Delay the commit of an IMS synchronous program switch target transaction until the original transaction performs the commit

IMS synchronous program switch can be used to synchronously call an IMS transaction from a different IMS application. This allows you to reuse existing functionality within new IMS applications without implementing it again or without copying the existing code. This is especially interesting for IMS application modernization, because it is the easiest way to call existing functionality implemented in COBOL, PL/I or Assembler from a new IMS Java application.

Actually the original transaction of an IMS synchronous program switch notices ABENDs in the target transaction, but the target transaction will be already committed when the original transaction ABENDs after the response from the target transaction was received. This could cause inconsistent data and because of this IMS synchronous program switch actually cannot be used for scenarios where both the original and the target transaction are manipulating databases.

Because IMS synchronous program switch is using OTMA and OTMA allows you to delay the commit of an IMS transaction until the caller of the transaction has received the response from the IMS transaction, it would be possible to delay the commit of an IMS synchronous program switch target transaction until the original transaction performs its commit by simply delaying the acknowledgement for the received response until this point in time. This RFE requests an option for being able to do this because this allows to preserve data consistency even in the case both the original and the target transaction of an IMS synchronous program switch are manipulating databases. Because this would mean that the target transaction stays longer active in an IMS region and its database locks will be held for a longer time, it is important to have this only as an option. It is not necessary to do this in every IMS synchronous program switch scenario. It would be also important to automatically send a NACK to the IMS synchronous program switch target transaction when the original transaction ABENDs such that the rollback of the target transaction is performed as soon as possible.