We recently ran into problem using Doctrine 2 connecting to a Rackspace Cloud Database using the MySqli Driver.
We have a long running PHP script that can sometimes run for hours at a time whilst processing information. This script requires a connection to a database, but has long periods of inactivity where there is no actual interaction with MySQL. By default MySQL uses the “wait_timeout” setting which states, how long an inactive connection can exist before it is killed. This is normally fine with web pages requests, as it is usually a short lived request. Unfortunately you do not have the ability to alter this setting when using Rackspaces Cloud Database.
When using the MySQLi extension you can create a connection in “interactive mode” by passing the “MYSQLI_CLIENT_INTERACTIVE” flag, which will then use the “interactive_timeout” setting. On Rackspace this is set to 8 hours!
Annoyingly Doctrine does not allow you to pass any flags to the MySQLi Connection. So we overrode Doctrine\DBAL\Driver\Connection with our own Driver which then allows us to pass a “flags” parameter through.
Feel free to look at some of the other helpful features in we have added to Doctrine 2 here: ZucchiDoctrine