The Art of Capacity Planning: Scaling Web Resources [Formato Kindle]

John Allspaw has done something that very few of his peers would have been able to do. He has taken a black art, Capacity Planning, and he turned it in to a series of steps that anyone can follow.

The book is filled with common case studies, for how to plan capacity for things like web server farms, database clusters, and caching layers. The real value is in watching how the author applies the same formula in each case, giving Systems Administrators and Executives the tools they need to do a better job of capacity planning in their own unique infrastructures.

As the earlier review says, it's a short book. In my opinion, that's a good thing: it's goal is to teach you how to perform capacity planning in any environment. If it was longer, it would have been full of more examples, which would likely only serve to lead the reader away from the core principles. You need to learn *how* to capacity plan an infrastructure, not get pat (and often incorrect) advice on how to measure your web farm.

The discussion on curve fitting and trend prediction is worth it alone - I'm aware of no other book on the topic that shows so clearly how to examine your data in service of capacity planning.

It's the process I'll follow from now on.

The Art of Capacity Planning is a good introduction to Capacity Planning for Web Operations that touches on the following topics:
* Why do you need capacity planning?
* What information should you gather for capacity planning and how?
* How to predict trends for your web applications?
* How and when to procure new hardware?
* How to create a sustainable capacity planning process?

As the author mentions in the preface, the book has a lot of common sense material. Most experienced enterprise web operations architects should be familiar with this material. But, it is refreshing to see this urban wisdom captured and printed in a book format. The book is unique in that it is not meticulously organized and illustrated like a text book or a reference guide. It provides a smattering of anecdotes, examples, gotchas, and tools from the author's experience in a rapidly growing start up environment at Flickr.

I am looking forward to a second edition of the book where the author can delve deeper into some missing aspects that are critical to capacity planning like log analysis and performance improvements. Enterprise web operations folks who are familiar with commercial tools like Sitescope, OpenView, Opsware, Gomez, etc. rather than free/open source tools and who manage a large number of diverse applications might have a learning curve to relate the examples in the book to their environment.

Right out of the gate, John covers a topic near and dear to my heart: metrics. His advice? "Measure, measure, measure." John reinforces this by including an incredible number of charts throughout the book. He goes on to say that our measurement tools need to provide an easy way to:
* Record and store data over time
* Build custom metrics
* Compare metrics from various sources
* Import and export metrics

As I read the book, I found myself nodding and thinking, "yes, yes, this is exactly what I learned!" Although it's been more than five years since I was buildmaster for My Yahoo!, I really resonated with the advice John provides, like this one: "Homogenize hardware to halt headaches". (You have to love the alliteration, too.)

In a thin book that's easy to read, John covers a large number of topics. He talks about load testing, with pointers to tools like Httperf and Siege. There are several sections that talk about caching architectures and the use of Squid. He provides guidelines when it comes to deployment, such as making all changes happen in one place, the importance of defining roles and services, and ensuring new servers start working automatically. At the end he even manages to cover virtualization and cloud computing, and how they come into play during capacity planning.

The Art of Capacity Planning is full of sage advice from a seasoned veteran, like this one: "The moral of this little story? When faced with the question of capacity, try to ignore those urges to make existing gear faster, and focus instead on the topic at hand: finding out what you need, and when." When I read a technical book, I'm really looking for takeaways. That's why I loved The Art of Capacity Planning, and I think you will, too.