Pre-Failover Actions

Failover is the recovery process within the cluster when the primary database fails. It detects failures and switches to a standby database thereby minimizing downtime. The failed database should be reconfigured back to the cluster when it becomes available.

REPMGR does not support automatic failover. In the event of a failover, you will need to manually “REJOIN” the failed node to the cluster with the following procedure:

1. Switch to root user.
   sudo su -
2. Stop the postgresql server.
   systemctl stop postgresql-10
3. Switch to postgres user.
   su - postgres
4. Manually force the standby node to rejoin using the commands:
   PGPASSWORD={repuser_Password_Here} /usr/pgsql-10/bin/repmgr -f /etc/repmgr/10/repmgr.conf -h {NEW_PRIMARY_IP} -U repuser -d postgres standby clone --force-rewind --force
exit
5. Start postgresql and execute the command below to register the database as standby.
   systemctl start postgresql-10
su - postgres
/usr/pgsql-10/bin/repmgr standby register --force
exit
   

Troubleshooting:
If the failover does not work, use the following commands on the standby machine:
su - postgres
repmgr standby promote