Unit of recovery disposition

IBM MQ for z/OS provides unit of recovery dispositions. This feature allows you to configure whether the second phase of 2-phase commit transactions can be driven, for example, during recovery, when connected to another queue manager within the same queue sharing group (QSG).

Unit of recovery disposition

The unit of recovery disposition is related to an application's connection and subsequently any transactions that it starts. There are two possible unit of recovery dispositions.

• A GROUP unit of recovery disposition identifies that a transactional application is logically connected to the queue sharing group and does not have an affinity to any specific queue manager. Any 2-phase commit transactions that it starts that have completed phase-1 of the commit process, that is, they are in doubt, can be inquired and resolved, when connected to any queue manager within the QSG. In a recovery scenario this means that the transaction coordinator does not have to reconnect to the same queue manager, which might be unavailable.
• A QMGR unit of recovery disposition identifies that an application has a direct affinity to the queue manager to which it is connected and any transactions that it starts also have this disposition.

  In a recovery scenario the transaction coordinator must reconnect to the same queue manager to inquire, and resolve, any in-doubt transactions, irrespective of whether the queue manager belongs to a queue sharing group.

See Unit of recovery disposition for details how to implement this feature.

Parent topic: Transactional support scenarios