Sparrow red?

Sparrow is a really fast lightweight queue written in Ruby that speaks memcache. That means you can use Sparrow with any memcached client library (Ruby or otherwise).

Sparrow keeps messages in memory, but persists them to disk, using Sqlite, when the queue is shutdown.

Basic tests shows that Sparrow processes messages at a rate of around 1660 per second. The load Sparrow can cope with increases exponentially as you add to the cluster. Sparrow also takes advantage of eventmachine, which uses a non-blocking io, offering great performance.