Using 'Global Configuration' for MPM Worker

The WHM Global Configuration interface doesn't properly handle Worker and Event settings. Seems like they've only thought about Prefork.

Yes, your MaxRequestWorkers setting should be 150 with a ServerLimit of 6 and a ThreadsPerChild of 25, but as you saw the WHM interface won't accept that value because it treats MaxRequestWorkers like Prefork's MaxClients setting which shouldn't exceed the ServerLimit but Worker and Event needs to allow it to exceed because of the ServerLimit x ThreadsPerChild = MaxRequestWorkers issue.

I get around it by manually editing the file.

/var/cpanel/conf/apache/local

and change the "MaxClients" setting to the correct MaxRequestWorkers value and then rebuild and restart apache. (Yes, even though you're set to Worker or Event, the cPanel config file still saves it as MaxClients even though that's not correct, but when Apache rebuilds its output correctly as MaxRequestWorkers)

Rebuild Apache script:
/scripts/rebuildhttpdconf

Restart Apache:
/scripts/restartsrv_apache


So, basically cPanel needs to fix their Global Configuration to work correctly if it is to be used with Worker and Event MPMs. Maybe even add settings for ThreadsPerChild, MinSpareThreads and MaxSpareThreads which I currently set with the Include Editor "Pre Main Include".

Code:

<IfModule worker.c>
ThreadsPerChild 25
MinSpareThreads 100
# Max must be >= (MinSpareThreads + ThreadsPerChild)
MaxSpareThreads 200
</IfModule>

<IfModule event.c>
ThreadsPerChild 25
MinSpareThreads 100
# Max must be >= (MinSpareThreads + ThreadsPerChild)
MaxSpareThreads 200
</IfModule>

 

Someone posted a Feature Request on this 2 years ago but it's apparently "Archived" now whatever that means. Maybe it wasn't clear to cPanel when it was submitted.

apache 2.4 MaxRequestWorkers

 

Interesting. This may actually explain why when we changed to MPM Event in Easy Apache and try increasing the values we still get the message to increase max request workers in error_log.

Are you saying we just add this to Pre main include and all should work fine?

<IfModule worker.c>
ThreadsPerChild 25
MinSpareThreads 100
# Max must be >= (MinSpareThreads + ThreadsPerChild)
MaxSpareThreads 200
</IfModule>

<IfModule event.c>
ThreadsPerChild 25
MinSpareThreads 100
# Max must be >= (MinSpareThreads + ThreadsPerChild)
MaxSpareThreads 200
</IfModule>

 

In addition to the Pre main includes, you need to manually modify the Apache local file and rebuild.

So, since your threads per child is 25, let's say you want MaxRequestWorkers to 1000. You would edit the Apache local file and set maxclients to 1000 and serverlimit to 40. (40 x 25 = 1000).

If you try to make these changes directly in WHM's Apache Configuration, it won't let you and will say the ServerLimit is too low. It want's you to set the ServerLimit to 1000 also, but that would technically be 25,000 workers.