concussion

https://github.com/chemica/concussion

Sucker Punch is an awesome gem which allows background tasks to be run from the current process. They can be set to run in the future, but they will disappear and not get run if the server or process running the jobs is stopped or restarted. Concussion provides a thin wrapper around Suckerpunch job objects, persisting them to an external storage system of your choice. When the server is restarted, any unprocessed jobs will be run immediately while future jobs will be reinstated to be run at the appropriate time.