUIDES

This section covers HugeGraph architecture, design, backup and restore, plugin development, security settings, and frequently asked questions.

6.1 - HugeGraph Architecture Overview

1 Overview

As a full-stack graph system covering Graph Database, Graph Computing, and Graph AI, HugeGraph is centered around a high-performance graph engine (HugeGraph Server) and supports both OLTP and OLAP graph computation types. For the OLTP layer, it implements the Apache TinkerPop3 framework and supports the Gremlin and Cypher query languages. It comes with a complete application toolchain and provides a pluggable backend storage driver framework.

Below is the overall architecture diagram of HugeGraph:

image

HugeGraph consists of three layers of functionality: the application layer, the graph engine layer, and the storage layer.

  • Application Layer:
    • Hubble: A one-stop visual analysis platform that covers the entire process from data modeling to rapid data import, online and offline analysis, and unified graph management, realizing wizard-style operations for the entire graph application process.
    • Loader: A data import component that can transform data from multiple data sources into graph vertices and edges and batch import them into the graph database.
    • Tools: Command-line tools for deploying, managing, and backing up/restoring data in HugeGraph.
    • Computer: A distributed graph processing system (OLAP), which is an implementation of Pregel and can run on Kubernetes.
    • Client: Client SDKs encapsulate the core operations for connecting to HugeGraph Server, managing schemas, reading and writing graph data, and running queries. HugeGraph currently provides Java, Python, and Go clients, while a Rust client is under development.
  • Graph Engine Layer:
    • REST Server: Provides a RESTful API for querying graph/schema information, supports the Gremlin and Cypher query languages, and offers APIs for service monitoring and operations.
    • Graph Engine: Supports both OLTP and OLAP graph computation types, with OLTP implementing the Apache TinkerPop3 framework.
    • Backend Interface: Implements the storage of graph data to the backend.
  • Storage Layer:
    • Storage Backend: Version 1.7.0 supports RocksDB, HStore, HBase, and Memory. Custom backends can be added through plugins.

6.2 - HugeGraph Design Concepts

1. Property Graph

There are two common graph data representation models, namely the RDF (Resource Description Framework) model and the Property Graph (Property Graph) model. Both RDF and Property Graph are the most basic and well-known graph representation modes, and both can represent entity-relationship modeling of various graphs. RDF is a W3C standard, while Property Graph is an industry standard and is widely supported by graph database vendors. HugeGraph currently uses Property Graph.

The storage concept model corresponding to HugeGraph is also designed with reference to Property Graph. For specific examples, see the figure below: ( This figure is outdated for the old version design, please ignore it and update it later )

image

Inside HugeGraph, each vertex/edge is identified by a unique VertexId/EdgeId, and the attributes are stored inside the corresponding vertex/edge. The relationship/mapping between vertices is stored through edges.

When the vertex attribute value is stored by edge pointer, if you want to update a vertex-specific attribute value, you can directly write it by overwriting. The disadvantage is that the VertexId is redundantly stored; if you want to update the attribute of the relationship, you need to use the read-and-modify method , read all attributes first, modify some attributes, and then write to the storage system, the update efficiency is low. According to experience, there are more requirements for modifying vertex attributes, but less for edge attributes. For example, calculations such as PageRank and Graph Cluster require frequent modification of vertex attribute values.

2. Graph Partition Scheme

For distributed graph databases, there are two partition storage methods for graphs: Edge Cut and Vertex Cut, as shown in the following figure. When using the Edge Cut method to store graphs, any vertex will only appear on one machine, while edges may be distributed on different machines. This storage method may lead to multiple storage of edges. When using the Vertex Cut method to store graphs, any edge will only appear on one machine, and each same point may be distributed to different machines. This storage method may result in multiple storage of vertices.

image

The EdgeCut partition scheme can support high-performance insert and update operations, while the VertexCut partition scheme is more suitable for static graph query analysis, so EdgeCut is suitable for OLTP graph query, and VertexCut is more suitable for OLAP graph query. HugeGraph currently adopts the partition scheme of EdgeCut.

3. VertexId Strategy

Vertex of HugeGraph supports three ID strategies. Different VertexLabels in the same graph database can use different Id strategies. Currently, the Id strategies supported by HugeGraph are:

  • Automatic generation (AUTOMATIC): Use the Snowflake algorithm to automatically generate a globally unique Id, Long type;
  • Primary Key (PRIMARY_KEY): Generate Id through VertexLabel+PrimaryKeyValues, String type;
  • Custom (CUSTOMIZE_STRING|CUSTOMIZE_NUMBER): User-defined Id, which is divided into two types: String and Long, and you need to ensure the uniqueness of the Id yourself;

The default Id policy is AUTOMATIC, if the user calls the primaryKeys() method and sets the correct PrimaryKeys, the PRIMARY_KEY policy is automatically enabled. After enabling the PRIMARY_KEY strategy, HugeGraph can implement data deduplication based on PrimaryKeys.

  1. AUTOMATIC ID Policy
schema.vertexLabel("person")
     .useAutomaticId()
     .properties("name", "age", "city")
     .create();
graph.addVertex(T.label, "person","name", "marko", "age", 18, "city", "Beijing");
  1. PRIMARY_KEY ID policy
schema.vertexLabel("person")
     .usePrimaryKeyId()
     .properties("name", "age", "city")
     .primaryKeys("name", "age")
     .create();
graph.addVertex(T.label, "person","name", "marko", "age", 18, "city", "Beijing");
  1. CUSTOMIZE_STRING ID Policy
schema.vertexLabel("person")
     .useCustomizeStringId()
     .properties("name", "age", "city")
     .create();
graph.addVertex(T.label, "person", T.id, "123456", "name", "marko","age", 18, "city", "Beijing");
  1. CUSTOMIZE_NUMBER ID Policy
schema.vertexLabel("person")
     .useCustomizeNumberId()
     .properties("name", "age", "city")
     .create();
graph.addVertex(T.label, "person", T.id, 123456, "name", "marko","age", 18, "city", "Beijing");

If users need Vertex deduplication, there are three options:

  1. Adopt PRIMARY_KEY strategy, automatic overwriting, suitable for batch insertion of large amount of data, users cannot know whether overwriting has occurred
  2. Adopt AUTOMATIC strategy, read-and-modify, suitable for small data insertion, users can clearly know whether overwriting occurs
  3. Using the CUSTOMIZE_STRING or CUSTOMIZE_NUMBER strategy, the user guarantees the uniqueness

4. EdgeId policy

The EdgeId of HugeGraph is composed of srcVertexId + edgeLabel + sortKey + tgtVertexId. Among them sortKey is an important concept of HugeGraph. There are two reasons for adding Edge sortKeyas the unique ID of Edge:

  1. If there are multiple edges of the same Label between two vertices, they can be sortKeydistinguished by
  2. For SuperNode nodes, it can be sortKeysorted and truncated by.

Since EdgeId is composed of srcVertexId + edgeLabel + sortKey + tgtVertexId, HugeGraph will automatically overwrite when the same Edge is inserted multiple times to achieve deduplication. It should be noted that the properties of Edge will also be overwritten in the batch insert mode.

In addition, because HugeGraph’s EdgeId adopts an automatic deduplication strategy, HugeGraph considers that there is only one edge in the case of self-loop (a vertex has an edge pointing to itself). The graph has two edges.

The edges of HugeGraph only support directed edges, and undirected edges can be realized by creating two edges, Out and In.

5. HugeGraph transaction overview

TinkerPop transaction overview

A TinkerPop transaction refers to a unit of work that performs operations on the database. A set of operations within a transaction either succeeds or all fail. For a detailed introduction, please refer to the official documentation of TinkerPop: http://tinkerpop.apache.org/docs/current/reference/#transactions:http://tinkerpop.apache.org/docs/current/reference/#transactions

TinkerPop transaction overview
  • open open transaction
  • commit commit transaction
  • rollback rollback transaction
  • close closes the transaction
TinkerPop transaction specification
  • The transaction must be explicitly committed before it can take effect (the modification operation can only be seen by the query in this transaction if it is not committed)
  • A transaction must be opened before it can be committed or rolled back
  • If the transaction setting is automatically turned on, there is no need to explicitly turn it on (the default method), if it is set to be turned on manually, it must be turned on explicitly
  • When the transaction is closed, you can set three modes: automatic commit, automatic rollback (default mode), manual (explicit shutdown is prohibited), etc.
  • The transaction must be closed after committing or rolling back
  • The transaction must be open after the query
  • Transactions (non-threaded tx) must be thread-isolated, and multi-threaded operations on the same transaction do not affect each other

For more transaction specification use cases, see: Transaction Test

HugeGraph transaction implementation
  • All operations in a transaction either succeed or fail
  • A transaction can only read what has been committed by another transaction (Read committed)
  • All uncommitted operations can be queried in this transaction, including:
    • Adding a vertex can query the vertex
    • Delete a vertex to filter out the vertex
    • Deleting a vertex can filter out the related edges of the vertex
    • Adding an edge can query the edge
    • Delete edge can filter out the edge
    • Adding/modifying (vertex, edge) attributes can take effect when querying
    • Delete (vertex, edge) attributes can take effect at query time
  • All uncommitted operations become invalid after the transaction is rolled back, including:
    • Adding and deleting vertices and edges
    • Addition/modification, deletion of attributes

Example: One transaction cannot read another transaction’s uncommitted content

    static void testUncommittedTx(final HugeGraph graph) throws InterruptedException {

        final CountDownLatch latchUncommit = new CountDownLatch(1);
        final CountDownLatch latchRollback = new CountDownLatch(1);

        Thread thread = new Thread(() -> {
            // this is a new transaction in the new thread
            graph.tx().open();

            System.out.println("current transaction operations");

            Vertex james = graph.addVertex(T.label, "author",
                                           "id", 1, "name", "James Gosling",
                                           "age", 62, "lived", "Canadian");
            Vertex java = graph.addVertex(T.label, "language", "name", "java",
                                          "versions", Arrays.asList(6, 7, 8));
            james.addEdge("created", java);

            // we can query the uncommitted records in the current transaction
            System.out.println("current transaction assert");
            assert graph.vertices().hasNext() == true;
            assert graph.edges().hasNext() == true;

            latchUncommit.countDown();

            try {
                latchRollback.await();
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }

            System.out.println("current transaction rollback");
            graph.tx().rollback();
        });

        thread.start();

        // query none result in other transaction when not commit()
        latchUncommit.await();
        System.out.println("other transaction assert for uncommitted");
        assert !graph.vertices().hasNext();
        assert !graph.edges().hasNext();

        latchRollback.countDown();
        thread.join();

        // query none result in other transaction after rollback()
        System.out.println("other transaction assert for rollback");
        assert !graph.vertices().hasNext();
        assert !graph.edges().hasNext();
    }
Principle of transaction realization
  • The server internally realizes isolation by binding transactions to threads (ThreadLocal)
  • The uncommitted content of this transaction overwrites the old data in chronological order for this transaction to query the latest version of data
  • The bottom layer relies on the back-end database to ensure transaction atomicity (for example, the batch interface of Cassandra/RocksDB guarantees atomicity)
Notice

The RESTful API does not expose the transaction interface for the time being

TinkerPop API allows open transactions, which are automatically closed when the request is completed (Gremlin Server forces close)

6.3 - HugeGraph Plugin mechanism and plug-in extension process

Background

  1. HugeGraph is not only open source and open, but also simple and easy to use. General users can easily add plug-in extension functions without changing the source code.
  2. HugeGraph supports a variety of built-in storage backends, and also allows users to extend custom backends without changing the existing source code.
  3. HugeGraph supports full-text search. The full-text search function involves word segmentation in various languages. Currently, there are 8 built-in Chinese word breakers, and it also allows users to expand custom word breakers without changing the existing source code.

Scalable dimension

Currently, the plug-in method provides extensions in the following dimensions:

  • backend storage
  • serializer
  • Custom configuration items
  • tokenizer

Plug-in implementation mechanism

  1. HugeGraph provides a plug-in interface HugeGraphPlugin, which supports plug-in through the Java SPI mechanism
  2. HugeGraph provides four extension registration functions: registerOptions(), registerBackend(), registerSerializer(),registerAnalyzer()
  3. The plug-in implementer implements the corresponding Options, Backend, Serializer or Analyzer interface
  4. The plug-in implementer implements register()the method of the HugeGraphPlugin interface, registers the specific implementation class listed in the above point 3 in this method, and packs it into a jar package
  5. The plug-in user puts the jar package in the HugeGraph Server installation directory plugins, modifies the relevant configuration items to the plug-in custom value, and restarts to take effect

Plug-in implementation process example

1 Create a new maven project

1.1 Name the project name: hugegraph-plugin-demo
1.2 Add hugegraph-core Jar package dependencies

The details of maven pom.xml are as follows:

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>
    <groupId>org.apache.hugegraph</groupId>
    <artifactId>hugegraph-plugin-demo</artifactId>
    <version>1.0.0</version>
    <packaging>jar</packaging>

    <name>hugegraph-plugin-demo</name>

    <dependencies>
        <dependency>
            <groupId>org.apache.hugegraph</groupId>
            <artifactId>hugegraph-core</artifactId>
            <version>${project.version}</version>
        </dependency>
    </dependencies>
</project>

2 Realize extended functions

2.1 Extending a custom backend
2.1.1 Implement the interface BackendStoreProvider
  • Realizable interfaces: org.apache.hugegraph.backend.store.BackendStoreProvider
  • Or inherit an abstract class:org.apache.hugegraph.backend.store.AbstractBackendStoreProvider

Take the RocksDB backend RocksDBStoreProvider as an example:

public class RocksDBStoreProvider extends AbstractBackendStoreProvider {

    protected String database() {
        return this.graph().toLowerCase();
    }

    @Override
    protected BackendStore newSchemaStore(String store) {
        return new RocksDBSchemaStore(this, this.database(), store);
    }

    @Override
    protected BackendStore newGraphStore(String store) {
        return new RocksDBGraphStore(this, this.database(), store);
    }

    @Override
    public String type() {
        return "rocksdb";
    }

    @Override
    public String version() {
        return "1.0";
    }
}
2.1.2 Implement interface BackendStore

The BackendStore interface is defined as follows:

public interface BackendStore {
    // Store name
    public String store();

    // Database name
    public String database();

    // Get the parent provider
    public BackendStoreProvider provider();

    // Open/close database
    public void open(HugeConfig config);
    public void close();

    // Initialize/clear database
    public void init();
    public void clear();

    // Add/delete data
    public void mutate(BackendMutation mutation);

    // Query data
    public Iterator<BackendEntry> query(Query query);

    // Transaction
    public void beginTx();
    public void commitTx();
    public void rollbackTx();

    // Get metadata by key
    public <R> R metadata(HugeType type, String meta, Object[] args);

    // Backend features
    public BackendFeatures features();

    // Generate an id for a specific type
    public Id nextId(HugeType type);
}
2.1.3 Extending custom serializers

The serializer must inherit the abstract class: org.apache.hugegraph.backend.serializer.AbstractSerializer ( implements GraphSerializer, SchemaSerializer) The main interface is defined as follows:

public interface GraphSerializer {
    public BackendEntry writeVertex(HugeVertex vertex);
    public BackendEntry writeVertexProperty(HugeVertexProperty<?> prop);
    public HugeVertex readVertex(HugeGraph graph, BackendEntry entry);
    public BackendEntry writeEdge(HugeEdge edge);
    public BackendEntry writeEdgeProperty(HugeEdgeProperty<?> prop);
    public HugeEdge readEdge(HugeGraph graph, BackendEntry entry);
    public BackendEntry writeIndex(HugeIndex index);
    public HugeIndex readIndex(HugeGraph graph, ConditionQuery query, BackendEntry entry);
    public BackendEntry writeId(HugeType type, Id id);
    public Query writeQuery(Query query);
}

public interface SchemaSerializer {
    public BackendEntry writeVertexLabel(VertexLabel vertexLabel);
    public VertexLabel readVertexLabel(HugeGraph graph, BackendEntry entry);
    public BackendEntry writeEdgeLabel(EdgeLabel edgeLabel);
    public EdgeLabel readEdgeLabel(HugeGraph graph, BackendEntry entry);
    public BackendEntry writePropertyKey(PropertyKey propertyKey);
    public PropertyKey readPropertyKey(HugeGraph graph, BackendEntry entry);
    public BackendEntry writeIndexLabel(IndexLabel indexLabel);
    public IndexLabel readIndexLabel(HugeGraph graph, BackendEntry entry);
}
2.1.4 Extend custom configuration items

When adding a custom backend, it may be necessary to add new configuration items. The implementation process mainly includes:

  • Add a configuration item container class and implement the interface org.apache.hugegraph.config.OptionHolder
  • Provide a singleton method public static OptionHolder instance(), and call the method when the object is initialized OptionHolder.registerOptions()
  • Add configuration item declaration, single-value configuration item type is ConfigOption, multi-value configuration item type is ConfigListOption

Take the RocksDB configuration item definition as an example:

public class RocksDBOptions extends OptionHolder {

    private RocksDBOptions() {
        super();
    }

    private static volatile RocksDBOptions instance;

    public static synchronized RocksDBOptions instance() {
        if (instance == null) {
            instance = new RocksDBOptions();
            instance.registerOptions();
        }
        return instance;
    }

    public static final ConfigOption<String> DATA_PATH =
            new ConfigOption<>(
                    "rocksdb.data_path",
                    "The path for storing data of RocksDB.",
                    disallowEmpty(),
                    "rocksdb-data"
            );

    public static final ConfigOption<String> WAL_PATH =
            new ConfigOption<>(
                    "rocksdb.wal_path",
                    "The path for storing WAL of RocksDB.",
                    disallowEmpty(),
                    "rocksdb-data"
            );

    public static final ConfigListOption<String> DATA_DISKS =
            new ConfigListOption<>(
                    "rocksdb.data_disks",
                    false,
                    "The optimized disks for storing data of RocksDB. " +
                    "The format of each element: `STORE/TABLE: /path/to/disk`." +
                    "Allowed keys are [graph/vertex, graph/edge_out, graph/edge_in, " +
                    "graph/secondary_index, graph/range_index]",
                    null,
                    String.class,
                    ImmutableList.of()
            );
}
2.2 Extend custom tokenizer

The tokenizer needs to implement the interface org.apache.hugegraph.analyzer.Analyzer, take implementing a SpaceAnalyzer space tokenizer as an example.

package org.apache.hugegraph.plugin;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

import org.apache.hugegraph.analyzer.Analyzer;

public class SpaceAnalyzer implements Analyzer {

    @Override
    public Set<String> segment(String text) {
        return new HashSet<>(Arrays.asList(text.split(" ")));
    }
}

3. Implement the plug-in interface and register it

The plug-in registration entry is HugeGraphPlugin.register(), the custom plug-in must implement this interface method, and register the extension items defined above inside it. The interface org.apache.hugegraph.plugin.HugeGraphPlugin is defined as follows:

public interface HugeGraphPlugin {

    public String name();

    public void register();

    public String supportsMinVersion();

    public String supportsMaxVersion();
}

And HugeGraphPlugin provides 4 static methods for registering extensions:

  • registerOptions(String name, String classPath): register configuration items
  • registerBackend(String name, String classPath): register backend (BackendStoreProvider)
  • registerSerializer(String name, String classPath): register serializer
  • registerAnalyzer(String name, String classPath): register tokenizer

The following is an example of registering the SpaceAnalyzer tokenizer:

package org.apache.hugegraph.plugin;

public class DemoPlugin implements HugeGraphPlugin {

    @Override
    public String name() {
        return "demo";
    }

    @Override
    public void register() {
        HugeGraphPlugin.registerAnalyzer("demo", SpaceAnalyzer.class.getName());
    }
}

4. Configure SPI entry

  1. Make sure the services directory exists: hugegraph-plugin-demo/resources/META-INF/services
  2. Create a text file in the services directory: org.apache.hugegraph.plugin.HugeGraphPlugin
  3. The content of the file is as follows: org.apache.hugegraph.plugin.DemoPlugin

5. Make Jar package

Through maven packaging, execute the command in the project directory mvn package, and a Jar package file will be generated in the target directory. Copy the Jar package to the plugins directory when using it, and restart the service to take effect.

