Delete a zone

Deleting a zone is typically used in scenarios such as cluster scale-down.

Prerequisites

Before deleting a zone, confirm the following:

• Ensure no nodes exist in the zone. For operations related to viewing nodes within a zone, see View nodes.

• Ensure the zone has been stopped.

  The statement to stop a zone is as follows:

  obclient [(none)]> ALTER SYSTEM STOP ZONE zone_name;
  

  Here, zone_name is the name of the zone to be stopped. Each statement only supports stopping one zone at a time.

  Example:

  obclient [(none)]> ALTER SYSTEM STOP ZONE zone4;
  

Procedure

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

   The connection example below is for reference only; please use your actual environment configurations when connecting to the database.

   obclient -h10.xx.xx.xx -P2883 -uroot@sys#obdemo -p***** -A
   

   For more detailed instructions on connecting to a database, see Overview of database connections (MySQL-compatible mode) and Overview of database connections (Oracle-compatible mode).

2. Execute the following command to delete a zone from the cluster.

   The statement is as follows:

   obclient [(none)]> ALTER SYSTEM DELETE ZONE zone_name;
   

   Here, zone_name is the name of the zone to be deleted. Each statement only supports deleting one zone at a time. If you need to delete multiple zones, repeat this statement.

   Example: To delete zone4 from the cluster:

   obclient [(none)]> ALTER SYSTEM DELETE ZONE zone4;
   

3. After the operation succeeds, you can query the oceanbase.DBA_OB_ZONES view to confirm it.

   obclient [(none)]> SELECT * FROM oceanbase.DBA_OB_ZONES;
   +-------+----------------------------+----------------------------+--------+-----+----------+-----------+
   | ZONE  | CREATE_TIME                | MODIFY_TIME                | STATUS | IDC | REGION   | TYPE      |
   +-------+----------------------------+----------------------------+--------+-----+----------+-----------+
   | zone1 | 2022-12-20 17:50:17.168745 | 2022-12-20 17:50:40.801054 | ACTIVE | HZ0 | hangzhou | ReadWrite |
   | zone2 | 2022-12-20 17:50:17.168745 | 2022-12-20 17:50:40.809504 | ACTIVE | HZ0 | hangzhou | ReadWrite |
   | zone3 | 2022-12-20 17:50:17.169804 | 2022-12-20 17:50:40.815833 | ACTIVE | SH0 | shanghai | ReadWrite |
   +-------+----------------------------+----------------------------+--------+-----+----------+-----------+
   3 rows in set
   

   If the zone is not in the query result, the zone was deleted successfully.

   For more information about the oceanbase.DBA_OB_ZONES view, see oceanbase.DBA_OB_ZONES.

References

For more information about zone-related O&M operations, see the following topics:

• Query zones

• Add a zone

• Modify a zone

• Isolate a zone