The figure shows requests going through a load balancer and into only the I2 instance. Instance I1 is stopped and added to Cluster2. Cluster2 now contains I1 and I2 instances. Cluster1 is empty.

Each instance contains an OC4J instance called OC4J_Clustered. Both instances I1 and I2 contain version 1 of the "App" application.

The two OC4J_Clustered instances are still in the same IP multicast replication group, but because I1 is not running, HttpSession replication is not taking place.