Modify attributes of a resource pool

You can modify the UNIT, UNIT_NUM, and ZONE_LIST parameters for a resource pool. This topic introduces the modification procedure.

You can use the ALTER RESOURCE POOL statement to modify attributes of a resource pool.

You can scale up or down a tenant by modifying the attributes of its resource pool. For example, you can increase the value of UNIT_NUM to increase the number of nodes in each zone to scale out the tenant.

Procedure

1. Log on to the sys tenant of the cluster as the root user.

   obclient -h172.30.xx.xx -P2883 -uroot@sys#cluster -p**** -A
   

2. Access the database named oceanbase.

   obclient [(none)]> USE oceanbase;
   

3. Query the DBA_OB_RESOURCE_POOLS view for the configuration information about resource pools.

   To query the configuration information about the resource pool named mq_pool_02, execute the following statement:

   obclient [oceanbase]> SELECT * FROM DBA_OB_RESOURCE_POOLS WHERE NAME = 'mq_pool_02';
   +------------------+------------+-----------+----------------------------+----------------------------+------------+----------------+-------------+--------------+
   | RESOURCE_POOL_ID | NAME       | TENANT_ID | CREATE_TIME                | MODIFY_TIME                | UNIT_COUNT | UNIT_CONFIG_ID | ZONE_LIST   | REPLICA_TYPE |
   +------------------+------------+-----------+----------------------------+----------------------------+------------+----------------+-------------+--------------+
   |             1026 | mq_pool_02 |      NULL | 2023-01-10 23:54:24.177685 | 2023-01-10 23:54:24.177685 |          1 |           1020 | zone1;zone2 | FULL         |
   +------------------+------------+-----------+----------------------------+----------------------------+------------+----------------+-------------+--------------+
   1 row in set
   

   For more information about the DBA_OB_RESOURCE_POOLSview, see oceanbase.DBA_OB_RESOURCE_POOLS.

4. Execute the ALTER RESOURCE POOL statement to modify the configurations of the resource pool.

   Notice

   • This statement modifies only one attribute at a time. To modify two or more of the UNIT, UNIT_NUM, and ZONE_LIST attributes, execute this statement multiple times.
   • When you modify the ZONE_LIST attribute, you can add or remove only one zone at a time.

   The syntax is as follows:

   ALTER RESOURCE POOL pool_name
       UNIT [=] unit_name,
       UNIT_NUM [=] unit_num,
       ZONE_LIST [=] ('zone' [, 'zone' ...]);
   

   The parameters are described as follows:

   • pool_name: the name of the resource pool.

   • UNIT: the unit config for the resource pool.

   • UNIT_NUM: the number of resource units. When you add resource units, make sure that the value of UNIT_NUM does not exceed the number of OBServer nodes in each zone.

     Notice

     If a resource pool is allocated to a tenant, you cannot modify the UNIT_NUM attribute. You must use the ALTER RESOURCE TENANT statement to modify it.

   • ZONE_LIST: the distribution of the resource pool in zones.

   For more information about the ALTER RESOURCE POOL statement, see ALTER RESOURCE POOL.

   For more information about the ALTER RESOURCE TENANT statement, see ALTER RESOURCE TENANT.

   Here are some examples:

   • The resource pool is not allocated to any tenant

     To set the unit config to 'S2_unit_config', the number of resource units to 3, and ZONE_LIST to 'zone1','zone2','zone3' for the mq_pool_02 tenant, execute the following statements:

     obclient [oceanbase]> ALTER RESOURCE POOL mq_pool_02 UNIT='S2_unit_config';
     Query OK, 0 rows affected
     
     obclient [oceanbase]> ALTER RESOURCE POOL mq_pool_02 UNIT_NUM=3;
     Query OK, 0 rows affected
     
     obclient [oceanbase]> ALTER RESOURCE POOL mq_pool_02 ZONE_LIST=('zone1','zone2','zone3');
     Query OK, 0 rows affected
     

   • The resource pool is allocated to a tenant

     You must use the ALTER RESOURCE TENANT statement to modify the UNIT_NUM attribute of a resource pool allocated to a tenant.

     To set the unit config to 'S2_unit_config', the number of resource units to 3, and ZONE_LIST to 'zone1','zone2','zone3' for the mq_pool_02 tenant, execute the following statements:

     obclient [oceanbase]> ALTER RESOURCE POOL mq_pool_02 UNIT='S2_unit_config';
     Query OK, 0 rows affected
     
     obclient [oceanbase]> ALTER RESOURCE TENANT mq_t2 UNIT_NUM=3;
     Query OK, 0 rows affected
     
     obclient [oceanbase]> ALTER RESOURCE POOL mq_pool_02 ZONE_LIST=('zone1','zone2','zone3');
     Query OK, 0 rows affected
     

5. Query the DBA_OB_RESOURCE_POOLS view to verify the modification result.

   The query result shows that the values of UNIT_COUNT, UNIT_CONFIG_ID, and ZONE_LIST are updated.

   obclient [oceanbase]> SELECT * FROM DBA_OB_RESOURCE_POOLS WHERE NAME = 'mq_pool_02';
   +------------------+------------+-----------+----------------------------+----------------------------+------------+----------------+-------------------+--------------+
   | RESOURCE_POOL_ID | NAME       | TENANT_ID | CREATE_TIME                | MODIFY_TIME                | UNIT_COUNT | UNIT_CONFIG_ID | ZONE_LIST         | REPLICA_TYPE |
   +------------------+------------+-----------+----------------------------+----------------------------+------------+----------------+-------------------+--------------+
   |             1026 | mq_pool_02 |      NULL | 2023-01-10 23:54:24.177685 | 2023-01-10 23:56:04.961771 |          2 |           1021 | zone1;zone2;zone3 | FULL         |
   +------------------+------------+-----------+----------------------------+----------------------------+------------+----------------+-------------------+--------------+
   1 row in set