Symptoms
Sites load slowly when visiting them, in some cases taking 2-3 minutes to load or timing out completely, and errors similar to the following appear in the Apache error log.
[Tue Sep 29 18:27:12.072221 2020] [mpm_worker:error] [pid 15422:tid 47647048848448] AH00288: scorebo
ard is full, not at MaxRequestWorkers
Description
When the Apache scoreboard is full, no more new connections can be made and pending connections must wait until an existing connection closes to be able to connect to the server. This can result in slow loading times and time-out errors. This is a known bug in Apache versions before 2.4.7.
https://bz.apache.org/bugzilla/show_bug.cgi?id=53555
cPanel currently uses ea-apache24-2.4.54, and thus it is still susceptible to this bug.
Workaround
Currently, there are two known workarounds. The first is to switch to MPM Prefork. The second workaround is to configure logrotate to restart Apache instead of reloading it and increasing the MaxRequestWorkers limit. You can read more about tuning the MaxReqeuestWorkers limit here:
Instructions for changing the Apache MPM can be found here:
Infomration on modifying logrotate configurations can be found here:
How to modify logrotate configurations
You can read more about tuning the MaxReqeuestWorkers limit here:
Tuning MaxRequestWorkers for Apache