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.

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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I would like to inform that the "utilizedProcUnits" is again calculated without idle cycles in case of use new HMC and Power10.
It's quite easy to miss that it has changed.

7063-CR1 (Logical Partition Processed and Aggregated Metrics JSON Specification - IBM Documentation)

Earlier:

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