For fire and forget type jobs you can use lists instead of pub/sub: save a job to a list by a producer, pop it on the other end by a consumer and execute it. It's also very easy to scale, just start more producers and consumers.
We're currently using this technique, to process ~2M jobs per day, and we're just getting started. Redis needs very little memory for this, just a few mb.
For fire and forget type jobs you can use lists instead of pub/sub: save a job to a list by a producer, pop it on the other end by a consumer and execute it. It's also very easy to scale, just start more producers and consumers.
We're currently using this technique, to process ~2M jobs per day, and we're just getting started. Redis needs very little memory for this, just a few mb.
Redis also supports acid style transactions.