如何计算龙卷风中的网络延迟？

Question

我正在使用 Tornado Web 套接字并想计算客户端的 Web 套接字延迟。我看过在tornado中使用ping/pong但是我没有看清楚，也没有很好的例子。

是否有发送ping/pong响应和计算网络响应的简单示例代码？

Answer 1

我已经使用下面的代码来计算 WebSocket 延迟。 Ping 将发送一个时间戳。在 pong 中，我们接收到 ping 时间戳，并通过从当前时间减去 ping 时间戳来计算延迟。

class EchoWebSocket(tornado.websocket.WebSocketHandler):

    def open(self):
        ping_errors = 0

        # Send a ping packet with the timestamp
        def send_ping():
            global ping_errors
            timestamp = time.time()
            try:
                self.ping(str(timestamp).encode('utf-8'))
                ping_errors = 0
            except tornado.websocket.WebSocketClosedError:
                msg = "Web socket closed. Stopped ping."
                logger.info(msg)
                pinger.stop()
            except Exception:
                ping_errors += 1
                msg = "Ping failed to send."
                logger.error(msg, exc_info=True)

                if ping_errors > 3:
                    msg = "Stopping ping."
                    logger.error(msg, exc_info=True)
                    pinger.stop()

        interval = 10000 #ms
        pinger = tornado.ioloop.PeriodicCallback(send_ping, interval)
        pinger.start()

    def on_pong(self, timestamp):
        curr_time = time.time()
        time_diff  = curr_time - float(timestamp)

        if time_diff < 0:
            logger.info("Lost a ping packet")
            return
        logger.info("WebSocket Latency: {0}ms".format(
            int(ceil(time_diff * 1000))))

    def on_close(self):
        print("WebSocket closed")

在处理程序中，

handlers = [
             ...,
             (r'/ping', EchoWebSocket),
           ]

在javascript,

protocol = (location.protocol === 'https:') ? 'wss://' : 'ws://';
ping_ws_url = protocol + window.location.host + "/ping";
ping_ws = new WebSocket(ping_ws_url);

如何计算龙卷风中的网络延迟？

How to calculate to web latency in torando?

python

tornado