This appendix describes how to install and configure the Ingres High Availability Option in Sun cluster environments.
The information in this appendix is intended for engineers with extensive knowledge of software and hardware in the cluster environment, including cluster concepts such as high availability (HA), global file systems, the resource management object model, resource properties, logical host names, shared addresses, failover, and switchover.
Note: This appendix refers to specific Sun Cluster administration commands. For additional information about these commands, consult your Sun Cluster documentation.
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Failover is the process by which a cluster automatically relocates a data service from a failed primary node to a designated secondary node. If a failover occurs, a brief interruption in service can occur, requiring you to reconnect after the failover has completed. Once reconnected, the physical server on which Ingres is running is transparent to the end user.
The automatic failover feature ensures that transactions are handled by an active node in the cluster if a hardware or software failure occurs.
Note: Any transactions that are in flight at the time of failure are lost.
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The Ingres High Availability Option for clusters runs application instances only on a single node. Depending on how the data service has been configured, when the fault monitor detects an error, it either attempts to restart the instance on the same node or to start the instance on another node for failover.
Note: The Ingres High Availability Option is not scalable; that is, it does not provide active instances on multiple nodes.