DROP RESOURCE UNIT

Purpose

This statement is used to drop a resource unit.

Syntax

DROP RESOURCE UNIT unit_name;

Parameters

Examples

• If a resource unit has not been assigned to a resource pool, you can directly drop it.

  obclient> DROP RESOURCE UNIT unit1;
  Query OK, 0 rows affected
  

• If a resource unit has been assigned to a resource pool, you cannot directly drop it. You need to remove it from the resource pool before dropping it.

  For example, in the following example, the resource unit unit1 has been assigned to the resource pool pool1.

  obclient> CREATE RESOURCE POOL pool1 UNIT='unit1', UNIT_NUM=1, ZONE_LIST=('zone2');
  

  If you directly drop the resource unit unit1, an error is returned.

  obclient> DROP RESOURCE UNIT unit1;
  ERROR 4634 (HY000): resource unit 'UNIT1' is referenced by some resource pool
  

  If you still want to remove the resource unit unit1 from the resource pool pool1, you can create a new resource unit unit2 and assign it to the resource pool pool1 before dropping the resource unit unit1. Here is an example:

  1. Create a new resource unit unit2.

     obclient> CREATE RESOURCE UNIT unit2 MAX_CPU 4, MEMORY_SIZE '5G', MAX_IOPS 1280,LOG_DISK_SIZE '10G', MIN_CPU=4, MIN_IOPS=1024;
     

  2. Remove the resource unit unit1 from the resource pool pool1.

     obclient> ALTER RESOURCE POOL pool1 UNIT='';
     

     Notice

     Each time you execute the ALTER RESOURCE POOL command, you can only add or remove one resource unit from the resource pool. Therefore, you need to remove unit1 first and then add unit2.

  3. Assign the resource unit unit2 to the resource pool pool1.

     obclient> ALTER RESOURCE POOL pool1 UNIT='unit2';
     

  4. Drop the resource unit unit1. The operation is successful.

     obclient> DROP RESOURCE UNIT unit1;
     Query OK, 0 rows affected
     

• If you want to drop a resource unit that has been assigned to a resource pool, you need to drop the resource pool first and then drop the resource unit.

  For example, in the following example, the resource unit unit1 has been assigned to the resource pool pool1.

  obclient> CREATE RESOURCE POOL pool1 UNIT='unit1', UNIT_NUM=1, ZONE_LIST=('zone2');
  

  If you directly drop the resource unit unit1, an error is returned.

  obclient> DROP RESOURCE UNIT unit1;
  ERROR 4634 (HY000): resource unit 'UNIT1' is referenced by some resource pool
  

  Drop the resource pool pool1 first and then drop the resource unit unit1. The operation is successful.

  obclient> DROP RESOURCE POOL pool1;
  Query OK, 0 rows affected
  

  obclient> DROP RESOURCE UNIT unit1;
  Query OK, 0 rows affected
  

References

Delete a resource specification