Take a look at the jobs that are currently running:
ps aux | grep delayed_job #or sudo service avalon_delayed_job status #You can also look at the stored pids here #but restarting delayed job should take care of it. cd tmp/pids
Kill Previous Delayed Job using a regular kill command and waiting a little while. If that doesn't work, ramp up to a kill -9.
Restart delayed job.
sudo service avalon_delayed_job start