Server Complete Configuration Manual
Gremlin Server Config Options
Corresponding configuration file gremlin-server.yaml
| config option | default value | description |
|---|---|---|
| host | 127.0.0.1 | The host or ip of Gremlin Server. |
| port | 8182 | The listening port of Gremlin Server. |
| graphs | {} | Graphs are loaded dynamically by the Server; do not configure them here. |
| evaluationTimeout | 30000 | Gremlin script evaluation timeout in milliseconds. |
| channelizer | org.apache.tinkerpop.gremlin.server.channel.WsAndHttpChannelizer | Handles both WebSocket and HTTP requests. |
| maxContentLength | 65536 | Maximum size in bytes of a request that the server accepts. |
| maxChunkSize | 8192 | Maximum chunk size in bytes of an HTTP request. |
| maxHeaderSize | 8192 | Maximum size in bytes of the HTTP request headers. |
| resultIterationBatchSize | 64 | Number of results returned per batch when streaming a result set. |
| ssl.enabled | false | Whether Gremlin Server serves over TLS. |
| authentication | Not configured | When enabling authentication, configure the authenticator, handler, and path to rest-server.properties. |
Rest Server & API Config Options
Corresponding configuration file rest-server.properties
| config option | default value | description |
|---|---|---|
| graphs | ./conf/graphs | Directory containing graph configuration properties files. |
| graph.load_from_local_config | false | Whether to read the graphs directory when the Server starts; set to true when using local graph configuration. |
| graphs.enable_dynamic_create_drop | true | Whether to enable create or drop graph dynamically. |
| init_store.enabled | true | Whether init-store initializes the local backend stores and the built-in admin account. Set false in distributed deployments (PD/HStore) where the storage side already owns the metadata. |
| server.id | Empty string | The optional legacy id of hugegraph-server. |
| server.role | master | The role of nodes in the cluster, available types are [master, worker, computer] |
| server.role_election | false | Whether to enable role election, if enabled, the server will elect a master node in the cluster. |
| server.node_id | node-id1 | The node id of the server. |
| server.node_role | worker | The node role of the server. |
| server.graphspace | DEFAULT | The graph space of the server. |
| server.service_id | DEFAULT | The service id of the server. |
| server.path_graphspace | DEFAULT | The default path graph space of the server. |
| server.start_ignore_single_graph_error | true | Whether to start ignore single graph error. |
| server.event_hub_threads | 1 | The event hub threads of server. |
| restserver.url | http://127.0.0.1:8080 | The url for listening of graph server. |
| ssl.keystore_file | conf/hugegraph-server.keystore | The path of server keystore file used when https protocol is enabled. |
| ssl.keystore_password | hugegraph | The password of the server keystore file when the https protocol is enabled. |
| white_ip.status | disable | The status of whether enable white ip. |
| restserver.max_worker_threads | 2 * CPUs | The maximum worker threads of rest server. |
| restserver.task_threads | max(4, CPUs / 2) | The task threads of rest server. |
| restserver.min_free_memory | 64 | The minimum free memory(MB) of rest server, requests will be rejected when the available memory of system is lower than this value. |
| restserver.request_timeout | 30 | The time in seconds within which a request must complete, -1 means no timeout. |
| restserver.connection_idle_timeout | 30 | The time in seconds to keep an inactive connection alive, -1 means no timeout. |
| restserver.connection_max_requests | 256 | The max number of HTTP requests allowed to be processed on one keep-alive connection, -1 means unlimited. |
| gremlinserver.url | http://127.0.0.1:8182 | The url of gremlin server. |
| gremlinserver.max_route | 2 * CPUs | The max route number for gremlin server. |
| gremlinserver.timeout | 30 | The timeout in seconds of waiting for gremlin server. |
| batch.max_edges_per_batch | 2500 | The maximum number of edges submitted per batch. |
| batch.max_vertices_per_batch | 2500 | The maximum number of vertices submitted per batch. |
| batch.max_write_ratio | 70 | The maximum thread ratio for batch writing, only take effect if the batch.max_write_threads is 0. |
| batch.max_write_threads | 0 | The 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. |
| raft.group_peers | 127.0.0.1:8090 | The rpc address of raft group initial peers. |
