High CPU load, consumed mostly by "/usr/libexec/webmin/proc/index_cpu.cgi" -- what is this and what may be causing this?

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#1 Sun, 03/06/2016 - 11:55

High CPU load, consumed mostly by "/usr/libexec/webmin/proc/index_cpu.cgi" -- what is this and what may be causing this?

Hi there,

I have recently been noticing an odd behaviour which I don't believe I've seen before, although it's very possible it has been there since the beginning and I just never noticed. I looked at the top command for a while one day after receiving notifications from an external monitor that websites were a bit on the sluggish side and in the odd case just straight-up timed out.

When looking, the resources always looked fine and loaded well for me, but after reviewing the output of top for about 10 minutes, I saw that there was a process that would suddenly come up and consume between 70-98% of the CPU, increasing my load averages to well above 3, even when the load is normally well under 0.7 on average.

The process in question is: /usr/libexec/webmin/proc/index_cpu.cgi

My first question is what exactly does this process do and how does it do it (just at a high level, nothing super detailed needed). I assume based on the name that it is indexing my CPU, but indexing it for what exactly? Top is it's own process, so at first I suspected it was maybe for running top for a while, but it settled down on its own while still reviewing top, plus top is really its own process anyways so shouldn't be related, at least in my understanding so far.

My second question is what can be done to troubleshoot why this is causing performance concerns / high CPU? I want to try and determine why this is happening suddenly (again, it's entirely possible that this has been ongoing for a while but I never noticed until I got an auto notification suggesting my site was offline for a bit, reason reported being that it timed out).

Any ideas or thoughts on this process and its behaviour and performance concerns? Your input would be greatly appreciated while I continue to troubleshoot this concern.

Fri, 12/22/2017 - 13:14
jbatun21564065's picture

Exactly, I have the same problem since I updated, my version of Webmin, Any idea how to lower the consumption of this process?

I use a server with 04 GB of Ram and Two processors, and it makes it perform very slowly

Sun, 12/31/2017 - 08:26

Ok I had this problem and something interesting came from it that may be the cause for others. Im running windows 7 with Oracle VirtualBox with centos 7 & webmin within a virtual environment, I had presumed all cpu processing cores to which I have a total 12 without hyperthreading and 24 with I presumed all CPU's where available to centos but when issuing the "nproc --all" command it showed only two cpu's where available to centos which then everything made sense. Im wondering how the process "/usr/libexec/webmin/proc/index_cpu.cgi" can max out my 12 core server and the resource hungry websites I had were'nt helping either..

If your unsure open a command ssh window and issue the following command.

nproc --all (this shows number cpu) theres other more in-depth commands that give more info on the cpu's

lscpu | egrep '^Thread|^Core|^Socket|^CPU('

cat /proc/cpuinfo

Anyway long story short the high CPU usage of "/usr/libexec/webmin/proc/index_cpu.cgi" highlighted another problem that I had missed a and very significant one since increasing the CPUs available to Centos and my virtual environment the problems solved ....

Sun, 12/31/2017 - 12:06
Joe's picture

These two new posts are about a different problem than the one originally discussed even though the symptom is kinda similar. Don't revive zombie threads of old topics; make a new topic for new problems, even if they seem kinda related.

There's a bug in Authentic theme that shipped with Webmin 1.870 that effects systems with no swap memory configured. There's an update to the theme available that fixes the problem (you can update in the Theme Configuration page at the bottom). We're also rolling an update to Webmin in the near future to address it.


Check out the forum guidelines!

Mon, 05/07/2018 - 01:47 (Reply to #4)

I know this is technically grave digging in itself but I think its important to note that you dont see any updates/notifications for said theme that fixes this, even when you go to the theme page, you have to install git with yum in console then reload the page and force update.

Its probably alot more steps most wouldnt bother with when updating a theme, unless of course like this instance it fixes issues.

Could you maybe make it more prominent and obvious the theme needs updating, and maybe some sort of script to install git if needed tyhen force update

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