Q:

Mongoose connect method fails on simple Node Server. Express, Mongoose, Path

This is the first time I'm running node with mongoose. I'm following some tutorials in this backbone book and I'm up to this chapter on creating a restful api using express, mongoose and I'm following the code exactly I've even come to copying and pasting but it's still not working. Here is the code:
http://addyosmani.github.io/backbone-fundamentals/#creating-the-back-end
// Module dependencies.
var application_root = __dirname,
    express = require( 'express' ), //Web framework
    path = require( 'path' ), //Utilities for dealing with file paths
    mongoose = require( 'mongoose' ); //MongoDB integration

//Create server
var app = express();

// Configure server
app.configure( function() {
    //parses request body and populates request.body
    app.use( express.bodyParser() );

    //checks request.body for HTTP method overrides
    app.use( express.methodOverride() );

    //perform route lookup based on url and HTTP method
    app.use( app.router );

    //Where to serve static content
    app.use( express.static( path.join( application_root, 'site') ) );

    //Show all errors in development
    app.use( express.errorHandler({ dumpExceptions: true, showStack: true }));
});

//Start server
var port = 4711;
app.listen( port, function() {
    console.log( 'Express server listening on port %d in %s mode', port, app.settings.env );
});

// Routes
app.get( '/api', function( request, response ) {
    response.send( 'Library API is running' );
});

//Connect to database
mongoose.connect( 'mongodb://localhost/library_database');

//Schemas
var Book = new mongoose.Schema({
    title: String,
    author: String,
    releaseDate: Date
});

//Models
var BookModel = mongoose.model( 'Book', Book );

I've been poking around on stack overflow and other sites trying to resolve the issue but nothing I found seemed to allow me to connect to the mongodb.
The first error is:
events.js:72
        throw er; // Unhandled 'error' event
              ^
Error: failed to connect to [localhost:27017]
    at null.<anonymous> (/Users/jeff/Sites/backbone-ex2/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/server.js:536:74)
    at EventEmitter.emit (events.js:106:17)
    at null.<anonymous> (/Users/jeff/Sites/backbone-ex2/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/connection_pool.js:140:15)
    at EventEmitter.emit (events.js:98:17)
    at Socket.<anonymous> (/Users/jeff/Sites/backbone-ex2/node_modules/mongoose/node_modules/mongodb/lib/mongodb/connection/connection.js:478:10)
    at Socket.EventEmitter.emit (events.js:95:17)
    at net.js:411:14
    at process._tickCallback (node.js:415:13)

This change seems to fix that issue:
    mongoose.connect( 'mongodb://localhost/library_database', function(err) { if (err) console.log(err); } );

After that express works but mongodb fails to connect:
Express server listening on port 4711 in development mode
[Error: failed to connect to [localhost:27017]]

I tried changing to this:
mongoose = require( 'mongoose' ).Mongoose;

I also tried running mongod in the cli with some variations on options in the cli but that seems to just bring up the help page. I'm totally stuck... Any help would be greatly appreciated. Thanks in advance.

A:

You need to actually successfully get mongod running and listening for connections. Just type mongod with no options, hit ENTER, and let it run. Then in a separate terminal start your express app. Note that mongod is the mongodb server daemon whereas mongo is the command line client where you can run an interactive REPL and issue database commands.

A:

You need to install the database itself. Refer here for mongodb installation guide.

