AssertionError: false == true at SharedHandle.add (cluster.js:97:3)

[FLYBYME]

Getting this error

assert.js:86
  throw new assert.AssertionError({
        ^
AssertionError: false == true
    at SharedHandle.add (cluster.js:97:3)
    at queryServer (cluster.js:480:12)
    at Worker.onmessage (cluster.js:438:7)
    at ChildProcess.<anonymous> (cluster.js:692:8)
    at ChildProcess.emit (events.js:129:20)
    at handleMessage (child_process.js:324:10)
    at Pipe.channel.onread (child_process.js:352:11)

$ node -v
v0.12.0

[cjihrig]

Thanks for reporting this. Can you please provide a reduced test case, with no external dependencies, that reproduces the issue?

[elliotstokes]

I'm also getting this error. Happens when I try to make a udp request from a cluster.

[elliotstokes]

test case. It will work first request and fail for the second.

var cluster = require('cluster');
var http = require('http');
var dgram = require('dgram');
var numCPUs = require('os').cpus().length;

if (cluster.isMaster) {
  // Fork workers.
  for (var i = 0; i < numCPUs; i++) {
    cluster.fork();
  }

} else {

  var server = http.createServer(function (request, response) {
    var client = dgram.createSocket("udp4");
    var message = new Buffer("Hello");
    client.send(message, 0, message.length, 80, "google.com", function(err, bytes) {
      client.close();
    });
    response.writeHead(200, {"Content-Type": "text/plain"});
    response.end("Hello World\n");
  });

  server.listen(1337);
}

[elliotstokes]

this doesn't look like it happens on 0.10.x only 0.12

[FLYBYME]

I tracked it down to been UDP as elliotstokes did.

[elliotstokes]

@FLYBYME did you find a workaround at all? i tried a few things but didn't get anywhere.

[cjihrig]

The solution to this is in #8643. It landed in master, but not 0.12. A workaround would be to create an exclusive UDP socket in your worker.

[rcrichton]

I'm getting the exact same problem and using node from master doesn't solve it. I'm only using UDP server sockets and I get the following when closing and restarting the UDP server:

AssertionError: false == true
    at SharedHandle.add (cluster.js:99:3)
    at queryServer (cluster.js:482:12)
    at Worker.onmessage (cluster.js:440:7)
    at ChildProcess.<anonymous> (cluster.js:694:8)
    at ChildProcess.emit (events.js:131:20)
    at handleMessage (child_process.js:326:10)
    at Pipe.channel.onread (child_process.js:354:11)

It works fine without using the cluster API, but breaks with it.

$ node --version v0.13.0-pre

See the above referenced commit if you want to see some code.

[nexflo]

This is a major break for clustering (which is a core feature for node).
Is there an ETA in which release this will appear?
Thanks in advance.

[pungoyal]

This has become a major problem for us. Our processes keep getting killed. Workaround is to put a monitoring tool/script, but we'd rather not do that.

[cjihrig]

The following code (the original test case posted in this issue) works in master, but not 0.12, as #8643 did not land in 0.12. Do you have a reduced test case, written in JavaScript, with no external dependencies, that reproduces the problem against the master branch? If you are using 0.12, you may want to look into using the exclusive option with your UDP sockets.

var cluster = require('cluster');
var http = require('http');
var dgram = require('dgram');
var numCPUs = require('os').cpus().length;

if (cluster.isMaster) {
  // Fork workers.
  for (var i = 0; i < numCPUs; i++) {
    cluster.fork();
  }

} else {

  var server = http.createServer(function (request, response) {
    var client = dgram.createSocket("udp4");
    var message = new Buffer("Hello");
    client.send(message, 0, message.length, 80, "google.com", function(err, bytes) {
      client.close();
    });
    response.writeHead(200, {"Content-Type": "text/plain"});
    response.end("Hello World\n");
  });

  server.listen(1337);
}