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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:

# Replace {version} with the latest version number, e.g., 1.5.0
wget https://downloads.apache.org/incubator/hugegraph/{version}/apache-hugegraph-incubating-{version}.tar.gz  
tar zxf apache-hugegraph-incubating-{version}.tar.gz
cd apache-hugegraph-incubating-{version}/apache-hugegraph-pd-incubating-{version}

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 successful compilation, the PD module build artifacts will be located at
#    apache-hugegraph-incubating-{version}/apache-hugegraph-pd-incubating-{version}
#    target/apache-hugegraph-incubating-{version}.tar.gz

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
  # Initial store list, stores in the list are automatically activated
  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

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

2024-xx-xx 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.

Additionally, you can verify the status of the Store node by querying the PD API:

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

If the Store is configured successfully, the response of the above interface should contain the status information of the current node. The status “Up” indicates that the node is running normally. Only the response of one node configuration is shown here. If all three nodes are configured successfully and are running, the storeId list in the response should contain three IDs, and the Up, numOfService, and numOfNormalService fields in stateCountMap should 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
}