Distributed sessions
WAS provides the following session mechanisms in a distributed environment:
- Database session persistence, where sessions are stored in the database specified.
- Memory-to-memory session replication, where sessions are stored in one or more specified WAS instances or profiles.
- WebSphere eXtreme Scale session replication, where sessions are stored in a data grid such as WebSphere eXtreme Scale.
When a session contains attributes that implement HttpSessionActivationListener, notification occurs anytime the session is activated (that is, session is read to the memory cache) or passivated (that is, 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 application server prior to activation in another application.
Related:
Sessions Task overview: Managing HTTP sessions