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Saturday
Apr232011

Wicked Fast

“Now, here, you see, it takes all the running you can do, to stay in the same place. If you want to get somewhere else, you must run at least twice as fast as that!” Lewis Carroll ~ Alice's Adventures in Wonderland

I really love Ruby on Rails. My biggest pet peeve with software development platforms has always been their quest for generality -- "with our program, you could build anything, from an iPhone tic-tac-toe app to systems code for the Space Shuttle!" The problem here is that nobody wants to build just "anything" -- people's needs at any given time tend to be pretty specific. A platform that claims to be good for everything is generally good for nothing. That's where Rails comes in -- web apps is all it does.

The best frameworks are in my opinion extracted, not envisioned. And the best way to extract is first to actually do. ~ David Heinemeier Hansson ~ Ruby on Rails

This is where the "PT boats to Battleships" metaphor I wrote about in my last post comes in. I believe Rails is unbeatable for web apps, as long as the definition of a web app doesn't change. It was perfect for what it did -- but do we still do that anymore?

As I mentioned last post -- the world is changing and the old patterns may not work anymore. So what do you do? Is there a "Rails" for Ajax applications between handheld devices?

NodeJS

There is -- or at least there's the start of a platform built around a very different set of assumptions of what Internet applications are all about. It's called Node.js, and it springs from work that Ryan Dahl first published in 2009.

Node is really interesting and it builds on a capability of its core JavaScript language that Joel Spolsky wrote about in 2006: Can Your Programming Language Do This? -- the ability to package rich objects (including inline functions) as parameters in function calls. Hmmmm ... this sounds like this could get deep and theoretical... but stay with me: here's why it matters:

  1. In the web-pagey world, to respond to a request you compose and send a page. With simple web pages you can do this sequentially and are probably fine, and threads are there to bail you out wherever you aren't fine.
  2. Today, with Big Data databases and media files, you might get a request and not know if that request is EVER going to complete!? Processes block, and even the fastest processor can't do much while it's just sitting and waiting.
  3. The solution? A non-blocking architecture. It's fine to have long requests -- as long as you're not stuck waiting for them to finish.... so how do we do that?
  4. This is the problem Dahl solves with Node.js. Node is an event-driven architecture -- when requests come in, Node processes them by attaching a callback routine to them and launching them, and then moving on to the next request.

This is the perfect architecture for a modern web age with a mix of skinny and chunky requests. Rather than grinding through it all in sequence, you tell each request "Here you go -- call me when you're done..." and move on to the next thing. It's a clean approach, and with modern JavaScript engines, such as Google V8 or Apache SpiderMonkey, this kind of approach is fast.

Wicked fast.

Node.js is tight and clean, and it's amazing what you can get done with just a little code. Like all Unix-y code since Kernighan and Ritchie, Node.js has its Hello World app:

var http = require('http');
http.createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/plain'});
res.end('Hello World\n');
}).listen(8124);
console.log('Server running at http://127.0.0.1:8124/');

The explanation of the code is really simple -- it's just as it reads:

  1. Create a HTTP server
  2. Make it request / response
  3. Write a 200 code for success with plain text
  4. Write "Hello World"
  5. Listen on port 8124
  6. Tell the console that we're listening on 8124

It really is just that simple. I'm not sure how you'd make space shuttle code with it, but if you're looking for evented web apps with a tiny footprint, Node.js is it. For this blog posting I wanted to try something a bit bigger, so I put Ben Gourley's little NodeJS-driven presentation page up on the Amazon cloud:

The code was adapted from Ben's CLOCK BLO" site, and while the presentation isn't exactly full-featured, it has less than 100 lines of code invested in it, and it is...

Wicked Fast.

As you can see, the presentation, but it's in the best 15 minute tradition of new web platform development.

One of the beauties of Node.js with the Express package is that, despite its simplicity, it is still full Model-View-Controller, so setting up the code was easy, and laid out in a nice, clean beautiful way:

There's a lot to write about Node.js, its package manager npm, and development packages like Express, Connect, and Websockets/socket.io, and those will come in other posts. There's a lot here -- maybe the future of the handheld, small-screened, peer-to-peer web.

It really is ... WICKED FAST!

"This is your last chance. After this, there is no turning back. You take the blue pill - the story ends, you wake up in your bed and believe whatever you want to believe. You take the red pill - you stay in Wonderland and I show you how deep the rabbit-hole goes." Morpheus ~ The Matrix