Redundancy

Redundancy within Application Server is achieved by deploying combinations of AppEngines and DI client objects on separate nodes (platforms). In its most basic configuration and and the one most generally used, there is one primary and one secondary node. This two-node primary and secondary configuration is natively supported by an device integration object dedicated to the task, the RedundantDIObject. Each node of the redundant pair has dual, dedicated NICs. At run time, the nodes will function as either active and standby. Note both the primary and secondary platforms can function as either active or standby. Active and standby status is set by the RedundantDIObject that links to the primary and secondary DI client objects running on the redundant platforms. If there is a failure that affects communication with the primary DI client object, the RedundantDIObject performs an automatic failover to the secondary object.

Implementing redundancy ensures continuous operation by providing an AppEngine that remains active in the event of a single system component failure. This configuration operates on the premise that one engine is in an Active State while the other is in a Standby State waiting to take control.

The following information describes redundancy in the context of Application Server.