When session failover is implemented for Access Manager, session information is replicated in two backend session store databases. This ensures that if one Access Manager fails or stops, the information stored in the backend session databases can be used to keep the user continuously authenticated. If session failover is not implemented and the Access Manager server in which a user's session was created fails, the user will have to reauthenticate to perform an operation that requires a session token. The following diagram illustrates the session failover architecture.
For more information about Access Manager and session failover, see Chapter 6, Implementing Session Failover, in Sun Java System Access Manager 7.1 Postinstallation Guide.