320 WebSphere Application Server V8.5 Concepts, Planning, and Design Guide
If the data is mostly read-only, consider using replication facilities to keep multiple copies
synchronized behind a virtual IP. Most commercial database management systems offer
some form of replication facility to keep copies of a database synchronized.
Session data
WebSphere Application Server provides the following options for persisting the session data:
Using memory-to-memory replication to create a copy of the session data in one or more
additional servers (several options are available)
Storing the session data in an external database
The choice of which option to use is up to you, and performance results can vary. External
database persistence survives node ...