| auth.authenticator | The class path of authenticator implementation. e.g., org.apache.hugegraph.auth.StandardAuthenticator, or a custom implementation. | |
| auth.graph_store | hugegraph | The name of graph used to store authentication information, like users, only for org.apache.hugegraph.auth.StandardAuthenticator. |
| auth.admin_pa | pa | The default password for built-in admin account, takes effect on first startup. It must be changed before deployment. |
| auth.audit_log_rate | 1000.0 | The max rate of audit log output per user, default value is 1000 records per second. |
| auth.cache_capacity | 10240 | The max cache capacity of each auth cache item. |
| auth.cache_expire | 600 | The expiration time in seconds of auth cache in auth client and auth server. |
| auth.remote_url | If 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_expire | 86400 | The expiration time in seconds after token created |
| auth.token_secret | Randomly generated at startup | HS256 secret; configure it explicitly if existing tokens must remain valid across restarts. |
| exception.allow_trace | true | Whether to allow exception trace stack. |
| memory_monitor.threshold | 0.85 | Threshold for JVM memory usage monitoring, 1 means disabling the memory monitoring task. |
| memory_monitor.period | 2000 | The period in ms of JVM memory usage monitoring, in each period we will detect the jvm memory usage and take corresponding actions. |
| log.slow_query_threshold | 1000 | The threshold time(ms) of logging slow query, 0 means logging slow query is disabled. |
| log.slow_query_body_limit | 512 | The max bytes of request body recorded in the slow query log, 0 means the body is not recorded. The recorded prefix is written as-is and may contain sensitive Gremlin or Cypher literals. |
Role Election Config Options (Optional)
Corresponding configuration file rest-server.properties, only used when server.role_election=true.
| config option | default value | description |
|---|---|---|
| server.role.node_external_url | http://127.0.0.1:8080 | The url of external accessibility. |
| server.role.base_timeout | 500 | The role state machine candidate state base timeout time, in ms. |
| server.role.random_timeout | 1000 | The random timeout in ms that be used when candidate node request to become master state to reduce competitive voting. |
| server.role.heartbeat_interval | 2 | The role state machine heartbeat interval second time. |
| server.role.fail_count | 5 | When the node failed count of update or query heartbeat is reaches this threshold, the node will become abdication state to guardsafe property. |
| server.role.master_dead_times | 10 | When the worker node detects that the number of times the master node fails to update heartbeat reaches this threshold, the worker node will become to a candidate node. |
PD/Meta Config Options (Distributed Mode)
Corresponding configuration file rest-server.properties
| config option | default value | description |
|---|---|---|
| usePD | false | Whether use pd. |
| pd.peers | 127.0.0.1:8686 | The pd server peers, separated with commas. |
| cluster | hg-test | The cluster name. |
| metrics.data_to_pd | true | Whether to report metrics data to pd. |
| meta.endpoints | http://127.0.0.1:2379 | The URL of meta endpoints. No code reads this option, so setting it has no effect; the meta connection is built from pd.peers. |
| meta.use_ca | false | Whether to use ca to meta server. |
| meta.ca | The ca file of meta server. | |
| meta.client_ca | The client ca file of meta server. | |
| meta.client_key | The client key file of meta server. |
The HStore backend also reads two options from the graph configuration file {graph-name}.properties. Both default to
0, which means the value is decided by PD:
| config option | default value | description |
|---|---|---|
| hstore.partition_count | 0 | Number of partitions, which PD controls partitions based on. |
| hstore.shard_count | 0 | Number of copies, which PD controls partition copies based on. |
Basic Config Options
Basic Config Options and Backend Config Options correspond to configuration files:{graph-name}.properties, such as hugegraph.properties
| config option | default value | description |
|---|---|---|
| gremlin.graph | org.apache.hugegraph.HugeFactory | Gremlin entrance to create graph. |
| backend | memory | The data store type. For version 1.7.0+ the allowed values are [memory, rocksdb, hstore, hbase]; the shipped conf/graphs/hugegraph.properties sets rocksdb and conf/graphs/hstore.properties.template sets hstore. Note: cassandra, scylladb, mysql, postgresql were removed in 1.7.0 (use <= 1.5.x for legacy backends). |
