https://www.kinamo.be/en/support/faq/determining-the-correct-number-of-child-processes-for-php-fpm-on-nginx
https://serverfault.com/questions/939436/understand-correctly-pm-max-children-tuning
Adjusting child processes for PHP-FPM (Nginx)
When setting these options consider the following:
- How long is your average request?
- What is the maximum number of simultaneous visitors the site(s) get?
- How much memory on average does each child process consume?