Important

You are viewing the documentation of an older version of the TiDB database (TiDB v4.0).

It is recommended that you use the latest LTS version of the TiDB database.

CLUSTER_LOAD

The CLUSTER_LOAD cluster load table provides the current load information of the server where each instance of the TiDB cluster is located.

USE information_schema;
DESC cluster_load;
+-------------+--------------+------+------+---------+-------+
| Field       | Type         | Null | Key  | Default | Extra |
+-------------+--------------+------+------+---------+-------+
| TYPE        | varchar(64)  | YES  |      | NULL    |       |
| INSTANCE    | varchar(64)  | YES  |      | NULL    |       |
| DEVICE_TYPE | varchar(64)  | YES  |      | NULL    |       |
| DEVICE_NAME | varchar(64)  | YES  |      | NULL    |       |
| NAME        | varchar(256) | YES  |      | NULL    |       |
| VALUE       | varchar(128) | YES  |      | NULL    |       |
+-------------+--------------+------+------+---------+-------+
6 rows in set (0.00 sec)

Field description:

  • TYPE: Corresponds to the TYPE field in the information_schema.cluster_info table. The optional values are tidb, pd, and tikv.
  • INSTANCE: Corresponds to the INSTANCE field in the information_schema.cluster_info cluster information table.
  • DEVICE_TYPE: Hardware type. Currently, you can query the cpu, memory, disk, and net types.
  • DEVICE_NAME: Hardware name. The value of DEVICE_NAME varies with DEVICE_TYPE.
    • cpu: The hardware name is cpu.
    • disk: The disk name.
    • net: The network card name.
    • memory: The hardware name is memory.
  • NAME: Different load types. For example, cpu has three load types: load1, load5, and load15, which respectively mean the average load of cpu within 1 minute, 5 minutes, and 15 minutes.
  • VALUE: The value of the hardware load. For example, 1min, 5min, and 15min respectively mean the average load of the hardware within 1 minute, 5 minutes, and 15 minutes.

The following example shows how to query the current load information of cpu using the CLUSTER_LOAD table:

SELECT * FROM cluster_load WHERE device_type='cpu' AND device_name='cpu';
+------+-----------------+-------------+-------------+--------+-------+
| TYPE | INSTANCE        | DEVICE_TYPE | DEVICE_NAME | NAME   | VALUE |
+------+-----------------+-------------+-------------+--------+-------+
| tidb | 0.0.0.0:4000    | cpu         | cpu         | load1  | 0.13  |
| tidb | 0.0.0.0:4000    | cpu         | cpu         | load5  | 0.25  |
| tidb | 0.0.0.0:4000    | cpu         | cpu         | load15 | 0.31  |
| pd   | 127.0.0.1:2379  | cpu         | cpu         | load1  | 0.13  |
| pd   | 127.0.0.1:2379  | cpu         | cpu         | load5  | 0.25  |
| pd   | 127.0.0.1:2379  | cpu         | cpu         | load15 | 0.31  |
| tikv | 127.0.0.1:20165 | cpu         | cpu         | load1  | 0.13  |
| tikv | 127.0.0.1:20165 | cpu         | cpu         | load5  | 0.25  |
| tikv | 127.0.0.1:20165 | cpu         | cpu         | load15 | 0.31  |
+------+-----------------+-------------+-------------+--------+-------+
9 rows in set (1.50 sec)
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