The Barbarian Programmer: Architecting Simplicity

I am amazed at the plethora of products and technologies that are required to deliver a best-of-breed, leading-edge, enterprise-scale, line-of-business software system.

As an example, a system that I am currently working on has an architecture that uses the following products and technologies:

None of the aforementioned technologies are being used gratuitously; the architecture that aggregates all of the above is necessarily complex, given the requirements. A senior developer working on this project needs to understand all of these technologies and will be writing “code” in HTML, CSS, JavaScript, XML, C# and TSQL on a daily basis. That’s a lot of tech to wrap one’s head around. And that does not include understanding the domain “problems” that the system needs to solve, which are typically complex in their own right. And this amount of technology is not atypical for enterprise line-of-business application development.

Does software that solves complex problems really need to have so many moving parts? Isn’t Simplicity one of the core tenets of great software design?

I recently had the opportunity to chat with Rob Boyes, a Technical Director at airG, about the technologies that they are using for their latest product and service offerings. airG is a leading mobile social entertainment provider based in Vancouver, and they have millions of users from across the planet using their software. Rob told me that, though in the past they have used the LAMP stack for their backend platform, they are now using node.js and mongoDB. Though I knew of the existence of mongoDB, I had to admit to Rob that I had not heard of node.js. Since I love nothing more than tinkering with new software technology, this conversation motivated me to do a little hands-on research into these technologies, and I have to say that I have been super-impressed; these two technologies are, in a word, “awesome”! And much of that awesomeness derives from their elegant simplicity.

node.js, or just “node”, is a server-side JavaScript runtime based on Google’s V8 JavaScript Engine; the same JavaScript engine that is in Google Chrome. It includes built-in HTTP support (though it is not limited to the HTTP protocol for network IO).

Here is a very simple example of node JavaScript code:

var http = require('http');
http.createServer(function (request, response) {
response.writeHead("Content-Type", "text/html");
response.end('<html><body><h1>The Barbarian Programmer</h1></body></html>');
}).listen(8000, "127.0.0.1");

Obviously being able to write JavaScript on the server gives web applications elegant symmetry, but node’s execution model is also very simple; the runtime, which will run on just about any modern operating system, runs user code on a single thread (though the runtime itself is multi-threaded). Request processing is non-blocking and is based on an asynchronous event/call-back model, so the entire server is super-scalable, and developers do not need to concern themselves with pernicious thread synchronization issues. There is also nothing to stop you from running multiple hardware-thread-affined instances of the node runtime on a single box and using a load-balancer, probably also running on node, if you want to take advantage of multiple cores or CPUs for additional scalability and/or throughput. How to Node is a good place to learn about all things node.

There are also a lot of additional JavaScript libraries for node, including Connect and express, which further simplify the development of web applications. There is also a great package manager available for node called npm, which makes installing these libraries dead easy. It is currently “experimental” on Windows.

mongoDB is a super-scalable “document-oriented” database, which natively supports the storage and retrieval of JSON(ish) documents. This makes it the perfect choice for use with node.js. A node.js driver is available for mongoDB, and drivers are also available for just about every platform under the sun, including the .NET Framework. mongoDB binaries are available for Windows, Linux, OS X and Solaris, and since it is open source, so is the source code. You can install the node.js drivers using npm.

When node.js and mongoDB are combined with HTML50, CSS3.0, JQuery and client-side JavaScript they represent a super-scalable, simple, consistent, and powerful web application platform. And it’s JavaScript (and JSON) all the way down! Obviously these technologies are not going to be suitable for every type of application, but I will most definitely be looking for opportunities to use them in upcoming systems that I design. Perhaps you should too.

Mad props to Rob, for reminding me that there are indeed new things under the sun.

Tuesday, October 11, 2011

Architecting Simplicity

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