Auto scale a delayed job server Rails?

I have a Ruby on Rails application and that is using delayed jobs.

gem 'delayed_job', '4.1.8'

I want to auto-scale the server running the delayed jobs. But by AWS convention it is going to terminate the delayed job server is the load on CPU is less than a threshold value even is it is having a delayed job still executing on it. I do not want it to happen. can any body suggest the strategy to be used in this place.

I want it like is no. of delayed jobs > threshold spin new server instance with delayed job worker then the jobs and let them execute. if the delayed_jobs locked by a specific a host host goes 0 then terminate that delayed server.