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Splunk Add-on for Unix and Linux: Why does the Percent_CPU_by_Host() macro include %iowait?

kiyoshi_miyake
Explorer

I use the Splunk Add-on for Unix and Linux.
I use the Percent_CPU_by_Host() macro.
The macro returns a time-series chart of CPU usage statistics, by host.
However, the CPU usage include %iowait.
I think the %iowait is idle time of CPU. You use CPU usage that is not include iowait.
Is it correct?

0 Karma

kiyoshi_miyake
Explorer

The Percent_CPU_by_Host macro shows percent of CPU Load.
There are another macro Percent_Load_by_Host that shows the result looks like as same as Percent_CPU_by_Host macro.
Is there CPU_Utilizaton macro???

0 Karma

adamsaul
Communicator

kiyoshi miyake,

%IOWAIT is the amount of time the CPU waited (in an idle state) for an INPUT/OUTPUT device (Hard drive usually) to respond to its request.

Running the 'iostat' command (if on a NIX platform) will yield a lot more information and help you to diagnose an issue with I/O.

0 Karma

kiyoshi_miyake
Explorer

No, I have checked the man page of iostat. I see below.

          %user
                 Show the percentage of CPU utilization that occurred while executing at the user level (application).
          %nice
                 Show the percentage of CPU utilization that occurred while executing at the user level with nice priority.
          %system
                 Show the percentage of CPU utilization that occurred while executing at the system level (kernel).
          %iowait
                 Show the percentage of time that the CPU or CPUs were idle during which the system had an outstanding disk I/O request.
          %steal
                 Show the percentage of time spent in involuntary wait by the virtual CPU or CPUs while the hypervisor was servicing another virtual processor.
          %idle
                 Show the percentage of time that the CPU or CPUs were idle and the system did not have an outstanding disk I/O request.

It mean that %iowait is not CPU utilization, I think.
The CPU utilization = %user + %nice + %system.
Do I misunderstand?

0 Karma

adamsaul
Communicator

You are correct, direct CPU utilization is related to what you said:
CPU utilization = %user + %nice + %system

My answer above was simply to elaborate on what you had stated in your question as the description for %IOWAIT.

0 Karma
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