13.8 IBM EAR extensions: Sharing session context

In accordance with the servlet 2.4 API specification, the session manager supports session scoping by Web module only. Only servlets in the same Web module can access the data associated with a particular session. WAS provides an option that use to extend the scope of the session attributes to an enterprise application. Therefore, you can share session attributes across all the Web modules in an enterprise application.

This option can be set in the toolkit in the enterprise application deployment descriptor.

1.	Open the deployment descriptor by double-clicking the enterprise application.

2.	Check the Shared session context option in the WebSphere Extensions section.

Figure 13-22 EAR deployment descriptor

Important: To use this option, install all the Web modules in the enterprise application in the same appserver. You cannot use this option when one Web module is installed in one server and the second Web module is installed in a different server. In such split installations, applications might share session attributes across Web modules using distributed sessions. However, session data integrity is compromised when concurrent access to a session is made in different Web modules. Sharing HTTP session context also severely restricts the use of some session management features, like time-based writes. For enterprise applications on which this option is enabled, the session management configuration set at the Web module level is ignored. Instead, the session management configuration defined at the enterprise application level is used.