在node.js中运行应用程序时出现连接超时错误

当我运行我的node js应用程序给节点app.js，设置NODE_ENV =生产，它不是被设置为生产，而是它给了连接超时错误，当我运行应用程序。我想它实际上得到连接与蒙古ab请等待您的建议。提前谢谢你。

 C:'Users'Desktop'myapp>node app.js
    ChatBox working on port 3000
    Mode:development
    C:'Users'Desktop'myapp'node_modules'mongoose'node_modules'mongodb'lib'se
    rver.js:228
            process.nextTick(function() { throw err; })
                                                ^
    Error: connect ETIMEDOUT
        at exports._errnoException (util.js:746:11)
        at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1010:19)

var express = require('express'),
app = express(),
path =require('path'),
cookieParser = require('cookie-parser'),
session = require('express-session'),
config = require('./config/config.js'),
ConnectMongo = require('connect-mongo')(session)
mongoose = require('mongoose').connect(config.dbURL)
app.set('views', path.join(__dirname, 'views'));
app.engine('html', require('hogan-express'));
app.set('view engine' , 'html');
app.use(express.static(path.join(__dirname,'images')));
app.use(cookieParser());
//app.route('/').get(function(req,res,next){
//  res.render('index', {title:'Welcome to ChatBox'});
//})
var env = process.env.NODE_ENV || 'development';
    if(env ==='development'){
        app.use(session({secret:config.sessionSecret,
                        saveUninitialized:true,
                        resave:true}))
    }
    else
    {
                app.use(session({
                secret:config.sessionSecret,
                saveUninitialized:true,
                        resave:true,
                store:new ConnectMongo({
                    url:config.dbURL,
                    stringify:true
                })
                }))
    }

    var userSchema = mongoose.Schema({
        username:String,
        password:String,
        fullname:String
    })
    var Person = mongoose.model('users',userSchema);
    var Kajol= new Person({
        username:'Kajol',
        password:'kajol_123',
        fullname:'Kajol Sakshi'
    })
    Sunitha.save(function(err){
        console.log('done');
    })

require('./route/route.js')(express , app);
app.listen(3000,function(){
    console.log('ChatBox working on port 3000');
    console.log("Mode:" +env);
})

这是假的URL，我没有把我的原始URL贴在这里。仅用于格式

{
        "dbURL" :"mongodb://chatboxuser:chatbox1234@ds051803.mongolab.com:41603/chatbox",
        "sessionSecret":"ALKKLHFDOI7UW98U3209UNFER923YH"

    }