| title | summary | aliases | |||
|---|---|---|---|---|---|
CLUSTER_CONFIG |
了解 information_schema 表 `CLUSTER_CONFIG`。 |
|
CLUSTER_CONFIG 表用于获取集群当前所有组件实例的配置。在 TiDB 早期的版本，用户需要逐个访问各个实例的 HTTP API 才能收集到所有组件配置。TiDB v4.0 后，该表的引入提高了易用性。
{{< copyable "sql" >}}
USE information_schema;
DESC cluster_config;+----------+--------------+------+------+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------+--------------+------+------+---------+-------+
| TYPE | varchar(64) | YES | | NULL | |
| INSTANCE | varchar(64) | YES | | NULL | |
| KEY | varchar(256) | YES | | NULL | |
| VALUE | varchar(128) | YES | | NULL | |
+----------+--------------+------+------+---------+-------+字段解释：
TYPE：节点的类型，可取值为tidb，pd和tikv。INSTANCE：节点的服务地址。KEY：配置项名。VALUE：配置项值。
以下示例查询 TiKV 实例的 coprocessor 相关配置：
{{< copyable "sql" >}}
SELECT * FROM cluster_config WHERE type='tikv' AND `key` LIKE 'coprocessor%';+------+-----------------+-----------------------------------+---------+
| TYPE | INSTANCE | KEY | VALUE |
+------+-----------------+-----------------------------------+---------+
| tikv | 127.0.0.1:20165 | coprocessor.batch-split-limit | 10 |
| tikv | 127.0.0.1:20165 | coprocessor.region-max-keys | 1440000 |
| tikv | 127.0.0.1:20165 | coprocessor.region-max-size | 144MiB |
| tikv | 127.0.0.1:20165 | coprocessor.region-split-keys | 960000 |
| tikv | 127.0.0.1:20165 | coprocessor.region-split-size | 96MiB |
| tikv | 127.0.0.1:20165 | coprocessor.split-region-on-table | false |
+------+-----------------+-----------------------------------+---------+
6 rows in set (0.00 sec)