Task waits on a resource

CICS performance problems — slow response, hung regions, task limits — need task-level diagnosis, not guesses.

What it means

• CEMT INQUIRE TASK shows what every task is doing right now.
• Most "hangs" are tasks waiting on a resource, not deadlocks.

Common causes

• Tasks waiting on file, DB2 or MQ resources.
• Runaway tasks consuming CPU (AICA).
• Task limit (MXT) reached during peaks.
• Storage shortage (SOS).

How to diagnose

• CEMT INQUIRE TASK — look at SUSPEND states.
• Check CSMT for abends and stalls.
• Monitor storage: CEMT INQUIRE STORAGE.

How to fix it

• Resolve the waited-on resource.
• Fix runaway programs.
• Tune MXT and storage with systems support.

Example: See what tasks are doing

SUSPEND reason names the bottleneck.

Interview tip

• Q: How would you troubleshoot a Task waits on a resource in production?
• A: I would list tasks with CEMT, identify what they are waiting on, resolve that resource, and tune limits with systems.

Prevention checklist

• Capacity-plan for peaks.
• Monitor task counts and storage.