6.4 - HugeGraph Toolchain Local Testing Guide

This guide helps developers run HugeGraph toolchain tests locally.

1. Core Concepts

1.1 Core Dependency: HugeGraph Server

Integration and functional tests of the toolchain depend on HugeGraph Server, including Client, Loader, Hubble, Spark Connector, Tools, and other components.

1.2 Test Types

  • Unit Tests: Test individual functions/methods, no external dependencies required
  • API Tests (ApiTestSuite): Test API interfaces, requires running HugeGraph Server
  • Functional Tests (FuncTestSuite): End-to-end tests, require complete system environment

2. Environment Setup

2.1 System Requirements

  • Operating System: Linux / macOS (Windows use WSL2)
  • JDK: >= 11, configure JAVA_HOME
  • Maven: >= 3.6
  • Python: >= 3.11 (only required for Hubble tests)

2.2 Clone Code

git clone https://github.com/apache/hugegraph-toolchain.git
cd hugegraph-toolchain

3. Deploy Test Environment

Deployment Options

  • Script Deployment: Specify a Server commit to reproduce the server version used by CI
  • Docker Deployment: Suitable for quick checks; if tests fail, first verify compatibility between the image and Toolchain

For detailed installation instructions, refer to Community Documentation

3.1 Script Deployment

Parameter Description

  • $COMMIT_ID: Specify Server source code Git Commit ID
  • $DB_DATABASE / $DB_PASS: MySQL database name and password for Loader JDBC tests

Deployment Steps

1. Install HugeGraph Server

# Set the Server baseline; use a full commit SHA for reproducible results
export COMMIT_ID="master"

# Execute installation (script located in /assembly/travis/ directory)
hugegraph-client/assembly/travis/install-hugegraph-from-source.sh $COMMIT_ID
  • The script starts HTTP and HTTPS instances on ports 8080 and 8443 and configures admin/pa authentication.
  • Ensure both ports are available before running it.

2. Install Optional Dependencies

# Hadoop (only required for Loader HDFS tests)
hugegraph-loader/assembly/travis/install-hadoop.sh

# MySQL (only required for Loader JDBC tests)
hugegraph-loader/assembly/travis/install-mysql.sh $DB_DATABASE $DB_PASS

3. Health Check

curl -u admin:pa http://localhost:8080/graphspaces/DEFAULT/graphs
# Returns {"graphs":["hugegraph"]} indicates success

3.2 Docker Deployment

Note: Docker images may have version lag, use script deployment if encountering compatibility issues

Quick Start

docker network create hugegraph-net
docker run -itd --name=server -p 8080:8080 --network hugegraph-net hugegraph/hugegraph:latest

docker-compose Configuration (Optional)

Complete configuration example including Server, MySQL, Hadoop services (requires Docker Compose V2):

version: '3.8'

services:
  hugegraph-server:
    image: hugegraph/hugegraph:latest  # Can be replaced with a specific version, or build your own image
    container_name: hugegraph-server
    ports:
      - "8080:8080"  # HugeGraph Server HTTP port
    environment:
      # Configure HugeGraph Server parameters as needed, e.g., backend storage
      - HUGEGRAPH_SERVER_OPTIONS="-Dstore.backend=rocksdb"
    volumes:
      # If you need to persist data or mount configuration files, add volumes here
      # - ./hugegraph-data:/opt/hugegraph/data
    healthcheck:
      test: ["CMD-SHELL", "curl -f http://localhost:8080/graphspaces/DEFAULT/graphs || exit 1"]
      interval: 10s
      timeout: 3s
      retries: 5
    networks:
      - hugegraph-net
  
  # If you need JDBC tests for hugegraph-loader, you can add the following service
  #   mysql:
  #     image: mysql:5.7
  #     container_name: mysql-db
  #     environment:
  #       MYSQL_ROOT_PASSWORD: ${DB_PASS:-your_mysql_root_password} # Read from environment variable, or use default
  #       MYSQL_DATABASE: ${DB_DATABASE:-hugegraph_test_db} # Read from environment variable, or use default
  #     ports:
  #       - "3306:3306"
  #     volumes:
  #       - ./mysql-data:/var/lib/mysql # Data persistence
  #     healthcheck:
  #       test: ["CMD", "mysqladmin", "ping", "-h", "localhost", "-p${DB_PASS:-your_mysql_root_password}"]
  #       interval: 5s
  #       timeout: 3s
  #       retries: 5
  #     networks:
  #       - hugegraph-net

  # If you need Hadoop/HDFS tests for hugegraph-loader, you can add the following services
  #   namenode:
  #     image: johannestang/hadoop-namenode:2.0.0-hadoop2.8.5-java8
  #     container_name: namenode
  #     ports:
  #       - "0.0.0.0:9870:9870"
  #       - "0.0.0.0:8020:8020"
  #     environment:
  #       - CLUSTER_NAME=test-cluster
  #       - HDFS_NAMENODE_USER=root
  #       - HADOOP_CONF_DIR=/hadoop/etc/hadoop
  #     volumes:
  #       - ./config/core-site.xml:/hadoop/etc/hadoop/core-site.xml
  #       - ./config/hdfs-site.xml:/hadoop/etc/hadoop/hdfs-site.xml
  #       - namenode_data:/hadoop/dfs/name
  #     command: bash -c "if [ ! -d /hadoop/dfs/name/current ]; then hdfs namenode -format; fi && /entrypoint.sh"
  #     healthcheck:
  #       test: ["CMD", "hdfs", "dfsadmin", "-report"]
  #       interval: 5s
  #       timeout: 3s
  #       retries: 5
  #     networks:
  #       - hugegraph-net

  #   datanode:
  #     image: johannestang/hadoop-datanode:2.0.0-hadoop2.8.5-java8
  #     container_name: datanode
  #     depends_on:
  #       - namenode
  #     environment:
  #       - CLUSTER_NAME=test-cluster
  #       - HDFS_DATANODE_USER=root
  #       - HADOOP_CONF_DIR=/hadoop/etc/hadoop
  #     volumes:
  #       - ./config/core-site.xml:/hadoop/etc/hadoop/core-site.xml
  #       - ./config/hdfs-site.xml:/hadoop/etc/hadoop/hdfs-site.xml
  #       - datanode_data:/hadoop/dfs/data
  #     healthcheck:
  #       test: ["CMD", "hdfs", "dfsadmin", "-report"]
  #       interval: 5s
  #       timeout: 3s
  #       retries: 5
  #     networks:
  #       - hugegraph-net

networks:
  hugegraph-net:
    driver: bridge
volumes:
  namenode_data:
  datanode_data:

Hadoop Configuration Mounts

Create a ./config folder in the same directory as docker-compose.yml to mount Hadoop configuration files. You can skip this step if HDFS testing is not required.

📁 ./config/core-site.xml content:

<configuration>
    <property>
        <name>fs.defaultFS</name>
        <value>hdfs://namenode:8020</value>
    </property>
</configuration>

📁 ./config/hdfs-site.xml content:

<configuration>
    <property>
        <name>dfs.namenode.name.dir</name>
        <value>/hadoop/hdfs/name</value>
    </property>
    <property>
        <name>dfs.datanode.data.dir</name>
        <value>/hadoop/hdfs/data</value>
    </property>
    <property>
        <name>dfs.permissions.superusergroup</name>
        <value>hadoop</value>
    </property>
    <property>
        <name>dfs.support.append</name>
        <value>true</value>
    </property>
</configuration>

Docker Operations

# Start services
docker compose up -d

# Check status
docker compose ps
lsof -i:8080  # Server
lsof -i:8020  # Hadoop
lsof -i:3306  # MySQL

# Stop services
docker compose down

4. Run Tests

Test process for each tool:

HugeGraph Toolchain Testing Process

4.1 hugegraph-client

Compile

mvn -e compile -pl hugegraph-client -Dmaven.javadoc.skip=true -ntp

Dependent Services

Start HugeGraph Server (refer to Section 3)

Server Authentication Configuration

ApiTest requires authentication. No additional configuration is needed when using the script in Section 3.1. For a manually deployed Server, the authentication settings and test credentials must match the test code.

# 1. Modify authentication mode
cp conf/rest-server.properties conf/rest-server.properties.backup
sed -i 's|#auth.authenticator=.*|auth.authenticator=org.apache.hugegraph.auth.StandardAuthenticator|' conf/rest-server.properties
grep auth.authenticator conf/rest-server.properties
sed -i 's|gremlin.graph=org.apache.hugegraph.HugeFactory|gremlin.graph=org.apache.hugegraph.auth.HugeFactoryAuthProxy|' conf/graphs/hugegraph.properties

# 2. Set password
# Note: Test code uses "pa" as default password, must match for tests to work
bin/stop-hugegraph.sh
export PASSWORD="pa"  # Set to test default password
echo -e "${PASSWORD}" | bin/init-store.sh
bin/start-hugegraph.sh

Run Tests

# Check environment
curl -u admin:pa http://localhost:8080/graphspaces/DEFAULT/graphs

# Run tests
cd hugegraph-client
mvn test -Dtest=UnitTestSuite -ntp      # Unit tests
mvn test -Dtest=ApiTestSuite -ntp       # API tests (requires Server)
mvn test -Dtest=FuncTestSuite -ntp      # Functional tests (requires Server)

Check Server log if tests fail: logs/hugegraph-server.log

4.2 hugegraph-loader

Compile

mvn install -pl hugegraph-client,hugegraph-loader -am -Dmaven.javadoc.skip=true -DskipTests -ntp

Dependent Services

  • Required: HugeGraph Server
  • Optional: Hadoop (HDFS tests), MySQL (JDBC tests)

Run Tests

cd hugegraph-loader
mvn test -P unit -ntp   # Unit tests
mvn test -P file -ntp   # File tests (requires Server)
mvn test -P hdfs -ntp   # HDFS tests (requires Server + Hadoop)
mvn test -P jdbc -ntp   # JDBC tests (requires Server + MySQL)
mvn test -P kafka -ntp  # Kafka tests (requires Server)

4.3 hugegraph-hubble

Compile

mvn install -pl hugegraph-client,hugegraph-loader -am -Dmaven.javadoc.skip=true -DskipTests -ntp
cd hugegraph-hubble
mvn -e compile -Dmaven.javadoc.skip=true -ntp

Dependent Services

1. Start Server (refer to Section 3)

2. Python Environment

python -m venv venv
source venv/bin/activate  # Windows: venv\Scripts\activate
python -m pip install -r hubble-dist/assembly/travis/requirements.txt

3. Build and Verify

mvn package -Dmaven.test.skip=true
# Optional: Start and verify
cd apache-hugegraph-hubble*/bin
./start-hubble.sh -d && sleep 10
curl http://localhost:8088/actuator/health
./stop-hubble.sh

Run Tests

# Unit tests
mvn test -P unit-test -pl hugegraph-hubble/hubble-be -ntp

# Legacy Python API tests (requires Server; the script installs and starts Hubble)
curl -u admin:pa http://localhost:8080/graphspaces/DEFAULT/graphs  # Check Server
cd hugegraph-hubble
./hubble-dist/assembly/travis/run-api-test.sh

# Full verification entry point used by current CI (build the Hubble tarball first)
HUBBLE_TARBALL="$(ls target/apache-hugegraph-hubble-*.tar.gz | head -n 1)"
hubble-dist/assembly/travis/verify-hubble-issue-694.sh \
  "$HUBBLE_TARBALL" http://127.0.0.1:8080

4.4 hugegraph-spark-connector

Compile

mvn install -pl hugegraph-client,hugegraph-spark-connector -am -Dmaven.javadoc.skip=true -DskipTests -ntp

Run Tests

cd hugegraph-spark-connector
mvn test -ntp  # Requires Server running

4.5 hugegraph-tools

Compile

mvn install -pl hugegraph-client,hugegraph-tools -am -Dmaven.javadoc.skip=true -DskipTests -ntp

Run Tests

cd hugegraph-tools
mvn test -Dtest=FuncTestSuite -ntp  # Requires Server running

5. Common Issues

Service Connection Issues

If Server, MySQL, or Hadoop cannot be reached:

  • Confirm services are running (Server must be on port 8080)
  • Check port usage: lsof -i:8080
  • Docker check: docker compose ps and docker compose logs

Configuration Issues

If files cannot be found or parameters are invalid:

  • Check environment variables: echo $COMMIT_ID
  • Script permissions: chmod +x hugegraph-*/assembly/travis/*.sh

HDFS Test Failures

  • Confirm NameNode/DataNode running normally
  • Check Hadoop logs
  • Verify HDFS connection: hdfs dfsadmin -report

JDBC Test Failures

  • Confirm MySQL running normally
  • Verify database connection: mysql -u root -p$DB_PASS
  • Check MySQL logs

6. References

6.5 - Backup and Restore

Description

Backup and Restore are functions of backup map and restore map. The data backed up and restored includes metadata (schema) and graph data (vertex and edge).

Backup

Export the metadata and graph data of a graph in the HugeGraph system in JSON format.

Restore

Re-import the data in JSON format exported by Backup to a graph in the HugeGraph system.

Restore has two modes:

  • In Restoring mode, the metadata and graph data exported by Backup are restored to the HugeGraph system intact. It can be used for graph backup and recovery, and the general target graph is a new graph (without metadata and graph data). for example:
    • System upgrade, first back up the map, then upgrade the system, and finally restore the map to the new system
    • Graph migration, from a HugeGraph system, use the Backup function to export the graph, and then use the Restore function to import the graph into another HugeGraph system
  • In the Merging mode, the metadata and graph data exported by Backup are imported into another graph that already has metadata or graph data. During the process, the ID of the metadata may change, and the IDs of vertices and edges will also change accordingly.
    • Can be used to merge graphs

Instructions

You can use hugegraph-tools to backup and restore the graph.

Backup

bin/hugegraph backup -t all -d data

This command backs up all the metadata and graph data of the hugegraph graph of http://127.0.0.1 to the data directory.

Backup works fine in all three graph modes

Restore

Restore has two modes: RESTORING and MERGING. Before backup, you must first set the graph mode according to your needs.

Step 1: View and set graph mode
bin/hugegraph graph-mode-get

This command is used to view the current graph mode, including: NONE, RESTORING, MERGING.

bin/hugegraph graph-mode-set -m RESTORING

This command is used to set the graph mode. Before Restore, it can be set to RESTORING or MERGING mode. In the example, it is set to RESTORING.

Step 2: Restore data
bin/hugegraph restore -t all -d data

This command re-imports all metadata and graph data in the data directory to the hugegraph graph at http://127.0.0.1.

Step 3: Restoring Graph Mode
bin/hugegraph graph-mode-set -m NONE

This command is used to restore the graph mode to NONE.

So far, a complete graph backup and graph recovery process is over.

help

For detailed usage of backup and restore commands, please refer to the hugegraph-tools documentation.

API description for Backup/Restore usage and implementation

Backup

Backup uses the corresponding list(GET) API export of metadata and graph data, and no new API is added.

Restore

Restore uses the corresponding create(POST) API imports for metadata and graph data, and does not add new APIs.

There are two different modes for Restore: Restoring and Merging. In addition, there is a regular mode of NONE (default), the differences are as follows:

  • In None mode, the writing of metadata and graph data is normal, please refer to the function description. special:
    • ID is not allowed when metadata (schema) is created
    • Graph data (vertex) is not allowed to specify an ID when the id strategy is Automatic
  • Restoring mode, restoring to a new graph, in particular:
    • ID is allowed to be specified when metadata (schema) is created
    • Graph data (vertex) allows specifying an ID when the id strategy is Automatic
  • Merging mode, merging into a graph with existing metadata and graph data, in particular:
    • ID is not allowed when metadata (schema) is created
    • Graph data (vertex) allows specifying an ID when the id strategy is Automatic

Normally, the graph mode is None. When you need to restore the graph, you need to temporarily change the graph mode to Restoring mode or Merging mode as needed, and when the Restore is completed, restore the graph mode to None.

The implemented RESTful API for setting graph mode is as follows:

View the schema of a graph. This operation requires administrator privileges
Method & Url
GET http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/mode
Response Status
200
Response Body
{
    "mode": "NONE"
}

Legal graph modes include: NONE, RESTORING, MERGING

Set the mode of a graph. ““This operation requires administrator privileges**
Method & Url
PUT http://localhost:8080/graphspaces/DEFAULT/graphs/{graph}/mode
Request Body
"RESTORING"

Legal graph modes include: NONE, RESTORING, MERGING

Response Status
200
Response Body
{
    "mode": "RESTORING"
}

6.6 - FAQ

  • How to choose the back-end storage? RocksDB or distributed storage?

    HugeGraph supports multiple deployment modes. Choose based on your data scale and scenario:

    • Standalone Mode: Server + RocksDB, suitable for development/testing and small to medium-scale data (≤ 2 TB)
    • Distributed Mode: HugeGraph-PD + HugeGraph-Store (HStore), for deployments that require horizontal scaling and multiple replicas, supporting data scales up to 1 PB

    Version 1.7.0 supports RocksDB, HStore, HBase, and Memory. Legacy backends such as Cassandra, ScyllaDB, MySQL, and PostgreSQL require version 1.5.x or earlier.

  • Prompt when starting the service: xxx (core dumped) xxx

    First confirm that the JDK version is Java 11 or later. HugeGraph 1.7.0 no longer supports Java 8.

  • The service is started successfully, but there is a prompt similar to “Unable to connect to the backend or the connection is not open” when operating the graph

    Persistent local backends such as RocksDB and HBase must be initialized with init-store before their first startup. HStore is managed by PD and Store and does not use this script.

  • Do all backends need to be executed before use init-store, and can the serialization options be filled in at will?

    Memory and HStore do not use init-store; persistent local backends such as RocksDB and HBase must be initialized before first use. The serializer must match the backend—for example, RocksDB uses binary.

  • Execution init-store error: Exception in thread "main" java.lang.UnsatisfiedLinkError: /tmp/librocksdbjni3226083071221514754.so: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.10' not found (required by /tmp/librocksdbjni3226083071221514754.so)

    RocksDB requires gcc 4.3.0 (GLIBCXX_3.4.10) and above

  • The bin directory contains start-hugegraph.sh, start-restserver.sh and start-gremlinserver.sh. These scripts seem to be related to startup. Which one should be used?

    Current release packages retain only start-hugegraph.sh as the Server startup script. GremlinServer and the REST Server run in the same process.

