zAAP CPU Time Bug in Type 72 Record – OA29974 Is The Cure

(Originally posted 2009-12-07.)

If you use RMF Postprocessor you won’t see this one. If you use Service Units rather than CPU seconds fields in the SMF 72-3 record you also won’t see it. It’s only if (like me) you use the CPU time for zAAPs in your CPU Utilisation calculation that you’ll run into this problem.

If you examine fields R723IFAT (zAAP CPU Time) and R723IFCT (zAAP on GCP CPU Time) you might find them zero when you don’t expect them to be i.e. when the Service Units analogues (R723CIFA and R723CIFC) are non-zero. IFAT and IFCT are indeed out of line and CIFA and CIFC (and the Workload Activity Report) are correct.

A (sensible) suggested workaround is to use CIFA and CIFC, converting from service units to CPU time.

The answer is to apply the fix for APAR OA29974. I think I’d apply it anyway. It seems like a fairly harmless PTF.

I ran into this because a colleague showed me a Workload Activity postprocessor report with substantial zAAP on GCP time in it, whereas MY code showed zero. (My code was correct but misdirected by the data.) 🙂

Because I can’t control the SMF that customers send me I think I’m going to have to code around this one – if I start seeing this regularly.

Published by Martin Packer

I'm a mainframe performance guy and have been for the past 35 years. But I play with lots of other technologies as well.

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