We have a Rails application that is running in a MySQL master-slave set-up for a while now, using the master_slave_adapter plugin. Recently, there was a need for background processing of long running tasks. So we settled on DelayedJob.
DelayedJob's table/model uses the same master-slave adapter. And it keeps the slave connection alive by polling the table. But the master connection remains idle for long periods of time, closes overnight, and the next time someone activates a job this happens:
Mysql::Error: MySQL server has gone away: UPDATE `delayed_jobs` SET locked_by = null, locked_at = null WHERE (locked_by = 'delayed_job host:[snip] pid:20481')
I've heard bad things about using the reconnect option in my database.yml, because it allegedly doesn't set the connection character set after a reconnect, like it does on the first connection initialization.
What's the proper way to make this work?