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Query Nebula Graph metrics

Nebula Graph supports querying the monitoring metrics through HTTP ports.

Metrics structure

Each metric of Nebula Graph consists of three fields: name, type, and time range. The fields are separated by periods, for example, num_queries.sum.600. Different Nebula Graph services (Graph, Storage, or Meta) support different metrics. The detailed description is as follows.

Field Example Description
Metric name num_queries Indicates the function of the metric.
Metric type sum Indicates how the metrics are collected. Supported types are SUM, AVG, RATE, and the P-th sample quantiles such as P75, P95, P99, and P99.9.
Time range 600 The time range in seconds for the metric collection. Supported values are 5, 60, 600, and 3600, representing the last 5 seconds, 1 minute, 10 minutes, and 1 hour.

Space-level metrics

The Graph service supports a set of space-level metrics that record the information of different graph spaces separately.

To enable space-level metrics, set the value of enable_space_level_metrics to true in the Graph service configuration file before starting Nebula Graph. For details about how to modify the configuration, see Configuration Management.

Note

Space-level metrics can be queried only by querying all metrics, for example, curl -G "http://192.168.8.40:19559/stats". The return result contains the graph space name in the form of '{space=space_name}', for example, num_active_queries{space=basketballplayer}.sum.5=0.

Query metrics over HTTP

Syntax

curl -G "http://<ip>:<port>/stats?stats=<metric_name_list> [&format=json]"
Parameter Description
ip The IP address of the server. You can find it in the configuration file in the installation directory.
port The HTTP port of the server. You can find it in the configuration file in the installation directory. The default ports are 19559 (Meta), 19669 (Graph), and 19779 (Storage).
metric_name_list The metrics names. Multiple metrics are separated by commas (,).
&format=json Optional. Returns the result in the JSON format.

Note

If Nebula Graph is deployed with Docker Compose, run docker-compose ps to check the ports that are mapped from the service ports inside of the container and then query through them.

Examples

  • Query a single metric

    Query the query number in the last 10 minutes in the Graph Service.

    $ curl -G "http://192.168.8.40:19669/stats?stats=num_queries.sum.600"
    num_queries.sum.600=400
    
  • Query multiple metrics

    Query the following metrics together:

    • The average heartbeat latency in the last 1 minute.
    • The average latency of the slowest 1% heartbeats, i.e., the P99 heartbeats, in the last 10 minutes.

      $ curl -G "http://192.168.8.40:19559/stats?stats=heartbeat_latency_us.avg.60,heartbeat_latency_us.p99.600"
      heartbeat_latency_us.avg.60=281
      heartbeat_latency_us.p99.600=985
      
  • Return a JSON result.

    Query the number of new vertices in the Storage Service in the last 10 minutes and return the result in the JSON format.

    $ curl -G "http://192.168.8.40:19779/stats?stats=num_add_vertices.sum.600&format=json"
    [{"value":1,"name":"num_add_vertices.sum.600"}]
    
  • Query all metrics in a service.

    If no metric is specified in the query, Nebula Graph returns all metrics in the service.

    $ curl -G "http://192.168.8.40:19559/stats"
    heartbeat_latency_us.avg.5=304
    heartbeat_latency_us.avg.60=308
    heartbeat_latency_us.avg.600=299
    heartbeat_latency_us.avg.3600=285
    heartbeat_latency_us.p75.5=652
    heartbeat_latency_us.p75.60=669
    heartbeat_latency_us.p75.600=651
    heartbeat_latency_us.p75.3600=642
    heartbeat_latency_us.p95.5=930
    heartbeat_latency_us.p95.60=963
    heartbeat_latency_us.p95.600=933
    heartbeat_latency_us.p95.3600=929
    heartbeat_latency_us.p99.5=986
    heartbeat_latency_us.p99.60=1409
    heartbeat_latency_us.p99.600=989
    heartbeat_latency_us.p99.3600=986
    num_heartbeats.rate.5=0
    num_heartbeats.rate.60=0
    num_heartbeats.rate.600=0
    num_heartbeats.rate.3600=0
    num_heartbeats.sum.5=2
    num_heartbeats.sum.60=40
    num_heartbeats.sum.600=394
    num_heartbeats.sum.3600=2364
    ...
    

