I have a new CentOS server set up, with Apache and php-fpm.
The php application fails to connect to an external MySQL server. This server is reachable from other servers, the firewall on the database server isn't the problem.
I've checked the apache and php-fpm logs, but I can't find any clues there. If I connect to the external database through MySQL on the CentOS server there's no problem, but the php application fails.
This makes me conclude that the route from client to database server is without obstacles, but that CentOS 7 or php-fpm causes trouble somewhere.
Someone any idea what this could be? I don't know where else to look. Perhaps some new security changes in CentOS 7 that I'm not aware of?