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 is not assigned to a resource pool, you can directly drop it.

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

• If a resource unit is assigned to a resource pool, you cannot directly drop it. You must first remove it from the resource pool before dropping it.

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

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

  When you attempt to 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 need to remove unit1 from the resource pool pool1, you can create a new resource unit unit2, assign unit2 to pool1, and then drop 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 unit1 from the resource pool pool1.

     obclient> ALTER RESOURCE POOL pool1 UNIT='';
     

     Notice

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

  3. Assign unit2 to the resource pool pool1.

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

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

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

• If you want to drop a resource unit that is assigned to a resource pool and also clean up the resource pool, you must first drop the resource pool and then drop the resource unit.

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

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

  When you attempt to 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
  

  First, drop the resource pool pool1, and then drop the resource unit unit1. The drop 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