  • Two graphs are configured, the names are hugegraph and hugegraph1, and the command to start the service is start-hugegraph.sh. Is only the hugegraph graph opened?

    The script name is unrelated to the graph name. To load multiple local graphs from the graphs directory, set graph.load_from_local_config=true in rest-server.properties; its default value in the source code is false.

  • After the service starts successfully, garbled characters are returned when using curl to query all vertices

    The batch vertices/edges returned by the server are compressed (gzip), and can be redirected to gunzip for decompression (curl http://example | gunzip), or can be sent with the postman of Firefox or the restlet plug-in of Chrome browser. request, the response data will be decompressed automatically.

  • When using the vertex Id to query the vertex through the RESTful API, it returns empty, but the vertex does exist

    Check the type of the vertex ID. If it is a string type, the “id” part of the API URL needs to be enclosed in double quotes, while for numeric types, it is not necessary to enclose the ID in quotes.

  • Vertex Id has been double quoted as required, but querying the vertex via the RESTful API still returns empty

    Check whether the vertex id contains +, space, /, ?, %, &, and = reserved characters of these URLs. If they exist, they need to be encoded. The following table gives the coded values:

    special character | encoded value
    ------------------| -------------
    +                 | %2B
    space             | %20
    /                 | %2F
    ?                 | %3F
    %                 | %25
    #                 | %23
    &                 | %26
    =                 | %3D
  • Timeout when querying vertices or edges of a certain category (query by label)

    Since the amount of data belonging to a certain label may be relatively large, please add a limit limit.

  • It is possible to operate the graph through the RESTful API, but when sending Gremlin statements, an error is reported: Request Failed(500)

    It may be that the configuration of GremlinServer is wrong, check whether the host and port of gremlin-server.yaml match the gremlinserver.url of rest-server.properties, if they do not match, modify them, and then Restart the service.

  • When using Loader to import data, a Socket Timeout exception occurs, and then Loader is interrupted

    Continuously importing data will put too much pressure on the Server, which will cause some requests to time out. The pressure on Server can be appropriately relieved by adjusting the parameters of Loader (such as: number of retries, retry interval, error tolerance, etc.), and reduce the frequency of this problem.

  • How to delete all data from a graph

    An administrator can call DELETE /graphspaces/{graphspace}/graphs/{graph}/clear. The request must include the confirm_message required by the source code; see the Graph API for the exact format. This operation removes schemas, vertices, edges, and indexes.

  • The database has been cleared and init-store has been executed, but when trying to add a schema, the prompt “xxx has existed” appeared.

    There is a cache in the HugeGraphServer, and it is necessary to restart the Server when the database is cleared, otherwise the residual cache will be inconsistent.

  • An error is reported during the process of inserting vertices or edges: Id max length is 128, but got xxx {yyy} or Big id max length is 32768, but got xxx

    In order to ensure query performance, the current backend storage limits the length of the id column. The vertex id cannot exceed 128 bytes, the edge id cannot exceed 32768 bytes, and the index id cannot exceed 128 bytes.

  • Is there support for nested attributes, and if not, are there any alternatives?

    Nested attributes are currently not supported. Alternative: Nested attributes can be taken out as individual vertices and connected with edges.

  • Can an EdgeLabel connect multiple pairs of VertexLabel, such as “investment” relationship, which can be “individual” investing in “enterprise”, or “enterprise” investing in “enterprise”?

    An EdgeLabel does not support connecting multiple pairs of VertexLabels, users need to split the EdgeLabel into finer details, such as: “personal investment”, “enterprise investment”.

  • Prompt HTTP 415 Unsupported Media Type when sending a request through RestAPI

    Content-Type: application/json needs to be specified in the request header

Other issues can be searched in the issue area of the corresponding project, such as Server-Issues / Loader Issues

6.7 - Security Report

Reporting New Security Problems with Apache HugeGraph

Adhering to the specifications of ASF, the HugeGraph community maintains a highly proactive and open attitude towards addressing security issues in the remediation projects.

We strongly recommend that users first report such issues to our dedicated security email list, with detailed procedures specified in the ASF SEC code of conduct.

Please note that the security email group is reserved for reporting undisclosed security vulnerabilities and following up on the vulnerability resolution process. Regular software Bug/Error reports should be directed to Github Issue/Discussion or the HugeGraph-Dev email group. Emails sent to the security list that are unrelated to security issues will be ignored.

The independent security email (group) address is: security@hugegraph.apache.org

The general process for handling security vulnerabilities is as follows:

  • The reporter privately reports the vulnerability to the Apache HugeGraph SEC email group (including as much information as possible, such as reproducible versions, relevant descriptions, reproduction methods, and the scope of impact)
  • The HugeGraph project security team collaborates privately with the reporter to discuss the vulnerability resolution (after preliminary confirmation, a CVE number can be requested for registration)
  • The project creates a new version of the software package affected by the vulnerability to provide a fix
  • At an appropriate time, a general description of the vulnerability and how to apply the fix will be publicly disclosed (in compliance with ASF standards, the announcement should not disclose sensitive information such as reproduction details)
  • Official CVE release and related procedures follow the ASF-SEC page

Known Security Vulnerabilities (CVEs)

HugeGraph main project (Server/PD/Store)

HugeGraph-Toolchain project (Hubble/Loader/Client/Tools/..)

7 - Query Languages

HugeGraph supports Gremlin and Cypher. This section mainly covers Gremlin; see the Cypher API for the Cypher HTTP interface.

7.1 - HugeGraph Gremlin

Overview

HugeGraph supports Gremlin, a graph traversal query language of Apache TinkerPop3. While SQL is a query language for relational databases, Gremlin is a general-purpose query language for graph databases. Gremlin can be used to create entities (Vertex and Edge) of a graph, modify the properties of entities, delete entities, as well as perform graph queries.

Gremlin can be used to create entities (Vertex and Edge) of a graph, modify the properties of entities, and delete entities. More importantly, it can be used to perform graph querying and analysis operations.

TinkerPop Features

HugeGraph implements the TinkerPop framework, but not all TinkerPop features are implemented.

The table below lists the support status of various TinkerPop features in HugeGraph:

Graph Features

NameDescriptionSupport
ComputerDetermines if the {@code Graph} implementation supports {@link GraphComputer} based processingfalse
TransactionsDetermines if the {@code Graph} implementations supports transactions.true
PersistenceDetermines if the {@code Graph} implementation supports persisting it’s contents natively to disk.This feature does not refer to every graph’s ability to write to disk via the Gremlin IO packages(.e.g. GraphML), unless the graph natively persists to disk via those options somehow. For example,TinkerGraph does not support this feature as it is a pure in-sideEffects graph.true
ThreadedTransactionsDetermines if the {@code Graph} implementation supports threaded transactions which allow a transaction be executed across multiple threads via {@link Transaction#createThreadedTx()}.false
ConcurrentAccessDetermines if the {@code Graph} implementation supports more than one connection to the same instance at the same time. For example, Neo4j embedded does not support this feature because concurrent access to the same database files by multiple instances is not possible. However, Neo4j HA could support this feature as each new {@code Graph} instance coordinates with the Neo4j cluster allowing multiple instances to operate on the same database.false

Vertex Features

NameDescriptionSupport
UserSuppliedIdsDetermines if an {@link Element} can have a user defined identifier. Implementation that do not support this feature will be expected to auto-generate unique identifiers. In other words, if the {@link Graph} allows {@code graph.addVertex(id,x)} to work and thus set the identifier of the newly added {@link Vertex} to the value of {@code x} then this feature should return true. In this case, {@code x} is assumed to be an identifier data type that the {@link Graph} will accept.false
NumericIdsDetermines if an {@link Element} has numeric identifiers as their internal representation. In other words,if the value returned from {@link Element#id()} is a numeric value then this method should be return {@code true}. Note that this feature is most generally used for determining the appropriate tests to execute in the Gremlin Test Suite.false
StringIdsDetermines if an {@link Element} has string identifiers as their internal representation. In other words, if the value returned from {@link Element#id()} is a string value then this method should be return {@code true}. Note that this feature is most generally used for determining the appropriate tests to execute in the Gremlin Test Suite.false
UuidIdsDetermines if an {@link Element} has UUID identifiers as their internal representation. In other words,if the value returned from {@link Element#id()} is a {@link UUID} value then this method should be return {@code true}.Note that this feature is most generally used for determining the appropriate tests to execute in the Gremlin Test Suite.false
CustomIdsDetermines if an {@link Element} has a specific custom object as their internal representation.In other words, if the value returned from {@link Element#id()} is a type defined by the graph implementations, such as OrientDB’s {@code Rid}, then this method should be return {@code true}.Note that this feature is most generally used for determining the appropriate tests to execute in the Gremlin Test Suite.false
AnyIdsDetermines if an {@link Element} any Java object is a suitable identifier. TinkerGraph is a good example of a {@link Graph} that can support this feature, as it can use any {@link Object} as a value for the identifier. Note that this feature is most generally used for determining the appropriate tests to execute in the Gremlin Test Suite. This setting should only return {@code true} if {@link #supportsUserSuppliedIds()} is {@code true}.false
AddPropertyDetermines if an {@link Element} allows properties to be added. This feature is set independently from supporting “data types” and refers to support of calls to {@link Element#property(String, Object)}.true
RemovePropertyDetermines if an {@link Element} allows properties to be removed.true
AddVerticesDetermines if a {@link Vertex} can be added to the {@code Graph}.true
MultiPropertiesDetermines if a {@link Vertex} can support multiple properties with the same key.false
DuplicateMultiPropertiesDetermines if a {@link Vertex} can support non-unique values on the same key. For this value to be {@code true}, then {@link #supportsMetaProperties()} must also return true. By default this method, just returns what {@link #supportsMultiProperties()} returns.false
MetaPropertiesDetermines if a {@link Vertex} can support properties on vertex properties. It is assumed that a graph will support all the same data types for meta-properties that are supported for regular properties.false
RemoveVerticesDetermines if a {@link Vertex} can be removed from the {@code Graph}.true

Edge Features

NameDescriptionSupport
UserSuppliedIdsDetermines if an {@link Element} can have a user defined identifier. Implementation that do not support this feature will be expected to auto-generate unique identifiers. In other words, if the {@link Graph} allows {@code graph.addVertex(id,x)} to work and thus set the identifier of the newly added {@link Vertex} to the value of {@code x} then this feature should return true. In this case, {@code x} is assumed to be an identifier data type that the {@link Graph} will accept.false
NumericIdsDetermines if an {@link Element} has numeric identifiers as their internal representation. In other words,if the value returned from {@link Element#id()} is a numeric value then this method should be return {@code true}. Note that this feature is most generally used for determining the appropriate tests to execute in the Gremlin Test Suite.false
StringIdsDetermines if an {@link Element} has string identifiers as their internal representation. In other words, if the value returned from {@link Element#id()} is a string value then this method should be return {@code true}. Note that this feature is most generally used for determining the appropriate tests to execute in the Gremlin Test Suite.false
UuidIdsDetermines if an {@link Element} has UUID identifiers as their internal representation. In other words,if the value returned from {@link Element#id()} is a {@link UUID} value then this method should be return {@code true}.Note that this feature is most generally used for determining the appropriate tests to execute in the Gremlin Test Suite.false
CustomIdsDetermines if an {@link Element} has a specific custom object as their internal representation.In other words, if the value returned from {@link Element#id()} is a type defined by the graph implementations, such as OrientDB’s {@code Rid}, then this method should be return {@code true}.Note that this feature is most generally used for determining the appropriate tests to execute in the Gremlin Test Suite.false
AnyIdsDetermines if an {@link Element} any Java object is a suitable identifier. TinkerGraph is a good example of a {@link Graph} that can support this feature, as it can use any {@link Object} as a value for the identifier. Note that this feature is most generally used for determining the appropriate tests to execute in the Gremlin Test Suite. This setting should only return {@code true} if {@link #supportsUserSuppliedIds()} is {@code true}.false
AddPropertyDetermines if an {@link Element} allows properties to be added. This feature is set independently from supporting “data types” and refers to support of calls to {@link Element#property(String, Object)}.true
RemovePropertyDetermines if an {@link Element} allows properties to be removed.true
AddEdgesDetermines if an {@link Edge} can be added to a {@code Vertex}.true
RemoveEdgesDetermines if an {@link Edge} can be removed from a {@code Vertex}.true

Data Type Features

NameDescriptionSupport
BooleanValuestrue
ByteValuestrue
DoubleValuestrue
FloatValuestrue
IntegerValuestrue
LongValuestrue
MapValuesSupports setting of a {@code Map} value. The assumption is that the {@code Map} can contain arbitrary serializable values that may or may not be defined as a feature itselffalse
MixedListValuesSupports setting of a {@code List} value. The assumption is that the {@code List} can contain arbitrary serializable values that may or may not be defined as a feature itself. As this{@code List} is “mixed” it does not need to contain objects of the same type.false
BooleanArrayValuesfalse
ByteArrayValuestrue
DoubleArrayValuesfalse
FloatArrayValuesfalse
IntegerArrayValuesfalse
LongArrayValuesfalse
SerializableValuesfalse
StringArrayValuesfalse
StringValuestrue
UniformListValuesSupports setting of a {@code List} value. The assumption is that the {@code List} can contain arbitrary serializable values that may or may not be defined as a feature itself. As this{@code List} is “uniform” it must contain objects of the same type.false

Gremlin Steps

HugeGraph supports all steps of Gremlin. For complete reference information about Gremlin, please refer to the Gremlin official website.

StepDescriptionDocumentation
addEAdd an edge between two vertices.addE step
addVadd vertices to graph.addV step
andMake sure all traversals return values.and step
asStep modulator for assigning variables to the step’s output.as step
byStep Modulators used in conjunction with group and order.by step
coalesceReturns the first traversal that returns a result.coalesce step
constantReturns a constant value. Used in conjunction with coalesce.constant step
countReturns a count from the traversal.count step
dedupReturns values with duplicates removed.dedup step
dropDiscards a value (vertex/edge).drop step
foldActs as a barrier for computing aggregated values from results.fold step
groupGroups values based on specified labels.group step
hasUsed to filter properties, vertices, and edges. Supports hasLabel, hasId, hasNot, and has variants.has step
injectInjects values into the stream.inject step
isUsed to filter by a Boolean expression.is step
limitUsed to limit the number of items in a traversal.limit step
localLocally wraps a part of a traversal, similar to a subquery.local step
notUsed to generate the negation result of a filter.not step
optionalReturns the result of a specified traversal if it generates any results, otherwise returns the calling element.optional step
orEnsures that at least one traversal returns a value.or step
orderReturns results in the specified order.order step
pathReturns the full path of the traversal.path step
projectProjects properties as a map.project step
propertiesReturns properties with specified labels.properties step
rangeFilters based on a specified range of values.range step
repeatRepeats a step a specified number of times. Used for looping.repeat step
sampleUsed to sample results returned by the traversal.sample step
selectUsed to project the results returned by the traversal.select step
storeThis step is used fo.r non-blocking aggregation of results returned by traversalstore step
treeAggregate the paths in vertices into a tree.tree step
unfoldUnfolds an iterator as a step.unfold step
unionMerge the results returned by multiple traversals.union step
VThese are the steps required for traversing between vertices and edges: V, E, out, in, both, outE, inE, bothE, outV, inV, bothV, and otherV.order step
whereUsed to filter the results returned by a traversal. Supports eq, neq, lt, lte, gt, gte, and between operators.where step

7.2 - HugeGraph Examples

1 Overview

This example uses the TitanDB Getting Started guide as a template to demonstrate how to use HugeGraph. By comparing HugeGraph and TitanDB, you can understand the differences between them.

1.1 Similarities and Differences between HugeGraph and TitanDB

Both HugeGraph and TitanDB are graph databases based on the Apache TinkerPop3 framework. They both support the Gremlin graph query language and share many similarities in terms of usage and interfaces. However, HugeGraph is a completely new design and development, characterized by its clear code structure, richer features, and more user-friendly interfaces.

Compared to TitanDB, HugeGraph’s main features are as follows:

  • HugeGraph currently offers a comprehensive suite of tools, including HugeGraph-API, HugeGraph-Client, HugeGraph-Loader, HugeGraph-Studio, and HugeGraph-Spark. These components facilitate system integration, data loading, visual graph querying, Spark connectivity, and other functionalities.
  • HugeGraph incorporates the concepts of Server and Client, allowing third-party systems to connect via multiple methods such as JAR references, clients, and APIs. In contrast, TitanDB only supports connections via JAR references.
  • HugeGraph requires explicit schema definition, and all insertions and queries must pass strict schema validation. Implicit schema creation is not supported at the moment.
  • HugeGraph makes full use of the characteristics of the underlying storage system to achieve efficient data access, whereas TitanDB ignores the differences of the backend with a unified Kv structure.
  • HugeGraph’s update operations can be performed on-demand (e.g., updating a specific attribute), offering better performance. TitanDB uses a read-and-update approach for updates.
  • Both VertexId and EdgeId in HugeGraph support concatenation, allowing for automatic deduplication and better query performance. In TitanDB, all IDs are auto-generated and require indexing for queries.

1.2 Character Relationship Graph

This example uses the Property Graph Model to describe the relationships between characters in Greek mythology, also known as the character relationship graph. The specific relationships are shown in the diagram below.

image

In the diagram, circular nodes represent entities (Vertices), arrows represent relationships (Edges), and the content in the boxes represents attributes.

There are two types of vertices in this graph: characters and locations, as shown in the table below:

NameTypeAttributes
charactervertexname,age,type
locationvertexname

There are six types of relationships: father, mother, brother, battled, lives, and pet. The details of these relationships are as follows:

NameTypeSource Vertex LabelTarget Vertex LabelAttributes
fatheredgecharactercharacter-
motheredgecharactercharacter-
brotheredgecharactercharacter-
petedgecharactercharacter-
livesedgecharacterlocationreason

In HugeGraph, each edge label can only act on one pair of source and target vertex labels. In other words, if a relationship called “father” is defined in the graph to connect character to character, then “father” cannot be used to connect to other vertex labels.

Therefore, in this example, the original TitanDB’s monster, god, human, and demigod are all represented using the same vertex label: character in HugeGraph, with an additional type attribute to indicate the type of character. The edge labels remain consistent with the original TitanDB. Of course, to satisfy the edge label constraints, adjustments can be made to the name of the edge label.

2 Graph Schema and Data Ingest Examples

HugeGraph requires explicit schema creation, which involves creating PropertyKeys, VertexLabels, and EdgeLabels in sequence. If indexing is needed, IndexLabels must also be created.

