RESOURCE_GROUPS

RESOURCE_GROUPS 表展示所有资源组 (resource group) 的信息，见使用资源管控 (Resource Control) 实现资源隔离。

USE information_schema;
DESC resource_groups;

+------------+-------------+------+------+---------+-------+
| Field      | Type        | Null | Key  | Default | Extra |
+------------+-------------+------+------+---------+-------+
| NAME       | varchar(32) | NO   |      | NULL    |       |
| RU_PER_SEC | bigint(21)  | YES  |      | NULL    |       |
| PRIORITY   | varchar(6)  | YES  |      | NULL    |       |
| BURSTABLE  | varchar(3)  | YES  |      | NULL    |       |
+------------+-------------+------+------+---------+-------+
3 rows in set (0.00 sec)

示例

SELECT * FROM information_schema.resource_groups; -- 查看资源组，TiDB 默认预置 `default` 资源组

+---------+------------+----------+-----------+
| NAME    | RU_PER_SEC | PRIORITY | BURSTABLE |
+---------+------------+----------+-----------+
| default | UNLIMITED  | MEDIUM   | YES       |
+---------+------------+----------+-----------+

CREATE RESOURCE GROUP rg1 RU_PER_SEC=1000; -- 创建资源组 `rg1`

Query OK, 0 rows affected (0.34 sec)

SHOW CREATE RESOURCE GROUP rg1; -- 显示 `rg1` 资源组的定义

+----------------+---------------------------------------------------------------+
| Resource_Group | Create Resource Group                                         |
+----------------+---------------------------------------------------------------+
| rg1            | CREATE RESOURCE GROUP `rg1` RU_PER_SEC=1000 PRIORITY="MEDIUM" |
+----------------+---------------------------------------------------------------+
1 row in set (0.00 sec)

SELECT * FROM information_schema.resource_groups WHERE NAME = 'rg1'; -- 查看资源组 `rg1`

+------+------------+----------+-----------+
| NAME | RU_PER_SEC | PRIORITY | BURSTABLE |
+------+------------+----------+-----------+
| rg1  |       1000 | MEDIUM   | NO        |
+------+------------+----------+-----------+
1 row in set (0.00 sec)

RESOURCE_GROUPS 表中列的含义如下：

• NAME：资源组名称。
• RU_PER_SEC：资源组的回填速度，单位为每秒回填的 Request Unit (RU) 数量。
• PRIORITY：任务在 TiKV 上处理的绝对优先级。不同的资源按照 PRIORITY 的设置进行调度，PRIORITY 高的任务会被优先调度。如果资源组的 PRIORITY 相同，则会根据 RU_PER_SEC 的配置按比例调度。如果不指定 PRIORITY，资源组的默认优先级为 MEDIUM。
• BURSTABLE：是否允许此资源组超额使用剩余的系统资源。