Session replication uses the JvmRouteValve to detect session failover and modify the session id so mod_jk knows to thereafter pin the the session to the new node.

JBossCacheManager also has logic that understands how to strip out the jvmRoute from the session id.

Need to make this logic a pluggable policy, so we can deal with other load balancers that may have a different mechanism for tracking to which node a session is pinned.