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information-schema-cluster-hardware.md

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CLUSTER_HARDWARE
Learn the `CLUSTER_HARDWARE` information_schema table.
/docs/dev/system-tables/system-table-cluster-hardware/
/docs/dev/reference/system-databases/cluster-hardware/
/tidb/dev/system-table-cluster-hardware/

CLUSTER_HARDWARE

The CLUSTER_HARDWARE hardware system table provides the hardware information of the server where each instance of the cluster is located.

Note:

This table is only applicable to TiDB Self-Managed and not available on TiDB Cloud.

{{< copyable "sql" >}}

USE information_schema;
DESC cluster_hardware;
+-------------+--------------+------+------+---------+-------+
| 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.
    • memory: The hardware name is memory.
    • disk: The disk name.
    • net: The network card name.
  • NAME: The different information names of the hardware. For example, cpu has two information names: cpu-logical-cores and cpu-physical-cores, which respectively mean logical core numbers and physical core numbers.
  • VALUE: The value of the corresponding hardware information, such as the disk volume and CPU core numbers.

The following example shows how to query the CPU information using the CLUSTER_HARDWARE table:

{{< copyable "sql" >}}

SELECT * FROM cluster_hardware WHERE device_type='cpu' AND device_name='cpu' AND name LIKE '%cores';
+------+-----------------+-------------+-------------+--------------------+-------+
| TYPE | INSTANCE        | DEVICE_TYPE | DEVICE_NAME | NAME               | VALUE |
+------+-----------------+-------------+-------------+--------------------+-------+
| tidb | 0.0.0.0:4000    | cpu         | cpu         | cpu-logical-cores  | 16    |
| tidb | 0.0.0.0:4000    | cpu         | cpu         | cpu-physical-cores | 8     |
| pd   | 127.0.0.1:2379  | cpu         | cpu         | cpu-logical-cores  | 16    |
| pd   | 127.0.0.1:2379  | cpu         | cpu         | cpu-physical-cores | 8     |
| tikv | 127.0.0.1:20165 | cpu         | cpu         | cpu-logical-cores  | 16    |
| tikv | 127.0.0.1:20165 | cpu         | cpu         | cpu-physical-cores | 8     |
+------+-----------------+-------------+-------------+--------------------+-------+
6 rows in set (0.03 sec)