Distributed sessions
In a distributed environment, you can save sessions in a database using database session persistence or you can store sessions in multiple WAS instances using memory-to-memory session replication.
When a session contains attributes that implement HttpSessionActivationListener, notification occurs anytime the session is activated (session is read to the memory cache) or passivated (session leaves the memory cache). Passivation can occur because of a server shutdown or when the session memory cache is full and an older session is removed from the memory cache to make room for a newer session. It is not guaranteed that a session is passivated in one appserver prior to activation in another application.
Related concepts
Sessions
Related tasks
Task overview: Managing HTTP sessions