EJB.6.3 A Container s Management of Its Working Set

EJB.6.3 A Container's Management of Its Working Set

To efficiently manage the size of its working set, a session bean container may need to temporarily transfer the state of an idle stateful session bean instance to some form of secondary storage. The transfer from the working set to secondary storage is called instance passivation . The transfer back is called activation .

A container may only passivate a session bean instance when the instance is not in a transaction.

To help the container manage its state, a session bean is specified at deployment as having one of the following state management modes:

• STATELESS ” The session bean instances contain no conversational state between methods ; any instance can be used for any client.

• STATEFUL ” The session bean instances contain conversational state which must be retained across methods and transactions.