Delete a zone

You can delete a zone to scale in a cluster.

Prerequisites

Before you delete a zone, make sure that:

• The zone contains no nodes. For more information about how to view the nodes in a zone, see View a node.

• The zone is stopped.

  You can execute the following statement to stop a zone:

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

  In the statement, zone_name specifies the name of the zone to be stopped. This statement stops only one zone at a time.

  Here is an example:

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

Procedure

1. Log on to the sys tenant of an OceanBase cluster as the root user.

   Note that you must specify the corresponding fields in the following sample code based on your actual database configurations.

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

   For more information about how to connect to a database, see Connection methods (MySQL mode) or Connection methods (Oracle mode).

2. Execute the following statement to delete a zone from a cluster:

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

   In the statement, zone_name specifies the name of the zone to be deleted. This statement deletes only one zone at a time. To delete multiple zones, execute this statement repeatedly.

   For example, to delete a zone named zone4 from the cluster, execute the following statement:

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

3. After the statement is executed, you can query the oceanbase.DBA_OB_ZONES view to verify whether the zone is deleted.

   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 this zone does not appear in the query result, the zone is successfully deleted.

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

References

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

• View a zone

• Add a zone

• Modify a zone

• Isolate a zone