Website shows 500 internal server error on Plesk: mod_fcgid: read data timeout

Symptoms

• A website is not loading and "500 internal server error" is being shown after ~30-60 seconds.

• The following error can be observed in the domain error log /var/www/vhosts/example.com/logs/error_log file:

  CONFIG_TEXT: [warn] mod_fcgid: read data timeout in 45 seconds, referer: http://www.example.com/admin/orders.php
  [error] Premature end of script headers: PDF.php, referer: http://www.example.com/admin/orders.php

  OR:

  The following error can be found in /var/log/apache2/error.log :

  CONFIG_TEXT: [warn] mod_fcgid: process 16576 graceful kill fail, sending SIGKILL

Cause

The FcgidIOTimeout value - the maximum period of time the module will wait while trying to read from or write to a FastCGI application - has been exceeded.

Resolution

Increase the parameter value or optimize FastCGI application.

FcgidIOTimeout parameter for a domain is set to the same value as max_execution_time PHP parameter.

1. Set "max_execution_time" to "120" in Plesk > Domains > example.com > PHP settings

2. Increase "FastCGI" timeout by adding the following Apache dirctives in Plesk > Domains > example.com > Apache & Nginx settings > Additional Apache directives:

   CONFIG_TEXT: <IfModule mod_fcgid.c>
   FcgidIOTimeout 120
   </IfModule>

Additional Information

When setting max_execution_time to 0, FcgidIOTimeout value is not set in virtual host configuration