session replication

i have some question regarding session replication in a clustered environment..

i am doing a poc on session replication in a clustered environment

1.how session replication happens ?
2.in a two server cluster server 1 and server2
when server 1 is down all its session is replicated to server 2 which is active..
is the replicated session comes back when the server 1 is active again?
3.is there any way we can find out which server currently serves the request for information purpose?

thnks
samal

Hi Samal,

Using in-memory replication, WebLogic Server copies a session state from one server instance to another. The primary server creates a primary session state on the server to which the client first connects, and a secondary replica on another WebLogic Server instance in the cluster. The replica is kept up-to-date so that it may be used if the server that hosts the servlet fails.

(from docs) read more at

http://download.oracle.com/docs/cd/E11035_01/wls100/cluster/failover.html#wp1022034

ALso the flow chart at the end gives you good idea of Failover with proxy plug-in

http://download.oracle.com/docs/cd/E11035_01/wls100/plugins/nsapi.html