If you use php with fpm standalone (without any hosting automation tool like plesk or whm/cpanel) then you need some tweaks for your busy php coded websites.I think the best fpm methot ise “on demand”.The fpm pool can be used for a website or multiple websites.All you have to do is finding your pool configuration file which belongs to your website.

Your pool file should look like this below

You can increase pm_max_children. and pm.start_servers but probably increasing the “max_children” will enough for you.After the file is changed restart the fpm service.

; By default use ondemand spawning (this requires php-fpm >= 5.3.9)
pm = ondemand
pm.max_children = 5
pm.process_idle_timeout = 10s
; Following pm.* options are used only when ‘pm = dynamic’
pm.start_servers = 1
pm.min_spare_servers = 1
pm.max_spare_servers = 1

[php-fpm-pool-settings] pm.max_children = 100