Socket.IO server hangs up

Question

I am new to socket.io. So my socket.io server sometimws crashes giving this below error

timers.js:103
        if (!process.listeners('uncaughtException').length) throw e;
                                                                  ^
Error: socket hang up
    at createHangUpError (http.js:1360:15)
    at ServerResponse.OutgoingMessage._writeRaw (http.js:507:26)
    at ServerResponse.OutgoingMessage._send (http.js:476:15)
    at ServerResponse.OutgoingMessage.write (http.js:749:16)
    at XHRPolling.doWrite (E:\sitesroot\0\node_modules\socket.io\lib\transports\
xhr-polling.js:67:17)
    at XHRPolling.HTTPPolling.write (E:\sitesroot\0\node_modules\socket.io\lib\t
ransports\http-polling.js:132:8)
    at XHRPolling.Transport.packet (E:\sitesroot\0\node_modules\socket.io\lib\tr
ansport.js:515:15)
    at Object.<anonymous> (E:\sitesroot\0\node_modules\socket.io\lib\transports\
http-polling.js:79:12)
    at Timer.list.ontimeout (timers.js:101:19)

It doesnt show where or why the error is happening so pretty sure its nothing to do with the code i have written. Could be something with the transports? I dont have much knowledge on it. Any suggestions on how to stop it from crashing would be highly appreciated. Thanks

Answer 1

The problem is as @miktam stated. To fix this you need to add an error listener to your code. Add this code to your application:

//Error handler
process.on('uncaughtException', function (exception) {
  // handle or ignore error
  console.log(exception);
});

When ever there is an error it will console.log it instead of crashing it. I had the exact same problem and this fixed it.