Archive for March, 2007

In the final installment of this March 1st trilogy, I’ll hit something really topical, the precipitous fall of the Dow Jones Industrial Average (DJIA) two days ago on February 26th. For those of you just diligently minding your stakes in the market, you probably got wind that all the major indexes tanked pretty badly on the 26th. The Dow, however, tanked in a rather unnatural fashion that was quite different from the others.

How the Dow Lost 200 Points in the Blink of an Eye

You can see the “Live” and recalculated Dow Jones numbers on the graph above. Although the actual Dow (in orange) did drop pretty steeply, there’s no way it could have done the near vertical drop that the graph indicates without some outside intervention. It turns out that this outside intervention was provided by a “computer glitch”, as reported in the general press. More specifically, one of the queuing systems that feeds data to the system that actually calculates the Dow Jones index got backed up under record trading volumes. When market watchers got suspicious that the index movement did not align with the sliding values of its core components, they decided to investigate. Discovering the backlog, they manually switched over to alternate systems. When these systems worked down the backload, a new DJIA was calculated and voila, we had a 200 point drop in a couple of minutes.

As painful as this must have been for professional traders and as painful as it’s likely to be (in terms of lawsuits) for the Dow Jones company, this is really interesting from an IT point of view. If you’re an IT person looking for insight into how these markets work, I thoroughly recommend the book Practical .NET for Financial Markets. It’s one of the most advanced .NET texts I’ve ever read and, as a positive side effect, introduced me to a completely unfamiliar business domain, financial markets. Reading this book will not only make you a more educated developer (whether or not you use .NET), it will help you understand the causes and effects of events like those on the DOW two days ago.

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If you work in the IT world today, you have a greater chance of not finding a Starbucks on a randomly selected block in Manhattan than you do of not hearing the term “SOA” during your daily workday. It’s unfortunately not nearly as often that I hear or read something about SOA that sounds reasonable, practicable, and overcomes my otherwise skeptic view of all the hype that so often masquerades as SOA. The recent ITConverations Podcast with Todd Biske and Ed Vasquez from MomentumSI is just the sort of real-world advice that avoids the hype and gives a heavy dose of ground truth reality.

SOA Governance

Todd and Ed offer some pragmatic advice with respect to SOA and highlight challenges that really resonate with me based upon my experiences. Amongst these are the lack of a single design time and run time governance toolset and the importance of the mindshift from developing enterprise applications to developing reusable enterprise functionality that can be leveraged by different applications. Most importantly, however, is their insight in the importance of thinking of services as products. I have found this to be one of the single largest hurdles to achieving reuse – be it component-based or service-based reuse. Proficiency in application development in no way guarantees proficiency in product-based service development. In fact, most application development organizations that I have dealt with have little or no experience with product-based development. I couldn’t possibly cover all of the disciplines needed to master product-based development in this short post but I’ll refer you to a couple of sources that I feel give more than an adequate introduction.

I plan on recommending this Podcast to a number of people that I work with or have worked with in the past. I can’t expect everyone that I deal with to spend time digesting countless books and articles on the topic of SOA. As a matter of fact, given some of the materials out there, this might just prove more confusing than useful. An hour of time to listen to a Podcast (especially this one) isn’t too much to ask though. You’ll learn an awful lot in this hour.

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In the first of my beginning-of-the-month speed blogs, I’d like to start with the topic that I’ve been putting off longest, building applications on top of Amazon’s Web services. For those of you that think of as just a book store, or an e-commerce platform, or [add your assumption here], think again. In the last year or so, Amazon has released a number of services that have not only established them as a first-class platform, but have pushed the envelope considerably on the idea of virtualization.

Building Applications in the Cloud

This trend started with Amazon’s Simple Storage Service (S3) and was expanded on with their Simple Queue Service (SQS). Late last year, Amazon blew the roof off with the limited release of their Elastic Compute Cloud (EC2) service. EC2 is a configurable computing environment where you can load up virtual instances (roughly equivalent to your average Linux server) – on demand. You can load or unload these instances to meet cyclical demand and you only get charged for the computing time that you use. Couple this grid computing potential with S3 for storage and SQS for queuing and let your imagination be the limit.

Doug Kaye’s architecture for GigaVox Audio Lite, an audio file transcoder, might give you some ideas about what can be done with these services. The related ITConversations podcast contains plenty of details, with both Kaye and Jeff Barr, from Amazon, on the wire with Phil Windley. This podcast does a good job of conveying the vision and the realities of using these services. Some of the discussions, like managing and developing on top of a globally distributed queuing system where a call like size = MyQueue.size doesn’t really make any sense, will cause you to stop and think.

The final new Amazon service that I didn’t mention is Mechanical Turk, which is, simply put, a computer interface onto human services. This one has been around for a while and never got much attention from me until I heard the Podcast. Interestingly, the site, which produces Podcast transcriptions, farms out their work via Mechanical Turk. The combination – digital input in (MP3); digital input out (electronic transcript); virtual computing; virtual workforce – that’s pretty radical. There are some other great uses for this service mentioned on the Podcast as well.
The Podcast is absolutely worth a listen. And if this sort of thing piques your interest, you’re not alone. The queue to get into the EC2 beta program is a few months long. If you’re even remotely interested, get in line now.

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