CI Session - Lost connection to MySQL server during query

This isn't a CodeIgniter issue. Same errors can be seen in your logs with any framework. This is a problem with the server. I know this because I usually modify the error handler so it emails me when there are errors, and I get these errors from multiple accounts/websites, at the same time, and they are not all using CodeIgniter. Unless you are in control of the server, or your host can provide more information, it's unlikely there's anything you can do about it.

Expert Website Development - Temecula, CA
Community Auth For CodeIgniter 3