Since sysplex-scope ENQUEUE supports deadlock timeout there should be no possibility of an unresolved deadlock across CICS® systems.
If a CICS task fails, the NQ domain releases all MVS™ ENQs held on behalf of that CICS task
If a CICS system fails, MVS releases all MVS ENQs owned by that CICS region. This applies even if the reason for the CICS system failure was an MVS or CEC failure.
When there is a rogue task with enqueues held, which hangs or loops but is not subject to runaway, the entire region can halt. CPSM tries to assist in the determination of which task to purge to free-up the system. CPSM allows you to put out an alert when a task's suspend time is too long. Once this has occurred, you need to find the task causing the problem. To do this:
If the suspend reason is ENQUEUE, you have to find out which enqueue is being waited upon by this task.
You are now in a position to analyze the problem to determine the cause of the problem.