resque-sliders

https://github.com/kmullin/resque-sliders

Resque-Sliders is a plugin for Resque that enables you to control multiple hosts' running resque workers with a monitor PID watching over them. From the resque-web UI, you can add/delete/change which queues are running on each host running the monitor PID. Sliders are in the UI and allow you to adjust how many workers on either host should be running.