Using transient data

CICS application programs commonly use transient data queues (TD). To enable transactions that use a TD queue that must be shared, to be dynamically routed to a target region, you must ensure that the TD queues are globally accessible.

The dynamic transaction routing considerations for TD queues have much in common with those for temporary storage.

All transient data queues must be defined to CICS, and must be installed before the resources become available to a CICS region. These definitions can be changed to support a remote transient data queue-owning region (QOR).

However, there is a restriction for TD queues that use the trigger function. The transaction to be invoked when the trigger level is reached must be defined as a local transaction in the region where the queue resides (in the QOR). Thus the trigger transaction must execute in the QOR. However, any terminal associated with the queue need not be defined as a local terminal in the QOR. This does not create an inter-transaction affinity.

Figure 1 illustrates the use of a remote transient data queue-owning region.

Figure 1. Using remote queues to avoid inter-transaction affinity relating to transient data. The transient data queue definitions installed in the target regions are defined as owned by the QOR (CICQ). All the transient data queue definitions installed in the QOR are local, some with trigger levels.