2.1 Graph Schema

schema = hugegraph.schema()

schema.propertyKey("name").asText().ifNotExist().create()
schema.propertyKey("age").asInt().ifNotExist().create()
schema.propertyKey("time").asInt().ifNotExist().create()
schema.propertyKey("reason").asText().ifNotExist().create()
schema.propertyKey("type").asText().ifNotExist().create()

schema.vertexLabel("character").properties("name", "age", "type").primaryKeys("name").nullableKeys("age").ifNotExist().create()
schema.vertexLabel("location").properties("name").primaryKeys("name").ifNotExist().create()

schema.edgeLabel("father").link("character", "character").ifNotExist().create()
schema.edgeLabel("mother").link("character", "character").ifNotExist().create()
schema.edgeLabel("battled").link("character", "character").properties("time").ifNotExist().create()
schema.edgeLabel("lives").link("character", "location").properties("reason").nullableKeys("reason").ifNotExist().create()
schema.edgeLabel("pet").link("character", "character").ifNotExist().create()
schema.edgeLabel("brother").link("character", "character").ifNotExist().create()

2.2 Graph Data

// add vertices
Vertex saturn = graph.addVertex(T.label, "character", "name", "saturn", "age", 10000, "type", "titan")
Vertex sky = graph.addVertex(T.label, "location", "name", "sky")
Vertex sea = graph.addVertex(T.label, "location", "name", "sea")
Vertex jupiter = graph.addVertex(T.label, "character", "name", "jupiter", "age", 5000, "type", "god")
Vertex neptune = graph.addVertex(T.label, "character", "name", "neptune", "age", 4500, "type", "god")
Vertex hercules = graph.addVertex(T.label, "character", "name", "hercules", "age", 30, "type", "demigod")
Vertex alcmene = graph.addVertex(T.label, "character", "name", "alcmene", "age", 45, "type", "human")
Vertex pluto = graph.addVertex(T.label, "character", "name", "pluto", "age", 4000, "type", "god")
Vertex nemean = graph.addVertex(T.label, "character", "name", "nemean", "type", "monster")
Vertex hydra = graph.addVertex(T.label, "character", "name", "hydra", "type", "monster")
Vertex cerberus = graph.addVertex(T.label, "character", "name", "cerberus", "type", "monster")
Vertex tartarus = graph.addVertex(T.label, "location", "name", "tartarus")

// add edges
jupiter.addEdge("father", saturn)
jupiter.addEdge("lives", sky, "reason", "loves fresh breezes")
jupiter.addEdge("brother", neptune)
jupiter.addEdge("brother", pluto)
neptune.addEdge("lives", sea, "reason", "loves waves")
neptune.addEdge("brother", jupiter)
neptune.addEdge("brother", pluto)
hercules.addEdge("father", jupiter)
hercules.addEdge("mother", alcmene)
hercules.addEdge("battled", nemean, "time", 1)
hercules.addEdge("battled", hydra, "time", 2)
hercules.addEdge("battled", cerberus, "time", 12)
pluto.addEdge("brother", jupiter)
pluto.addEdge("brother", neptune)
pluto.addEdge("lives", tartarus, "reason", "no fear of death")
pluto.addEdge("pet", cerberus)
cerberus.addEdge("lives", tartarus)

2.3 Indices

HugeGraph by default automatically generates IDs. However, if a user specifies the primaryKeys field list for a VertexLabel through primaryKeys, the ID strategy for that VertexLabel will automatically switch to the primaryKeys strategy. Once the primaryKeys strategy is enabled, HugeGraph generates VertexId by concatenating vertexLabel+primaryKeys, which allows for automatic deduplication. Additionally, there is no need to create extra indexes to use the properties in primaryKeys for fast querying. For example, both “character” and “location” have the primaryKeys("name") attribute, so without creating additional indexes, vertices can be queried using g.V().hasLabel('character') .has('name','hercules').

3 Graph Traversal Examples

3.1 Traversal Query

1. Find the grandfather of hercules

g.V().hasLabel('character').has('name','hercules').out('father').out('father')

It can also be done using the repeat method:

g.V().hasLabel('character').has('name','hercules').repeat(__.out('father')).times(2)

2. Find the name of Hercules’s father

g.V().hasLabel('character').has('name','hercules').out('father').value('name')

3. Find the characters with age > 100

g.V().hasLabel('character').has('age',gt(100))

4. Find who are pluto’s cohabitants

g.V().hasLabel('character').has('name','pluto').out('lives').in('lives').values('name')

5. Find pluto can’t be his own cohabitant

pluto = g.V().hasLabel('character').has('name', 'pluto')
g.V(pluto).out('lives').in('lives').where(is(neq(pluto)).values('name')

// use 'as'
g.V().hasLabel('character').has('name', 'pluto').as('x').out('lives').in('lives').where(neq('x')).values('name')

6. Pluto’s Brothers

pluto = g.V().hasLabel('character').has('name', 'pluto').next()
// where do pluto's brothers live?
g.V(pluto).out('brother').out('lives').values('name')

// which brother lives in which place?
g.V(pluto).out('brother').as('god').out('lives').as('place').select('god','place')

// what is the name of the brother and the name of the place?
g.V(pluto).out('brother').as('god').out('lives').as('place').select('god','place').by('name')

It is recommended to use HugeGraph-Hubble to execute the above code visually. Additionally, the code can be executed through various other methods such as HugeGraph-Client, HugeGraph-Api, GremlinConsole, and GremlinDriver.

3.2 Summary

HugeGraph currently supports Gremlin syntax, and users can implement various query requirements through Gremlin / REST-API.

8 - PERFORMANCE

8.1 - HugeGraph BenchMark Performance

Note:

The current performance metrics are based on an earlier version. The latest version has significant improvements in both performance and functionality. We encourage you to refer to the most recent release featuring autonomous distributed storage and enhanced computational push down capabilities. Alternatively, you may wait for the community to update the data with these enhancements.

1 Test environment

1.1 Hardware information

CPUMemory网卡磁盘
48 Intel(R) Xeon(R) CPU E5-2650 v4 @ 2.20GHz128G10000Mbps750GB SSD

1.2 Software information

1.2.1 Test cases

Testing is done using the graphdb-benchmark, a benchmark suite for graph databases. This benchmark suite mainly consists of four types of tests:

  • Massive Insertion, which involves batch insertion of vertices and edges, with a certain number of vertices or edges being submitted at once.
  • Single Insertion, which involves the immediate insertion of each vertex or edge, one at a time.
  • Query, which mainly includes the basic query operations of the graph database:
    • Find Neighbors, which queries the neighbors of all vertices.
    • Find Adjacent Nodes, which queries the adjacent vertices of all edges.
    • Find the Shortest Path, which queries the shortest path from the first vertex to 100 random vertices.
  • Clustering, which is a community detection algorithm based on the Louvain Method.
1.2.2 Test dataset

Tests are conducted using both synthetic and real data.

The size of the datasets used in this test is not mentioned.

NameNumber of VerticesNumber of EdgesFile Size
email-enron.txt36,691367,6614MB
com-youtube.ungraph.txt1,157,8062,987,62438.7MB
amazon0601.txt403,3933,387,38847.9MB
com-lj.ungraph.txt399796134681189479MB

1.3 Service configuration

  • HugeGraph version: 0.5.6, RestServer and Gremlin Server and backends are on the same server

    • RocksDB version: rocksdbjni-5.8.6
  • Titan version: 0.5.4, using thrift+Cassandra mode

    • Cassandra version: cassandra-3.10, commit-log and data use SSD together
  • Neo4j version: 2.0.1

The Titan version adapted by graphdb-benchmark is 0.5.4.

2 Test results

2.1 Batch insertion performance

Backendemail-enron(30w)amazon0601(300w)com-youtube.ungraph(300w)com-lj.ungraph(3000w)
HugeGraph0.6295.7115.24367.033
Titan10.15108.569150.2661217.944
Neo4j3.88418.93824.890281.537

Instructions

  • The data scale is in the table header in terms of edges
  • The data in the table is the time for batch insertion, in seconds
  • For example, HugeGraph(RocksDB) spent 5.711 seconds to insert 3 million edges of the amazon0601 dataset.
Conclusion
  • The performance of batch insertion: HugeGraph(RocksDB) > Neo4j > Titan(thrift+Cassandra)

2.2 Traversal performance

2.2.1 Explanation of terms
  • FN(Find Neighbor): Traverse all vertices, find the adjacent edges based on each vertex, and use the edges and vertices to find the other vertices adjacent to the original vertex.
  • FA(Find Adjacent): Traverse all edges, get the source vertex and target vertex based on each edge.
2.2.2 FN performance
Backendemail-enron(3.6w)amazon0601(40w)com-youtube.ungraph(120w)com-lj.ungraph(400w)
HugeGraph4.07245.11866.006609.083
Titan8.08492.507184.5431099.371
Neo4j2.42410.53711.609106.919

Instructions

  • The data in the table header “()” represents the data scale, in terms of vertices.
  • The data in the table represents the time spent traversing vertices in seconds.
  • For example, HugeGraph uses the RocksDB backend to traverse all vertices in amazon0601, and search for adjacent edges and another vertex, which takes a total of 45.118 seconds.
2.2.3 FA performance
Backendemail-enron(30w)amazon0601(300w)com-youtube.ungraph(300w)com-lj.ungraph(3000w)
HugeGraph1.54010.76411.243151.271
Titan7.36193.344169.2181085.235
Neo4j1.6734.7754.28440.507

Explanation

  • The data size in the header “()” is based on the number of vertices.
  • The data in the table is the time it takes to traverse the vertices in seconds.
  • For example, HugeGraph with RocksDB backend traverses all vertices in the amazon0601 dataset, and it looks up adjacent edges and other vertices, taking a total of 45.118 seconds.
Conclusion
  • Traversal performance: Neo4j > HugeGraph(RocksDB) > Titan(thrift+Cassandra)

2.3 Performance of Common Graph Analysis Methods in HugeGraph

Terminology Explanation
  • FS (Find Shortest Path): finding the shortest path between two vertices
  • K-neighbor: all vertices that can be reached by traversing K hops (including 1, 2, 3…(K-1) hops) from the starting vertex
  • K-out: all vertices that can be reached by traversing exactly K out-edges from the starting vertex.
FS performance
Backendemail-enron(30w)amazon0601(300w)com-youtube.ungraph(300w)com-lj.ungraph(3000w)
HugeGraph0.4940.1033.3648.155
Titan11.8180.239377.709575.678
Neo4j1.7191.8001.9568.530

Explanation

  • The data in the header “()” represents the data scale in terms of edges
  • The data in the table is the time it takes to find the shortest path from the first vertex to 100 randomly selected vertices in seconds
  • For example, HugeGraph using the RocksDB backend to find the shortest path from the first vertex to 100 randomly selected vertices in the amazon0601 graph took a total of 0.103s.
Conclusion
  • In scenarios with small data size or few vertex relationships, HugeGraph outperforms Neo4j and Titan.
  • As the data size increases and the degree of vertex association increases, the performance of HugeGraph and Neo4j tends to be similar, both far exceeding Titan.
K-neighbor Performance
VertexDepthDegree 1Degree 2Degree 3Degree 4Degree 5Degree 6
v1Time0.031s0.033s0.048s0.500s11.27sOOM
v111Time0.027s0.034s0.115s1.36sOOM
v1111Time0.039s0.027s0.052s0.511s10.96sOOM

Explanation

  • HugeGraph-Server’s JVM memory is set to 32GB and may experience OOM when the data is too large.
K-out performance
VertexDepth1st Degree2nd Degree3rd Degree4th Degree5th Degree6th Degree
v1Time0.054s0.057s0.109s0.526s3.77sOOM
Degree10133245350,8301,128,688
v111Time0.032s0.042s0.136s1.25s20.62sOOM
Degree1021149441131502,629,970
v1111Time0.039s0.045s0.053s1.10s2.92sOOM
Degree101402555508251,070,230

Explanation

  • The JVM memory of HugeGraph-Server is set to 32GB, and OOM may occur when the data is too large.
Conclusion
  • In the FS scenario, HugeGraph outperforms Neo4j and Titan in terms of performance.
  • In the K-neighbor and K-out scenarios, HugeGraph can achieve results returned within seconds within 5 degrees.

2.4 Comprehensive Performance Test - CW

DatabaseSize 1000Size 5000Size 10000Size 20000
HugeGraph(core)20.804242.099744.7801700.547
Titan45.790820.6332652.2359568.623
Neo4j5.91350.267142.354460.880

Explanation

  • The “scale” is based on the number of vertices.
  • The data in the table is the time required to complete community discovery in seconds. For example, if HugeGraph uses the RocksDB backend and operates on a dataset of 10,000 vertices, and the community aggregation is no longer changing, it takes 744.780 seconds.
  • The CW test is a comprehensive evaluation of CRUD operations.
  • In this test, HugeGraph, like Titan, did not use the client and directly operated on the core.
Conclusion
  • Performance of community detection algorithm: Neo4j > HugeGraph > Titan

8.2 - HugeGraph-API Performance

The HugeGraph API performance test mainly tests HugeGraph-Server’s ability to concurrently process RESTful API requests, including:

  • Single insertion of vertices/edges
  • Batch insertion of vertices/edges
  • Vertex/Edge Queries

For the performance test of the RESTful API of each release version of HugeGraph, please refer to:

Updates coming soon, stay tuned!

8.2.1 - v0.5.6 Stand-alone(RocksDB)

Note:

The current performance metrics are based on an earlier version. The latest version has significant improvements in both performance and functionality. We encourage you to refer to the most recent release featuring autonomous distributed storage and enhanced computational push down capabilities. Alternatively, you may wait for the community to update the data with these enhancements.

1 Test environment

Compressed machine information:

CPUMemory网卡磁盘
48 Intel(R) Xeon(R) CPU E5-2650 v4 @ 2.20GHz128G10000Mbps750GB SSD,2.7T HDD
  • Information about the machine used to generate loads: configured the same as the machine that is being tested under load.
  • Testing tool: Apache JMeter 2.5.1

Note: The load-generating machine and the machine under test are located in the same local network.

2 Test description

2.1 Definition of terms (the unit of time is ms)

  • Samples: The total number of threads completed in the current scenario.
  • Average: The average response time.
  • Median: The statistical median of the response time.
  • 90% Line: The response time below which 90% of all threads fall.
  • Min: The minimum response time.
  • Max: The maximum response time.
  • Error: The error rate.
  • Throughput: The number of requests processed per unit of time.
  • KB/sec: Throughput measured in terms of data transferred per second.

2.2 Underlying storage

RocksDB is used for backend storage, HugeGraph and RocksDB are both started on the same machine, and the configuration files related to the server remain as default except for the modification of the host and port.

3 Summary of performance results

  1. The speed of inserting a single vertex and edge in HugeGraph is about 1w per second
  2. The batch insertion speed of vertices and edges is much faster than the single insertion speed
  3. The concurrency of querying vertices and edges by id can reach more than 13000, and the average delay of requests is less than 50ms

4 Test results and analysis

4.1 batch insertion

4.1.1 Upper limit stress testing
Test methods

The upper limit of stress testing is to continuously increase the concurrency and test whether the server can still provide services normally.

Stress Parameters

Duration: 5 minutes

Maximum insertion speed for vertices:
image
in conclusion:
  • With a concurrency of 2200, the throughput for vertices is 2026.8. This means that the system can process data at a rate of 405360 per second (2026.8 * 200).
Maximum insertion speed for edges
image
Conclusion:
  • With a concurrency of 900, the throughput for edges is 776.9. This means that the system can process data at a rate of 388450 per second (776.9 * 500).

4.2 Single insertion

4.2.1 Stress limit testing
Test Methods

Stress limit testing is a process of continuously increasing the concurrency level to test the upper limit of the server’s ability to provide normal service.

Stress parameters
  • Duration: 5 minutes.
  • Service exception indicator: Error rate greater than 0.00%.
Single vertex insertion
image
Conclusion:
  • With a concurrency of 11500, the throughput is 10730. This means that the system can handle a single concurrent insertion of vertices at a concurrency level of 11500.
Single edge insertion
image
Conclusion:
  • With a concurrency of 9000, the throughput is 8418. This means that the system can handle a single concurrent insertion of edges at a concurrency level of 9000.

4.3 Search by ID

4.3.1 Stress test upper limit
Testing method

Continuously increasing the concurrency level to test the upper limit of the server’s ability to provide service under normal conditions.

stress parameters
  • Duration: 5 minutes
  • Service abnormality indicator: error rate greater than 0.00%
Querying vertices by ID
image
Conclusion:
  • Concurrency is 14,000, throughput is 12,663. The concurrency capacity for querying vertices by ID is 14,000, with an average delay of 44ms.
Querying edges by ID
image
Conclusion:
  • Concurrency is 13,000, throughput is 12,225. The concurrency capacity for querying edges by ID is 13,000, with an average delay of 12ms.

8.2.2 - v0.5.6 Cluster(Cassandra)

Note:

The current performance metrics are based on an earlier version. The latest version has significant improvements in both performance and functionality. We encourage you to refer to the most recent release featuring autonomous distributed storage and enhanced computational push down capabilities. Alternatively, you may wait for the community to update the data with these enhancements.

1 Test environment

Compressed machine information

CPUMemory网卡磁盘
48 Intel(R) Xeon(R) CPU E5-2650 v4 @ 2.20GHz128G10000Mbps750GB SSD,2.7T HDD
  • Starting Pressure Machine Information: Configure the same as the compressed machine.
  • Testing tool: Apache JMeter 2.5.1.

Note: The machine used to initiate the load and the machine being tested are located in the same data center (or server room)

2 Test Description

2.1 Definition of terms (the unit of time is ms)

  • Samples – The total number of threads completed in this scenario.
  • Average – The average response time.
  • Median – The median response time in statistical terms.
  • 90% Line – The response time below which 90% of all threads fall.
  • Min – The minimum response time.
  • Max – The maximum response time.
  • Error – The error rate.
  • Throughput – The number of transactions processed per unit of time.
  • KB/sec – The throughput measured in terms of data transmitted per second.

2.2 Low-Level Storage

A 15-node Cassandra cluster is used for backend storage. HugeGraph and the Cassandra cluster are located on separate servers. Server-related configuration files are modified only for host and port settings, while the rest remain default.

3 Summary of Performance Results

  1. The speed of a single vertex and edge insertion in HugeGraph is 9000 and 4500 per second, respectively.
  2. The speed of bulk vertex and edge insertion is 50,000 and 150,000 per second, respectively, which is much higher than the single insertion speed.
  3. The concurrency for querying vertices and edges by ID can reach more than 12,000, and the average request delay is less than 70ms.

4 Test Results and Analysis

4.1 Batch Insertion

4.1.1 Pressure Upper Limit Test
Test Method

Continuously increase the concurrency level to test the upper limit of the server’s ability to provide services.

Pressure Parameters

Duration: 5 minutes.

Maximum Insertion Speed of Vertices:
image
Conclusion:
  • At a concurrency level of 3500, the throughput of vertices is 261, and the amount of data processed per second is 52,200 (261 * 200).
Maximum Insertion Speed of Edges:
image
Conclusion:
  • At a concurrency level of 1000, the throughput of edges is 323, and the amount of data processed per second is 161,500 (323 * 500).

4.2 Single Insertion

4.2.1 Pressure Upper Limit Test
Test Method

Continuously increase the concurrency level to test the upper limit of the server’s ability to provide services.

Pressure Parameters
  • Duration: 5 minutes.
  • Service exception mark: Error rate greater than 0.00%.
Single Insertion of Vertices:
image
Conclusion:
  • At a concurrency level of 9000, the throughput is 8400, and the single-insertion concurrency capability for vertices is 9000.
Single Insertion of Edges:
image
Conclusion:
  • At a concurrency level of 4500, the throughput is 4160, and the single-insertion concurrency capability for edges is 4500.

4.3 Query by ID

4.3.1 Pressure Upper Limit Test
Test Method

Continuously increase the concurrency and test the upper limit of the pressure that the server can still provide services normally.

