Node js ECONNRESET

Question

I m running an Express js application with socket.io for a chat webapp and I get the following error randomly around 5 times during 24h. The node process is wrapped in forever and it restarts itself immediately.

Problem is that restarting express kicks my users out of their rooms and nobody wants that.

The web server is proxied by HAProxy. There are no socket stability issues, just using websockets and flashsockets transports. I cannot reproduce this on purpose.

This is the error with node v0.10.11:

events.js:72
        throw er; // Unhandled 'error' event
              ^
Error: read ECONNRESET     //alternatively it s a 'write'
    at errnoException (net.js:900:11)
    at TCP.onread (net.js:555:19)
error: Forever detected script exited with code: 8
error: Forever restarting script for 2 time

EDIT (2013-07-22)

Added both socket.io client error handler and the uncaught exception handler. Seems that this one catches the error:

process.on('uncaughtException', function (err) {
  console.error(err.stack);
  console.log("Node NOT Exiting...");
});

So I suspect it's not a socket.io issue but an http request to another server that I do or a mysql/redis connection. Problem is that the error stack doesn't help me identify my code issue. Here is the log output:

Error: read ECONNRESET
    at errnoException (net.js:900:11)
    at TCP.onread (net.js:555:19)

How do I know what causes this? How do I get more out of the error?

Ok, not very verbose but here s the stacktrace with "longjohn":

Exception caught: Error ECONNRESET
{ [Error: read ECONNRESET]
  code: 'ECONNRESET',
  errno: 'ECONNRESET',
  syscall: 'read',
  __cached_trace__:
   [ { receiver: [Object],
       fun: [Function: errnoException],
       pos: 22930 },
     { receiver: [Object], fun: [Function: onread], pos: 14545 },
     {},
     { receiver: [Object],
       fun: [Function: fireErrorCallbacks],
       pos: 11672 },
     { receiver: [Object], fun: [Function], pos: 12329 },
     { receiver: [Object], fun: [Function: onread], pos: 14536 } ],
  __previous__:
   { [Error]
     id: 1061835,
     location: 'fireErrorCallbacks (net.js:439)',
     __location__: 'process.nextTick',
     __previous__: null,
     __trace_count__: 1,
     __cached_trace__: [ [Object], [Object], [Object] ] } }

Here I serve the flash socket policy file:

net = require("net")
net.createServer( (socket) =>
  socket.write("<?xml version=\"1.0\"?>\n")
  socket.write("<!DOCTYPE cross-domain-policy SYSTEM \"http://www.macromedia.com/xml/dtds/cross-domain-policy.dtd\">\n")
  socket.write("<cross-domain-policy>\n")
  socket.write("<allow-access-from domain=\"*\" to-ports=\"*\"/>\n")
  socket.write("</cross-domain-policy>\n")
  socket.end()
).listen(843)

Can this be the cause?

Answer 1

Another possible case (but rare) could be if you have server to server communications and have set server.maxConnections to a very low value.

In node's core lib net.js it will call clientHandle.close() which will also cause error ECONNRESET:

if (self.maxConnections && self._connections >= self.maxConnections) {
  clientHandle.close(); // causes ECONNRESET on the other end
  return;
}

Answer 2

Had the same problem today. After some research i found a very useful --abort-on-uncaught-exception node.js option. Not only it provides much more verbose and useful error stack trace, but also saves core file on application crash allowing further debug.

Answer 3

I also get ECONNRESET error during my development, the way I solve it is by not using nodemon to start my server, just use "node server.js" to start my server fixed my problem.

It's weird, but it worked for me, now I never see the ECONNRESET error again.

Answer 4

Try adding these options to socket.io:

const options = { transports: ['websocket'], pingTimeout: 3000, pingInterval: 5000 };

I hope this will help you !

Answer 5

I was facing the same issue but I mitigated it by placing:

server.timeout = 0;

before server.listen. server is an HTTP server here. The default timeout is 2 minutes as per the API documentation.

Answer 6

I solved the problem by simply connecting to a different network. That is one of the possible problems.

As discussed above, ECONNRESET means that the TCP conversation abruptly closed its end of the connection.

Your internet connection might be blocking you from connecting to some servers. In my case, I was trying to connect to mLab ( cloud database service that hosts MongoDB databases). And my ISP is blocking it.