Handling of ECONNREFUSED

Hi,

I’d like to start a connection before the server is up and keep retrying until the connection is finally accepted. I’m using ‘ws’ in node.js as the underlying ws implementation. The problem with this is the ‘close’ event comes before ‘open’ (actually no ‘open’ comes, only a ‘close’ and an ‘error’), so the timeout handler is not removed and I get the following error during the second try:

RWS: init
RWS: connect
RWS: bypass properties
error:  { Error: connect ECONNREFUSED 127.0.0.1:8167
    at Object.exports._errnoException (util.js:1024:11)
    at exports._exceptionWithHostPort (util.js:1047:20)
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1150:14)
  code: 'ECONNREFUSED',
  errno: 'ECONNREFUSED',
  syscall: 'connect',
  address: '127.0.0.1',
  port: 8167 }
RWS: handleClose { shouldRetry: true }
RWS: retries count: 1
RWS: handleClose - reconnectDelay: 2940.596362061423
Connection closed:  1006
RWS: connect
RWS: bypass properties
RWS: timeout
events.js:182
      throw er; // Unhandled 'error' event
      ^

Error: closed before the connection is established
    at WebSocket.close (<project>\node_modules\ws\lib\WebSocket.js:270:28)
    at Timeout._onTimeout (<project>\node_modules\reconnecting-websocket\dist\index.js:126:16)
    at ontimeout (timers.js:469:11)
    at tryOnTimeout (timers.js:304:5)
    at Timer.listOnTimeout (timers.js:264:5)

Extract from my code:

const ReconnectingWebSocket = require('reconnecting-websocket');
const WebSocket = require('ws');
this.ws = new ReconnectingWebSocket(url, [], {constructor: WebSocket, debug: true});

this.ws.on('error', (data) => {
   console.log('error: ', data);
});

this.ws.on('close', (code, reason) => {
   console.log('Connection closed: ', code, reason);
   this.connectionStatus = 'disconnected';
});

Is there any workaround for this? Is this an issue with reconnecting-websocket or ws?

[aysuio]

@aysuio I stopped using this library and started using https://github.com/websockets/ws with my own implementation of reconnection.

websocketService.js

const WebSocket = require('ws')

function connect() {
  console.log('Connecting...')
  let ws = new WebSocket('ws://localhost:3333')

  ws.on('open', () => {
    console.log('Connection open')
  })

  ws.on('message', data => {
    console.log(data.toString('utf-8'))
  })

  ws.on('close', () => {
    console.log('Connection close')
    ws = null
    setTimeout(connect, 1000)
  })

  ws.on('error', err => {
    console.log('Connection error')
    console.error(err)
  })
}

connect()

ws version: ^8.8.1

To see it working, try to stop your ws server or add handshakeTimeout: 1 option to the 2nd parameter of WebSocket instance.

...
let ws = new WebSocket('ws://localhost:3333', { handshakeTimeout: 1 })
...

It should now reconnect after the timeout and when the network is down.

I also used that library instead of this one, which just costed me around 1 hour to implement the reconnection feature. Should have done this long time ago, XD.

Thanks for the reply

[Szellem]

As mentioned in the linked issue, the event handlers of old ws instance are set to undefined after the connection error, so the following line removes all of them from the new instance too: https://github.com/pladaria/reconnecting-websocket/blob/31a0f01af4c96dfb1ba0c17b1124de204cd0e513/dist/index.js#L45

After commenting this block out and using addEventListener() instead of on in my code, it works with ws lib. A possible fix would be to skip assignment of undefined listeners in this block. What do you think?