Pressure Parameters
  • Duration: 5 minutes
  • Service exception flag: error rate greater than 0.00%
Query by ID for vertices
image
Conclusion:
  • The concurrent capacity of the vertex search by ID is 14500, with a throughput of 13576 and an average delay of 11ms.
Edge search by ID
image
Conclusion:
  • For edge ID-based queries, the server’s concurrent capacity is up to 12,000, with a throughput of 10,688 and an average latency of 63ms.

8.3 - HugeGraph-Loader Performance

Note:

The current performance metrics are based on an earlier version. The latest version has significant improvements in both performance and functionality. We encourage you to refer to the most recent release featuring autonomous distributed storage and enhanced computational push down capabilities. Alternatively, you may wait for the community to update the data with these enhancements.

Use Cases

When the number of graph data to be batch inserted (including vertices and edges) is at the billion level or below, or the total data size is less than TB, the HugeGraph-Loader tool can be used to continuously and quickly import graph data.

Performance

The test uses the edge data of website.

RocksDB single-machine performance (Update: multi-raft + rocksdb cluster is supported now)

  • When the label index is turned off, 228k edges/s.
  • When the label index is turned on, 153k edges/s.

Cassandra cluster performance

  • When label index is turned on by default, 63k edges/s.

8.4 - HugeGraph 0.4.4 Benchmark

1 测试环境

1.1 硬件信息

CPUMemory网卡磁盘
48 Intel(R) Xeon(R) CPU E5-2650 v4 @ 2.20GHz128G10000Mbps750GB SSD

1.2 软件信息

1.2.1 测试用例

测试使用graphdb-benchmark,一个图数据库测试集。该测试集主要包含4类测试:

  • Massive Insertion,批量插入顶点和边,一定数量的顶点或边一次性提交

  • Single Insertion,单条插入,每个顶点或者每条边立即提交

  • Query,主要是图数据库的基本查询操作:

    • Find Neighbors,查询所有顶点的邻居
    • Find Adjacent Nodes,查询所有边的邻接顶点
    • Find Shortest Path,查询第一个顶点到100个随机顶点的最短路径
  • Clustering,基于Louvain Method的社区发现算法

1.2.2 测试数据集

测试使用人造数据和真实数据

本测试用到的数据集规模
名称vertex数目edge数目文件大小
email-enron.txt36,691367,6614MB
com-youtube.ungraph.txt1,157,8062,987,62438.7MB
amazon0601.txt403,3933,387,38847.9MB

1.3 服务配置

  • HugeGraph版本:0.4.4,RestServer和Gremlin Server和backends都在同一台服务器上
  • Cassandra版本:cassandra-3.10,commit-log 和data共用SSD
  • RocksDB版本:rocksdbjni-5.8.6
  • Titan版本:0.5.4, 使用thrift+Cassandra模式

graphdb-benchmark适配的Titan版本为0.5.4

2 测试结果

2.1 Batch插入性能

Backendemail-enron(30w)amazon0601(300w)com-youtube.ungraph(300w)
Titan9.51688.123111.586
RocksDB2.34514.07616.636
Cassandra11.930108.709101.959
Memory3.07715.20413.841

说明

  • 表头"()“中数据是数据规模,以边为单位
  • 表中数据是批量插入的时间,单位是s
  • 例如,HugeGraph使用RocksDB插入amazon0601数据集的300w条边,花费14.076s,速度约为21w edges/s
结论
  • RocksDB和Memory后端插入性能优于Cassandra
  • HugeGraph和Titan同样使用Cassandra作为后端的情况下,插入性能接近

2.2 遍历性能

2.2.1 术语说明
  • FN(Find Neighbor), 遍历所有vertex, 根据vertex查邻接edge, 通过edge和vertex查other vertex
  • FA(Find Adjacent), 遍历所有edge,根据edge获得source vertex和target vertex
2.2.2 FN性能
Backendemail-enron(3.6w)amazon0601(40w)com-youtube.ungraph(120w)
Titan7.72470.935128.884
RocksDB8.87665.85263.388
Cassandra13.125126.959102.580
Memory22.309207.411165.609

说明

  • 表头”()“中数据是数据规模,以顶点为单位
  • 表中数据是遍历顶点花费的时间,单位是s
  • 例如,HugeGraph使用RocksDB后端遍历amazon0601的所有顶点,并查找邻接边和另一顶点,总共耗时65.852s
2.2.3 FA性能
Backendemail-enron(30w)amazon0601(300w)com-youtube.ungraph(300w)
Titan7.11963.353115.633
RocksDB6.03264.52652.721
Cassandra9.410102.76694.197
Memory12.340195.444140.89

说明

  • 表头”()“中数据是数据规模,以边为单位
  • 表中数据是遍历边花费的时间,单位是s
  • 例如,HugeGraph使用RocksDB后端遍历amazon0601的所有边,并查询每条边的两个顶点,总共耗时64.526s
结论
  • HugeGraph RocksDB > Titan thrift+Cassandra > HugeGraph Cassandra > HugeGraph Memory

2.3 HugeGraph-图常用分析方法性能

术语说明
  • FS(Find Shortest Path), 寻找最短路径
  • K-neighbor,从起始vertex出发,通过K跳边能够到达的所有顶点, 包括1, 2, 3…(K-1), K跳边可达vertex
  • K-out, 从起始vertex出发,恰好经过K跳out边能够到达的顶点
FS性能
Backendemail-enron(30w)amazon0601(300w)com-youtube.ungraph(300w)
Titan11.3330.313376.06
RocksDB44.3912.221268.792
Cassandra39.8453.337331.113
Memory35.6382.059388.987

说明

  • 表头”()“中数据是数据规模,以边为单位
  • 表中数据是找到从第一个顶点出发到达随机选择的100个顶点的最短路径的时间,单位是s
  • 例如,HugeGraph使用RocksDB查找第一个顶点到100个随机顶点的最短路径,总共耗时2.059s
结论
  • 在数据规模小或者顶点关联关系少的场景下,Titan最短路径性能优于HugeGraph
  • 随着数据规模增大且顶点的关联度增高,HugeGraph最短路径性能优于Titan
K-neighbor性能
顶点深度一度二度三度四度五度六度
v1时间0.031s0.033s0.048s0.500s11.27sOOM
v111时间0.027s0.034s0.1151.36sOOM
v1111时间0.039s0.027s0.052s0.511s10.96sOOM

说明

  • HugeGraph-Server的JVM内存设置为32GB,数据量过大时会出现OOM
K-out性能
顶点深度一度二度三度四度五度六度
v1时间0.054s0.057s0.109s0.526s3.77sOOM
10133245350,8301,128,688
v111时间0.032s0.042s0.136s1.25s20.62sOOM
1021149441131502,629,970
v1111时间0.039s0.045s0.053s1.10s2.92sOOM
101402555508251,070,230

说明

  • HugeGraph-Server的JVM内存设置为32GB,数据量过大时会出现OOM
结论
  • FS场景,HugeGraph性能优于Titan
  • K-neighbor和K-out场景,HugeGraph能够实现在5度范围内秒级返回结果

2.4 图综合性能测试-CW

数据库规模1000规模5000规模10000规模20000
Titan45.943849.1682737.1179791.46
Memory(core)41.0771825.905**
Cassandra(core)39.783862.7442423.1366564.191
RocksDB(core)33.383199.894763.8691677.813

说明

  • “规模"以顶点为单位
  • 表中数据是社区发现完成需要的时间,单位是s,例如HugeGraph使用RocksDB后端在规模10000的数据集,社区聚合不再变化,需要耗时763.869s
  • “*“表示超过10000s未完成
  • CW测试是CRUD的综合评估
  • 后三者分别是HugeGraph的不同后端,该测试中HugeGraph跟Titan一样,没有通过client,直接对core操作
结论
  • HugeGraph在使用Cassandra后端时,性能略优于Titan,随着数据规模的增大,优势越来越明显,数据规模20000时,比Titan快30%
  • HugeGraph在使用RocksDB后端时,性能远高于Titan和HugeGraph的Cassandra后端,分别比两者快了6倍和4倍

9 - Contribution Guidelines

Read the contribution process before submitting code or documentation. Separate pages cover committer nominations, mailing-list subscriptions, and release validation. Contributor agreements follow the official ASF ICLA/CCLA process.

9.1 - Contribute to the HugeGraph Community

Choose How to Contribute

You can report problems through GitHub Issues, or contribute code, tests, or documentation. Before starting a substantial change, consider opening an issue that explains its scope to avoid duplicated work.

The following example uses apache/hugegraph. The same process applies to other HugeGraph repositories, but follow each repository’s README.md, AGENTS.md, and CI configuration for its build and test commands.

Prepare the Repository

Fork the HugeGraph repository on GitHub

Fork apache/hugegraph on GitHub, then clone your fork:

git clone https://github.com/<your-name>/hugegraph.git
cd hugegraph
git remote add upstream https://github.com/apache/hugegraph.git
git fetch upstream master

Do not develop directly on master. Use a separate branch for each change:

git switch master
git merge --ff-only upstream/master
git switch -c fix/<short-description>

Make and Verify Changes

HugeGraph Server code is under hugegraph-server/. For example, the core module is located at:

hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/

Run the tests directly related to your change first. Common Server test commands include:

# Core tests with the in-memory backend
mvn test -pl hugegraph-server/hugegraph-test -am -P core-test,memory

# API tests with the RocksDB backend
mvn test -pl hugegraph-server/hugegraph-test -am -P api-test,rocksdb

# Format files and verify compilation
mvn editorconfig:format
mvn clean compile -Dmaven.javadoc.skip=true

GitHub requires a username and token for Git authentication instead of a username and password. Create a personal access token at https://github.com/settings/tokens:

Authenticate Git pushes with a personal access token

When adding a third-party dependency, also update the license information included in the distribution:

  1. Add the dependency’s license file to hugegraph-server/hugegraph-dist/release-docs/licenses/.
  2. Update hugegraph-server/hugegraph-dist/release-docs/LICENSE. If the dependency includes a NOTICE file, update NOTICE as well.
  3. Run hugegraph-server/hugegraph-dist/scripts/dependency/regenerate_known_dependencies.sh to update the known-dependency list.

Submit a Pull Request

Make sure the email address used for your commits is associated with your GitHub account. See https://github.com/settings/emails for instructions:

Verify your commit email on GitHub

Use the type(module): message format for commit messages, for example:

git add <changed-files>
git commit -m "fix(core): handle empty vertex query"
git push -u origin fix/<short-description>

Then open a pull request from your fork branch to apache/hugegraph:master. Explain the problem, the implementation, and the validation commands you actually ran. Include screenshots for UI changes.

Address Review Feedback

If CI fails or a reviewer requests changes, continue committing and pushing to the same branch. Rebase when you need to synchronize with upstream:

git fetch upstream master
git rebase upstream/master
git push --force-with-lease

Do not overwrite the remote branch with plain --force. After all CI and review requirements are satisfied, a project maintainer will merge the pull request.

Contributor agreements follow the official ASF process. See the Contributor Agreement.

9.2 - Subscribe to the Community Mailing List

HugeGraph uses dev@hugegraph.apache.org for development and usage discussions. Subscribe before sending messages to the list; messages from non-subscribers may be rejected.

Subscribe

  1. From the email address you want to subscribe, send a message with any subject and body to dev-subscribe@hugegraph.apache.org.
  2. Reply directly to the confirmation message.
  3. After receiving the subscription confirmation, you can send messages to dev@hugegraph.apache.org.

If the confirmation does not arrive, check your spam folder and automatic mail categories. If it is still missing, wait a while and send the subscription message again.

You can browse public messages in the ASF Mailing List Archives without subscribing.

Unsubscribe

  1. From your subscribed address, send a message to dev-unsubscribe@hugegraph.apache.org.
  2. Reply directly to the confirmation message from dev-help@hugegraph.apache.org.
  3. Unsubscription is complete when you receive a message whose subject contains GOODBYE.

For general ASF mailing-list guidance, see Apache Mailing Lists.

9.3 - Validate Apache Release

Note: this doc will be updated continuously. Use Java 11 for runtime verification. Since version 1.5.0, components other than the client no longer support Java 8.

Graduation note: Apache HugeGraph graduated in January 2026. Official release voting is now completed within the HugeGraph community (PMC binding votes on dev@hugegraph.apache.org), and no longer requires Incubator general@incubator.apache.org approval.

Verification

When the internal temporary release and packaging work is completed, other community developers ( especially PMC) need to participate in verification based on ASF release policy and checklist references:

  • ASF release policy
  • Incubator checklist (historical reference) To ensure the “correctness + completeness” of someone’s published version, here requires **everyone ** to participate as much as possible, and then explain which items you have checked in the subsequent email reply.(The following are the core items)

1. prepare

If there is no svn or gpg or wget environment locally, it is recommended to install it first (windows recommend using WSL2 environment, or at least git-bash), also make sure to install java (prefer Java 11) and maven software

# 1. install svn
# ubuntu/debian
sudo apt install subversion -y
# MacOS
brew install subversion
# To verify that the installation was successful, execute the following command:
svn --version

# 2. install gpg
# ubuntu/debian
sudo apt-get install gnupg -y
# MacOS
brew install gnupg
# To verify that the installation was successful, execute the following command:
gpg --version

# 3. install wget (we will enhance it later, like use `curl`)
# ubuntu/debian
sudo apt-get install wget -y
# MacOS
brew install wget

# 4. Download the hugegraph-svn directory 
# For version number, pay attention to fill in the verification version
svn co https://dist.apache.org/repos/dist/dev/hugegraph/1.x.x/
# (Note) If svn downloads a file very slowly, 
# you can consider wget to download a single file, as follows (or consider using a proxy)
wget https://dist.apache.org/repos/dist/dev/hugegraph/1.x.x/apache-hugegraph-toolchain-incubating-1.x.x.tar.gz

2. check hash value

First you need to check the file integrity of the source + binary package, Verify by shasum to ensure that it is consistent with the hash value published on apache/GitHub (Usually sha512), Here is the same as the last step of 0x02 inspection.

execute the following command:
for i in *.tar.gz; do echo $i; shasum -a 512 --check  $i.sha512; done

3. check gpg signature

This is to ensure that the published package is uploaded by a reliable person. Assuming tom signs and uploads, others should download A’s public key and then perform signature confirmation.

Related commands:

# 1. Download project trusted public key to local (required for the first time) & import
curl  https://downloads.apache.org/hugegraph/KEYS > KEYS
gpg --import KEYS

# After importing, you can see the following output, which means that x user public keys have been imported
gpg: /home/ubuntu/.gnupg/trustdb.gpg: trustdb created
gpg: key BA7E78F8A81A885E: public key "imbajin (apache mail) <jin@apache.org>" imported
gpg: key 818108E7924549CC: public key "vaughn <vaughn@apache.org>" imported
gpg: key 28DCAED849C4180E: public key "coderzc (CODE SIGNING KEY) <zhaocong@apache.org>" imported
...
gpg: Total number processed: x
gpg:               imported: x

# 2. Trust release users (trust n username mentioned in voting mail, if more than one user, 
#      just repeat the steps in turn or use the script below)
gpg --edit-key $USER # input the username, enter the interactive mode
gpg> trust
...output options..
Your decision? 5 # select 5
Do you really want to set this key to ultimate trust? (y/N) y # slect y, then q quits trusting the next user

# (Optional) You could also use the command to trust one user in non-interactive mode:
echo -e "5\ny\n" | gpg --batch --command-fd 0 --edit-key $USER trust
# Or trust all currently imported GPG public keys (review them carefully first):
for key in $(gpg --no-tty --list-keys --with-colons | awk -F: '/^pub/ {print $5}'); do
  echo -e "5\ny\n" | gpg --batch --command-fd 0 --edit-key "$key" trust
done


# 3. Check the signature (make sure there is no Warning output, every source/binary file prompts Good Signature)
#Single file verification
gpg --verify xx.asc xxx-src.tar.gz
gpg --verify xx.asc xxx.tar.gz # Note: without the bin/binary suffix

# One-click shell traversal verification (recommended)
for i in *.tar.gz; do echo $i; gpg --verify $i.asc $i ; done

First confirm the overall integrity/consistency, and then confirm the specific content (key)

4. Check the archive contents

Check the contents of the archive downloaded from preparation work. Divided into two aspects: source code package + binary package, The source code package is stricter, it can be said that the core part (Because it is longer, For a complete list refer to the official Wiki)

A. source package

After decompressing *hugegraph*src.tar.gz, Do the following checks:

  1. package/folder naming should match the release line (historical releases may still contain incubating), and no empty files/folders
  2. LICENSE + NOTICE exist and the content is normal; DISCLAIMER is required for historical incubating artifacts
  3. does not exist binaries (without LICENSE)
  4. The source code files all contain the standard ASF License header (this could be done with the Maven-MAT plugin)
  5. Check whether the pom.xml version number of each parent/child module is consistent (and meet expectations)
  6. Finally, make sure the source code works/compiles correctly
# prefer to use/switch to `java 11` for the following operations (compiling/running) (Note: `Computer` only supports `java >= 11`)
# java --version

# try to compile in the Unix env to check if it works well (-P is optional)
mvn clean package -DskipTests -Dcheckstyle.skip=true -P stage
B. binary package

After decompressing xxx-hugegraph.tar.gz, perform the following checks:

  1. package/folder naming should match the release line (historical releases may still contain incubating)
  2. LICENSE and NOTICE file exists and the content is normal (DISCLAIMER applies to historical incubating artifacts)
  3. start server
# hugegraph-server
bin/start-hugegraph.sh

# hugegraph-loader
bin/hugegraph-loader.sh -g hugegraph -f example/file/struct.json -s example/file/schema.groovy

# hugegraph-hubble
bin/start-hubble.sh

more reference official website: https://hugegraph.apache.org/docs/quickstart

Note: If a third-party dependency is introduced in the binary package, you need to update the LICENSE and add the third-party dependent LICENSE; if the third-party dependent LICENSE is Apache 2.0, and the corresponding project contains NOTICE, you also need to update Our NOTICE file

5. Check the official website and GitHub and other pages

  1. Make sure that the official website at least meets apache website check, and no circular links, etc.
  2. Update download link and release notes updated

Mail Template

After the check & test, you should reply to the mail with the following content: (normal devs & PMC)

[] +1 approve

[] +0 no opinion

[] -1 disapprove with the reason
+1 (non-binding)
I checked:
1. Download link/tag in mail are valid
2. Checksum and GPG signatures are OK
3. LICENSE & NOTICE & DISCLAIMER are exist
4. Build successfully on XX OS & Version XX
5. No unexpected binary files
6. Date is right in the NOTICE file
7. Compile from source is fine under JavaXX
8. No empty file & directory found
9. Test running XXX service OK
10. ....

and the PMC members should reply with binding, it’s important for summary the valid votes:

+1 (binding)
I checked:
1. Download link/tag in mail are valid
2. Checksum and GPG signatures are OK
3. LICENSE & NOTICE & DISCLAIMER are exist
4. Build successfully on XX OS & Version XX
5. No unexpected binary files
6. Date is right in the NOTICE file
7. Compile from source is fine under JavaXX
8. No empty file & directory found
9. Test running XX process OK
10. ....

9.4 - Setup Server in IDEA (Dev)

NOTE: The following configuration is for reference purposes only, and has been tested on Linux and macOS platforms based on this version.

