Unless you are using synchronous replication (locks up transactions if there is an issue with replication) there's no safe way to do automatic failover with an

Unless you are using synchronous replication (locks up transactions if there is an issue with replication) there's no safe way to do automatic failover with an RDBMS without using shared storage (expensive, pain in the butt). Corosync and pacemaker make setting up automatic failover with shared storage relatively painless. I don't do it this way personally because shared storage is a giant pain.