This was the sixth in a series of posts leading up to Node.js Knockout on how to use node.js. This post was written by 10gen and is cross-posted from their blog.
10gen is the corporate sponsor of MongoDB. MongoDB bridges the gap between key-value stores (which are fast and highly scalable) and traditional RDBMS systems (which provide rich queries and deep functionality).
Node and MongoDB
Node.js is turning out to be a framework of choice for building real-time applications of all kinds, from analytics systems to chat servers to location-based tracking services. If you're still new to Node, check out Simon Willison's excellent introductory post. If you're already using Node, you probably need a database, and you just might have considered using MongoDB.
The rationale is certainly there. Working with Node's JavaScript means that MongoDB documents get their most natural representation - as JSON - right in the application layer. There's also significant continuity between your application and the MongoDB shell, since the shell is essentially a JavaScript interpreter, so you don't have to change languages when moving from application to database.
Node.js MongodB Driver
Especially impressive to us at 10gen has been the community support for Node.js and MongoDB. First, there's Christian Kvalheim's excellent mongodb-node-native project, a non-blocking MongoDB driver implemented entirely in JavaScript using Node.js's system libraries. The project is a pretty close port of the MongoDB Ruby driver, making for an easy transition for those already used to the 10gen-supported drivers. If you're just starting, there's a helpful mongodb-node-native mailing list.
Hummingbird
Need a real-world example? Check out Hummingbird, Michael Nutt's real-time analytics app. It's built on top of MongoDB using Node.js and the mongodb-node-native driver. Hummingbird, which is used in production at Gilt Groupe, brings together an impressive array of technologies; it uses the express.js Node.js app framework and sports a responsive interface with the help of web sockets. Definitely worth checking out.
Mongoose
Of course, one of the admitted difficulties in working with Node.js is dealing with deep callback structures. If this poses a problem, or if you happen to want a richer data modeling library, then Mongoose is the answer. Created by Learnboost, Mongoose sits atop mongodb-node-native, providing a nice API for modeling your application.