start_processing

# File actionpack/lib/action_controller/log_subscriber.rb, line 7
    def start_processing(event)
      return unless logger.info?

      payload = event.payload
      params  = payload[:params].except(*INTERNAL_PARAMS)
      format  = payload[:format]
      format  = format.to_s.upcase if format.is_a?(Symbol)

      info "Processing by #{payload[:controller]}##{payload[:action]} as #{format}"
      info "  Parameters: #{params.inspect}" unless params.empty?
    end