Recovering from a Failed DG Broker Switchover

 

Problem Description

Should you find yourself in a situation where a Data Guard Broker switchover to Standby has failed and left your environment with 2 Physical Standby Databases, follow this simple procedure to switch the failed switchover Standby Database back to Primary.

 

You may also see the following error from a DGMGRL "show configuration" command:

 

ORA-16816: incorrect database role

 

Solution

 

1.       Logon (as sysdba) to the instance that was your Primary database instance before the switchover.

2.       Confirm the database role.

SQL> select database_role from v$database;

 

DATABASE_ROLE

----------------

PHYSICAL STANDBY

 

3.       Shutdown the instance.

SQL> shutdown immediate;

4.       Mount the database.

SQL> startup mount;

5.       Cancel the MRP process. You will receive “ORA-16136: Managed Standby Recovery not active” if it is not running, but you can ignore.

SQL> alter database recover managed standby database cancel;

6.       Terminate the current switchover to Standby that never completed fully.  

SQL> alter database recover managed standby database finish;

7.       Now switchover to Primary.

SQL> alter database commit to switchover to primary with session shutdown;

8.       Open the database.

SQL> alter database open;

9.       Confirm the database role.

SQL> select database_role from v$database;

 

DATABASE_ROLE

----------------

PRIMARY


Additional Steps

When attempting to open the Primary Database you may suffer the following error:

 

SQL> alter database open

*

ERROR at line 1:

ORA-16649: possible failover to another database prevents this database being opened

 

In this case, before you can open the database, you must disable Data Guard Broker as follows:

 

SQL> alter system set dg_broker_start=false scope=both sid=’*’;

 

System altered.

 

SQL> alter database open;

 

Database altered.

 

Now re-install Data Guard Broker.

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