topic Re: z/OS CPU metric in Open Q&A

z/OS CPU metric

barryla — Tue, 11 Oct 2022 12:03:29 GMT

I would like to understand which CPU metric does Dynatrace get its values from, example RMF, SDSF etc for the z/OS CPU metrics?

Regards

Barry

Re: z/OS CPU metric

dannemca — Tue, 11 Oct 2022 12:39:26 GMT

Hi @barryla , check if this help to answer your question: https://www.dynatrace.com/support/help/shortlink/zos-infrastructure-metrics

Re: z/OS CPU metric

kevin_cogley — Tue, 11 Oct 2022 12:57:31 GMT

Hi,

SMF metrics are used for MSU consumption.
4HRA (4 hour rolling Average) and CPU utilization all come from IBM control blocks.

Re: z/OS CPU metric

barryla — Tue, 11 Oct 2022 13:54:31 GMT

Hi Kevin

Thank you for the information:

I have a follow up question.

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We are trying to correlate the Dynatrace CPU to the RMF System Information (SYSINFO) values and don't seem to see the same values. We also compared these values to the SDSF (DA Panel) which display the CPU information and not seeing the same values for CPU utilisation.

Would you be able to give more detail on how the information gets calculated.

Re: z/OS CPU metric

kevin_cogley — Tue, 11 Oct 2022 14:14:49 GMT

Are you looking at process or host CPU time? For either it is going to be hard to match up exactly because of the intervals. The default interval for the zDC is 30 seconds. For SDSF the interval is from hitting the enter key to hitting the enter key. We use the IBM SDSF calculations you see here https://www.ibm.com/docs/en/zos/2.1.0?topic=jobs-cpu-usage-information . The cpu % can be a little off if jobs have went away or restarted during the interval. Even IBM states the SDSF value is approximate. The CPU Time should be very accurate for that interval. Hope this helps.