Background

The Quick Start section provides instructions on how to start and stop HugeGraph-Server using scripts. In this guide, we will explain how to run and debug HugeGraph-Server on the Linux platform using IntelliJ IDEA.

The core steps for local startup are the same as starting with scripts:

  1. Initialize the database backend by executing the InitStore class to initialize the graph.
  2. Start HugeGraph-Server by executing the HugeGraphServer class to load the initialized graph information and start the server.

Before proceeding with the following process, make sure that you have cloned the source code of HugeGraph and have configured the development environment, such as Java 11 & you could config your local environment with this config-doc

git clone https://github.com/apache/hugegraph.git

Steps

1. Copy Configuration Files

To avoid the impact of configuration file changes on Git tracking, it is recommended to copy the required configuration files to a separate folder. Run the following command to copy the files:

cp -r hugegraph-dist/src/assembly/static/scripts hugegraph-dist/src/assembly/static/conf path-to-your-directory

Replace path-to-your-directory with the path to the directory where you want to copy the files.

After introducing ToplingDB, developers need to execute the preload-topling.sh script, which automatically extracts the required dynamic libraries and Web Server static resources into the library directory located alongside the bin directory (the static resources will also be copied to /dev/shm/rocksdb_resource ).

2. Configure InitStore to initialize the graph

First, you need to configure the database backend in the configuration files. In this example, we will use RocksDB. Open path-to-your-directory/conf/graphs/hugegraph.properties and configure it as follows:

backend=rocksdb
serializer=binary
rocksdb.data_path=.
rocksdb.wal_path=.

Next, open the Run/Debug Configurations panel in IntelliJ IDEA and create a new Application configuration. Follow these steps for the configuration:

  • Select hugegraph-dist as the Use classpath of module.
  • Set the Main class to org.apache.hugegraph.cmd.InitStore.
  • Set the program arguments to conf/rest-server.properties. Note that the path here is relative to the working directory, so make sure to set the working directory to path-to-your-directory.
  • ToplingDB requires preloading dynamic libraries via the LD_PRELOAD mechanism. Developers need to set two environment variables: LD_LIBRARY_PATH should point to the library directory extracted by preload-topling.sh, and LD_PRELOAD should be set to libjemalloc.so:librocksdbjni-linux64.so to ensure the necessary libraries are correctly loaded at runtime.
    • LD_LIBRARY_PATH=/path/to/your/library:$LD_LIBRARY_PATH
    • LD_PRELOAD=libjemalloc.so:librocksdbjni-linux64.so

If user authentication (authenticator) is configured for HugeGraph-Server in the Java 11 environment, you need to refer to the script configuration in the binary package and add the following VM options:

--add-exports=java.base/jdk.internal.reflect=ALL-UNNAMED

Otherwise, an error will occur:

java.lang.reflect.InaccessibleObjectException: Unable to make public static synchronized void jdk.internal.reflect.Reflection.registerFieldsToFilter(java.lang.Class,java.lang.String[]) accessible: module java.base does not "exports jdk.internal.reflect" to unnamed module @xxx

Once the configuration is completed, run it. If the execution is successful, the following runtime logs will be displayed:

2023-06-05 00:43:37 [main] [INFO] o.a.h.u.ConfigUtil - Scanning option 'graphs' directory './conf/graphs'
2023-06-05 00:43:37 [main] [INFO] o.a.h.c.InitStore - Init graph with config file: ./conf/graphs/hugegraph.properties
......
2023-06-05 00:43:39 [main] [INFO] o.a.h.b.s.r.RocksDBStore - Write down the backend version: 1.11
2023-06-05 00:43:39 [main] [INFO] o.a.h.StandardHugeGraph - Graph 'hugegraph' has been initialized
2023-06-05 00:43:39 [main] [INFO] o.a.h.StandardHugeGraph - Close graph standardhugegraph[hugegraph]
2023-06-05 00:43:39 [db-open-1] [INFO] o.a.h.b.s.r.RocksDBStore - Opening RocksDB with data path: ./m
2023-06-05 00:43:39 [db-open-1] [INFO] o.a.h.b.s.r.RocksDBStore - Opening RocksDB with data path: ./s
2023-06-05 00:43:39 [db-open-1] [INFO] o.a.h.b.s.r.RocksDBStore - Opening RocksDB with data path: ./g
2023-06-05 00:43:39 [main] [INFO] o.a.h.HugeFactory - HugeFactory shutdown
2023-06-05 00:43:39 [hugegraph-shutdown] [INFO] o.a.h.HugeFactory - HugeGraph is shutting down

3. Running HugeGraphServer

Similarly, open the Run/Debug Configurations panel in IntelliJ IDEA and create a new Application configuration. Follow these steps for the configuration:

  • Select hugegraph-dist as the Use classpath of module.
  • Set the Main class to org.apache.hugegraph.dist.HugeGraphServer.
  • Set the program arguments to conf/gremlin-server.yaml conf/rest-server.properties. Similarly, note that the path here is relative to the working directory, so make sure to set the working directory to path-to-your-directory.

Similarly, if user authentication (authenticator) is configured for HugeGraph-Server in the Java 11 environment, you need to refer to the script configuration in the binary package and add the following VM options:

--add-exports=java.base/jdk.internal.reflect=ALL-UNNAMED --add-modules=jdk.unsupported --add-exports=java.base/sun.nio.ch=ALL-UNNAMED

Otherwise, an error will occur:

java.lang.reflect.InaccessibleObjectException: Unable to make public static synchronized void jdk.internal.reflect.Reflection.registerFieldsToFilter(java.lang.Class,java.lang.String[]) accessible: module java.base does not "exports jdk.internal.reflect" to unnamed module @xxx

Once the configuration is completed, run it. If you see the following logs, it means that HugeGraphServer has been successfully started:

......
2023-06-05 00:51:56 [gremlin-server-boss-1] [INFO] o.a.t.g.s.GremlinServer - Gremlin Server configured with worker thread pool of 1, gremlin pool of 8 and boss thread pool of 1.
2023-06-05 00:51:56 [gremlin-server-boss-1] [INFO] o.a.t.g.s.GremlinServer - Channel started at port 8182.

4. Debugging HugeGraphServer (optional)

After completing the above configuration, you can try debugging HugeGraphServer. Run HugeGraphServer in debug mode and set a breakpoint at the following location:

public String list(@Context GraphManager manager,
                   @PathParam("graph") String graph, @QueryParam("label") String label,
                   @QueryParam("properties") String properties, ......) {
    // ignore log
    Map<String, Object> props = parseProperties(properties);

Then use the RESTful API to request HugeGraphServer:

curl "http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/graph/vertices" | gunzip

At this point, you can view detailed variable information in the debugger.

5. Log4j2 Configuration

By default, when running InitStore and HugeGraphServer, the Log4j2 configuration file path read is hugegraph-dist/src/main/resources/log4j2.xml, not path-to-your-directory/conf/log4j2.xml. This configuration file is read when starting HugeGraph-Server using the script.

To avoid maintaining two separate configuration files, you can modify the Log4j2 configuration file path when running and debugging HugeGraph-Server in IntelliJ IDEA:

  1. Open the previously created Application configuration.
  2. Click on Modify options - Add VM options.
  3. Set the VM options to -Dlog4j.configurationFile=conf/log4j2.xml.

Possible Issues

1. java: package sun.misc does not exist

The reason may be that cross-compilation is triggered when using Java 11 to compile, causing the symbol of sun.misc.Unsafe used in the project to not be found. There are two possible solutions:

  1. In IntelliJ IDEA, go to Preferences/Settings and find the Java Compiler panel. Then, disable the --release option (recommended).
  2. Set the Project SDK to 8 (Deprecated soon).

2. java: *.store.raft.rpc.RaftRequests does not exist (RPC Generated Files)

The reason is that the source code didn’t include the RPC-generated files. You could try 2 ways to fix it:

  1. [CMD]mvn clean compile in the root directory (Recommend)
  2. [UI] right click on the hugegraph repo and select Maven->Generate Sources and Update Folders. This will rebuild the repo and correctly generate the required files.

3. Unable to Print Location Information (%l) in Log4j2

This is because Log4j2 uses asynchronous loggers. You can refer to the official documentation for configuration details.


References

  1. HugeGraph-Server Quick Start
  2. Local Debugging Guide for HugeGraph Server (Win/Unix)
  3. “package sun.misc does not exist” compilation error
  4. Cannot compile: java: package sun.misc does not exist
  5. The code-style config for HugeGraph in IDEA

9.5 - Apache HugeGraph Committer Guide

This document outlines the requirements and process for becoming an Apache Committer. The corresponding ASF official document can be found at: https://community.apache.org/newcommitter.html

Candidate Requirements

  1. Candidates must adhere to the Apache Code of Conduct.
  2. PMC members will assess candidates’ interactions with others and contributions through mailing lists, issues, pull requests, and official documentation.
  3. Considerations for evaluating candidates as potential Committers include:
    1. Ability to collaborate with community members
    2. Mentorship capabilities
    3. Community involvement
    4. Level of contribution
    5. Personal skills/abilities

Nomination Process

Discussion → Vote → Invitation → Announcement

Initiate Community Discussion (DISCUSS)

Any (P)PMC member of HugeGraph can initiate a voting discussion. After identifying valuable contributions from a community contributor and obtaining the candidate’s consent, a discussion can be initiated via private@hugegraph.apache.org. The initiator of the discussion should clearly state the candidate’s contributions in the discussion email and provide URLs or other information for confirming the contributions, facilitating discussion and analysis.

Below is a template for HugeGraph emails: (For reference only)

Note: The term xxx will be used to refer to the candidate. Typically, xxx represents an easily readable name (e.g., Simon Jay).

ASF-INFRA recommends avoiding the use of less readable ID directly as a reference to the person in emails (e.g., avoid simon321 or wh0isSim0n 😄).

In addition, it is best to choose the “pure text” mode, otherwise the typesetting may be chaotic in the ASF Mailing-list UI

To: private@hugegraph.apache.org
Subject: [DISCUSS] XXX as a HugeGraph Committer Candidate

Hi all:

I am pleased to nominate xxx for the role of HugeGraph Committer based on his/her contributions over the past few months.

[ Candidate's Contribution Summary ]

Here are the relevant PRs (issues) he/she has participated in:

**Core Features:**
- Feature 1: [ Reference Links ]
- ...

**Fix/Chore/Release:**

**Doc:**

[ Candidate's Current Notable Contributions ]

His/Her contributions bring the following benefits to the community, helping us in the following ways:

[ Candidate's Contributions and Benefits to the Community ]

In view of the above contributions, I elect xxx as Committer of the HugeGraph project.

[ Reference Links ]
1. PR1
2. PR2
3. ...

Welcome everyone to share opinions~

Thanks!

For contribution links in discussion emails, you can use the statistical feature of GitHub Search by entering corresponding keywords as needed. You can also adjust parameters and add new repositories such as repo:apache/incubator-hugegraph-computer. Pay special attention to adjusting the time range (below is a template reference, please adjust the parameters accordingly):

For participation in mailing lists, you can use https://lists.apache.org/list?dev@hugegraph.apache.org:lte=10M:xxx.

Initiate Community Voting Email (VOTE)

If there are no dissenting opinions within the specified time frame of the discussion email, the initiator of the discussion needs to initiate a voting email for the committer election at private@hugegraph.apache.org.

Below is the corresponding email template:

To: private@hugegraph.apache.org
Subject: [VOTE] xxx as a HugeGraph Committer

Hi all:

Through the discussion of last week:
[ Discussion Mailing List Link ]

We have discussed and listed what xxx participated in the HugeGraph community.
I believe making him/her a Committer will enhance the work for HugeGraph. 

So, I am happy to call VOTE to accept xxx as a HugeGraph Committer.
 
Voting will continue for at least 72 hours or until the required number of votes is reached.
 
Please vote accordingly:
[ ] +1 approve
[ ] +0 no opinion
[ ] -1 disapprove with the reason  

Thanks!

Then, (P)PMC members reply to the email with +1 or -1 to express their opinions. Generally, at least 3 votes of +1 are needed to conclude the vote.

Announcement of Voting Results (RESULT)

After the voting email concludes, the initiator of the vote needs to remind the end of the voting in the email. Additionally, the initiator needs to announce the voting results via email to private@hugegraph.apache.org. The email template can be as follows:

To: private@hugegraph.apache.org
Subject: [RESULTS][VOTE] xxx as a HugeGraph Committer

Hi all: The vote for "xxx" as a HugeGraph Committer has PASSED and closed now.

The result is as follows: X PMC +1 Votes: 
- A (PMC ID)
- B
- C...

Vote thread:
put vote thread link here
 
Then I'm going to invite xxx to join us soon. Thanks for everyone's support!

Send Invitation Email to Candidate (INVITE)

After the announcement of the voting results email is sent, the initiator of the vote should send an invitation email to the candidate. The invitation email is addressed to the candidate and cc’d to private@hugegraph.apache.org. The invited candidate must reply to the specified email address to accept or reject the invitation.

Below is a template for reference:

To: [ Candidate's Email ]
Cc: private@hugegraph.apache.org
Subject: Invitation to become HugeGraph committer: xxx

Hello xxx,

The HugeGraph Project Management Committee (PPMC)
hereby offers you committer privileges to the project.
These privileges are offered on the understanding that you'll use them
reasonably and with common sense. We like to work on trust
rather than unnecessary constraints.

Being a committer enables you to more easily make
changes without needing to go through the patch
submission process.

Being a committer does not require you to
participate any more than you already do. It does
tend to make one even more committed.  You will
probably find that you spend more time here.

Of course, you can decline and instead remain as a
contributor, participating as you do now.

A. This personal invitation is a chance for you to
accept or decline in private.  Either way, please
let us know in reply to the private@hugegraph.apache.org
address only.

B. If you accept, the next step is to register an iCLA:
    1. Details of the iCLA and the forms are found
    through this link: https://www.apache.org/licenses/#clas

    2. Instructions for its completion and return to
    the Secretary of the ASF are found at
    https://www.apache.org/licenses/#submitting

    3. When you transmit the completed iCLA, request
    to notify the Apache HugeGraph project and choose a
    unique Apache ID. Look to see if your preferred
    ID is already taken at
    https://people.apache.org/committer-index.html
    This will allow the Secretary to notify the PMC
    when your iCLA has been recorded.

When recording of your iCLA is noted, you will
receive a follow-up message with the next steps for
establishing you as a committer.

With the expectation of your acceptance, welcome!

The Apache HugeGraph(incubating) PPMC

Candidate Accepts Invitation (ACCEPT)

The candidate should reply to the aforementioned email (select reply all) to indicate acceptance of the invitation. Below is a template for the email:

To: [ Sender's Email ]
Cc: private@hugegraph.apache.org
Subject: Re: Invitation to become HugeGraph committer: xxx

Hello Apache HugeGraph(incubating) PPMC,

I accept the invitation.

Thanks to the Apache HugeGraph Community for recognizing my work, I
will continue to actively participate in the work of the Apache
HugeGraph(incubating).

Next, I will follow the instructions to complete the next steps:
Signing and submitting iCLA and registering Apache ID.

xxx

Of course, the candidate may also choose to decline the invitation, in which case there is no template:)

Once the invitation is accepted, the candidate needs to complete the following tasks:

ICLA Signing Process

  1. Download the ICLA
  2. Open the PDF and fill in the required information. All fields must be filled in English. It is recommended to use a PDF tool to edit and sign.
    1. Full name: First name followed by last name
    2. Public name: Optional, defaults to the same as Full name
    3. Check the box only if you entered names with your family name first
    4. Postal Address: English address, starting from small to large, including detailed street address
    5. Country: Country of residence in English
    6. E-mail: Email address, preferably the same as the one used in the invitation email
    7. (optional) preferred Apache id(s): Choose an SVN ID that is not listed on the Apache committer page
    8. (optional) notify project: Apache HugeGraph(incubating)
    9. Signature: Must be handwritten using a PDF tool
    10. Date: Format as xxxx-xx-xx
  3. After signing, rename icla.pdf to name-pinyin-icla.pdf
  4. Send the following email and attach name-pinyin-icla.pdf as a reference.
To: secretary@apache.org
Subject: ICLA Information

Hello everyone:

I have accepted the Apache HugeGraph(incubating) PPMC invitation to
become a HugeGraph committer, the attachment is my ICLA information.

(Optional) My GitHub account is https://github.com/xxx. Thanks!

xxx

For more details, please refer to https://github.com/apache/hugegraph/issues/1732.

PMC members will await confirmation of the ICLA record from the Apache secretary team. Candidates and PMC members will receive the following email:

Dear xxx,

This message acknowledges receipt of your ICLA, which has been filed in the Apache Software Foundation records.

Your account (with id xxx) has been requested for you and you should receive email with next steps
within the next few days (this process can take up to a week).

Please refer to https://www.apache.org/foundation/how-it-works.html#developers
for more information about roles at Apache.

Setting Up Apache Account and Development Environment (CONFIG)

After the record is completed, the candidate will receive an email from root@apache.org with the subject Welcome to the Apache Software Foundation. At this point, the candidate needs to follow the steps in the email to set up the Apache account and development environment:

  1. Reset the password at https://id.apache.org/reset/enter.
  2. Configure personal information at https://whimsy.apache.org/roster/committer/xxx.
  3. Associate GitHub account at https://gitbox.apache.org/boxer.
    • This step requires configuring GitHub Two-Factor Authentication (2FA).
  4. The nominating PMC member must add the new Committer to the official list of committers via the Roster page. (Important, otherwise repository permissions will not take effect).
    • After this step, the candidate becomes a new Committer and gains write access to the GitHub HugeGraph repository.
  5. (Optional) The new Committer can apply for free use of JetBrains’ full range of products with their Apache account here.

Announcing via Email (ANNOUNCE)

After the candidate completes the above steps, they will officially become a Committer of HugeGraph. At this point, they need to send an announcement email to dev@hugegraph.apache.org. Below is a template for the email:

To: dev@hugegraph.apache.org
Subject: [ANNOUNCE] New Committer: xxx

Hi everyone, The PPMC for Apache HugeGraph(incubating) has invited xxx to
become a Committer and we are pleased to announce that he/she has accepted.

xxx is being active in the HugeGraph community & dedicated to ... modules, 
and we are glad to see his/her more interactions with the community in the future.

(Optional) His/Her GitHub account is https://github.com/xxx

Welcome xxx, and please enjoy your community journey~ 

Thanks! 

The Apache HugeGraph PPMC

Update clutch status information

PMC members responsible for nominations need to download clutch status information and update it. Once effective, it can be viewed on the clutch and projects pages. The process is as follows:

# 1. Download clutch status information
svn co https://svn.apache.org/repos/asf/incubator/public/trunk/content/projects/

# 2. Modify and edit (note the following is for reference only)
cd projects
vim hugegraph.xml

<section id="News">
  <title>News</title>
  <ul>
    <li>YYYY-MM-DD New Committer: xxx</li>
    <li>...</li>
  </ul>
</section>

# 3. Commit
svn commit -m "update news for hugegraph"

References

  1. https://community.apache.org/newcommitter.html (ASF official documentation)
  2. https://infra.apache.org/new-committers-guide.html
  3. https://www.apache.org/dev/pmc.html#newcommitter
  4. https://linkis.apache.org/zh-CN/community/how-to-vote-a-committer-pmc
  5. https://www.apache.org/licenses/contributor-agreements.html#submitting
  6. https://www.apache.org/licenses/cla-faq.html#printer
  7. https://linkis.apache.org/zh-CN/community/how-to-sign-apache-icla
  8. https://github.com/apache/hugegraph/issues/1732 (HugeGraph ICLA related issue)

10 - CHANGELOGS

10.1 - HugeGraph 1.0.0 Release Notes

OLTP API & Client Changes

API Changes

  • feat(api): support hot set trace through /exception/trace API.
  • feat(api): support query by Cypher language.
  • feat(api): support swagger UI to viewing API.

