Long running tasks should use Dynflow::Action::Singleton
If the server has issues that result in unclean shutdown, its possible for the long-running tasks to not get cleaned up at termination. This prevents the long-running tasks from restarting upon server restart. Users have to shut down foreman-tasks again, clean the long-running tasks, and then restart.
The long-running tasks are "Listen On Candlepin Events" and "Monitor Event Queue".