Introduction to Failover:
Oracle Failover is a critical feature designed to ensure high availability and continuous operation of Oracle databases in the event of unexpected system failures. In enterprise environments where downtime can result in significant financial loss and operational disruption, Oracle Failover mechanisms provide robust solutions to minimize or eliminate the impact of hardware failures, network issues, or other unexpected outages.
Configuration Details:
Login to standby server:
Step:1 Check the database role and open_mode
SQL> select database_role from v$database;
DATABASE_ROLE
—————-
PHYSICAL STANDBY
Step:2 Cancel the MRP process
[oracle@standby dbs]$ ps -ef | grep mrp
oracle 79976 1 0 03:19? 00:00:02 ora_mrp0_prime
oracle 81638 81585 0 03:43 pts/2 00:00:00 grep –color=auto mrp
[oracle@standby dbs]$ sqlplus / as sysdba
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 – Production
Version 19.2.0.0.0
SQL> select database_role from v$database;
DATABASE_ROLE
—————-
PHYSICAL STANDBY
SQL> recover managed standby database cancel;
Media recovery complete.
Step 3:
Run the below command to bring up the standby as primary
SQL> alter database recover managed standby database finish;
Database altered.
SQL> select name,open_mode,database_role from v$database;
NAME OPEN_MODE DATABASE_ROLE
——— ——————– —————-
PRIME MOUNTED PHYSICAL STANDBY
SQL> alter database activate standby database;
Database altered.
Note:- Since the managed recovery process has been stopped between primary and standby database and standby becomes primary database.
To verify follow below steps:
Step 4:
Bounce your database and verify database name, its open mode and its role.
SQL> shutdown immediate;
Then start it again:
SQL> startup
Step 5:
select name,open_mode,database_role from v$database;
NAME OPEN_MODE DATABASE_ROLE
———- ——————— —————————-
PRIME READ WRITE PRIMARY
Conclusion:
Oracle Failover is a vital component for organizations that require high availability and resilience in their database environments. By implementing failover solutions such as Oracle RAC, Data Guard, ASM, and TAF, businesses can safeguard their operations against unexpected failures, ensuring minimal disruption to services and maintaining data integrity. These failover mechanisms not only protect against hardware and network failures but also provide peace of mind by offering a robust disaster recovery strategy.
