Cloud Application Architectures

Capacity Planning

Capacity planning is basically developing a strategy that guarantees your infrastructure can support the resource demands placed on it. Covering the intricacies of capacity planning could fill an entire book. In fact, John Allspaw has done just that with his O’Reilly book titled The Art of Capacity Planning. I recommend reading that book, as capacity planning is truly important to success in the cloud. For the purposes of this book, however, we will look at the core concerns for scaling in the cloud:

• Knowing your expected usage patterns as they vary during the day, over the course of a week, during holidays, and across the seasonal variance of your business

• Knowing how your application responds to load so that you can identify when and what kind of additional capacity you will need

• Knowing the value of your systems to the business so you can know when adding capacity provides value—and when it doesn’t

Some look at the ability of cloud environments to automatically scale based on demand and think they no longer need to engage in capacity planning. Some look at capacity planning and think of tens or hundreds of thousands of dollars in consulting fees. Both thoughts are dangerous myths that must be put to rest.

Capacity planning is just as important in the cloud as it is in a physical infrastructure. And you do not need to engage in some outlandish capacity planning project to develop a proper plan. In the end, your objective is simply to make sure that when you incur ...