Mysql Server has gone away. This issue is most commonly encountered with backed-up database with a large blob or longtext fields.
The MySQL server has gone away (error 2006) has two main causes:
1. Server Timed out
2. Server stopped due to large packet error.
Here are the solutions to fix the above issues:
1. In my.cnf (for Linux OS) and my.ini (for Windows OS), look for “wait_timeout” variable. Increase it and restart the server.
2. In my.cnf (for Linux OS) and my.ini (for Windows OS), look for “max_allowed_packet” variable. Increase the value and restart the server.