98 DB2 UDB V8 and WebSphere V5 Performance Tuning and Operations Guide
application servers from a single point. However, there is more installation
and maintenance associated with the additional machines.
Cost: More machines.
4.4.9 Session persistence considerations
If the application maintains state between HTTP requests and we are using
vertical or horizontal scaling, then we must consider using an appropriate
strategy for session management.
Each application server runs in its own JVM process. To allow a fail-over from
one application server to another without logging out users, we need to share the
session data between multiple processes. There are two different ways of doing
this in IBM WebSphere Application Server Network Deployment V5. ...