Beanstalkd + async_observer (Rails plugin) have worked well for me. Add a Munin script to monitor the queue size (http://gist.github.com/36116 http://gist.githu

Beanstalkd + async_observer (Rails plugin) have worked well for me. Add a Munin script to monitor the queue size (http://gist.github.com/36116 http://gist.github.com/36116) and it's a pretty effective and manageable system.