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) 实现资源组限制和流控。
USE information_schema;
DESC resource_groups;
+-------------+--------------+------+------+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------+--------------+------+------+---------+-------+
| NAME | varchar(32) | NO | | NULL | |
| RU_PER_SEC | varchar(21) | YES | | NULL | |
| PRIORITY | varchar(6) | YES | | NULL | |
| BURSTABLE | varchar(3) | YES | | NULL | |
| QUERY_LIMIT | varchar(256) | YES | | NULL | |
| BACKGROUND | varchar(256) | YES | | NULL | |
+-------------+--------------+------+------+---------+-------+
6 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 | QUERY_LIMIT | BACKGROUND |
+---------+------------+----------+-----------+-------------+------------+
| default | UNLIMITED | MEDIUM | UNLIMITED | NULL | NULL |
+---------+------------+----------+-----------+-------------+------------+
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 | QUERY_LIMIT | BACKGROUND |
+------+------------+----------+-----------+-------------+------------+
| rg1 | 1000 | MEDIUM | OFF | NULL | NULL |
+------+------------+----------+-----------+-------------+------------+
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。从 v9.0.0 开始,支持以下三种模式,如果没有为BURSTABLE
指定目标值,将默认启用MODERATED
模式。OFF
:表示不允许此资源组超额使用剩余的系统资源;MODERATED
:表示有限度地允许此资源组超额使用剩余的系统资源,优先保证资源组限额内的资源得到分配;UNLIMITED
:表示无限度地允许此资源组超额使用剩余的系统资源,与限额内资源同等竞争。