My nginx is stopping by itself, several times a day!

My nginx is stopping by itself, several times a day!

Hello guys. I am in a tightening, I am in trouble, time and other my sites are offline, when I go to check my nginx server is stopped, I call again, when it is a few hours later, the time varies a lot, it again, I have to send one <Service nginx start> and this is a vice that lasts almost a month. I've been analyzing, there is no precise time, so it's not a crazy cron, people what do I do? I use ubuntu 16.04 / 32 + WEBMIN / virtualmin + nginx + php7.0-fpm + mysql 5.7. I did not do anything on the server by the time he started it !! It is not about load, because I have little access and a lot of resources left over, I worked a lot configuring this and suddenly about 2 months after I finished configuring everything, the server starts that this crazy behavior: '(Would it be something in some webmin update? I have a VPS with ubuntu 14.01 where it to infrequently, but mysql is stopping !!!