# File lib/mcollective/connector/rabbitmq.rb, line 294
      def exponential_back_off
        if !@use_exponential_back_off
          return nil
        end

        backoff = @reconnect_delay

        # calculate next delay
        @reconnect_delay = @reconnect_delay * @back_off_multiplier

        # cap at max reconnect delay
        if @reconnect_delay > @max_reconnect_delay
          @reconnect_delay = @max_reconnect_delay
        end

        return backoff
      end