All Apps and Add-ons

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
Get Updates on the Splunk Community!

Building Reliable Asset and Identity Frameworks in Splunk ES

 Accurate asset and identity resolution is the backbone of security operations. Without it, alerts are ...

Cloud Monitoring Console - Unlocking Greater Visibility in SVC Usage Reporting

For Splunk Cloud customers, understanding and optimizing Splunk Virtual Compute (SVC) usage and resource ...

Automatic Discovery Part 3: Practical Use Cases

If you’ve enabled Automatic Discovery in your install of the Splunk Distribution of the OpenTelemetry ...