| serializer | text | The serializer for backend store, built-in values are [text, binary, binaryscatter]; a backend may register its own, like hbase. The shipped graph templates set binary. |
| serializer.buffer_max_capacity | 134217728 | The process-wide max capacity of one serialization buffer in bytes. |
| store | hugegraph | The backend database namespace. |
| store.connection_detect_interval | 600 | The 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.graph | g | The graph table name, which store vertex, edge and property. |
| graphspace | DEFAULT | The graph space name. |
| alias.graph.id | The graph alias id. | |
| graph.read_mode | OLTP_ONLY | The graph read mode, which could be ALL | OLTP_ONLY | OLAP_ONLY. |
| pd.peers | 127.0.0.1:8686 | The addresses of pd nodes, separated with commas. Only used by the hstore backend. |
| schema.illegal_name_regex | .\s+$|~. | The regex specified the illegal format for schema name. |
| schema.cache_capacity | 10000 | The max cache size(items) of schema cache. |
| schema.init_template | The template schema used to init graph. | |
| schema.index_rebuild_using_pushdown | true | Whether to use pushdown when to create/rebuild index. |
| vertex.cache_type | l2 | The type of vertex cache, allowed values are [l1, l2]. |
| vertex.cache_capacity | 10000000 | The max cache size(items) of vertex cache. |
| vertex.cache_expire | 600 | The expiration time in seconds of vertex cache. |
| vertex.check_customized_id_exist | false | Whether to check the vertices exist for those using customized id strategy. |
| vertex.default_label | vertex | The default vertex label. |
| vertex.tx_capacity | 10000 | The max size(items) of vertices(uncommitted) in transaction. |
| vertex.check_adjacent_vertex_exist | false | Whether to check the adjacent vertices of edges exist. |
| vertex.lazy_load_adjacent_vertex | true | Whether to lazy load adjacent vertices of edges. |
| vertex.part_edge_commit_size | 5000 | Whether to enable the mode to commit part of edges of vertex, enabled if commit size > 0, 0 means disabled. |
| vertex.encode_primary_key_number | true | Whether to encode number value of primary key in vertex id. |
| vertex.remove_left_index_at_overwrite | false | Whether remove left index at overwrite. |
| edge.cache_type | l2 | The type of edge cache, allowed values are [l1, l2]. |
| edge.cache_capacity | 1000000 | The max cache size(items) of edge cache. |
| edge.cache_expire | 600 | The expiration time in seconds of edge cache. |
| edge.tx_capacity | 10000 | The max size(items) of edges(uncommitted) in transaction. |
| query.page_size | 500 | The size of each page when querying by paging. |
| query.batch_size | 1000 | The size of each batch when querying by batch. |
| query.ignore_invalid_data | true | Whether to ignore invalid data of vertex or edge. |
| query.index_intersect_threshold | 1000 | The maximum number of intermediate results to intersect indexes when querying by multiple single index properties. |
| query.max_indexes_available | 1 | The upper limit of the number of indexes that can be used to query. |
| query.dedup_option | limit | The way to dedup data, allowed values are [limit, global]. |
| query.trust_index | false | Whether to trust index. |
| query.ramtable_edges_capacity | 20000000 | The maximum number of edges in ramtable, include OUT and IN edges. |
| query.ramtable_enable | false | Whether to enable ramtable for query of adjacent edges. |
| query.ramtable_vertices_capacity | 10000000 | The maximum number of vertices in ramtable, generally the largest vertex id is used as capacity. |
| query.optimize_aggregate_by_index | false | Whether to optimize aggregate query(like count) by index. |
| oltp.concurrent_depth | 10 | The min depth to enable concurrent oltp algorithm. |
| oltp.concurrent_threads | max(10, CPUs / 2) | Thread number to concurrently execute oltp algorithm. |
| oltp.collection_type | EC | The implementation type of collections used in oltp algorithm, allowed values are [JCF, EC, FU]. |
| oltp.query_batch_size | 10000 | The size of each batch when executing oltp algorithm. |
| oltp.query_batch_avg_degree_ratio | 0.95 | The ratio of exponential approximation for average degree of iterator when executing oltp algorithm. |
| oltp.query_batch_expect_degree | 100000000 | The expect sum of degree in each batch when executing oltp algorithm. |
| rate_limit.read | 0 | The max rate(times/s) to execute query of vertices/edges. |
