LEMP ready , just a tiny problem

Disabled local socket access (mysqld.sock) in my.cnf, or put the socket in an unusual location, other than rest of the suite and/or PHP binding expects it to reside.

Look for socket= line in /etc/mysql/my.cnf, in ALL the sections (so, [client], [mysqld], [mysqld_safe]).

Also, ps axu | grep mysqld and look for –socket parameter on the commandline.

Proper location of the socket for Debian (and derivatives?) is /var/run/mysqld/mysqld.sock, dunno where it is on other distros.