Metric description

Graph

Parameter Description
num_active_queries The number of queries currently being executed.
num_active_sessions The number of currently active sessions.
num_aggregate_executors The number of executions for the Aggregation operator.
num_auth_failed_sessions_bad_username_password The number of sessions where authentication failed due to incorrect username and password.
num_auth_failed_sessions_out_of_max_allowed The number of session that failed to authenticate logins because the parameter FLAG_OUT_OF_MAX_ALLOWED_CONNECTIONS was exceeded.
num_auth_failed_sessions The number of sessions in which login authentication failed.
num_indexscan_executors The number of executions for index scan operators.
num_killed_queries The number of killed queries.
num_opened_sessions The number of sessions connected to the server.
num_queries The number of queries.
num_query_errors_leader_changes The number of the raft leader changes due to query errors.
num_query_errors The number of query errors.
num_reclaimed_expired_sessions The number of expired sessions actively reclaimed by the server.
num_rpc_sent_to_metad_failed The number of failed RPC requests that the Graphd service sends to the Metad service.
num_rpc_sent_to_metad The number of RPC requests that the Graphd service sent to the Metad service.
num_rpc_sent_to_storaged_failed The number of failed RPC requests that the Graphd service sent to the Storaged service.
num_rpc_sent_to_storaged The number of RPC requests that the Graphd service sent to the Storaged service.
num_sentences The number of statements received by the Graphd service.
num_slow_queries The number of slow queries.
num_sort_executors The number of executions for the Sort operator.
optimizer_latency_us The latency of executing optimizer statements.
query_latency_us The average latency of queries.
slow_query_latency_us The average latency of slow queries.
num_queries_hit_memory_watermark The number of queries that reached the memory water mark.

Meta

Parameter Description
commit_log_latency_us The latency of committing logs in Raft.
commit_snapshot_latency_us The latency of committing snapshots in Raft.
heartbeat_latency_us The latency of heartbeats.
num_heartbeats The number of heartbeats.
num_raft_votes The number of votes in Raft.
transfer_leader_latency_us The latency of transferring the raft leader.
num_agent_heartbeats The number of heartbeats for the AgentHBProcessor.
agent_heartbeat_latency_us The average latency of the AgentHBProcessor.

Storage

Parameter Description
add_edges_atomic_latency_us The average latency of adding edge single.
add_edges_latency_us The average latency of adding edges.
add_vertices_latency_us The average latency of adding vertices.
commit_log_latency_us The latency of committing logs in Raft.
commit_snapshot_latency_us The latency of committing snapshots in Raft.
delete_edges_latency_us The average latency of deleting edges.
delete_vertices_latency_us The average latency of deleting vertices.
get_neighbors_latency_us The average latency of querying neighbor vertices.
num_get_prop The number of executions for the GetPropProcessor.
num_get_neighbors_errors The number of execution errors for the GetNeighborsProcessor.
get_prop_latency_us The average latency of executions for the GetPropProcessor.
num_edges_deleted The number of deleted edges.
num_edges_inserted The number of inserted edges.
num_raft_votes The number of votes in Raft.
num_rpc_sent_to_metad_failed The number of failed RPC requests that the Storage service sent to the Meta service.
num_rpc_sent_to_metad The number of RPC requests that the Storaged service sent to the Metad service.
num_tags_deleted The number of deleted tags.
num_vertices_deleted The number of deleted vertices.
num_vertices_inserted The number of inserted vertices.
transfer_leader_latency_us The latency of transferring the raft leader.
lookup_latency_us The average latency of executions for the LookupProcessor.
num_lookup_errors The number of execution errors for the LookupProcessor.
num_scan_vertex The number of executions for the ScanVertexProcessor.
num_scan_vertex_errors The number of execution errors for the ScanVertexProcessor.
update_edge_latency_us The average latency of executions for the UpdateEdgeProcessor.
num_update_vertex The number of executions for the UpdateVertexProcessor.
num_update_vertex_errors The number of execution errors for the UpdateVertexProcessor.
kv_get_latency_us The average latency of executions for the Getprocessor.
kv_put_latency_us The average latency of executions for the PutProcessor.
kv_remove_latency_us The average latency of executions for the RemoveProcessor.
num_kv_get_errors The number of execution errors for the GetProcessor.
num_kv_get The number of executions for the GetProcessor.
num_kv_put_errors The number of execution errors for the PutProcessor.
num_kv_put The number of executions for the PutProcessor.
num_kv_remove_errors The number of execution errors for the RemoveProcessor.
num_kv_remove The number of executions for the RemoveProcessor.
forward_tranx_latency_us The average latency of transmission.

Space-level

Parameter Description
num_active_queries The number of queries currently being executed.
num_queries The number of queries.
num_sentences The number of statements received by the Graphd service.
optimizer_latency_us The latency of executing optimizer statements.
query_latency_us The average latency of queries.
num_slow_queries The number of slow queries.
num_query_errors The number of query errors.
num_query_errors_leader_changes The number of raft leader changes due to query errors.
num_killed_queries The number of killed queries.
num_aggregate_executors The number of executions for the Aggregation operator.
num_sort_executors The number of executions for the Sort operator.
num_indexscan_executors The number of executions for index scan operators.
num_oom_queries The number of queries that caused memory to run out.

Last update: March 9, 2022
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