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 theTYPE
field in theinformation_schema.cluster_info
table. The optional values aretidb
,pd
, andtikv
.INSTANCE
: Corresponds to theINSTANCE
field in theinformation_schema.cluster_info
cluster information table.DEVICE_TYPE
: Hardware type. Currently, you can query thecpu
,memory
,disk
, andnet
types.DEVICE_NAME
: Hardware name. The value ofDEVICE_NAME
varies withDEVICE_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
, andload15
, 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
, and15min
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)