Today's article is about understanding 'load average'.

[KGIII]

It wasn't easy to explain and I think I got it right. So, feedback is a great idea for this article!

The Meaning Of "Load Average" On Linux? • Linux Tips

You may have come across "Load Average" in your Linux travels. It's common for it to be misinterpreted but it's simpler than you might think.

linux-tips.us

Also, someone notified me that they were unable to view the article. If you have issues, hit the refresh button - but it seems to work just fine here.

(I'm running a bit behind today.)

 

[f33dm3bits]

Does your website use Google Analytics or something like that, if not I will consider it as a trusted website and use Firefox for it.

 

[KGIII]

Yes, it uses Google Analytics. Mostly, I find it confirms what I expected and so it indicates that I should continue with the types of articles that I'm already using.

It'll likely be removed at some point. It's not very accurate. I have internal metrics and even raw server logs and it's amazing how much traffic GA doesn't count.

 

[dcbrown73]

Another thing to be aware of when evaluating load average is iowait can highly affect your load average. Load average is not a measurement of only CPU processing power, but also a CPU being busy. A CPU can be busy while not even processing anything because it's in an iowait state. Meaning, waiting on io. Whether that be waiting on disk io or network based io.

A term many people maybe familiar with is "blocking". Especially if they are programmers. If you write a program that blocks. It can block a CPU from doing things while waiting on io. You may have heard a lot of hubbub about asynchronous programming lately. Asynchronous programming was created specifically to avoid io wait situations and allows a system to be more effiecnt by processing other waiting applications while one process is waiting on io.

Below is a screenshot of "top". Circled in red is the iowait status of each individual CPU. CPU *total* usage and iowait are combined when calculating load average. (among other things)

 

[KGIII]

Below is a screenshot of "top".

An article about 'top' is on my list, though I may decide to do it on htop, which is what I prefer.