The figure shows requests going through a load balancer and into only one Oracle Application Server instance, I1, because the second instance I2 is stopped. The instance I1 is still in a cluster, Cluster1, but there is now a second cluster, Cluster2, and instance I2 belongs to that cluster. I2 is still stopped.

Each instance contains an OC4J instance called OC4J_Clustered. Version 0 of an application called "App" is running in OC4J_Clustered in I1. In I2, there is a new version of the application, version 1.

The two OC4J_Clustered instances are still in the same IP multicast replication group, but because I2 is still stopped, HttpSession replication is not taking place.