> [!CAUTION]
> **Caution:** This documentation covers Edge for Private Cloud 4.17.09, which is no longer supported. Google does not provide security patches, bug fixes, or technical support for this version. The current supported version is 4.54.00. See the [Edge for Private Cloud documentation](https://docs.apigee.com/private-cloud/latest/overview) for the current version, or [All versions](https://docs.apigee.com/private-cloud/versions) to compare releases.

*Edge for Private Cloud v. 4.17.09*

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/  

   **Note**: If necessary, you can backup this data before deleting it.
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  

      Validate that it says it is the master.
   2. On the standby node:  
      \> /opt/apigee/apigee-service/bin/apigee-service apigee-postgresql postgres-check-standby  

      Validate that it says it is the standby.