Configuring failover for Professional Edition

Follow the steps given below to configure failover in the Professional Edition setup:

Note: The following steps are for configuring failover with MS SQL as a common backend database. For PostgreSQL as backend DB, follow the steps mentioned here.

1. Configuring Primary server

  • Install Applications Manager in the Primary server. While configuring the database backend, make sure you select the database as MSSQL and specify the DB name (By default, it is AMDB) and port number.
  • Once the installation is complete, start the primary server.

2. Configuring Secondary/Failover server

  • Install Applications Manager in the Secondary server. While configuring the database backend, make sure you select the database as MS SQL and give the same DB name, and port number as in Step 1. Make sure to give the same SQL Server's hostname, DB name, and port as that of the Primary server.

Upon completing the above steps, Failover will be enabled by default. The Secondary server will be connected to the MS SQL database and will listen to the Primary server. However, the installation will not be started completely as the Primary is already up and running.

You can verify whether the failover setup is configured properly with the help of logs generated by Applications Manager. Click here to view the sample output.

Note:
  • You can also choose to retain the Primary server as the preferred server choice in the failover setup by specifying the value for the key am.failover.preferredstandby as true in AMServer.properties file (available under <Applications Manager Home>/conf/ directory). Doing this will signal the secondary server to go into standby mode whenever the primary server becomes available. However, make sure to save the file and then restart Application Manager for the changes to take effect.
  • In case you are facing issues in primary and secondary failover communication or server IP change, stop both primary and secondary servers. Then connect to the backend database and execute the following query: TRUNCATE TABLE BEFAILOVER
    After executing the above query, start the primary server first and then proceed to start the secondary server.