How is CPU utilization calculated for AIX servers taking dynamic resources from CPU pool

Products

• DX Unified Infrastructure Management (Nimsoft / UIM)
• CA Unified Infrastructure Management On-Premise (Nimsoft / UIM)

Issue/Introduction

Had a query about CPU utilization calculation for AIX servers taking dynamic resources from CPU pool.

Example:

If the AIX server releases one CPU(CPU32) and next time takes another CPU (CPU64) form the CPU pool, then while calculating the CPU utilization aggregate,

will the cdm probe still consider CPU 32 or will it consider only the CPUs being used currently by the AIX servers?

Environment

Release : 20.4.x

probe : cdm: Any supported release

OS: AIX 

Resolution

The CPU usage information is found by running the command "/usr/sbin/sar -P ALL" in a separate thread and parsing the data it provides.
For each individual cpu and for the system as a whole user, system, wait and idle are collected.

Probe fetches data per interval basis and it will consider CPUs being used currently by the AIX servers whose data is fetched by the command.

If Calculate Load Average per Processor is selected in the Setup > General tab the average CPU usage values are calculated for each processor.

UIM - CDM calculation of CPU