RESOURCE_GROUPS
The RESOURCE_GROUPS
table shows the information about all resource groups. For more information, see Use Resource Control to Achieve Resource Group Limitation and Flow Control.
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)
Examples
SELECT * FROM information_schema.resource_groups; -- View all resource groups. TiDB has a `default` resource group.
+---------+------------+----------+-----------+-------------+------------+
| NAME | RU_PER_SEC | PRIORITY | BURSTABLE | QUERY_LIMIT | BACKGROUND |
+---------+------------+----------+-----------+-------------+------------+
| default | UNLIMITED | MEDIUM | UNLIMITED | NULL | NULL |
+---------+------------+----------+-----------+-------------+------------+
CREATE RESOURCE GROUP rg1 RU_PER_SEC=1000; -- Create a resource group `rg1`
Query OK, 0 rows affected (0.34 sec)
SHOW CREATE RESOURCE GROUP rg1; -- Show the definition of the `rg1` resource group
+----------------+---------------------------------------------------------------+
| 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'; -- View the resource groups `rg1`
+------+------------+----------+-----------+-------------+------------+
| NAME | RU_PER_SEC | PRIORITY | BURSTABLE | QUERY_LIMIT | BACKGROUND |
+------+------------+----------+-----------+-------------+------------+
| rg1 | 1000 | MEDIUM | OFF | NULL | NULL |
+------+------------+----------+-----------+-------------+------------+
1 row in set (0.00 sec)
The descriptions of the columns in the RESOURCE_GROUPS
table are as follows:
NAME
: the name of the resource group.RU_PER_SEC
: the backfilling speed of the resource group. The unit is RU/second, in which RU means Request Unit.PRIORITY
: the absolute priority of tasks to be processed on TiKV. Different resources are scheduled according to thePRIORITY
setting. Tasks with highPRIORITY
are scheduled first. For resource groups with the samePRIORITY
, tasks will be scheduled proportionally according to theRU_PER_SEC
configuration. IfPRIORITY
is not specified, the default priority isMEDIUM
.BURSTABLE
: whether to allow the resource group to overuse the available remaining system resources. Starting from v9.0.0, the following three modes are supported. If no value is specified forBURSTABLE
, theMODERATED
mode is enabled by default.OFF
: indicates that the resource group is not allowed to overuse any remaining system resources.MODERATED
: indicates that the resource group is allowed to overuse remaining system resources to a limited extent, with priority given to allocated resources within its quota.UNLIMITED
: indicates that the resource group can overuse remaining system resources without limitation, and the excess system resources are treated as equal to the resources within the quota during allocation.