Client Changes

  • feat(client) support Cypher query API.
  • refact(client): change ’limit’ type from long to int.
  • feat(client): server bypass for hbase writing (Beta).

Core & Server

Feature Changes

  • feat: support Java 11.
  • feat(core): support adamic-adar & resource-allocation algorithms.
  • feat(hbase): support hash rowkey & pre-init tables.
  • feat(core): support query by Cypher language.
  • feat(core): support automatic management and fail-over for cluster role.
  • feat(core): support 16 OLAP algorithms, like: LPA, Louvain, PageRank, BetweennessCentrality, RingsDetect.
  • feat: prepare for Apache release.

Bug Fix

  • fix(core): can’t query edges by multi labels + properties.
  • fix(core): occasionally NoSuchMethodError Relations().
  • fix(core): limit max depth for cycle detection.
  • fix(core): traversal contains Tree step has different result.
  • fix edge batch update error.
  • fix unexpected task status.
  • fix(core): edge cache not clear when update or delete associated vertex.
  • fix(mysql): run g.V() is error when it’s MySQL backend.
  • fix: close exception and server-info EXPIRED_INTERVAL.
  • fix: export ConditionP.
  • fix: query by within + Text.contains.
  • fix: schema label race condition of addIndexLabel/removeIndexLabel.
  • fix: limit admin role can drop graph.
  • fix: ProfileApi url check & add build package to ignore file.
  • fix: can’t shut down when starting with exception.
  • fix: Traversal.graph is empty in StepStrategy.apply() with count().is(0).
  • fix: possible extra comma before where statement in MySQL backend.
  • fix: JNA UnsatisfiedLinkError for Apple M1.
  • fix: start RpcServer NPE & args count of ACTION_CLEARED error & example error.
  • fix: rpc server not start.
  • fix: User-controlled data in numeric cast & remove word dependency.
  • fix: closing iterators on errors for Cassandra & Mysql.

Option Changes

  • move raft.endpoint option from graph scope to server scope.

Other Changes

  • refact(core): enhance schema job module.
  • refact(raft): improve raft module & test & install snapshot and add peer.
  • refact(core): remove early cycle detection & limit max depth.
  • cache: fix assert node.next==empty.
  • fix apache license conflicts: jnr-posix and jboss-logging.
  • chore: add logo in README & remove outdated log4j version.
  • refact(core): improve CachedGraphTransaction perf.
  • chore: update CI config & support ci robot & add codeQL SEC-check & graph option.
  • refact: ignore security check api & fix some bugs & clean code.
  • doc: enhance CONTRIBUTING.md & README.md.
  • refact: add checkstyle plugin & clean/format the code.
  • refact(core): improve decode string empty bytes & avoid array-construct columns in BackendEntry.
  • refact(cassandra): translate ipv4 to ipv6 metrics & update cassandra dependency version.
  • chore: use .asf.yaml for apache workflow & replace APPLICATION_JSON with TEXT_PLAIN.
  • feat: add system schema store.
  • refact(rocksdb): update rocksdb version to 6.22 & improve rocksdb code.
  • refact: update mysql scope to test & clean protobuf style/configs.
  • chore: upgrade Dockerfile server to 0.12.0 & add editorconfig & improve ci.
  • chore: upgrade grpc version.
  • feat: support updateIfPresent/updateIfAbsent operation.
  • chore: modify abnormal logs & upgrade netty-all to 4.1.44.
  • refact: upgrade dependencies & adopt new analyzer & clean code.
  • chore: improve .gitignore & update ci configs & add RAT/flatten plugin.
  • chore(license): add dependencies-check ci & 3rd-party dependency licenses.
  • refact: Shutdown log when shutdown process & fix tx leak & enhance the file path.
  • refact: rename package to apache & dependency in all modules (Breaking Change).
  • chore: add license checker & update antrun plugin & fix building problem in windows.
  • feat: support one-step script for apache release v1.0.0 release.

Computer (OLAP)

Algorithm Changes

  • feat: implement page-rank algorithm.
  • feat: implement wcc algorithm.
  • feat: implement degree centrality.
  • feat: implement triangle_count algorithm.
  • feat: implement rings-detection algorithm.
  • feat: implement LPA algorithm.
  • feat: implement kcore algorithm.
  • feat: implement closeness centrality algorithm.
  • feat: implement betweenness centrality algorithm.
  • feat: implement cluster coefficient algorithm.

Platform Changes

  • feat: init module computer-core & computer-algorithm & etcd dependency.
  • feat: add Id as base type of vertex id.
  • feat: init Vertex/Edge/Properties & JsonStructGraphOutput.
  • feat: load data from hugegraph server.
  • feat: init basic combiner, Bsp4Worker, Bsp4Master.
  • feat: init sort & transport interface & basic FileInput/Output Stream.
  • feat: init computation & ComputerOutput/Driver interface.
  • feat: init Partitioner and HashPartitioner
  • feat: init Master/WorkerService module.
  • feat: init Heap/LoserTree sorting.
  • feat: init rpc module.
  • feat: init transport server, client, en/decode, flowControl, heartbeat.
  • feat: init DataDirManager & PointerCombiner.
  • feat: init aggregator module & add copy() and assign() methods to Value class.
  • feat: add startAsync and finishAsync on client side, add onStarted and onFinished on server side.
  • feat: init store/sort module.
  • feat: link managers in worker sending end.
  • feat: implement data receiver of worker.
  • feat: implement StreamGraphInput and EntryInput.
  • feat: add Sender and Receiver to process compute message.
  • feat: add seqfile fromat.
  • feat: add ComputeManager.
  • feat: add computer-k8s and computer-k8s-operator.
  • feat: add startup and make docker image code.
  • feat: sort different type of message use different combiner.
  • feat: add HDFS output format.
  • feat: mount config-map and secret to container.
  • feat: support java11.
  • feat: support partition concurrent compute.
  • refact: abstract computer-api from computer-core.
  • refact: optimize data receiving.
  • fix: release file descriptor after input and compute.
  • doc: add operator deploy readme.
  • feat: prepare for Apache release.

Toolchain (loader, tools, hubble)

  • feat(loader): support use SQL to construct graph.
  • feat(loader): support Spark-Loader mode(include jdbc source).
  • feat(loader): support Flink-CDC mode.
  • fix(loader): fix NPE when loading ORC data.
  • fix(loader): fix schema is not cached with Spark/Flink mode.
  • fix(loader): fix json deserialize error.
  • fix(loader): fix jackson conflicts & missing dependencies.
  • feat(hubble): supplementary algorithms UI.
  • feat(hubble): support highlighting and hints for Gremlin text.
  • feat(hubble): add docker-file for hubble.
  • feat(hubble): display packaging log output progress while building.
  • fix(hubble): fix port-input placeholder UI.
  • feat: prepare for Apache release.

Commons (common,rpc)

  • feat: support assert-throws method returning Future.
  • feat: add Cnm and Anm to CollectionUtil.
  • feat: support custom content-type.
  • feat: prepare for Apache release.

Release Details

Please check the release details in each repository:

10.2 - HugeGraph 1.2.0 Release Notes

Java version statement

In the future, we will gradually upgrade the java version, Java 11 -> Java 17 -> Java 21.

  1. hugegraph, hugegraph-toolchain, hugegraph-commons consider use Java 11, also compatible with Java 8 now.
  2. hugegraph-computer required to use Java 11, not compatible with Java 8 now!

v1.2.0 may be the last major version compatible with Java 8, compatibility with Java 8 will totally end in v1.5 when PD/Store merged into master branch (Except for the java-client).

hugegraph

API Changes

  • feat(api&core): in oltp apis, add statistics info and support full info about vertices and edges (#2262)
  • feat(api): support embedded arthas agent in hugegraph-server (#2278,#2337)
  • feat(api): support metric API Prometheus format & add statistic metric api (#2286)
  • feat(api-core): support label & property filtering for both edge and vertex & support kout dfs mode (#2295)
  • feat(api): support recording slow query log (#2327)

Feature Changes

  • feat: support task auto manage by server role state machine (#2130)
  • feat: support parallel compress snapshot (#2136)
  • feat: use an enhanced CypherAPI to refactor it (#2143)
  • feat(perf): support JMH benchmark in HG-test module (#2238)
  • feat: optimising adjacency edge queries (#2242)
  • Feat: IP white list (#2299)
  • feat(cassandra): adapt cassandra from 3.11.12 to 4.0.10 (#2300)
  • feat: support Cassandra with docker-compose in server (#2307)
  • feat(core): support batch+parallel edges traverse (#2312)
  • feat: adapt Dockerfile for new project structur (#2344)
  • feat(server):swagger support auth for standardAuth mode by (#2360)
  • feat(core): add IntMapByDynamicHash V1 implement (#2377)

Bug Fix

  • fix: transfer add_peer/remove_peer command to leader (#2112)
  • fix query dirty edges of a vertex with cache (#2166)
  • fix exception of vertex-drop with index (#2181)
  • fix: remove dup ‘From’ in filterExpiredResultFromFromBackend (#2207)
  • fix: jdbc ssl mode parameter redundant (#2224)
  • fix: error when start gremlin-console with sample script (#2231)
  • fix(core): support order by id (#2233)
  • fix: update ssl_mode value (#2235)
  • fix: optimizing ClassNotFoundException error message for MYSQL (#2246)
  • fix: asf invalid notification scheme ‘discussions_status’ (#2247)
  • fix: asf invalid notification scheme ‘discussions_comment’ (#2250)
  • fix: incorrect use of ‘NO_LIMIT’ variable (#2253)
  • fix(core): close flat mapper iterator after usage (#2281)
  • fix(dist): avoid var PRELOAD cover environmnet vars (#2302)
  • fix: base-ref/head-ref missed in dependency-review on master (#2308)
  • fix(core): handle schema Cache expandCapacity concurrent problem (#2332)
  • fix: in wait-storage.sh, always wait for storage with default rocksdb (#2333)
  • fix(api): refactor/downgrade record logic for slow log (#2347)
  • fix(api): clean some code for release (#2348)
  • fix: remove redirect-to-master from synchronous Gremlin API (#2356)
  • fix HBase PrefixFilter bug (#2364)
  • chore: fix curl failed to request https urls (#2378)
  • fix(api): correct the vertex id in the edge-existence api (#2380)
  • fix: github action build docker image failed during the release 1.2 process (#2386)
  • fix: TinkerPop unit test lack some lables (#2387)

Option Changes

  • feat(dist): support pre-load test graph data in docker container (#2241)

Other Changes

  • refact: use standard UTF-8 charset & enhance CI configs (#2095)
  • move validate release to hugegraph-doc (#2109)
  • refact: use a slim way to build docker image on latest code & support zgc (#2118)
  • chore: remove stage-repo in pom due to release done & update mail rule (#2128)
  • doc: update issue template & README file (#2131)
  • chore: cmn algorithm optimization (#2134)
  • add github token for license check comment (#2139)
  • chore: disable PR up-to-date in branch (#2150)
  • refact(core): remove lock of globalMasterInfo to optimize perf (#2151)
  • chore: async remove left index shouldn’t effect query (#2199)
  • refact(rocksdb): clean & reformat some code (#2200)
  • refact(core): optimized batch removal of remaining indices consumed by a single consumer (#2203)
  • add com.janeluo.ikkanalyzer dependency to core model (#2206)
  • refact(core): early stop unnecessary loops in edge cache (#2211)
  • doc: update README & add QR code (#2218)
  • chore: update .asf.yaml for mail rule (#2221)
  • chore: improve the UI & content in README (#2227)
  • chore: add pr template (#2234)
  • doc: modify ASF and remove meaningless CLA (#2237)
  • chore(dist): replace wget to curl to download swagger-ui (#2277)
  • Update StandardStateMachineCallback.java (#2290)
  • doc: update README about start server with example graph (#2315)
  • README.md tiny improve (#2320)
  • doc: README.md tiny improve (#2331)
  • refact: adjust project structure for merge PD & Store[Breaking Change] (#2338)
  • chore: disable raft test in normal PR due to timeout problem (#2349)
  • chore(ci): add stage profile settings (#2361)
  • refact(api): update common 1.2 & fix jersey client code problem (#2365)
  • chore: move server info into GlobalMasterInfo (#2370)
  • chore: reset hugegraph version to 1.2.0 (#2382)

hugegraph-computer

Feature Changes

  • feat: implement fast-failover for MessageRecvManager and DataClientManager (#243)
  • feat: implement parallel send data in load graph step (#248)
  • feat(k8s): init operator project & add webhook (#259, #263)
  • feat(core): support load vertex/edge snapshot (#269)
  • feat(k8s): Add MinIO as internal(default) storage (#272)
  • feat(algorithm): support random walk in computer (#274, #280)
  • feat: use ‘foreground’ delete policy to cancel k8s job (#290)

Bug Fix

  • fix: superstep not take effect (#237)
  • fix(k8s): modify inconsistent apiGroups (#270)
  • fix(algorithm): record loop is not copied (#276)
  • refact(core): adaptor for common 1.2 & fix a string of possible CI problem (#286)
  • fix: remove okhttp1 due to conflicts risk (#294)
  • fix(core): io.grpc.grpc-core dependency conflic (#296)

Option Changes

  • feat(core): isolate namespace for different input data source (#252)
  • refact(core): support auth config for computer task (#265)

Other Changes

  • remove apache stage repo & update notification rule (#232)
  • chore: fix empty license file (#233)
  • chore: enhance mailbox settings & enable require ci (#235)
  • fix: typo errors in start-computer.sh (#238)
  • [Feature-241] Add PULL_REQUEST_TEMPLATE (#242, #257)
  • chore: change etcd url only for ci (#245)
  • doc: update readme & add QR code (#249)
  • doc(k8s): add building note for missing classes (#254)
  • chore: reduce mail to dev list (#255)
  • add: dependency-review (#266)
  • chore: correct incorrect comment (#268)
  • refactor(api): ListValue.getFirst() replaces ListValue.get(0) (#282)
  • Improve: Passing workerId to WorkerStat & Skip wait worker close if master executes failed (#292)
  • chore: add check dependencies (#293)
  • chore(license): update license for 1.2.0 (#299)

hugegraph-toolchain

API Changes

  • feat(client): support edgeExistence api (#544)
  • refact(client): update tests for new OLTP traverser APIs (#550)

Feature Changes

  • feat(spark): support spark-sink connector for loader (#497)
  • feat(loader): support kafka as datasource (#506)
  • feat(client): support go client for hugegraph (#514)
  • feat(loader): support docker for loader (#530)
  • feat: update common version and remove jersey code (#538)

Bug Fix

  • fix: convert numbers to strings (#465)
  • fix: hugegraph-spark-loader shell string length limit (#469)
  • fix: spark loader meet Exception: Class is not registered (#470)
  • fix: spark loader Task not serializable (#471)
  • fix: spark with loader has dependency conflicts (#480)
  • fix: spark-loader example schema and struct mismatch (#504)
  • fix(loader): error log (#499)
  • fix: checkstyle && add suppressions.xml (#500)
  • fix(loader): resolve error in loader script (#510)
  • fix: base-ref/head-ref missed in dependency-check-ci on branch push (#516, #551)
  • fix yarn network connection on linux/arm64 arch (#519)
  • fix(hubble): drop-down box could not display all options (#535)
  • fix(hubble): build with node and yarn (#543)
  • fix(loader): loader options (#548)
  • fix(hubble): parent override children dep version (#549)
  • fix: exclude okhttp1 which has different groupID with okhttp3 (#555)
  • fix: github action build docker image failed (#556, #557)
  • fix: build error with npm not exist & tiny improve (#558)

Option Changes

  • set default data when create graph (#447)

Other Changes

  • chore: remove apache stage repo & update mail rule (#433, #474, #479)
  • refact: clean extra store file in all modules (#434)
  • chore: use fixed node.js version 16 to avoid ci problem (#437, #441)
  • chore(hubble): use latest code in Dockerfile (#440)
  • chore: remove maven plugin for docker build (#443)
  • chore: improve spark parallel (#450)
  • doc: fix build status badge link (#455)
  • chore: keep hadoop-hdfs-client and hadoop-common version consistent (#457)
  • doc: add basic contact info & QR code in README (#462, #475)
  • chore: disable PR up-to-date in branch (#473)
  • chore: auto add pr auto label by path (#466, #528)
  • chore: unify the dependencies versions of the entire project (#478)
  • chore(deps): bump async, semver, word-wrap, browserify-sign in hubble-fe (#484, #491, #494, #529)
  • chore: add pr template (#498)
  • doc(hubble): add docker-compose to start with server (#522)
  • chore(ci): add stage profile settings (#536)
  • chore(client): increase the api num as the latest server commit + 10 (#546)
  • chore(spark): install hugegraph from source (#552)
  • doc: adjust docker related desc in readme (#559)
  • chore(license): update license for 1.2 (#560, #561)

hugegraph-commons

Feature Changes

  • feat(common): replace jersey dependencies with OkHttp (Breaking Change) (#133)

Bug Fix

  • fix(common): handle spring-boot2/jersey dependency conflicts (#131)
  • fix: Assert.assertThrows() should check result of exceptionConsumer (#135)
  • fix(common): json param convert (#137)

Other Changes

  • refact(common): add more construction methods for convenient (#132)
  • add: dependency-review (#134)
  • refact(common): rename jsonutil to avoid conflicts with server (#136)
  • doc: update README for release (#138)
  • update licence (#139)

Release Details

Please check the release details in each repository:

10.3 - HugeGraph 1.3.0 Release Notes

Operating Environment / Version Description

  1. consider using Java 11 in hugegraph/toolchain/commons, also compatible with Java 8 now.
  2. hugegraph-computer required to use Java 11, not compatible with Java 8!
  3. Using Java8 may loss some security ensured, we recommend using Java 11 in production env with AuthSystem enabled.

1.3.0 is the last major version compatible with Java 8, compatibility with Java 8 will end in next release(1.5.0) when PD/Store merged into master branch (Except for the java-client).

