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。

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 tidbpdtikv
  • 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:

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)