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Version: Nightly

CLUSTER_INFO

The CLUSTER_INFO table provides the topology information of the cluster.

USE INFORMATION_SCHEMA;

DESC TABLE CLUSTER_INFO;

The output is as follows:

+--------------+----------------------+------+------+---------+---------------+
| Column       | Type                 | Key  | Null | Default | Semantic Type |
+--------------+----------------------+------+------+---------+---------------+
| peer_id      | Int64                |      | NO   |         | FIELD         |
| peer_type    | String               |      | NO   |         | FIELD         |
| peer_addr    | String               |      | YES  |         | FIELD         |
| cpus         | UInt32               |      | NO   |         | FIELD         |
| memory_bytes | UInt64               |      | NO   |         | FIELD         |
| version      | String               |      | NO   |         | FIELD         |
| git_commit   | String               |      | NO   |         | FIELD         |
| start_time   | TimestampMillisecond |      | YES  |         | FIELD         |
| uptime       | String               |      | YES  |         | FIELD         |
| active_time  | String               |      | YES  |         | FIELD         |
| node_status  | String               |      | YES  |         | FIELD         |
+--------------+----------------------+------+------+---------+---------------+

The columns in table:

  • peer_id: the server id of the node. It's always 0 for standalone mode and -1 for frontends because it doesn't make sense in such cases.
  • peer_type: the node type, METASRV,FRONTEND, or DATANODE for distributed clusters and STANDALONE for standalone deployments.
  • peer_addr: the GRPC server address of the node. It's always empty for standalone deployments.
  • cpus: the number of CPUs of the node.
  • memory_bytes: the memory size of the node.
  • version: The build version of the node, such as 0.7.2 etc.
  • git_commit: The build git commit of the node.
  • start_time: The node start time.
  • uptime: The uptime of the node, in the format of duration string 24h 10m 59s 150ms.
  • active_time: The duration string in the format of 24h 10m 59s 150ms since the node's last active time(sending the heartbeats), it's always empty for standalone deployments.
  • node_status: the status info of the peer.

Query the table:

SELECT * FROM CLUSTER_INFO;

An example output in standalone deployments:

+---------+------------+-----------+------+--------------+---------+-----------+----------------------------+--------+-------------+-------------+
| peer_id | peer_type  | peer_addr | cpus | memory_bytes | version | git_commit| start_time                 | uptime | active_time | node_status |
+---------+------------+-----------+------+--------------+---------+-----------+----------------------------+--------+-------------+-------------+
| 0       | STANDALONE |           | 16   | 17179869184  | 0.7.2   | 86ab3d9   | 2024-04-30T06:40:02.074    | 18ms   |             | NULL        |
+---------+------------+-----------+------+--------------+---------+-----------+----------------------------+--------+-------------+-------------+

Another example is from a distributed cluster that has three Datanodes, one Frontend, and one Metasrv.

+---------+-----------+----------------+------+--------------+---------+-----------+----------------------------+----------+-------------+-------------------------------------------------------------------+
| peer_id | peer_type | peer_addr      | cpus | memory_bytes | version | git_commit| start_time                 | uptime   | active_time | node_status                                                       |
+---------+-----------+----------------+------+--------------+---------+-----------+----------------------------+----------+-------------+-------------------------------------------------------------------+
| 1       | DATANODE  | 127.0.0.1:4101 | 16   | 17179869184  | 0.7.2   | 86ab3d9   | 2024-04-30T06:40:04.791    | 4s 478ms | 1s 467ms    | {"workloads":["hybrid"],"leader_regions":46,"follower_regions":0} |
| 2       | DATANODE  | 127.0.0.1:4102 | 16   | 17179869184  | 0.7.2   | 86ab3d9   | 2024-04-30T06:40:06.098    | 3s 171ms | 162ms       | {"workloads":["hybrid"],"leader_regions":46,"follower_regions":0} |
| 3       | DATANODE  | 127.0.0.1:4103 | 16   | 17179869184  | 0.7.2   | 86ab3d9   | 2024-04-30T06:40:07.425    | 1s 844ms | 1s 839ms    | {"workloads":["hybrid"],"leader_regions":46,"follower_regions":0} |
| -1      | FRONTEND  | 127.0.0.1:4001 | 16   | 17179869184  | 0.7.2   | 86ab3d9   | 2024-04-30T06:40:08.815    | 454ms    | 47ms        | NULL                                                              |
| 0       | METASRV   | 127.0.0.1:3002 | 16   | 17179869184  | unknown | unknown   |                            |          |             | {"is_leader":true}                                                |
+---------+-----------+----------------+------+--------------+---------+-----------+----------------------------+----------+-------------+-------------------------------------------------------------------+