Web Server supports cluster-based session replication and failover. Session replication and failover provides high availability to web applications by replicating HTTP sessions from one server instance to another in the same server cluster. Because each HTTP session has a backup copy on a remote instance, a server failure that renders one instance in the cluster unavailable does not disturb session continuity.
For more information on Light Weight Session Replication support, Sun Java System Web Server 7.0 Update 6 Administrator’s Guide.