Patent ID: 8255369

Claim:
An automatic failover configuration comprising: a primary database system on a first host machine operating in a first database server that processes transactions and produces redo data therefor as a primary database system participant; a standby database system on a second host machine operating in a second database server that receives the redo data via a redo communications link as a standby database system participant; and an active observer, which is a client of the first and second database server, that provides a quorum for a failover operation in which the standby database system participant becomes the primary database system participant, the active observer exchanging first control messages with the primary database system and the standby database system via one or more non-redo communications links, the primary database system and the standby database system exchanging second control messages via the one or more non-redo communications links; the active observer being an independently executing entity from the primary database system and the standby database system, the active observer executing on system which is coupled to the non-redo communications links, and the active observer employing the same interface to communicate with the primary database system and the standby database system as any other client of the database servers; and wherein the first and second control messages propagate a current automatic failover configuration state among participants of the automatic failover configuration, the current automatic failover configuration state including an indication which changes when the active observer is to request further state information from the primary database system, the active observer responding to the changed indication by requesting the further state information from the primary database system.