| rate_limit.write | 0 | The max rate(items/s) to add/update/delete vertices/edges. |
| task.schedule_period | 10 | Period time in seconds when scheduler to schedule task. |
| task.wait_timeout | 10 | Timeout in seconds for waiting for the task to complete, such as when truncating or clearing the backend. |
| task.retry | 0 | Task retry times, allowed range is [0, 3]. |
| task.input_size_limit | 16777216 | The job input size limit in bytes. |
| task.result_size_limit | 16777216 | The job result size limit in bytes. |
| task.sync_deletion | false | Whether to delete schema or expired data synchronously. |
| task.ttl_delete_batch | 1 | The batch size used to delete expired data. |
| computer.config | ./conf/computer.yaml | The config file path of computer job. |
| k8s.operator_template | ./conf/operator-template.yaml | The path of operator container template. |
| k8s.quota_template | ./conf/resource-quota-template.yaml | The path of resource quota template. |
| search.text_analyzer | ikanalyzer | Choose a text analyzer for searching the vertex/edge properties, available type are [ansj, hanlp, smartcn, jieba, jcseg, mmseg4j, ikanalyzer]. The shipped graph templates set jieba. 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_mode | smart | Specify the mode for the text analyzer, the available mode of analyzer are {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_id | 0 | The datacenter id of snowflake id generator. |
| snowflake.force_string | false | Whether to force the snowflake long id to be a string. |
| snowflake.worker_id | 0 | The worker id of snowflake id generator. |
| memory.mode | off-heap | The memory mode used for query in HugeGraph. |
| memory.max_capacity | 1073741824 | The maximum memory capacity in bytes that can be managed for all queries in HugeGraph. |
| memory.one_query_max_capacity | 104857600 | The maximum memory capacity in bytes that can be managed for a query in HugeGraph. |
| memory.alignment | 8 | The alignment used for round memory size. |
Raft Config Options (Deprecated)
The shipped graph configuration templates mark these options as deprecated. They only take effect when
raft.mode=true, and raft.group_peers is read from rest-server.properties instead of the graph file.
| config option | default value | description |
|---|---|---|
| raft.mode | false | Whether the backend storage works in raft mode. |
| raft.safe_read | false | Whether to use linearly consistent read. |
| raft.path | ./raftlog | The log path of current raft node. |
| raft.use_replicator_pipeline | true | Whether 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_timeout | 10000 | Timeout in milliseconds to launch a round of election. |
| raft.snapshot_interval | 3600 | The interval in seconds to trigger snapshot save. |
| raft.snapshot_threads | 4 | The thread number used to do snapshot. |
| raft.snapshot_parallel_compress | false | Whether to enable parallel compress. |
| raft.snapshot_compress_threads | 4 | The thread number used to do snapshot compress. |
| raft.snapshot_decompress_threads | 4 | The thread number used to do snapshot decompress. |
| raft.backend_threads | CPUs | The thread number used to apply task to backend. |
| raft.read_index_threads | 8 | The thread number used to execute reading index. |
| raft.read_strategy | ReadOnlyLeaseBased | The linearizability of read strategy, allowed values are [ReadOnlyLeaseBased, ReadOnlySafe]. |
| raft.apply_batch | 1 | The apply batch size to trigger disruptor event handler. |
| raft.queue_size | 16384 | The disruptor buffers size for jraft RaftNode, StateMachine and LogManager. |
| raft.queue_publish_timeout | 60 | The timeout in second when publish event into disruptor. |
| raft.rpc_threads | max(CPUs * 2, 80) | The rpc threads for jraft RPC layer. |
| raft.rpc_connect_timeout | 5000 | The rpc connect timeout in milliseconds for jraft rpc. |
| raft.rpc_timeout | 60 | The general rpc timeout in seconds for jraft rpc. |
| raft.install_snapshot_rpc_timeout | 36000 | The install snapshot rpc timeout in seconds for jraft rpc. |
| raft.rpc_buf_low_water_mark | 10485760 | The 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_mark | 20971520 | The 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. |
RocksDB Backend Config Options
| config option | default value | description |
|---|---|---|
| backend | Must be set to rocksdb. | |
| serializer | Must be set to binary. | |
| rocksdb.data_path | rocksdb-data/data | The path for storing data of RocksDB. |
