Modify the attributes of a resource pool

Modifying the attributes of a resource pool involves adjusting parameters such as UNIT, UNIT_NUM, and ZONE_LIST. This topic describes the modification procedure.

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

Modifying the attributes of a resource pool is another way to scale up or down a tenant. For example, you can increase the value of UNIT_NUM to increase the number of nodes in each zone to achieve scaling up.

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. Enter the oceanbase database.

   obclient [(none)]> USE oceanbase;
   

3. Use the DBA_OB_RESOURCE_POOLS view to query the configuration information of a resource pool.

   The following command uses the mq_pool_02 resource pool as an example:

   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_POOLS view, see oceanbase.DBA_OB_RESOURCE_POOLS.

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

   Notice

   • Only one attribute can be modified in a single statement. If two or more attributes in UNIT, UNIT_NUM, and ZONE_LIST need to be modified at the same time, multiple statements need to be executed separately.
   • When modifying the ZONE_LIST attribute, you can add or delete only one zone at a time.

   Syntax:

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

   Parameters:

   • 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, the number of resource units cannot be modified using ALTER RESOURCE POOL statement. Use the ALTER RESOURCE TENANT statement instead.

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

   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.

   Example:

   • If the resource pool is not allocated to any tenant

     Set UNIT to 'S2_unit_config', UNIT_NUM to 3, and ZONE_LIST to 'zone1','zone2','zone3' for the mq_pool_02 resource pool:

     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
     

   • If the resource pool is allocated to a tenant

     Set UNIT to 'S2_unit_config', UNIT_NUM to 3, and ZONE_LIST to 'zone1','zone2','zone3' for the mq_pool_02 resource pool. Note that UNIT_NUM must be modified using the ALTER RESOURCE TENANT statement.

     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