I've struggled with this issue myself now for a couple of days. My goal was to activate Apache + mpm_event + php7.3-fpm. For now, i playing around with a WordPress installation and it runs fast as hell (considering WordPress with OPCache and RedisCache-Server, without any WordPress caching plugin). TTFB is around 170ms, I am satisfied.
Finally I solved it ? (thankfully without fiddling in conf-Files) by disabling the Apache-conf for php7.3-fpm (in my case php7.3):
I searched for the string "php7.3-fpm.sock" in files like this:
grep -iRl [text-string-to-search] [search-in-this-folder]
grep -iRl 'php7.3-fpm.sock' /etc/
I found out this string is in /etc/apache2/conf-enabled/php7.3-fpm.conf. The file (or a symlink) php7.3-fpm.config MUST NOT be in the directory /etc/apache2/conf-enabled!!
Other steps I made to get Apache + mpm_event + php7.3-fpm to work:
a2dismod php7.3: the Apache php-module is not needed and anyway incompatible with mpm_event
service apache2 restart
Now check if mpm_event is running:
The output should contain "Server MPM: event". Also check via phpinfo() if under "Server API" the value "FPM/FastCGI" is written.
Other things I found out, it is not directly related to php-fpm, but I've struggled with issues at the same time:
/var/customers/tmp/froxlor.panel/ has do be owned by froxlorlocal:
chown froxlorlocal:froxlorlocal /var/customers/tmp/froxlor.panel
/var/www/php-fpm/froxlor.panel/ has do be owned by froxlorlocal:
chown froxlorlocal:froxlorlocal /var/www/php-fpm/froxlor.panel
Check your Webserver-Settings: Settings -> Webserver-Settings:
The username webserver and the groupname webserver has to be "www-data".
Hope this helps someone. If I wrote anything wrong, please just leave a reply, i'm also grateful for other hints on this topic.