One of the promises of Windows Azure and cloud computing in general is the ability to quickly and easily expand and contract computing resources based on demand. Microsoft Cloud Architect Bart Robertson shares a great real-world example of how this feature works in a new blog post, “Cloud Elasticity – A Real-World Example” that’s worth a read if you’re interested in learning more about Windows Azure and elasticity.
Microsoft’s Social eXperience Platform (SXP) is a multi-tenant web service that powers community and conversations for many sites on microsoft.com, including the Cloud Power web site. When the Cloud Power site sees an increase in traffic, SXP also sees an increase in traffic, which is exactly what happened in April, according Robertson.
In this case, Robertson explains, the web traffic spikes were due to ads, which typically ran for a day or two. Compared to March’s average daily traffic, SXP’s traffic spiked to over 700%. Traditionally, the only way to handle such spikes was to over-purchase capacity in advance of the ads running, but the SXP team decided instead to double their Windows Azure compute capacity to ensure they could handle the load.
They went from 3 servers to 6 servers on their web tier within an hour of making the decision. The total human time to accomplish this was a couple of minutes and a change to one value in an XML file - Windows Azure took care of the rest. Within half an hour, they validated via the logs they had doubled our capacity and all web servers were taking traffic. Full-retail cost for the burst capacity was $70 plus about 5 minutes of operations time.
It’s a great real-world example of how Windows Azure can seamlessly and cost-effectively enable elasticity; click here to read Bart’s post and learn more about this story. To learn more about SXP's experience using Windows Azure, read the related post, "Windows Azure and Microsoft SXP Serve Up to Two Million Media Rich Experiences Daily on Microsoft Showcase."