https://github.com/ixixi/fluent-plugin-sqs/blob/master/lib/fluent/plugin/in_sqs.rb#L58

in_sqs.rb

    def run_periodic
      until @finished
        begin
          sleep @receive_interval
          @queue.receive_message do |message|
            record = {}
            record[:body] = message.body.to_s
            record[:handle] = message.handle.to_s
            record[:id] = message.id.to_s
            record[:md5] = message.md5.to_s
            record[:url] = message.queue.url.to_s
            record[:sender_id] = message.sender_id.to_s

            //Engine.emit(@tag, Time.now, record)       // これだとこける
            Engine.emit(@tag, Time.now.to_i, record)    // to_i をつけると動く
          end
        rescue
          $log.error "failed to emit or receive", :error => $!.to_s, :error_class => $!.class.to_s
          $log.warn_backtrace $!.backtrace
        end
      end
    end