Resque

Resque is a Redis-backed library for creating background jobs, placing those jobs on multiple queues, and processing them later.

Background jobs can be any Ruby class or module that responds to perform. Your existing classes can easily be converted to background jobs or you can create new classes specifically to do work. Or, you can do both.

Resque is heavily inspired by DelayedJob (which rocks) and is comprised of three parts:

1. A Ruby library for creating, querying, and processing jobs
2. A Rake task for starting a worker which processes jobs
3. A Sinatra app for monitoring queues, jobs, and workers.

Resque workers can be distributed between multiple machines, support priorities, are resilient to memory bloat / "leaks," are optimized for REE (but work on MRI and JRuby), tell you what they're doing, and expect failure.

Resque queues are persistent; support constant time, atomic push and pop (thanks to Redis); provide visibility into their contents; and store jobs as simple JSON packages.

The Resque frontend tells you what workers are doing, what workers are not doing, what queues you're using, what's in those queues, provides general usage stats, and helps you track failures.