Automatic failover configuration with redundant abservers

An observer for use in an automatic failover configuration having a primary database system and a standby database system, the observer being one of a plurality of observers in the automatic failover configuration and being implemented in a processor having a storage device accessible to the processor and the observer having communication links to the primary database system and the standby database system, exchanging control messages with the primary and/or the standby, and providing a quorum to the primary or the standby for a transition from a configuration state of the automatic failover configuration to another configuration state thereof,

• the observer comprising:
• an active observer indicator that indicates whether the observer is exchanging control messages with the primary and/or the standby;
• an automatic failover configuration state handler that responds to the control messages when the observer is active by providing the quorum where necessary;
• and
• an active observer monitor which, when the observer is not active, monitors whether the active observer has become absent from the automatic failover configuration and when the active observer has become absent, acts to make another of the plurality of observers the active observer,
• the observer being linked by one or more non-redo communications links that are not redo communications links to the other observer, the primary database system, and the standby database system,
• the observer and the other observer operating on non-database system entities which are coupled to the non-redo communication link and having hardware and/or operating system platforms that are different from the hardware and/or operating system platforms used in the primary and standby database systems, and
• the active observer monitor detecting absence of the active observer by monitoring the primary database system and the standby database system via the non-redo communications links for receipt of control messages from the active observer.

A method practiced in an observer belonging to an automatic failover configuration having a primary database system and a standby database system and one or more observers, the observers being implemented in a processor having a storage device accessible to the processor, the observers having communication links to the primary database system and the standby database system, and an active observer of the observers exchanging control messages with the primary and/or the standby and providing a quorum to the primary or the standby for a transition from a configuration state of the automatic failover configuration to another configuration state thereof,

• the method comprising the steps of:
• when the observer is the active observer,
• ceasing to be the active observer in response to a control message indicating that the observer is no longer the active observer;
• when the observer is not the active observer,
• monitoring whether the active observer has become absent from the automatic failover configuration;
• and
• when the active observer has become absent, acting to make another of the observers the active observer,
• the observer being linked by one or more non-redo communications links that are not redo communications links to the other observer, the primary database system, and the standby database system,
• the observers operating on non-database system entities which are coupled to the non-redo communication link and having hardware and/or operating system platforms that are different from the hardware and/or operating system platforms used in the primary and standby database systems;
• and
• the active observer monitor detecting absence of the active observer by monitoring the primary database system and the standby database system via the non-redo communications links for receipt of control messages from the active observer.