My production server has been having a OOM issue. Upon investigating I find that a major memory eater is PHP-CGI processes. Each of my website, be it Joomla or Wordpress, is having 3 - 6 PHP-CGI processes and each of the processes is taking around 80MB memory.
So I created a brand new test server and transferred one of the simplest Wordpress sites over. This site has only a few common plugins like Astra and Elementor and no modification at all, besides I haven't pointed the A record to the new server, meaning there won't be any visitors even spiders. And I got the screenshot above. Even without any visitor, this new site(kcmc) has created 3 php-cgi processes. Meanwhile, I have checked another server of mine which hosts only 1 production Joomla site. On this server the website only creates 1 php-cgi process.
So this raises my question:
When and why is a php-cgi process created?
