“MySQL Server has gone away” is a cryptic error that can be hard to troubleshoot (look at all the various responses on Stack Overflow!) Many problems can cause this error; I would like to document one specific case. In this example, the client is a PHP app using the Phalcon framework:

[Mon, 09 Apr 18 03:34:08 -0400][ERROR]  SQLSTATE[HY000]: General error: 2006 MySQL server has gone away
exception 'PDOException' with message 'SQLSTATE[HY000]: General error: 2006 MySQL server has gone away' in /path/to/ModelBase.php:
Stack trace:
#0 [internal function]: PDOStatement->execute()
...
#17 {main}

This error can be tricky to troubleshoot. I looked in three logs: