I am running a Drupal 7 site on AWS with an EC2 micro instance and RDS on Ubuntu 12.04. When I navigated to the URL patterns for Pathauto admin/config/search/path/patterns I was getting a nasty white screen with an error along the lines of PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away. As it turns out, this is not the fault of Pathauto. The solution to this problem was to increase the max_allowed_packet value in the mysql server configuration.

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