I know I’m late to finding this particular paper since it was first published about two years ago. Better late than never!

I found it interesting that Amazon uses a service-orientated-architecture of about 150 services to compose any one page. I just drew a few boxes on this page to illustrate some obvious ones that the end user sees. I’m sure there are other services working in the background that track how many times you’ve viewed the page, what parts of the page you scroll to and what buttons you click on to name just a few.

The paper goes on to describe four “other key principles” which I think are important architectural keys when building a SOA-based system.

• Incremental scalability – As new systems are added to the overall fabric of Dynamo, it increases the overall capability of the system.
• Symmetry – Except for processing capacity and hardware vintage, all nodes act the same.
• Decentralization – Peering instead of master-slave. The “master” will always become a bottleneck!
• Heterogeneity – Basically the Dynamo system allows the workload to scale out onto whatever type of server is available as long as the platform is the same. I bet that allows Amazon the flexibility of “purchasing and forgetting” hardware. The commodity hardware spans several generations of hardware improvements as servers are added and retired.

Some interesting solutions for large-scale systems:

• DHTs - Distributed Hash Tables
• Consistent Hashing
• Vector clocks
• Quorum
• anti-entropy based recovery – Couldn’t find a link for this concept.

Thanks to Werner Vogels for publishing the paper!

ASP.NET Charting Tools

The ASP.NET controls were released in the late fall of 2008. The chart controls were finally included in the C# 4.0 release as part of the standard ASP.NET platform.  If you’re looking for reasons to upgrade to C# 4.0, this three part series is a big reason to do so if you rely on reporting in your web application using SQL Reporting Service. Part 1, Part 2, Part 3.

Google Chart Tools

Google Chart Tools comes in two flavors:  Image Charts and Interactive Charts. Both sets have some very cool features. Your application just needs access to the internet.

This is a QR Code (That's also the message that appears if you have a decoder)

The only issue I see with using some external charting provider like Google is that you rely on them for core aspects of understanding your business. Say, one day, Google’s server’s go down for a 3 hour period — or the route to Google’s servers is unavailable. I see that happening about as often as the power going out at home — but it does happen. What does your application do to recover? What do you show when the graphics don’t appear?

That  minor issue aside, there are so many cool features with the Google Charting tools, that it outweighs the downside for small the medium sized applications. The good thing is that these tools are free but I wonder how Google views “customers” of its free services with respect to long-term API support.

Check out the googlechartsharp project at Google Code Project Hosting for a .NET implementation. Matt Durrant has another version with source code available.

Tip: If you want to use Google Chart Tools – Image Charts — over HTTPS, you need to change the base URL from

http://chart.apis.google.com/chart?

to

https://www.google.com/chart?.

Google doesn’t have a valid SSL certificate on “chart.apis.google.com”.

Example:

https://www.google.com/chart?cht=p3&chd=t:60,40&chs=250×100&chl=Sample|Chart

Some sample Google Chart Images

Idea Chart - Venn Diagram Example

USA Thematic Map

The R Project for Statistical Computing

R is a Unix-based statistical analysis package that has the ability to create any type of visual representation imaginable. Here’s a brief description from the About Us page at the R project

R provides a wide variety of statistical (linear and nonlinear modelling, classical statistical tests, time-series analysis, classification, clustering, …) and graphical techniques, and is highly extensible. The S language is often the vehicle of choice for research in statistical methodology, and R provides an Open Source route to participation in that activity.

• WebServius – 3rd party billing for your web service. Handles things like signup, metering, api key gen, quotas & analytics.
• DynInc – Who knew DNS could be so cool? Regional DNS routing, global traffic management, geo targeting traffic, load balancing. This is what sys admins do when they go to heaven.
• Twilio – Phone API (Press 1 for “Services”, Press 2 for “Billing”). I couldn’t remember their name for the longest time until last night when they were mentioned by the speaker from WebServius. Didn’t actually present.

• AWS feature rollout since November (A December to remember)
• AWS DB offering overview (EC2 AMIs, RDS and SimpleDB). Don’t forget the 4 hour maintenance window! Rollout of 5.1.4.2 is coming soon.
• Senior VP Engineering Bob Wise from  nuTsie.com (aka Melodeo)
• OpsCode‘s CTO Adam Jacob and VP Engineering Christopher Brown.

Take aways:

• Amazon’s 8th floor presentation room had some rockin’ views of the sound!
• Both presentations hinted that small AWS instances really don’t provide the best bang for your buck. Medium (High CPU) and Large sizes tend to provide better performance.
• Didn’t know that Windows 2008 R2 was now available on AWS (haven’t checked since December).
• CIDR addresses should be “/32″ unless you know what you’re doing!
• HIPPA compliance is at the App level, SAS 70 is at the physical layer.
• Locking your AWS instances can prevent accidental/unintentional shutdowns.
• memcached, memcached, memcached.
• Ecualyptus: Your own private Idaho (in the cloud) is AWS API compatible!