[...]... of resource planning, rather than the practical implementation of the whole process A lot of literature addressed only rudimentary models of website use cases, and lacked specific information or advice Instead, they tended to offer mathematical models designed to illustrate the principles of queuing theory, which is the foundation of traditional capacity planning This approach might be mathematically... process Quite often the person you might need to persuade is the CFO, who sits across the hall from you In the early days of Flickr, we used to be able to get quotes from a vendor and simply walk over to the founder of the company (seated 20 feet away), who could cut and send a check The servers would arrive in about a week, and we’d rack them in the data center the day they came out of the box Easy!... larger amount of hardware for a better price In either case, the concern is the same: the procurement process should be baked into your larger planning exercise It takes time and effort, just like all the other steps There is more about this in Chapter 4 Performance and Capacity: Two Different Animals The relationship between performance tuning and capacity planning is often misunderstood While they affect... number of trucks—and the bacon has to get there within an hour The butcher needs to determine what type of trucks, and how many of them he’ll need to get the bacon to San Jose The demand for the bacon in San Jose is increasing with time It’s hard having the best bacon in the state, but it’s a good problem to have The butcher has three trucks that suffice for the moment But he knows he might be doubling the. .. an intolerable amount of latency at high volumes before any system-level metrics (CPU, disk, memory) raise a red flag Again, this can have more to do with the construction of the web page than the capacity of the servers sending the content But as capacity is one of the more expensive pieces to change, it warrants investigation Perceived slowness of a web page could be the result of a page that is simply... road This is the approach I’m presenting to capacity planning: adaptive, not theoretical Keep in mind a good deal of the information in this book will seem a lot like common sense—this is a good thing Quite often the simplest approaches to problem solving are the best ones, and capacity planning is no exception This book will cover the process of capacity planning for growing websites, including measurement,... ISSUES, AND PROCESSES IN CAPACITY PLANNING 7 Here’s a quick example of the difference between performance and capacity Suppose there is a butcher in San Francisco who prepares the most delectable bacon in the state of California Let’s assume the butcher shop has an arrangement with a store in San Jose to sell their great bacon there Every day, the butcher needs to transport the bacon from San Francisco... popularity of your site will dramatically increase the amount of traffic you experience, then please read this book Organization of the Material Chapter 1, Goals, Issues, and Processes in Capacity Planning, presents the issues that arise over and over on heavily trafficked websites Chapter 2, Setting Goals for Capacity, illustrates the various concerns involved with planning for the growth of a web application,... under the control of the site’s creators—a large portion of that control is in the hands of the user community, as shown by my example in the Preface concerning the London subway bombing This can be scary for people accustomed to building sites with very predictable growth patterns, because it means capacity is hard to predict and needs to be on the radar of all those invested—both the business and the. .. affect the user’s experience beside capacity It’s possible to have plenty of capacity but a slow website nonetheless Designing fast web pages is beyond the scope of this book, but you can find a lot of great information in Steve Souders’ excellent book, High Performance Web Sites (O’Reilly) Even though capacity is only one part of making the end-user experience fast, that experience is still one of the . on the topic of computer capacity planning were focused on the mathematical theory of resource planning, rather than the practical implementation of the. Tokyo The Art of Capacity Planning John Allspaw The Art of Capacity Planning by John Allspaw Copyright © 2008 Yahoo! Inc. All rights reserved. Printed in the