Embodiments of a request failover mechanism may be used to failover
requests from clients of server instances in a cluster to alternative
server instances. One embodiment may use cluster-aware remote references
that include the IIOP endpoints at which the application server instances
forming the cluster listen to IIOP requests. Using a cluster-aware remote
reference to an object on an application server instance, a request to
the object may be failed-over to an alternate endpoint in the cluster
when the primary endpoint is unreachable. In one embodiment, once a
request for a referenced object is failed over to a new server instance,
all the subsequent requests to that object will continue to go to the
same server instance even if the original server instance becomes
available. One embodiment may provide client-side IIOP request load
balancing in clustered application server environments through a load
balancer subsystem using the cluster-aware remote references.