Troubleshooting
Problem
Your CICS Transaction Server for z/OS (CICS TS) region is experiencing a slowdown in processing. Users report poor response time. The CICS region does not appear to be getting any CPU time. It also does not respond to commands you enter at the console. You are using DumpMaster by Macro 4.
Cause
The started task for DumpMaster had a higher dispatching priority than CICS. Therefore, it was using all of the CPU time.
Diagnosing The Problem
If you have a dump of the CICS region at the time of the slowdown, you can do the following to determine the dispatching priority of the CICS QR TCB:
- Enter IPCS command verbx dfhpdxxx 'ke=3'.
- Enter F 'KTCB QR' to find the KE_KTCB associated with the CICS QR KTCB. This should be near the top of the Kernel Domain KE_TASK Summary.
- Enter F 'KTCB xxxxxxxx' where xxxxxxx is the QR KTCB and look at offset x'50' (in CICS TS V1.3 and above) to determine the MVS TCB for the CICS QR KTCB.
- Enter IPCS command summ format to display the MVS TCBs.
- Enter F 'TCB: xxxxxxxx' where xxxxxxxx is the MVS TCB for the CICS QR KTCB.
- Enter F DSP to find the dispatching priority of this TCB. TCBDSP is at offset x'23' for z/OS V2.5 and many other releases. Find "TCBDSP" in topic TCB information of the z/OS documentation for the release you are using to make sure the offset has not changed.
Resolving The Problem
Change the dispatching priority for CICS to be higher than the dispatching priority for DumpMaster. You can refer to the z/OS MVS Programming: Assembler Services Guide, section Address space priority for additional information.
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Product Synonym
CICS/TS CICS TS CICS Transaction Server
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Document Information
Modified date:
25 August 2026
UID
swg21110891