Amazon EC2: Persistent Storage

Amazon has just started a private beta program for a new persistent storage API in EC2. According to their documentation, they provide an API to create and manage volumes between 1GB and 1TB in size that behave like unformatted disks. Each volume is persistent and independent of EC2 instances and a single EC2 instance can mount multiple volumes. Their disks are supposed to be low-latency and high throughput with calls to store snapshots onto S3.

A lack of persistent storage has been the biggest challenge for developers as EC2 (in my experience) has rather high failure rates. With this persistent storage API (scheduled for public release later this year), Amazon has just made EC2 a dead-easy buy-in.

A Closer Look: Amazon Web Services

Amazon has been doing some pretty nifty stuff lately. They've exposed their computing infrastructure to the rest of the world via RESTful web services. I think it's a brilliant move by Jeff Bezos and it realizes some of the technology promises of the last decade or so.

Amazon's web services have been getting a lot of great reviews from many bloggers and deservedly so. With their pay-as-you-use model, it's amazingly easy to scale up or down based entirely on workload; there's virtually no need for capacity planning and no need to manage physical systems at all! I've been using their web services for over a year now for a variety of tasks and it has been, for the most part, quite pleasant. They've saved me a lot of time and money but their services do have their faults. I'll be talking about some of the issues I've encountered with the design or implementation of their services over the next few posts.

Google Web Toolkit: a quick look

While writing the last blog post, I had a miserable time trying to get the Java snippets formatted correctly. I suppose the problem is that I'm using Blogger instead of a full-blown publishing platform like Movable Type which has plugins for code highlighting. Once I got the post up, I decided to build a web service that would take a code snippet in your language of choice and return highlighted HTML code.

Along the way, I found a neat package called GeSHi, a generic code highlighter that would make my life a lot easier. I then got the idea of making an AJAXed front-end to that along with other useful web services... Eventually, I came across the Google Web Toolkit and it looks like the Google folks are really on to something!

Now, I'm sorry to say that I've done my share of AJAX code before, both client side and server side, and it has been one of the most painful coding experiences of my life. The runtime errors, the lack of decent developer tools, the browser incompatibilites, the ridiculous workarounds... web development has been just one enormous nightmare. The guys and gals at Google managed to take a large part of that away with GWT; they're actually compiling Java code to JavaScript with all of the compile-time checks (hooray, no more typo-bugs rearing their heads at runtime!), development tools (including a debugger!), and patterns kept intact! The really nice bit is that they abstract all of the cross-browser differences via their core library. Now this is a step in the right direction for web development!

Of course, it's not a perfect system. They're building this on top of Java 1.4 so we still don't have safe container classes or enumerated values (sigh). What's more, since AJAX is event driven by nature, I think it would be so much easier to use a functional source language so we can pass functions and closures around instead of anonymous inner classes.