| rocksdb.wal_path | rocksdb-data/wal | The path for storing WAL of RocksDB. |
| rocksdb.sst_path | The path for ingesting SST file into RocksDB. | |
| 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.log_level | INFO | The info log level of RocksDB. |
| rocksdb.num_levels | 7 | Set the number of levels for this database. |
| rocksdb.compaction_style | LEVEL | Set compaction style for RocksDB: LEVEL/UNIVERSAL/FIFO. |
| rocksdb.optimize_mode | true | Optimize for heavy workloads and big datasets. |
| rocksdb.bulkload_mode | false | Switch to the mode to bulk load data into RocksDB. |
| rocksdb.compression_per_level | [none, none, snappy, snappy, snappy, snappy, snappy] | The compression algorithms for different levels of RocksDB, allowed values are none/snappy/z/bzip2/lz4/lz4hc/xpress/zstd. |
| rocksdb.bottommost_compression | none | The compression algorithm for the bottommost level of RocksDB, allowed values are none/snappy/z/bzip2/lz4/lz4hc/xpress/zstd. |
| rocksdb.compression | snappy | The compression algorithm for compressing blocks of RocksDB, allowed values are none/snappy/z/bzip2/lz4/lz4hc/xpress/zstd. |
| rocksdb.max_background_jobs | 8 | Maximum number of concurrent background jobs, including flushes and compactions. |
| rocksdb.max_subcompactions | 4 | The value represents the maximum number of threads per compaction job. |
| rocksdb.delayed_write_rate | 16777216 | The rate limit in bytes/s of user write requests when need to slow down if the compaction gets behind. |
| rocksdb.max_open_files | -1 | The maximum number of open files that can be cached by RocksDB, -1 means no limit. |
| rocksdb.max_manifest_file_size | 104857600 | The max size of manifest file in bytes. |
| rocksdb.skip_stats_update_on_db_open | false | Whether to skip statistics update when opening the database, setting this flag true allows us to not update statistics. |
| rocksdb.skip_check_sst_size_on_db_open | false | Whether to skip checking sizes of all sst files when opening the database. |
| rocksdb.max_file_opening_threads | 16 | The max number of threads used to open files. |
| rocksdb.max_total_wal_size | 0 | Total 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.bytes_per_sync | 0 | Allows OS to incrementally sync SST files to disk while they are being written, asynchronously in the background. Issue one request for every bytes_per_sync written. 0 turns it off. |
| rocksdb.wal_bytes_per_sync | 0 | Allows OS to incrementally sync WAL files to disk while they are being written, asynchronously in the background. Issue one request for every bytes_per_sync written. 0 turns it off. |
| rocksdb.strict_bytes_per_sync | false | When true, guarantees SST/WAL files have at most bytes_per_sync/wal_bytes_per_sync bytes submitted for writeback at any given time. This can be used to handle cases where processing speed exceeds I/O speed. |
| rocksdb.db_write_buffer_size | 0 | Total size of write buffers in bytes across all column families, 0 means no limit. |
| rocksdb.log_readahead_size | 0 | The number of bytes to prefetch when reading the log. 0 means the prefetching is disabled. |
| rocksdb.compaction_readahead_size | 0 | The number of bytes to perform bigger reads when doing compaction. If running RocksDB on spinning disks, you should set this to at least 2MB. 0 means the prefetching is disabled. |
| rocksdb.row_cache_capacity | 0 | The capacity in bytes of global cache for table-level rows. 0 means the row_cache is disabled. |
| rocksdb.delete_obsolete_files_period | 21600 | The periodicity in seconds when obsolete files get deleted, 0 means always do full purge. |
| rocksdb.write_buffer_size | 134217728 | Amount of data in bytes to build up in memory. |
| rocksdb.max_write_buffer_number | 6 | The maximum number of write buffers that are built up in memory. |
| rocksdb.min_write_buffer_number_to_merge | 2 | The minimum number of write buffers that will be merged together. |
| rocksdb.max_write_buffer_number_to_maintain | 0 | The total maximum number of write buffers to maintain in memory for conflict checking when transactions are used. |
| rocksdb.memtable_bloom_size_ratio | 0.0 | If prefix-extractor is set and memtable_bloom_size_ratio is not 0, or if memtable_whole_key_filtering is set true, create bloom filter for memtable with the size of write_buffer_size * memtable_bloom_size_ratio. If it is larger than 0.25, it is santinized to 0.25. |
| rocksdb.memtable_whole_key_filtering | false | Enable whole key bloom filter in memtable, it can potentially reduce CPU usage for point-look-ups. Note this will only take effect if memtable_bloom_size_ratio > 0. |
