How do I troubleshoot Apache MaxRequestWorkers errors?

Question

How do I troubleshoot Apache MaxRequestWorkers errors?

Answer

You can modify the MaxRequestWorkers limitation in WHM:

Home / Service Configuration / Apache Configuration / Global Configuration

Start by looking at the Apache error_log to check for any reports of the error. Apache can be quickly checked by running the following search in the command line:

# grep MaxRequestWorkers /etc/apache2/logs/error_log
[Fri May 22 11:51:07.896632 2020] [mpm_prefork:error] [pid 9697] AH00161: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting
[Fri May 22 11:52:15.819243 2020] [mpm_prefork:error] [pid 10331] AH00161: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting

MaxRequestWorkers can be increased up to the value of the ServerLimit that is defined. By default, cPanel installation's ServerLimit is set to 256. If you wish to increment MaxRequestWorkers beyond 256, update the ServerLimit to the new value you need as well.

The following article addresses tuning the appropriate values for your environment:

Tuning MaxRequestWorkers for Apache