Prune stale Resque workers.

resque_stale_worker_cleaner.rb

class ResqueStaleWorkerCleaner
  SLOWEST_JOB = (ENV["SLOWEST_JOB"] || 30).to_i # minutes

  def call
    Resque.workers.each do |worker|
      worker.unregister_worker if old_worker?(worker)
    end
  end

  private

  def old_worker?(worker)
    worker.processing.empty? || 
      Time.now - worker.processing["run_at"].to_time > 60 * SLOWEST_JOB
  end
end

ResqueStaleWorkerCleaner.new.call