| rocksdb.memtable_huge_page_size | 0 | The page size for huge page TLB for bloom in memtable. If <= 0, not allocate from huge page TLB but from malloc. |
| rocksdb.inplace_update_support | false | Allows thread-safe inplace updates if a put key exists in current memtable and sizeof new value is smaller. |
| rocksdb.level_compaction_dynamic_level_bytes | false | Whether 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_base | 536870912 | The upper-bound of the total size of level-1 files in bytes. |
| rocksdb.max_bytes_for_level_multiplier | 10.0 | The ratio between the total size of level (L+1) files and the total size of level L files for all L. |
| rocksdb.target_file_size_base | 67108864 | The target file size for compaction in bytes. |
| rocksdb.target_file_size_multiplier | 1 | The size ratio between a level L file and a level (L+1) file. |
| rocksdb.level0_file_num_compaction_trigger | 2 | Number of files to trigger level-0 compaction. |
| rocksdb.level0_slowdown_writes_trigger | 20 | Soft limit on number of level-0 files for slowing down writes. |
| rocksdb.level0_stop_writes_trigger | 36 | Hard limit on number of level-0 files for stopping writes. |
| rocksdb.soft_pending_compaction_bytes_limit | 68719476736 | The soft limit to impose on pending compaction in bytes. |
| rocksdb.hard_pending_compaction_bytes_limit | 274877906944 | The hard limit to impose on pending compaction in bytes. |
| rocksdb.allow_mmap_writes | false | Allow the OS to mmap file for writing. |
| rocksdb.allow_mmap_reads | false | Allow the OS to mmap file for reading sst tables. |
| rocksdb.use_direct_reads | false | Enable the OS to use direct I/O for reading sst tables. |
| rocksdb.use_direct_io_for_flush_and_compaction | false | Enable the OS to use direct read/writes in flush and compaction. |
| rocksdb.use_fsync | false | If true, then every store to stable storage will issue a fsync. |
| rocksdb.atomic_flush | false | If true, flushing multiple column families and committing their results atomically to MANIFEST. Note that it’s not necessary to set atomic_flush=true if WAL is always enabled. |
| rocksdb.format_version | 5 | The format version of BlockBasedTable, allowed values are 0~5. |
| rocksdb.index_type | kBinarySearch | The index type used to lookup between data blocks with the sst table, allowed values are [kBinarySearch,kHashSearch,kTwoLevelIndexSearch,kBinarySearchWithFirstKey]. |
| rocksdb.data_block_index_type | kDataBlockBinarySearch | The search type used to point lookup in data block with the sst table, allowed values are [kDataBlockBinarySearch,kDataBlockBinaryAndHash]. |
| rocksdb.data_block_hash_table_util_ratio | 0.75 | The hash table utilization ratio value of entries/buckets. It is valid only when data_block_index_type=kDataBlockBinaryAndHash. |
| rocksdb.block_size | 4096 | Approximate size of user data packed per block, Note that it corresponds to uncompressed data. |
| rocksdb.block_size_deviation | 10 | The percentage of free space used to close a block. |
| rocksdb.block_restart_interval | 16 | The block restart interval for delta encoding in blocks. |
| rocksdb.block_cache_capacity | 8388608 | The amount of block cache in bytes that will be used by RocksDB, 0 means no block cache. |
| rocksdb.cache_index_and_filter_blocks | true | Set this option true if we’d put index/filter blocks to the block cache. |
| rocksdb.pin_l0_filter_and_index_blocks_in_cache | true | Set this option true if we’d pin L0 index/filter blocks to the block cache. |
| rocksdb.bloom_filter_bits_per_key | -1 | The bits per key in bloom filter, a good value is 10, which yields a filter with ~ 1% false positive rate. Set bloom_filter_bits_per_key > 0 to enable bloom filter, -1 means no bloom filter (0~0.5 round down to no filter). |
| rocksdb.bloom_filter_block_based_mode | false | If bloom filter is enabled, set this option true to use block based filter rather than full filter. |
| rocksdb.bloom_filter_whole_key_filtering | true | If bloom filter is enabled, set this option true to place whole keys in the bloom filter, else place the prefix of keys when prefix-extractor is set. |
| rocksdb.optimize_filters_for_hits | true | If bloom filter is enabled, this flag allows us to not store filters for the last level. set this option true to optimize the filters mainly for cases where keys are found rather than also optimize for keys missed. |
