ALTER TENANT

Purpose

The ALTER TENANT statement is used to modify the properties of a user tenant, including the Locality, primary zone, resource pool list, and system variable values.

To modify the name of a user tenant, you can use the ALTER TENANT ... RENAME statement.

To lock or unlock a user tenant, you can use the ALTER TENANT ... LOCK / UNLOCK statement. After executing the ALTER TENANT ... LOCK statement, the system will no longer allow users to create new connections to the locked tenant, but existing connections will remain unaffected.

Privilege requirements

Only the root user of the sys tenant (root@sys) can modify a tenant. Other tenants do not support modifying tenants.

Syntax

ALTER TENANT

ALTER TENANT tenant_name
    [SET] [tenant_option_list] [set_sys_var];

tenant_option_list:
    tenant_option [, tenant_option ...]

tenant_option:
      LOCALITY [=] 'locality_description'
    | PRIMARY_ZONE [=] zone
    | RESOURCE_POOL_LIST [=](pool_name [, pool_name...])
    | ENABLE_ARBITRATION_SERVICE [=] {True | False}
    | [DEFAULT] TABLEGROUP [=] {NULL | tablegroup_name}
    | ENABLE_EXTENDED_ROWID [=] {true | false}  
    | COMMENT [=]'string'   

set_sys_var:
    VARIABLES var_name {TO | =} var_value [,var_name {TO | =} var_value...]

ALTER TENANT ... RENAME

ALTER TENANT tenant_name RENAME GLOBAL_NAME TO new_tenant_name;

ALTER TENANT ... LOCK / UNLOCK

ALTER TENANT tenant_name LOCK | UNLOCK;

Parameters

Examples

• Change the primary zone of tenant tenant1 to zone2.

  obclient [oceanbase]> ALTER TENANT tenant1 primary_zone='zone2';
  

• Change the primary zone of tenant tenant1 to RANDOM.

  obclient [oceanbase]> ALTER TENANT tenant1 primary_zone = RANDOM;
  

  If the tenant has three zones, zone1, zone2, and zone3, the preceding statement is equivalent to

  obclient [oceanbase]> ALTER TENANT tenant1 primary_zone = 'zon1,zone2,zone3';
  

• Modifying a resource pool is typically used in scenarios where you want to upgrade or downgrade the number of replicas for a tenant. When modifying a resource pool, you can only add or remove one resource pool at a time. You cannot directly replace the resource pool pool1 of a tenant with pool2 using the following statement, otherwise, the following error will occur.

  obclient [oceanbase]> ALTER TENANT tenant1 resource_pool_list=('pool2');
  

  The error message is as follows:

  ERROR 1210 (HY000): Incorrect arguments to resource pool list
  

  If you want to adjust the available resources for a tenant, such as expanding the tenant, you can increase the specifications of the resource units.

  obclient [oceanbase]> ALTER RESOURCE UNIT unit1 MAX_CPU 15, MEMORY_SIZE '20G', MAX_IOPS 1280, MIN_CPU=10, MIN_IOPS=1024;
  

• Change the locality of tenant tenant1 to add replicas. In this example, F indicates a full-featured replica, and B_4 is the name of the new zone.

  1. Create a resource unit named unit2.

     obclient [oceanbase]> CREATE RESOURCE UNIT unit2, MAX_CPU=5, MIN_CPU=2.5, MEMORY_SIZE= '32G', MAX_IOPS=10000, MIN_IOPS=5000, LOG_DISK_SIZE=5301023539200;
     

  2. Create a resource pool named pool2.

     obclient [oceanbase]> CREATE RESOURCE POOL pool2 unit='unit2',unit_num=1,zone_list=('B_4');
     

  3. Add the resource pool pool2 to the tenant.

     obclient [oceanbase]> ALTER TENANT tenant1 resource_pool_list=('pool1','pool2');
     

  4. Change the locality of the tenant.

     obclient [oceanbase]> ALTER TENANT tenant1 locality="F@B_1,F@B_2,F@B_3,F@B_4";
     

• In a scenario where an arbitration service is deployed, enable the arbitration service for tenant1.

  obclient [oceanbase]> ALTER TENANT tenant1 ENABLE_ARBITRATION_SERVICE=true;
  

• Rename the name of the regular tenant tenant1 to tenant101.

  obclient [oceanbase]> ALTER TENANT tenant1 RENAME GLOBAL_NAME TO tenant101;
  

• Lock the tenant tenant1.

  obclient [oceanbase]> ALTER TENANT tenant1 LOCK;