NGINX RESTARTING EVERY 1/2 HOURS

Hi,

I have a strange issue with Nginx, which is causing it to restart every 1 or 2 hours and send out a watchdog email.

The config seems fine

service nginx configtest
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful


Messages log contains.

mysqld: 2018-07-02 16:28:58 140201424836352 [Warning] Access denied for user 'wordpress_4'@'localhost' (using password: YES)

nginx error.log

2018/07/01...

NGINX RESTARTING EVERY 1/2 HOURS