| rocksdb.partition_filters_and_indexes | false | If bloom filter is enabled, set this option true to use partitioned full filters and indexes for each sst file. This option is incompatible with block-based filters. |
| rocksdb.pin_top_level_index_and_filter | true | If partition_filters_and_indexes is set true, set this option true if we’d pin top-level index of partitioned filter and index blocks to the block cache. |
| rocksdb.prefix_extractor_n_bytes | 0 | The prefix-extractor uses the first N bytes of a key as its prefix, it will use the full key when a key is shorter than the N. 0 means unset prefix-extractor. |
K8s Config Options (Optional)
Corresponding configuration file rest-server.properties
| config option | default value | description |
|---|---|---|
| server.use_k8s | false | Whether to use k8s to support multiple tenancy. |
| server.deploy_in_k8s | false | Whether to deploy server in k8s. |
| server.urls_to_pd | http://0.0.0.0:8080 | Used as the server address reserved for PD and provided to clients, only used when starting the server in k8s. |
| server.k8s_url | https://127.0.0.1:8888 | The url of k8s. |
| server.k8s_use_ca | false | Whether to use ca to k8s api server. |
| server.k8s_ca | The ca file of k8s api server. | |
| server.k8s_client_ca | The client ca file of k8s api server. | |
| server.k8s_client_key | The client key file of k8s api server. | |
| k8s.api | false | The k8s api start status when the computer service is enabled. |
| k8s.namespace | hugegraph-computer-system | The namespace used for k8s work when the computer service is enabled. |
| k8s.kubeconfig | The k8s kube config file when the computer service is enabled. | |
| k8s.hugegraph_url | The hugegraph url for k8s work when the computer service is enabled. | |
| k8s.enable_internal_algorithm | true | Whether to open k8s internal algorithm. |
| service.access_pd_name | hg | Service name for server to access pd service. |
| service.access_pd_token | Service token for server to access pd service. | |
| server.k8s_oltp_image | 127.0.0.1/kgs_bd/hugegraphserver:3.0.0 | The oltp server image of k8s. |
| server.k8s_olap_image | hugegraph/hugegraph-server:v1 | The olap server image of k8s. |
| server.k8s_storage_image | hugegraph/hugegraph-server:v1 | The storage server image of k8s. |
| server.default_oltp_k8s_namespace | hugegraph-server | The default oltp namespace for HugeGraph default graph space. |
| server.default_olap_k8s_namespace | hugegraph-computer-system | The default olap namespace for HugeGraph default graph space. |
| k8s.internal_algorithm | [page-rank, degree-centrality, wcc, triangle-count, rings, rings-with-filter, betweenness-centrality, closeness-centrality, lpa, links, kcore, louvain, clustering-coefficient, ppr, subgraph-match] | The names of the built-in k8s algorithms. |
| k8s.algorithms | See ServerOptions.K8S_ALGORITHMS | The name:paramsClass mapping of the built-in k8s algorithms. |
Arthas Diagnostic Config Options (Optional)
Corresponding configuration file rest-server.properties
| config option | default value | description |
|---|---|---|
| arthas.telnetPort | 8562 | Arthas telnet port. |
| arthas.httpPort | 8561 | Arthas HTTP port. |
| arthas.ip | 0.0.0.0 | Arthas bind IP. |
| arthas.disabledCommands | jad | Disabled Arthas commands, separated by commas. |
RPC Server Config Options
Corresponding configuration file rest-server.properties
| config option | default value | description |
|---|---|---|
| rpc.server_host | The hosts/ips bound by rpc server to provide services, empty value means not enabled. | |
| rpc.server_port | 8090 | The port bound by rpc server to provide services. |
| rpc.server_adaptive_port | false | Whether the bound port is adaptive, if it’s enabled, when the port is in use, automatically +1 to detect the next available port. Note that this process is not atomic, so there may still be port conflicts. |
| rpc.server_timeout | 30 | The timeout(in seconds) of rpc server execution. |
| rpc.remote_url | The remote urls of rpc peers, it can be set to multiple addresses, which are concat by ‘,’, empty value means not enabled. | |
| rpc.client_connect_timeout | 20 | The timeout(in seconds) of rpc client connect to rpc server. |
| rpc.client_reconnect_period | 10 | The period(in seconds) of rpc client reconnect to rpc server. |
| rpc.client_read_timeout | 40 | The timeout(in seconds) of rpc client read from rpc server. |
| rpc.client_retries | 3 | Failed retry number of rpc client calls to rpc server. |
| rpc.client_load_balancer | consistentHash | The rpc client uses a load-balancing algorithm to access multiple rpc servers in one cluster. Default value is ‘consistentHash’, means forwarding by request parameters. |