PS: In the future, we will gradually upgrade the java version from Java 11 -> Java 17 -> Java 21.

hugegraph

In this version, we have fixed some SEC-related issues. If used in an online service or exposed to the public, please upgrade to the latest version and enable authorization authentication

API Changes

  • feat(api): optimize adjacent-edges query (#2408)

Feature Changes

  • feat: support docker use the auth when starting (#2403)
  • feat: added the OpenTelemetry trace support (#2477)

Bug Fix

  • fix(core): task restore interrupt problem on restart server (#2401)
  • fix(server): reinitialize the progress to set up graph auth friendly (#2411)
  • fix(chore): remove zgc in dockerfile for ARM env (#2421)
  • fix(server): make CacheManager constructor private to satisfy the singleton pattern (#2432)
  • fix(server): unify the license headers (#2438)
  • fix: format and clean code in dist and example modules (#2441)
  • fix: format and clean code in core module (#2440)
  • fix: format and clean code in modules (#2439)
  • fix(server): clean up the code (#2456)
  • fix(server): remove extra blank lines (#2459)
  • fix(server): add tip for gremlin api NPE with an empty query (#2467)
  • fix(server): fix the metric name when promthus collects hugegraph metric, see issue (#2462)
  • fix(server): serverStarted error when execute gremlin example (#2473)
  • fix(auth): enhance the URL check (#2422)

Option Changes

  • refact(server): enhance the storage path in RocksDB & clean code (#2491)

Other Changes

  • chore: add a license link (#2398)
  • doc: enhance NOTICE info to keep it clear (#2409)
  • chore(server): update swagger info for default server profile (#2423)
  • fix(server): unify license header for protobuf file (#2448)
  • chore: improve license header checker confs and pre-check header when validating (#2445)
  • chore: unify to call SchemaLabel.getLabelId() (#2458)
  • chore: refine the hg-style.xml specification (#2457)
  • chore: Add a newline formatting configuration and a comment for warning (#2464)
  • chore(server): clear context after req done (#2470)

hugegraph-toolchain

API Changes

Feature Changes

  • fix(loader): update shade plugin for spark loader (#566)
  • fix(hubble): yarn install timeout in arm64 (#583)
  • fix(loader): support file name with prefix for hdfs source (#571)
  • feat(hubble): warp the exception info in HugeClientUtil (#589)

Bug Fix

  • fix: concurrency issue causing file overwrite due to identical filenames (#572)

Option Changes

  • feat(client): support user defined OKHTTPClient configs (#590)

Other Changes

  • doc: update copyright date(year) in NOTICE (#567)
  • chore(deps): bump ip from 1.1.5 to 1.1.9 in /hugegraph-hubble/hubble-fe (#580)
  • refactor(hubble): enhance maven front plugin (#568)
  • chore(deps): bump es5-ext from 0.10.53 to 0.10.63 in /hugegraph-hubble/hubble-fe (#582)
  • chore(hubble): Enhance code style in hubble (#592)
  • chore: upgrade version to 1.3.0 (#596)
  • chore(ci): update profile commit id for 1.3 (#597)

hugegraph-commons

Feature Changes

  • feat: support user defined RestClientConfig/HTTPClient params (#140)

Bug Fix

Other Changes

  • chore: disable clean flatten for deploy (#141)

hugegraph-ai

This is the first release version of hugegraph-ai, it contains a variety of features, including an initialized Python client, knowledge graph construction capabilities through LLM, and the integration of RAG based on HugeGraph.

It also adds significant functionalities on python-client such as variable APIs, auth, metric, traverser, and task APIs, as well as interactive and visual demo creation with Gradio. In addition to these features, the release addresses several bugs and issues, ensuring a more stable and error-free user experience. Maintenance tasks such as dependency updates, project structure improvements, and the addition of basic CI further enhance the project’s robustness and developer workflow.

This release encapsulates the collaborative efforts of the HugeGraph community, with contributions from various members, ensuring the project’s continuous growth and improvement.

Feature Changes

  • feat: initialize hugegraph python client (#5)
  • feat(llm): knowledge graph construction by llm (#7)
  • feat: initialize rag based on HugeGraph (#20)
  • feat(client): add variables api and test (#24)
  • feat: add llm wenxinyiyan & config util & spo_triple_extract (#27)
  • feat: add auth&metric&traverser&task api and ut (#28)
  • feat: refactor construct knowledge graph task (#29)
  • feat: Introduce gradio for creating interactive and visual demo (#30)

Bug Fix

  • fix: invalid GitHub label (#3)
  • fix: import error (#13)
  • fix: function getEdgeByPage(): the generated query url does not include the parameter page (#15)
  • fix: issue template (#23)
  • fix: base-ref/head-ref missed in dependency-check-ci on branch push (#25)

Other Changes

  • chore: add asf.yaml and ISSUE_TEMPLATE (#1)
  • Bump urllib3 from 2.0.3 to 2.0.7 in /hugegraph-python (#8)
  • chore: create .gitignore file for py (#9)
  • refact: improve project structure & add some basic CI (#17)
  • chore: Update LICENSE and NOTICE (#31)
  • chore: add release scripts (#33)
  • chore: change file chmod 755 (#34)

Release Details

Please check the release details/contributor in each repository:

10.4 - HugeGraph 1.5.0 Release Notes

WIP: This doc is under construction, please wait for the final version (BETA)

Operating Environment / Version Description

  1. From hugegraph version 1.5.0 and later, related components only support Java11.

PS: In the future, HugeGraph components will evolve through versions of Java 11 -> Java 17 -> Java 21.

hugegraph

This version introduces many new features and optimizations, particularly support for the new distributed backend HStore(Raft + RocksDB).

API Changes

  • BREAKING CHANGE: Support “parent & child” EdgeLabel type #2662

Feature Changes

  • Integrate pd-grpc, pd-common, and pd-client #2498
  • Integrate store-grpc, store-common, and store-client #2476
  • Integrate store-rocksdb submodule #2513
  • Integrate pd-core into HugeGraph #2478
  • Integrate pd-service into HugeGraph #2528
  • Integrate pd-dist into HugeGraph and add core tests, client tests, and REST tests for PD #2532
  • Integrate server-hstore into HugeGraph #2534
  • Integrate store-core submodule #2548
  • Integrate store-node submodule #2537
  • Support new backend Hstore #2560
  • Support Docker deployment for PD and Store #2573
  • Add a tool method encode #2647
  • Add basic MiniCluster module for distributed system testing #2615
  • Support disabling RocksDB auto-compaction via configuration #2586

Bug Fixes

  • Switch RocksDB backend to memory when executing Gremlin examples #2518
  • Avoid overriding backend config in Gremlin example scripts #2519
  • Update resource references #2522
  • Randomly generate default values #2568
  • Update build artifact path for Docker deployment #2590
  • Ensure thread safety for range attributes in PD #2641
  • Correct server Docker copy source path #2637
  • Fix JRaft Timer Metrics bug in Hstore #2602
  • Enable JRaft MaxBodySize configuration #2633

Option Changes

  • Mark old raft configs as deprecated #2661
  • Enlarge bytes write limit and remove big parameter when encoding/decoding string ID length #2622

Other Changes

  • Add Swagger-UI LICENSE files #2495
  • Translate CJK comments and punctuations to English across multiple modules #2536, #2623, #2645
  • Introduce install-dist module in root #2552
  • Enable up-to-date checks for UI (CI) #2609
  • Minor improvements for POM properties #2574
  • Migrate HugeGraph Commons #2628
  • Tar source and binary packages for HugeGraph with PD-Store #2594
  • Refactor: Enhance cache invalidation of the partition → leader shard in ClientCache #2588
  • Refactor: Remove redundant properties in LogMeta and PartitionMeta #2598

hugegraph-toolchain

API Changes

  • Support “parent & child” EdgeLabel type #624

Feature Changes

  • Support English interface & add a script/doc for it in Hubble #631

Bug Fixes

  • Serialize source and target label for non-father EdgeLabel #628
  • Encode/decode Chinese error after building Hubble package #627
  • Configure IPv4 to fix timeout of yarn install in Hubble #636
  • Remove debugging output to speed up the frontend construction in Hubble #638

Other Changes

  • Bump express from 4.18.2 to 4.19.2 in Hubble Frontend #598
  • Make IDEA support IssueNavigationLink #600
  • Update yarn.lock for Hubble #605
  • Introduce editorconfig-maven-plugin for verifying code style defined in .editorconfig #614
  • Upgrade distribution version to 1.5.0 #639

Documentation Changes

  • Clarify the contributing guidelines #604
  • Enhance the README file for Hubble #613
  • Update README style referring to the server’s style #615

hugegraph-ai

API Changes

  • Added local LLM API and version API. #41, #44
  • Implemented new API and optimized code structure. #63
  • Support for graphspace and refactored all APIs. #67

Feature Changes

  • Added openai’s apibase configuration and asynchronous methods in RAG web demo. #41, #58
  • Support for multi reranker and enhanced UI. #73
  • Node embedding, node classify, and graph classify with models based on DGL. #83
  • Graph learning algorithm implementation (10+). #102
  • Support for any openai-style API (standard). #95

Bug Fixes

  • Fixed fusiform_similarity test in traverser for server 1.3.0. #37
  • Avoid generating config twice and corrected e_cache type. #56, #117
  • Fixed null value detection on vid attributes. #115
  • Handled profile regenerate error. #98

Option Changes

  • Added auth for fastapi and gradio. #70
  • Support for multiple property types and importing graph from the entire doc. #84

Other Changes

  • Reformatted documentation and updated README. #36, #81
  • Introduced a black for code format in GitHub actions. #47
  • Updated dependencies and environment preparations. #45, #65
  • Enhanced user-friendly README. #82

hugegraph-computer

Feature Changes

  • Support Single Source Shortest Path Algorithm #285
  • Support Output Filter #303

Bug Fixes

  • Fix: base-ref/head-ref Missed in Dependency-Review on Schedule Push #304

Option Changes

  • Refactor(core): StringEncoding #300

Other Changes

  • Improve(algorithm): Random Walk Vertex Inactive #301
  • Upgrade Version to 1.3.0 #305
  • Doc(readme): Clarify the Contributing Guidelines #306
  • Doc(readme): Add Hyperlink to Apache 2.0 #308
  • Migrate Project to Computer Directory #310
  • Update for Release 1.5 #317
  • Fix Path When Exporting Source Package #319

Release Details

Please check the release details/contributor in each repository:

10.5 - HugeGraph 1.7.0 Release Notes

WIP: This doc is under construction, please wait for the final version (BETA)

Operating Environment / Version Description

For 1.7.0 version hugegraph, related components only support Java11.

hugegraph

API Changes

  • BREAKING CHANGE: Disable legacy backends include MySQL/PG/c*(.etc) #2746
  • BREAKING CHANGE: Release version 1.7.0 [server + pd + store] #2889

Feature Changes

  • Support MemoryManagement for graph query framework #2649
  • LoginAPI support token_expire field #2754
  • Add option for task role election #2843
  • Optimize perf by avoid boxing long #2861
  • StringId hold bytes to avoid decode/encode #2862
  • Add PerfExample5 and PerfExample6 #2860
  • RocksDBStore remove redundant checkOpened() call #2863
  • Add path filter #2898
  • Init serena memory system & add memories #2902

Bug Fixes

  • Filter dynamice path(PUT/GET/DELETE) with params cause OOM #2569
  • JRaft Histogram Metrics Value NaN #2631
  • Update server image desc #2702
  • Kneigbor-api has unmatched edge type with server #2699
  • Add license for swagger-ui & reset use stage to false in ci yml #2706
  • Fix build pd-store arm image #2744
  • Fix graph server cache notifier mechanism #2729
  • Tx leak when stopping the graph server #2791
  • Ensure backend is initialized in gremlin script #2824
  • Fix some potential lock & type cast issues #2895
  • Fix npe in getVersion #2897
  • Fix the support for graphsapi in rocksdb and add testing for graphsapi #2900
  • Remove graph path in auth api path #2899
  • Migrate to LTS jdk11 in all Dockerfile #2901
  • Remove the judgment for java8 compatibility in the init-store #2905
  • Add missing license and remove binary license.txt & fix tinkerpop ci & remove duplicate module #2910

Option Changes

  • Remove some outdated configuration #2678

Other Changes

  • Update outdated docs for release 1.5.0 #2690
  • Fix licenses and remove empty files #2692
  • Update repo artifacts references #2695
  • Adjust release fury version #2698
  • Fix the JSON license issue #2697
  • Add debug info for tp test #2688
  • Enhance words in README #2734
  • Add collaborators in asf config #2741
  • Adjust the related filters of sofa-bolt #2735
  • Reopen discussion in .asf.yml config #2751
  • Fix typo in README #2806
  • Centralize version management in project #2797
  • Update notice year #2826
  • Improve maven Reproducible Builds → upgrade plugins #2874
  • Enhance docker instruction with auth opened graph #2881
  • Remove the package existing in java8 #2792
  • Revise Docker usage instructions in README #2882
  • Add DeepWiki badge to README #2883
  • Update guidance for store module #2894
  • Update test commands and improve documentation clarity #2893
  • Bump rocksdb version from 7.2.2 to 8.10.2 #2896

hugegraph-toolchain

API Changes

  • Support graphspace #633

Feature Changes

  • Support jdbc date type & sync .editorconfig #648
  • Add a useSSL option for mysql #650
  • Patch for father sub edge #654
  • Improve user experience for user script #666
  • Support concurrent readers, short-id & Graphsrc #683
  • Init serena onboarding & project memory files #692

Bug Fixes

  • Typo word in display #655
  • Patch up missing classes and methods for hubble #657
  • Adjust Client to 1.7.0 server #689
  • Remove json license for release 1.7.0 #698

Other Changes

  • Update hugegraph source commit id #640
  • Add collaborators in asf config #656
  • Update pom for version-1.7.0 #681
  • Add DeepWiki badge to README #684
  • Adjust APIs to compatible with 1.7.0 server #685
  • Adjust LoadContext to 1.7.0 version #687
  • Migrate to LTS jdk11 in all Dockerfile #691
  • Update copyright year in NOTICE file #697

hugegraph-computer

Feature Changes

  • Migration Vermeer to hugegraph-computer #316
  • Make startChan’s size configurable #328
  • Assign WorkerGroup via worker configuration #332
  • Support task priority based scheduling #336
  • Avoid 800k #340

Bug Fixes

  • Fix docker file build #341

Other Changes

  • Update release version to 1.5.0 #318
  • Update go depends module & fix headers #321
  • Update go version to 1.23 #322
  • Add collaborator in .asf.yaml #323
  • Update the Go version in docker image #333
  • Add DeepWiki badge to README #337
  • Bump project version to 1.7.0 (RELEASE) #338
  • Update copyright year in NOTICE file #342

hugegraph-ai

API Changes

  • Support choose template in api #135
  • Add post method for paths-api #162
  • Support switch graph in api & add some query configs #184
  • Text2gremlin api #258
  • Support switching prompt EN/CN #269
  • BREAKING CHANGE: Update keyword extraction method #282

Feature Changes

  • Added the process of text2gql in graphrag V1.0 #105
  • Use pydantic-settings for config management #122
  • Timely execute vid embedding & enhance some HTTP logic #141
  • Use retry from tenacity #143
  • Modify the summary info and enhance the request logic #147
  • Automatic backup graph data timely #151
  • Add a button to backup data & count together #153
  • Extract topk_per_keyword & topk_return_results to .env #154
  • Modify clear buttons #156
  • Support intent recognition V1 #159
  • Change vid embedding x:yy to yy & use multi-thread #158
  • Support mathjax in rag query block V1 #157
  • Use poetry to manage the dependencies #149
  • Return schema.groovy first when backup graph data #161
  • Merge all logs into one file #171
  • Use uv for the CI action #175
  • Use EN prompt for keywords extraction #174
  • Support litellm LLM provider #178
  • Improve graph extraction default prompt #187
  • Replace vid by full vertexes info #189
  • Support asynchronous streaming generation in rag block by using async_generator and asyncio.wait #190
  • Generalize the regex extraction func #194
  • Create quick_start.md #196
  • Support Docker & K8s deployment way #195
  • Multi-stage building in Dockerfile #199
  • Support graph checking before updating vid embedding #205
  • Disable text2gql by default #216
  • Use 4.1-mini and 0.01 temperature by default #214
  • Enhance the multi configs for LLM #212
  • Textbox to Code #217
  • Replace the IP + Port with URL #209
  • Update gradio’s version #235
  • Use asyncio to get embeddings #215
  • Change QPS -> RPM for timer decorator #241
  • Support batch embedding #238
  • Using nuitka to provide a binary/perf way for the service #242
  • Use uv instead poetry #226
  • Basic compatible in text2gremlin generation #261
  • Enhance config path handling and add project root validation #262
  • Add vermeer python client for graph computing #263
  • Use uv in client & ml modules & adapter the CI #257
  • Use uv to manage pkgs & update README #272
  • Limit the deps version to handle critical init problems #279
  • Support semi-automated prompt generation #281
  • Support semi-automated generated graph schema #274
  • Unify all modules with uv #287
  • Add GitHub Actions for auto upstream sync and update SEALData subsample logic #289
  • Add a basic LLM/AI coding instruction file #290
  • Add rules for AI coding guideline - V1.0 #293
  • Replace QianFan by OpenAI-compatible format #285
  • Optimize vector index with asyncio embedding #264
  • Refactor embedding parallelization to preserve order #295
  • Support storing vector data for a graph instance by model type/name #265
  • Add AGENTS.md as new document standard #299
  • Add Fixed Workflow Execution Engine: Flow, Node, and Scheduler Architecture #302
  • Support vector db layer V1.0 #304

Bug Fixes

  • Limit the length of log & improve the format #121
  • Pylint in ml #125
  • Critical bug with pylint usage #131
  • Multi vid k-neighbor query only return the data of first vid #132
  • Replace getenv usage to settings #133
  • Correct header writing errors #140
  • Update prompt to fit prefix cache #137
  • Extract_graph_data use wrong method #145
  • Use empty str for llm config #155
  • Update gremlin generate prompt to apply fuzzy match #163
  • Enable fastapi auto reload function #164
  • Fix tiny bugs & optimize reranker layout #202
  • Enable tasks concurrency configs in Gradio #188
  • Align regex extraction of json to json format of prompt #211
  • Fix documentation sample code error #219
  • Failed to remove vectors when updating vid embedding #243
  • Skip empty chunk in LLM steaming mode #245
  • Ollama batch embedding bug #250
  • Fix Dockerfile to add pyproject.toml anchor file #266
  • Add missing ‘properties’ in gremlin prompt formatting #298
  • Fixed cgraph version #305
  • Ollama embedding API usage and config param #306

Option Changes

  • Remove enable_gql logic in api & rag block #148

Other Changes

  • Update README for python-client/SDK #150
  • Enable pip cache #142
  • Enable discussion & change merge way #201
  • Synchronization with official documentation #273
  • Fix grammar errors #275
  • Improve README clarity and deployment instructions #276
  • Add docker-compose deployment and improve container networking instructions #280
  • Update docker compose command #283
  • Reduce third-party library log output #244
  • Update README with improved setup instructions #294
  • Add collaborators in asf config #182

Release Details

Please check the release details/contributor in each repository:

11 - Apache Contributor Agreements

Apache Contributor Agreements

HugeGraph uses the standard Apache Software Foundation (ASF) contributor agreements. It no longer uses a project-specific CLA or the GitHub CLA Assistant workflow.

Routine, small contributions are submitted under Section 5 of the Apache License 2.0. Before becoming a committer, or when making a substantial contribution, you must sign the ASF Individual Contributor License Agreement (ICLA). If a company owns the intellectual property in your contribution, a Corporate Contributor License Agreement (CCLA) may also be required; a CCLA does not replace your individual ICLA.

Refer to the official ASF pages for the agreement text, completion instructions, and submission process:

After reading and signing the agreement as instructed, send the completed file as a standalone attachment to secretary@apache.org. Do not send it to the HugeGraph developer mailing list or commit it to a GitHub repository.