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CONL transaction has extremely high CPU in CICS TS region

Troubleshooting


Problem

You look at performance monitoring data for your CICS Transaction Server for z/OS (CICS TS) regions and notice that one of the regions has an extremely high amount of CPU usage for transaction CONL. This is the long-running CICSPlex SM (CPSM) transaction. You might see high CPU usage for other long running CPSM transactions such as COI0, CONA, and CONL.

Cause

If you have CPSM running, CONL will run on the CICS region from initialization until the region is brought down. If the system initialization parameter (SIT) monitoring frequency parameter MNFREQ is allowed to default, the CICS monitoring data is never reset. Therefore, it appears that the transaction is taking large amounts of CPU. This is true for any long running transaction.

Resolving The Problem

Set the MNFREQ SIT parameter, instead of allowing it to default to zero.

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Product Synonym

CICSPLex SM CICSPlexSM CPSM CP/SM

Document Information

Modified date:
05 January 2026

UID

swg21225535