Cannot set property 'readyState' of undefined

[p493z3r0]

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Current behaviour

NodeJS Server crashes on tab refresh.

Steps to reproduce (if the current behaviour is a bug)

Use transports: ['websocket'] on your client. I'm using this library with socket-controller, which itself uses Socket-IO. But i'm quite sure, that the error tracks down to this library.

Expected behaviour

Should not crash.

Setup

• OS: Darwin MacBook-Pro.local 19.3.0 Darwin Kernel Version 19.3.0: Thu Jan 9 20:58:23 PST 2020; root:xnu-6153.81.5~1/RELEASE_X86_64 x86_64
• browser: All
• engine.io version: 3.4.0

Other information (e.g. stacktraces, related issues, suggestions how to fix)

Stacktrace

with this StackTrace.
error: uncaughtException: Cannot set property 'readyState' of undefined
TypeError: Cannot set property 'readyState' of undefined
at Socket.socketOnClose (backend/node_modules/ws/lib/websocket.js:838:24)
at Socket.emit (events.js:203:15)
at Socket.EventEmitter.emit (domain.js:448:20)
at TCP._handle.close (net.js:607:12) {"error":{},"stack":"TypeError: Cannot set property 'readyState' of undefined\n at Socket.socketOnClose (backend/node_modules/ws/lib/websocket.js:838:24)\n at Socket.emit (events.js:203:15)\n at Socket.EventEmitter.emit (domain.js:448:20)\n at TCP._handle.close (net.js:607:12)","exception":true,"date":"Mon Apr 13 2020 11:18:39 GMT+0200 (Central European Summer Time)","process":{"pid":48795,"uid":501,"gid":20,"cwd":"backend","execPath":"/usr/local/Cellar/node@10/10.18.1/bin/node","version":"v10.18.1","argv":["/usr/local/Cellar/node@10/10.18.1/bin/node","^backend/src/app.ts"],"memoryUsage":{"rss":146661376,"heapTotal":79376384,"heapUsed":63015720,"external":1091116}},"os":{"loadavg":[3.15966796875,3.02978515625,2.65869140625],"uptime":95890},"trace":[{"column":24,"file":"backend/node_modules/ws/lib/websocket.js","function":"Socket.socketOnClose","line":838,"method":"socketOnClose","native":false},{"column":15,"file":"events.js","function":"Socket.emit","line":203,"method":"emit","native":false},{"column":20,"file":"domain.js","function":"Socket.EventEmitter.emit","line":448,"method":"emit","native":false},{"column":12,"file":"net.js","function":"TCP._handle.close","line":607,"method":"close","native":false}]}

[darrachequesne]

Hi @dominic12 ! Do you know which version of ws you are using? engine.io#3.4.0 includes ws^7.1.2, and there are several occurences of your issue there: https://github.com/websockets/ws/search?q=Cannot+set+property+%27readyState%27+of+undefined&type=Issues

[p493z3r0]

Hi @darrachequesne, i'm using ws@7.2.3. I know that these issues exist, but it was always a wrong usage of WS.

[darrachequesne]

That's weird. It might be due to the socketOnClose method being called twice, so the this[kWebSocket] gets set to undefined in the first call, but it should be prevented by:

// https://github.com/websockets/ws/blob/7.2.4/lib/websocket.js#L834
this.removeListener('close', socketOnClose);

Maybe:

-- socket.on('close', socketOnClose);
++ socket.once('close', socketOnClose);

Could fix your issue? Could you please open an issue in the ws repository?

[p493z3r0]

I can confirm, that the method is called twice. Sometimes, i also get an "failed: Invalid frame header" error back. However, additionally to this issue, i will create an issue in the WS Repo too.

[p493z3r0]

If i remove transports: ['websocket'] from my client, all seems to work perfectly. But i need to have that set, because of Google Flex Env restrictions. Maybe this helps in some way?

[lpinca]

You can reproduce with the following code:

const eio = require('engine.io');
const eioc = require('engine.io-client');
const http = require('http');

const server = http.createServer();
const engineioServer1 = eio.attach(server);
const engineioServer2 = eio.attach(server);

server.listen(function () {
  const socket = eioc(`ws://localhost:${server.address().port}`, {
    transports: ['websocket']
  });
});

or

const eio = require('engine.io');
const eioc = require('engine.io-client');
const http = require('http');

const engineioServer = new eio.Server();
const server = http.createServer();

server.on('upgrade', function (request, socket, head) {
  engineioServer.handleUpgrade(request, socket, head);
  engineioServer.handleUpgrade(request, socket, head);
});

server.listen(function () {
  const socket = eioc(`ws://localhost:${server.address().port}`, {
    transports: ['websocket']
  });
});

This is invalid usage of ws. There must be a 1 on 1 correspondence between a net.Socket and a WebSocket. The above code creates 2 WebSocket from the same net.Socket.

[lpinca]

Try to monkey patch this line https://github.com/websockets/ws/blob/7.2.4/lib/websocket.js#L153 and change it like this:

if (socket[kWebSocket]) {
  throw new Error('Invalid usage');
} else {
  socket[kWebSocket] = this;
}

Your server process should crash with that error.

[p493z3r0]

It crashed with that error. I'll try to examine where the faulty code is. Most likely socket.io or socket-controller.

[nxz91]

Hi Dominic, did you get to the root of this already? Really scratching my head here...

[p493z3r0]

Had no luck yet. How do you use socket.io? I'm using it with socket-controller.

[nxz91]

I need to use transports: ['websocket'] as you do because Heroku is failing to provide session affinity between different server instances otherwise.

[nxz91]

I'm just using default socket.io-client and socket.io without any tooling

[p493z3r0]

I see. So it's not just me. @darrachequesne do you have an Idea where this originates? I had no luck so far..

[p493z3r0]

@nxz91 Did you find a solution to your problem?

[nxz91]

Yes and no: I decided to start by scaling vertically using the sticky-cluster package. This will suffice for now (moving from a single processor to at least multiple processors). We moved from Heroku to Digitalocean in the process which made server costs drop substantially. Once we need to scale horizontally, we'll probably make the switch to pure Websockets (and maybe even a Kubernetes deployment).

[p493z3r0]

@nxz91 Thanks for your response. I found the mistake. express-status-monitor spawned a second instance of socket.io and that caused the problems. BTW: We have also switched to Digitalocean, as it seems to be way cheaper than GCP or Heroku. I'm closing this issue now.

[nxz91]

Sounds like an interesting package, unfortunately I'm not using it so I must be having another issue... :-(

…

On Wed, 29 Apr 2020 at 19:59, Dominic ***@***.***> wrote: @nxz91 <https://github.com/nxz91> Thanks for your response. I found the mistake. express-status-monitor spawned a second instance of socket.io and that caused the problems. BTW: We have also switched to Digitalocean, as it seems to be way cheaper than GCP or Heroku. I'm closing this issue now. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#600 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADGA7Y2UCQ2A5PVBYQS7Y2TRPBTHFANCNFSM4MG25EHQ> .

[darrachequesne]

Closed due to inactivity, please reopen if needed.