Remove resource pools from a tenant

Removing resource pools from a tenant usually happens when you want to reduce the number of replicas for a tenant. You can use the ALTER TENANT statement to remove resource pools from a tenant.

The corresponding SQL syntax is as follows:

ALTER TENANT tenant_name RESOURCE_POOL_LIST [=](pool_name [, pool_name...]) ;

Note the following:

• This statement can only be executed by the administrator of the sys tenant.

• For RESOURCE_POOL_LIST, only one resource pool can be deleted at a time.

Example

Assuming that a cluster has a total of 5 zones, z1, z2, z3, z4, and z5, all belonging to the same region, with one OBServer in each zone. There is a regular tenant named tenant1 with the following locality: locality='F@z1,F@z2,F@z3,F@z4,F@z5', resource_pool_list=('pool1','pool2'). The resource distribution of the resource pools is as follows: CREATE RESOURCE POOL pool1 UNIT 'uc1', UNIT_NUM 1, ZONE_LIST ('z1', 'z2', 'z3') and CREATE RESOURCE POOL pool2 UNIT 'uc2', UNIT_NUM 1, ZONE_LIST ('z4', 'z5').

According to business requirements, it is necessary to reduce the number of replicas from 5 to 3 and the number of resource pools from 2 to 1 for tenant1. That is, the locality of the tenant needs to be changed to locality='F@z1,F@z2,F@z3,', resource_pool_list=('pool1').

Procedure

1. Log in to the sys tenant of the cluster using the root user.

2. Modify the locality of tenant1 to delete replicas.

   According to the locality modification rules, only one zone’s locality can be deleted at a time. For more information about the locality modification rules, see Modify locality.

   obclient>ALTER TENANT tenant1 LOCALITY='F@z1,F@z2,F@z3,F@z4';
   
   obclient>ALTER TENANT tenant1 LOCALITY='F@z1,F@z2,F@z3';
   

3. Delete the pool2 resource pool from z4 and z5.

   obclient>ALTER TENANT tenant1 RESOURCE_POOL_LIST =('pool1') ;
   

More information

For other scenarios where you need to adjust the available resources for a tenant, you can modify the configuration and number of resource units in the resource pools.

• For instructions on modifying resource unit configurations, see Modify a unit config.
• For instructions on modifying the number of resource units in a resource pool, see Modify attributes of a resource pool.