Handling a PostgreSQL database failover

Edge for Private Cloud v4.18.05

Perform the following during a PostgreSQL database failover:

1. Stop apigee-postgresql on the current master if it is still running:

   /opt/apigee/apigee-service/bin/apigee-service apigee-postgresql stop

2. Go to standby node and invoke the following command to make it the master:

   /opt/apigee/apigee-service/bin/apigee-service apigee-postgresql promote-standby-to-master IPorDNSofOldMaster

If old master is restored at some time in the future, make it a standby node:

1. On the current master, edit the config file to set:

   PG_MASTER=IPorDNSofNewMaster
   PG_STANDBY=IPorDNSofOldMaster

2. Enable replication on the new master:

   /opt/apigee/apigee-service/bin/apigee-service apigee-postgresql setup-replication-on-master -f configFIle

3. On the old master, edit the config file to set:

   PG_MASTER=IPorDNSofNewMaster
   PG_STANDBY=IPorDNSofOldMaster

4. Stop apigee-postgresql on the old master:

   /opt/apigee/apigee-service/bin/apigee-service apigee-postgresql stop

5. On the old master, clean out any old Postgres data:

   rm -rf /opt/apigee/data/apigee-postgresql/

6. Configure the old master as a standby:

   /opt/apigee/apigee-service/bin/apigee-service apigee-postgresql setup-replication-on-standby -f configFile

7. On completion of replication, verify the replication status by issuing the following scripts on both servers. The system should display identical results on both servers to ensure a successful replication:
   1. On the master node, run:

      /opt/apigee/apigee-service/bin/apigee-service apigee-postgresql postgres-check-master

      Verify that it says it is the master.

   2. On the standby node:

      /opt/apigee/apigee-service/bin/apigee-service apigee-postgresql postgres-check-standby

      Verify that it says it is the standby.