| rpc.protocol | bolt | Rpc communication protocol, client and server need to be specified the same value. |
| rpc.serialization | hessian2 | Rpc serialization type, client and server must set the same value. Note: If you choose ‘protobuf’, you need to add the relative IDL file. (Could refer PD/Store *.proto) |
| rpc.config_order | 999 | Sofa-RPC configuration file loading order, the larger the more later loading. |
| rpc.logger_impl | com.alipay.sofa.rpc.log.SLF4JLoggerImpl | Sofa-RPC log implementation class. |
HBase Backend Config Options
| config option | default value | description |
|---|---|---|
| backend | Must be set to hbase. | |
| serializer | Must be set to hbase. | |
| hbase.hosts | localhost | The hostnames or ip addresses of HBase zookeeper, separated with commas. |
| hbase.port | 2181 | The port address of HBase zookeeper. |
| hbase.threads_max | 64 | The max threads num of hbase connections. |
| hbase.znode_parent | /hbase | The znode parent path of HBase zookeeper. |
| hbase.zk_retry | 3 | The recovery retry times of HBase zookeeper. |
| hbase.truncate_timeout | 30 | The timeout in seconds of waiting for store truncate. |
| hbase.aggregation_timeout | 43200 | The timeout in seconds of waiting for aggregation. |
| hbase.kerberos_enable | false | Is Kerberos authentication enabled for HBase. |
| hbase.kerberos_keytab | The HBase’s key tab file for kerberos authentication. | |
| hbase.kerberos_principal | The HBase’s principal for kerberos authentication. | |
| hbase.krb5_conf | /etc/krb5.conf | Kerberos configuration file, including KDC IP, default realm, etc. |
| hbase.hbase_site | /etc/hbase/conf/hbase-site.xml | The HBase’s configuration file |
| hbase.enable_partition | true | Is pre-split partitions enabled for HBase. |
| hbase.vertex_partitions | 10 | The number of partitions of the HBase vertex table. |
| hbase.edge_partitions | 30 | The 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 option | default value | description |
|---|---|---|
| backend | Must be set to cassandra. | |
| serializer | Must be set to cassandra. | |
| cassandra.host | localhost | The seeds hostname or ip address of cassandra cluster. |
| cassandra.port | 9042 | The seeds port address of cassandra cluster. |
| cassandra.connect_timeout | 5 | The cassandra driver connect server timeout(seconds). |
| cassandra.read_timeout | 20 | The cassandra driver read from server timeout(seconds). |
| cassandra.keyspace.strategy | SimpleStrategy | The 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.username | The username to use to login to cassandra cluster. | |
| cassandra.password | The password corresponding to cassandra.username. | |
| cassandra.compression_type | none | The compression algorithm of cassandra transport: none/snappy/lz4. |
| cassandra.jmx_port=7199 | 7199 | The port of JMX API service for cassandra. |
| cassandra.aggregation_timeout | 43200 | The timeout in seconds of waiting for aggregation. |
ScyllaDB Backend Config Options
| config option | default value | description |
|---|---|---|
| backend | Must be set to scylladb. | |
| serializer | Must be set to scylladb. |
Other options are consistent with the Cassandra backend.
MySQL & PostgreSQL Backend Config Options
| config option | default value | description |
|---|---|---|
| backend | Must be set to mysql. | |
| serializer | Must be set to mysql. | |
| jdbc.driver | com.mysql.jdbc.Driver | The JDBC driver class to connect database. |
| jdbc.url | jdbc:mysql://127.0.0.1:3306 | The url of database in JDBC format. |
| jdbc.username | root | The username to login database. |
| jdbc.password | ****** | The password corresponding to jdbc.username. |
| jdbc.ssl_mode | false | The SSL mode of connections with database. |
| jdbc.reconnect_interval | 3 | The interval(seconds) between reconnections when the database connection fails. |
| jdbc.reconnect_max_times | 3 | The reconnect times when the database connection fails. |
| jdbc.storage_engine | InnoDB | The storage engine of backend store database, like InnoDB/MyISAM/RocksDB for MySQL. |
| jdbc.postgresql.connect_database | template1 | The database used to connect when init store, drop store or check store exist. |
PostgreSQL Backend Config Options
| config option | default value | description |
|---|---|---|
| backend | Must be set to postgresql. | |
| serializer | Must 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.Driverjdbc.url=jdbc:postgresql://localhost:5432/