ws4py.websocket：从客户端长时间延迟关闭连接

Question

我使用 ws4py.websocket 包创建了一个安全的 WebSocket 服务器。

一个 javascript 客户端连接到这个 Websocket 并向它发送一些 JSON 消息。

现在当我的 JS 客户端关闭连接 (function disconnect) 时，大约需要 30 秒才能调用服务器的 closed 函数

代码如下：

服务器

class ControlWebSocket(WebSocket):

    def opened(self):
        print("Client connected")

    def closed(self, code, reason=None):
        print("Connection closed [%d]" % (code))

    def received_message(self, m):
        #some business logic using 'm'
server = make_server('', 8999, server_class=WSGIServer, handler_class=WebSocketWSGIRequestHandler, app=WebSocketWSGIApplication(handler_cls=ControlWebSocket))
server.socket = ssl.wrap_socket (server.socket, certfile='./cert.pem', keyfile='key.pem', server_side=True)
server.initialize_websockets_manager()
server.serve_forever()

客户

ws = new WebSocket("wss://192.168.42.1:8999/");

ws.onopen = function() {
    console.log("Connected to WebSocket server");
};

ws.onmessage = function(e) {
    //some business logic using e
};

ws.onclose = function() {
    console.log("Disconnected from WebSocketServer");
};

function disconnect() {
    console.log("Disconnecting from WebSocketServer");
    ws.close();
}

关于为什么关闭连接这么长时间的任何线索？有什么方法可以更快地终止连接？

Answer 1

这是您的客户端问题。如果您查看ws 模块。在顶部你有

const closeTimeout = 30 * 1000; // Allow 30 seconds to terminate the connection cleanly.

然后你有下面的代码

  if (!this._finalized) {
    if (this._closeFrameReceived) this._socket.end();

    //
    // Ensure that the connection is cleaned up even when the closing
    // handshake fails.
    //
    this._closeTimer = setTimeout(this._finalize, closeTimeout, true);
  }

这是为了确保连接不会在 30 秒之前关闭，并给每一方足够的时间来清理连接。这次是const，而不是configurable。但是，如果您希望立即终止，您可以在ws.close() 之后添加ws.finalize()，它会立即断开连接

const WebSocket = require('ws');
let ws = new WebSocket("wss://127.0.0.1:8999/", {
    rejectUnauthorized: false
});

ws.onopen = function() {
    console.log("Connected to WebSocket server");
};

ws.onmessage = function(e) {
    //some business logic using e
};

ws.onclose = function() {
    console.log("Disconnected from WebSocketServer");
};

function disconnect() {
    console.log("Disconnecting from WebSocketServer");
    ws.close();
    ws.finalize();
}

setTimeout(disconnect, 100)

Edit-1

深入挖掘后，ws4py 似乎有一些不符合rfc6455 的东西。

当你从 NodeJS 进行关闭时，它会发送一个 \x88\x80 的关闭帧，表示应该关闭连接并发送一个关闭帧。文件ws4py/streaming.py 有一些问题，它无法正确响应此帧。它基本上期望读取更多数据并等待相同的数据。这会导致连接从客户端关闭，默认为 30 秒超时。

所以这是您正在使用的 python 库中的一个错误。我使用 NodeJS WebSocket.server 创建了一个客户端，它正确关闭。

为什么不在 NodeJS 本身中使用服务器？下面的链接有一个很好的例子来做同样的事情

https://github.com/websockets/ws/blob/master/examples/ssl.js

代码供参考

'use strict';

const https = require('https');
const fs = require('fs');

const WebSocket = require('..');

const server = https.createServer({
  cert: fs.readFileSync('../test/fixtures/certificate.pem'),
  key: fs.readFileSync('../test/fixtures/key.pem')
});

const wss = new WebSocket.Server({ server });

wss.on('connection', function connection (ws) {
  ws.on('message', function message (msg) {
    console.log(msg);
  });
});

server.listen(function listening () {
  //
  // If the `rejectUnauthorized` option is not `false`, the server certificate
  // is verified against a list of well-known CAs. An 'error' event is emitted
  // if verification fails.
  //
  // The certificate used in this example is self-signed so `rejectUnauthorized`
  // is set to `false`.
  //
  const ws = new WebSocket(`wss://localhost:${server.address().port}`, {
    rejectUnauthorized: false
  });

  ws.on('open', function open () {
    ws.send('All glory to WebSockets!');
  });
});