One of our sites keeps going offline and I'm running out of ideas. It's a wordpress site built with the Avada theme and it's goal is to server as a calendar of events using The Events Calendar plugin.
It runs on Ubuntu 16.04 with nginx hosted with Amazon. I've tried a lot of things to improve mysql performance as I think it is the heart of the issue but I cannot be sure. php_log is empty there is some things coming into debug.log however these mostly relate to the database being inaccessible.
The first day the issue appeared (Tuesday) I was able to continue getting into wordpress by restarting mysql from PuTTY. That does not seem to be working anymore. We thought it was due to the number of events in our database (6000+) so I purged everything from wp_posts table that was created prior to 2017.
We get brief moments where the site works, sometimes for up to an hour and then it is taken offline again. I have run linux malware detection on the server and it came up empty handed. I think the issue stems from a plugin most likely the-events-calendar as it is the biggest thing we use but I can't be sure.
Website URL: http://calendar.childmags.com.au/
Edit: It is not a plugin as disabling did not fix the issue. Something is up with the database. nginx error and access logs had nothing substantial in them.