External Product Interface › EPI Failure Recovery › EPI Session Failure

EPI Session Failure

When a session between the EPI and an application fails, all communication between the two ceases. Any of the following conditions can cause an EPI session failure:

• An EPI system failure will result in a failure of all sessions using that EPI.
• Deactivation of an EPI application name in VTAM will result in a failure of all sessions using that EPI application ID.
• An EPI session to a cross-domain application will fail if disruption of the communications link between two systems (lost phone connection, lost satellite link, and so on) occurs.

After an EPI session failure, no commands can be issued over that session. If the session is the only one to a particular VTAM application, all communication is lost to that application. If other sessions exist to the same application, communication may still be possible over the remaining sessions.

If possible, the EPI will write messages to the system log to identify the commands that were being processed at the time a session failed.

After a session failure, systems that have defined the session with the RETRY option will automatically attempt to reestablish the session (assuming that both systems involved in the session are still operative).