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  • 1.  HCM PCM understanding server_procesor and server_physicalProcessorPool

    Posted 29 days ago
    Edited by Piper Wilson 21 days ago

    Hello,

    I have concern regarding 2 values from HMC. I am working on presenting the data from HMC using REST API (Nextract plus).

    I cannot understand difference between 2 values

    1) server_processor - utilizedProcUnits

    2) server_physicalProcessorPool utilizedProcUnits

    Bellow we are looking on comparison of those 2 value on P9 Frame (40CPU). This yellow one is representing what lpar2rrd represents as CPU Pool, however I cannot understand what is a green one - server_processor - utilizedProcUnits and how can I use it for monitoring.

    Looking for example to understand how it works, thank you! :)


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    Marcin Michalowski
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  • 2.  RE: HCM PCM understanding server_procesor and server_physicalProcessorPool

    User Group Leader
    Posted 27 days ago
    Edited by Piper Wilson 21 days ago

    Hi Marcin,

    This is something that doesn't give me peace of mind either:)

    I have noticed that the utilization of "utilizedProcUnits" taken from "server_processor" matches the sum of the "utilizedProcUnits" utilization of LPARs on the machine (left side of the screenshot), and the utilization of "utilizedProcUnits" taken from "server_physicalProcessorPool" corresponds to the sum of the LPAR utilization expressed as ("utilizedUnCappedProcUnits" + "utilizedCappedProcUnits").
    I think the similarity is clearly visible in the screenshot.

    It is worth noting that documentation says: (link)
    utilizedProcUnits = utilizedUnCappedProcUnits + utilizedCappedProcUnits - idleProcUnits

    If you are use HMC older than V10R2M1040 then the formula is different:(link to old documentation)
    utilizedProcUnits = utilizedUnCappedProcUnits + utilizedCappedProcUnits

    Therefore, my hypothesis is that in the case of "server_processor" the CPU Idle, ("idleProcUnits") is subtracted, but I would like to see an explanation from someone smarter than me :)


    Queries which I used:

    • Left side:
      SELECT "utilizedProcUnits" FROM "lpar_processor" WHERE ("servername" =~ /^$Servername$/) AND $timeFilter GROUP BY "lparname"
      SELECT "utilizedProcUnits" FROM "server_processor" WHERE ("servername" =~ /^$Servername$/) AND $timeFilter 

    • Right side:
      SELECT "utilizedCappedProcUnits" + "utilizedUncappedProcUnits" FROM "lpar_processor" WHERE ("servername" =~ /^$Servername$/) AND $timeFilter GROUP BY "lparname"
      SELECT "utilizedProcUnits" FROM "server_physicalProcessorPool" WHERE ("servername" =~ /^$Servername$/) AND $timeFilter 




    Best regards,
    Michal Wiktorek



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    https://www.linkedin.com/in/michal-wiktorek-83b2b47b
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    Original Message


  • 3.  RE: HCM PCM understanding server_procesor and server_physicalProcessorPool

    Posted 15 days ago

    Hi Marcin,

    it look like something what will be included in next LPAR2RRD release as well (June 2024).

    It is CPU usage from OS point of view: CPU physical allocation (what LPAR2RRD presents now) - CPU idle (OS idle cycles)

    It has been already implemented in our new tool called XorMon Next Generation, check some detailed explanation with examples https://xormon.com/IBM-Power-CPU-monitoring.php



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    Pavel Hampl
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    Original Message