node-issue-2928.js

#!/usr/bin/env node
'use strict';

// The master must be reasonably stressed for the crash to appear. These
// parameters can be tweaked to accomplish that. Increasing them too far can
// cause backlog fill and undesirable connection resets.
//
// These particular values seem to work on Ubuntu 15.04 running on an EC2
// c3.large instance with official node.js 4.1.0 binaries. (Everything 64-bit)
var WORKERS = 50;
var CONN_PER_WORKER = 200;

var cluster = require('cluster');
if (cluster.isMaster) {
    var http = require('http');

    // Simple HTTP upgrade server that simply ignores all data.
    var server = http.createServer();
    server.on('upgrade', function(req, sock) {
        sock.resume();
    });
    server.listen(function() {
        var port = server.address().port;
        cluster.setupMaster({ args: [port] });
        for (var i = 0; i < WORKERS; i++)
            cluster.fork();
    });
}
else {
    var net = require('net');

    var port = process.argv[2];
    var connections = [];
    var numConnect = 0;

    // Create connections up to the per worker limit.
    var connectInterval = setInterval(doConnect, 20);
    function doConnect() {
        if (numConnect++ === CONN_PER_WORKER)
            clearInterval(connectInterval);

        var conn = net.connect(port);
        conn.on('connect', function() {
            conn.write(
                'GET / HTTP/1.1\r\n' +
                'Host: localhost:' + port + '\r\n' +
                'Upgrade: nonsense\r\n' +
                'Connection: upgrade\r\n' +
                '\r\n'
            );

            connections.push(conn);
            if (connections.length === CONN_PER_WORKER) {
                setInterval(doMsg, 0);
                process.stdout.write('.');
            }
        });
        conn.resume();
    }

    // Send data on random open connection.
    function doMsg() {
        for (var i = 0; i < CONN_PER_WORKER; i++)
            connections[i].write('garbage');
    }
}