Worker down when Redis cluster switch to another master.

Resque::Worker.class_eval do
  def work(interval = 5.0, &block)
    interval = Float(interval)
    $0 = "resque: Starting"
    startup

    loop do
      break if shutdown?
      begin
        if not paused? and job = reserve
          log_with_severity :info, "got: #{job.inspect}"
          job.worker = self
          working_on job

          procline "Processing #{job.queue} since #{Time.now.to_i} [#{job.payload_class_name}]"
          if @child = fork(job)
            srand # Reseeding
            procline "Forked #{@child} at #{Time.now.to_i}"
            begin
              Process.waitpid(@child)
            rescue SystemCallError
              nil
            end
            job.fail(DirtyExit.new("Child process received unhandled signal #{$?.stopsig}")) if $?.signaled?
          else
            unregister_signal_handlers if will_fork? && term_child
            begin

              reconnect if will_fork?
              perform(job, &block)

            rescue Exception => exception
              report_failed_job(job,exception)
            end

            if will_fork?
              run_at_exit_hooks ? exit : exit!
            end
          end

          done_working
          @child = nil
        else
          break if interval.zero?
          log_with_severity :debug, "Sleeping for #{interval} seconds"
          procline paused? ? "Paused" : "Waiting for #{queues.join(',')}"
          sleep interval
        end
      rescue Redis::CannotConnectError
        sleep interval
      end
    end

    unregister_worker
  rescue Exception => exception
    unless exception.class == SystemExit && !@child && run_at_exit_hooks
      log_with_severity :error, "Failed to start worker : #{exception.inspect}"

      unregister_worker(exception)
    end
  end
end