Session failure

In the event of a session failure, a CPI Communications driven application program can provide full integrity by issuing commit (SRRCMIT) or a backout (SRRBACK) calls. If an LU 6.2 session fails during an LU 6.2 conversation, you can end the conversation or continue processing.

If the session fails before the transaction completes phase one of the two-phase commit sync-point protocol, IMS takes action as follows:

• For both standard and modified standard DL/I application programs, if the original conversation is asynchronous, IMS commits all database changes, sends all output messages asynchronously, and deallocates any established conversations.
• For standard DL/I application programs:
  • If the conversation is synchronous and a user destination exit routine is provided, the routine determines whether to abort or commit. If it commits, IMS sends all output messages asynchronously and commits all database changes. If it aborts, or if no user destination exit routine is provided, IMS aborts the transaction and backs out all changes.
• For modified standard DL/I application programs:
  • If the user destination exit routine commits, IMS commits database changes and inserts all messages to the IMS message queue asynchronously.
  • If the original conversation is synchronous and the user destination exit routine aborts, IMS aborts the transaction, backs out all database changes, and discards all messages inserted to the IMS message queue (unless the insert used an express PCB).

If the session fails after the transaction starts phase two of the two-phase commit, IMS sync-point processing continues for both standard and modified DL/I application programs, despite a session failure.