Even Faster Web Sites: Performance Best Practices for Web Developers

by Steve Souders, O'Reilly and Associates, Inc. Staff (Created by), Tim O'Reilly (Created by)

Overview

Performance is critical to the success of any web site, and yet today's web applications push browsers to their limits with increasing amounts of rich content and heavy use of Ajax. In this book, Steve Souders, web performance evangelist at Google and former Chief Performance Yahoo!, provides valuable techniques to help you optimize your site's performance.

Souders' previous book, the bestselling High Performance Web Sites, shocked the web development world by revealing that 80% of the time it takes for a web page to load is on the client side. In Even Faster Web Sites, Souders and eight expert contributors provide best practices and pragmatic advice for improving your site's performance in three critical categories:

• JavaScript—Get advice for understanding Ajax performance, writing efficient JavaScript, creating responsive applications, loading scripts without blocking other components, and more.
• Network—Learn to share resources across multiple domains, reduce image size without loss of quality, and use chunked encoding to render pages faster.
• Browser—Discover alternatives to iframes, how to simplify CSS selectors, and other techniques.

Speed is essential for today's rich media web sites and Web 2.0 applications. With this book, you'll learn how to shave precious seconds off your sites' load times and make them respond even faster.

This book contains six guest chapters contributed by Dion Almaer, Doug Crockford, Ben Galbraith, Tony Gentilcore, Dylan Schiemann, Stoyan Stefanov, Nicole Sullivan, and Nicholas C. Zakas.

Product Details

ISBN-13:	9780596522308
Publisher:	O'Reilly Media, Incorporated
Publication date:	06/17/2009
Edition description:	Original
Pages:	254
Product dimensions:	6.90(w) x 9.10(h) x 0.60(d)

About the Author

Steve Souders works at Google on web performance and open source initiatives. His books High Performance Web Sites and Even Faster Web Sites explain his best practices for performance along with the research and real-world results behind them. Steve is the creator of YSlow, the performance analysis extension to Firebug with more than 1 million downloads. He serves as co-chair of Velocity, the web performance and operations conference sponsored by O'Reilly. Steve taught CS193H: High Performance Web Sites at Stanford, and he frequently speaks at such conferences as OSCON, Rich Web Experience, Web 2.0 Expo, and The Ajax Experience.



Steve previously worked at Yahoo! as the Chief Performance Yahoo!, where he blogged about web performance on Yahoo! Developer Network. He was named a Yahoo! Superstar. Steve worked on many of the platforms and products within the company, including running the development team for My Yahoo!. Prior to Yahoo! Steve worked at several small to mid-sized startups including two companies he co-founded, Helix Systems and CoolSync. He also worked at General Magic, WhoWhere?, and Lycos.

Table of Contents

Credits; Preface; How This Book Is Organized; Conventions Used in This Book; Comments and Questions; Using Code Examples; Safari® Books Online; Acknowledgments; Chapter 1: Understanding Ajax Performance; 1.1 Trade-offs; 1.2 Principles of Optimization; 1.3 Ajax; 1.4 Browser; 1.5 Wow!; 1.6 JavaScript; 1.7 Summary; Chapter 2: Creating Responsive Web Applications; 2.1 What Is Fast Enough?; 2.2 Measuring Latency; 2.3 Threading; 2.4 Ensuring Responsiveness; 2.5 Summary; Chapter 3: Splitting the Initial Payload; 3.1 Kitchen Sink; 3.2 Savings from Splitting; 3.3 Finding the Split; 3.4 Undefined Symbols and Race Conditions; 3.5 Case Study: Google Calendar; Chapter 4: Loading Scripts Without Blocking; 4.1 Scripts Block; 4.2 Making Scripts Play Nice; 4.3 Browser Busy Indicators; 4.4 Ensuring (or Avoiding) Ordered Execution; 4.5 Summarizing the Results; 4.6 And the Winner Is; Chapter 5: Coupling Asynchronous Scripts; 5.1 Code Example: menu.js; 5.2 Race Conditions; 5.3 Preserving Order Asynchronously; 5.4 Multiple External Scripts; 5.5 General Solution; 5.6 Asynchronicity in the Real World; Chapter 6: Positioning Inline Scripts; 6.1 Inline Scripts Block; 6.2 Preserving CSS and JavaScript Order; 6.3 Danger: Stylesheet Followed by Inline Script; Chapter 7: Writing Efficient JavaScript; 7.1 Managing Scope; 7.2 Efficient Data Access; 7.3 Flow Control; 7.4 String Optimization; 7.5 Avoid Long-Running Scripts; 7.6 Summary; Chapter 8: Scaling with Comet; 8.1 How Comet Works; 8.2 Transport Techniques; 8.3 Cross-Domain; 8.4 Effects of Implementation on Applications; 8.5 Summary; Chapter 9: Going Beyond Gzipping; 9.1 Why Does This Matter?; 9.2 What Causes This?; 9.3 How to Help These Users?; Chapter 10: Optimizing Images; 10.1 Two Steps to Simplify Image Optimization; 10.2 Image Formats; 10.3 Automated Lossless Image Optimization; 10.4 Alpha Transparency: Avoid AlphaImageLoader; 10.5 Optimizing Sprites; 10.6 Other Image Optimizations; 10.7 Summary; Chapter 11: Sharding Dominant Domains; 11.1 Critical Path; 11.2 Who’s Sharding?; 11.3 Downgrading to HTTP/1.0; 11.4 Rolling Out Sharding; Chapter 12: Flushing the Document Early; 12.1 Flush the Head; 12.2 Output Buffering; 12.3 Chunked Encoding; 12.4 Flushing and Gzip; 12.5 Other Intermediaries; 12.6 Domain Blocking During Flushing; 12.7 Browsers: The Last Hurdle; 12.8 Flushing Beyond PHP; 12.9 The Flush Checklist; Chapter 13: Using Iframes Sparingly; 13.1 The Most Expensive DOM Element; 13.2 Iframes Block Onload; 13.3 Parallel Downloads with Iframes; 13.4 Connections per Hostname; 13.5 Summarizing the Cost of Iframes; Chapter 14: Simplifying CSS Selectors; 14.1 Types of Selectors; 14.2 The Key to Efficient CSS Selectors; 14.3 CSS Selector Performance; 14.4 Measuring CSS Selectors in the Real World; Performance Tools; Packet Sniffers; Web Development Tools; Performance Analyzers; Miscellaneous; Colophon;