editing
/etc/sysctl.conf
fs.file-max = 2459688
editing
/etc/security/limits.conf
mysql soft nofile 4096
mysql hard nofile 4096
editing
/etc/my.cnf.d/my-hugh.cnf
max_connections=1024
max_user_connections=1024
table_open_cache = 4096
table_definition_cache = 4096
open_files_limit=4096
ref:
https://codepoets.co.uk/2015/mysql-max_connections-stuck-on-214/
http://blog.endpoint.com/2013/12/increasing-mysql-55-maxconnections-on.html