RMF reports shows CPU more than 100%.

How to do Performance analysis and Capacity Planning for a shop. We also talk about Software Cost here.

Topic author
Jyoti Chibber
Registered Member
Posts: 16
Joined: Wed Aug 20, 2014 5:40 pm

RMF reports shows CPU more than 100%.

Postby Jyoti Chibber » Sat May 21, 2016 8:23 pm

Hi,

I am not a performance person and have not worked on such activities eough and my question might be trivial. I looked at one fo the summary report with RMF. The reports are on 20-minutes intervals. If we add the values of CPU busy field for this interval the result is over the 100%.  Can anyone please help me to understand why would this happen?

Is it average value for this interval or a peak value? How do they calculate the values? :unknown:



Online
User avatar

Robert Sample
Global Moderator
Global Moderator
Posts: 1275
Joined: Fri Jun 28, 2013 1:22 am
Location: East Dubuque Illinois
Has thanked: 2 times
Been thanked: 90 times

Re: RMF reports shows CPU more than 100%.

Postby Robert Sample » Sat May 21, 2016 9:07 pm

Since there are quite a few RMF reports, and there is RMF Monitor I, Monitor II, and Monitor III to complicate the report source, you need to provide more information -- and you could even post the report data you are asking about -- to help us out.  The CPU Activity report I most often use has LPAR Busy and MVS Busy but there is no CPU Busy field on the report.

In general, the CPU activity in RMF reports is average per LPAR, so if you start adding them yes you could EASILY go over 100%.  If the LPARs use non-dedicated processors, or one or more LPARs are parked during some part of the interval, or different LPARs use different numbers of processors, CPU busy percentage calculations can get a bit messy.  If they are all dedicated (or all use the same number of processors), and none were parked for the interval, you can merely add up the percentages and divide by the number of LPARs to compute the overall percentage.

Some reports for some RMF Monitors have peak values while others have average values.  Without knowing the precise report you are referring to, it is not really possible to say which is used for that report.




Return to “Mainframe Performance, Capacity Planning and Software Cost.”

Who is online

Users browsing this forum: CommonCrawl [Bot] and 0 guests