server.handleUpgrade() causes an attempt to reconnect the ws socket on refresh

See original GitHub issue

I am running a nodejs application which runs great the first time I use it but when I refresh and enter the new data Node crashes and gives me this. The error looks like this :

/www/wwwroot/domain.to/node_modules/ws/lib/websocket-server.js:267
      throw new Error(
      ^
Error: server.handleUpgrade() was called more than once with the same socket, possibly due to a misconfiguration
    at WebSocketServer.completeUpgrade (/www/wwwroot/domain.to/node_modules/ws/lib/websocket-server.js:267:13)
    at WebSocketServer.handleUpgrade (/www/wwwroot/domain.to/node_modules/ws/lib/websocket-server.js:245:10)
    at Server.upgrade (/www/wwwroot/tehran.us.to/node_modules/ws/lib/websocket-server.js:89:16)
    at Server.emit (events.js:327:22)
    at onParserExecuteCommon (_http_server.js:646:14)
    at onParserExecute (_http_server.js:587:3)

Here is my current config :

“ws”: “^7.3.1”, Node.js version(s): v14.4.0 OS version(s): Linux Ubuntu 18.04 LTS

I am not sure if this a bug with WS or nodejs but the socket is created twice upon refreshing. Is there a way to avoid this recreation? How can I assure every user from each browser can access the application and reuse it?

This is the rest of the code for partial reproduction :

const app = express();
const options = {
key: fs.readFileSync('./key.pem'),
cert: fs.readFileSync('./cert.pem')
};
const server = https.createServer(options, app)

server.listen(3000, function () {
  console.log("Express server listening on port " + 3000);
});
I also use Websocket on the same end point and the code looks like this :

const wss = new Websocket.Server({ server })
    console.log(url)
    wss.on('connection', ws => {
        console.log('user is connected to the server #mainpage')

Issue Analytics

State:
Created 3 years ago
Comments:8 (5 by maintainers)

Top GitHub Comments

1reaction

lpincacommented, Aug 25, 2020

If I use noServer I cannot use SSL anymore, is that correct?

No, it is totally unrelated. You can use an external HTTPS server.

const server = https.createServer(options);
const wss = new Websocket.Server({ noServer: true });

wss.on('connection', function (ws, request) {
  // ...
});

server.on('upgrade', function (request, socket, head) {
  wss.handleUpgrade(request, socket, head, function (ws) {
    wss.emit('connection', ws, request);
  });
});

I think this is happening because my code runs once without error, the second time I do not close ws so it tries to reopen the port which it cannot and then the error occurs. I tried to close the socket with ws.close() at a timer but I don’t think this is the correct way of doing this.

It doesn’t matter, the browser closes the connection when you refresh the page.

0reactions

lpincacommented, Aug 26, 2020

export default async (url, server) => {
    const wss = new Websocket.Server({ server })
    console.log(url)
    
    wss.on('connection', ws => {
        console.log('user is connected to the server #mainpage')
        ws.send(JSON.stringify({
            percentage: 100,
            status: done,
            fileName: nameofmyfile
        }))
    })
    wss.on('close', ws => {
        ws.send('connection close')
    })
}

This creates a new WebSocket server every time the function is called and it seems you are calling it from the handler of app.get('/x'). This is wrong, you should create a single WebSocket server and use the existing WebSocket connection, if there is one, when the user visits /x.

Take a look at this example https://github.com/websockets/ws/blob/master/examples/express-session-parse/index.js to get an idea.

When the user visit /x you get the WebSocket connection from the map of WebSocket connections and use it.