Each HTTP session has a validity set to it. HTTP sessions that have exceeded validity, found as a result of checking validity on the basis of the information of last access time, are deleted. When an HTTP session is deleted because it exceeds validity, the corresponding global session information is also deleted as an extension of that processing.

Validity monitoring threads existing in the Web container periodically monitor the validity of HTTP sessions. A validity monitoring thread exists for every Web application.

The following figure shows the flow of processing executed when deleting global session information due to expiry of validity:

Figure 7-8 Processing when validity of global session information expires (EADs session failover functionality)

1. HTTP sessions that are determined to have expired by the validity monitoring thread are disabled.
2. HTTP session and global session information are deleted.
3. User functions provided by the EADs session failover functionality are executed on the EADs server.
4. The contents of the J2EE identifier, owned by the HTTP session, are checked on the EADs sever. If the contents match with the identifier of the J2EE server under operation, the global session information is deleted.