Asymmetric or active / passive configuration

In an asymmetric configuration, an application runs on a primary server. A dedicated redundant server is present to take over on any failure. The redundant server is not configured to perform any other functions.

Figure: Asymmetric failover shows failover within an asymmetric cluster configuration, where a database application is moved, or failed over, from the master to the redundant server.

Figure: Asymmetric failover

Asymmetric failover

This configuration is the simplest and most reliable. The redundant server is on stand-by with full performance capability. If other applications are running, they present no compatibility issues.