django频道 /达芙妮的WebSocket超时

Question

简短问题版本：我在达芙妮（Daphne）配置或消费者代码或我的客户端代码中做错了什么？

channels==1.1.8
daphne==1.3.0
Django==1.11.7

详细信息下面：

---

我正在尝试使用Django频道和Daphne接口服务器保持持久的Websocket连接。我正在启动大多数默认参数的达芙妮： daphne -b 0.0.0.0 -p 8000 my_app.asgi:channel_layer。

我看到连接在浏览器中闲置的时间后不久，不久将在20秒内关闭。以断开连接发送的CloseEvent具有code的1006（异常闭合），无reason设置，并且wasClean设置为false。此应该是关闭连接的服务器而不会发送明显的关闭框架。

Daphne CLI具有--ping-interval和--ping-timeout标志，默认值分别为20和30秒。这被记录在"向前者"中，"在发送keepalive ping之前必须闲置的秒数必须是空闲的"，以及"如果没有对keepalive ping响应的响应，则封闭了网络网络之前的秒数"。我读到这一点是因为达芙妮（Daphne）将等到Websocket闲置20秒钟发送PING，如果30秒后未收到响应，将关闭Websocket。相反，我看到的是连接在20秒后闲置之后被关闭。（违约的三次尝试，在20081ms，20026ms和20032毫秒之后关闭）

如果我更改了使用daphne -b 0.0.0.0 -p 8000 --ping-interval 10 --ping-timeout 60 my_app.asgi:channel_layer启动的服务器，则连接仍然很接近，大约20秒的空闲时间。（经过三次更新ping的尝试，在19892毫秒之后关闭，20011ms，19956ms）

代码下面：

---

consumer.py：

import logging
from channels import Group
from channels.generic.websockets import JsonWebsocketConsumer
from my_app import utilities
logger = logging.getLogger(__name__)
class DemoConsumer(JsonWebsocketConsumer):
    """
    Consumer echos the incoming message to all connected Websockets,
    and attaches the username to the outgoing message.
    """
    channel_session = True
    http_user_and_session = True
    @classmethod
    def decode_json(cls, text):
        return utilities.JSONDecoder.loads(text)
    @classmethod
    def encode_json(cls, content):
        return utilities.JSONEncoder.dumps(content)
    def connection_groups(self, **kwargs):
        return ['demo']
    def connect(self, message, **kwargs):
        super(DemoConsumer, self).connect(message, **kwargs)
        logger.info('Connected to DemoConsumer')
    def disconnect(self, message, **kwargs):
        super(DemoConsumer, self).disconnect(message, **kwargs)
        logger.info('Disconnected from DemoConsumer')
    def receive(self, content, **kwargs):
        super(DemoConsumer, self).receive(content, **kwargs)
        content['user'] = self.message.user.username
        # echo back content to all groups
        for group in self.connection_groups():
            self.group_send(group, content)

routing.py：

from channels.routing import route
from . import consumers
channel_routing = [
    consumers.DemoConsumer.as_route(path=r'^/demo/'),
]

demo.js：

// Tracks the cursor and sends position via a Websocket
// Listens for updated cursor positions and moves an icon to that location
$(function () {
  var socket = new WebSocket('ws://' + window.location.host + '/demo/');
  var icon;
  var moveTimer = null;
  var position = {x: null, y: null};
  var openTime = null;
  var lastTime = null;
  function sendPosition() {
    if (socket.readyState === socket.OPEN) {
      console.log('Sending ' + position.x + ', ' + position.y);
      socket.send(JSON.stringify(position));
      lastTime = Date.now();
    } else {
      console.log('Socket is closed');
    }
    // sending at-most 20Hz
    setTimeout(function () { moveTimer = null; }, 50);
  };
  socket.onopen = function (e) {
    var box = $('#websocket_box');
    icon = $('<div class="pointer_icon"></div>').insertAfter(box);
    box.on('mousemove', function (me) {
      // some browsers will generate these events much closer together
      // rather than overwhelm the server, batch them up and send at a reasonable rate
      if (moveTimer === null) {
        moveTimer = setTimeout(sendPosition, 0);
      }
      position.x = me.offsetX;
      position.y = me.offsetY;
    });
    openTime = lastTime = Date.now();
  };
  socket.onclose = function (e) {
    console.log("!!! CLOSING !!! " + e.code + " " + e.reason + " --" + e.wasClean);
    console.log('Time since open: ' + (Date.now() - openTime) + 'ms');
    console.log('Time since last: ' + (Date.now() - lastTime) + 'ms');
    icon.remove();
  };
  socket.onmessage = function (e) {
    var msg, box_offset;
    console.log(e);
    msg = JSON.parse(e.data);
    box_offset = $('#websocket_box').offset();
    if (msg && Number.isFinite(msg.x) && Number.isFinite(msg.y)) {
      console.log((msg.x + box_offset.left) + ', ' + (msg.y + box_offset.top));
      icon.offset({
        left: msg.x + box_offset.left,
        top: msg.y + box_offset.top
      }).text(msg.user || '');
    }
  };
});

asgi.py：

import os
from channels.asgi import get_channel_layer
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "my_project.settings")
channel_layer = get_channel_layer()

settings.py：

CHANNEL_LAYERS = {
    'default': {
        'BACKEND': 'asgi_redis.RedisChannelLayer',
        'ROUTING': 'main.routing.channel_routing',
        'CONFIG': {
            'hosts': [
                'redis://redis:6379/2',
            ],
            'symmetric_encryption_keys': [
                SECRET_KEY,
            ],
        }
    }
}

Answer 1

基本问题原来是接口服务器前面的Nginx代理。代理设置为proxy_read_timeout 20s;。如果服务器生成的keepalive ping，则没有将其计入上游阅读超时。将此超时增加到更大的值可以使Websocket保持更长的时间。我将proxy_connect_timeout和proxy_send_timeout保留在20s。