OSCON and Page Responsiveness videos
I had a great time at OSCON a few weeks back. It was in San Jose this year. (Pro: I don’t have to travel and my wife can go to the parties. Con: I miss Portland.) Just as I wrote about last year, Gregg Pollack was there asking speakers to summarize their talks in 30 seconds. He published the results in the video series 5 Days of OSCON. I’m in the video for Day 3.
Gregg also pointed me to his Page Responsiveness webcast/video, where he talks about YSlow and the Google Ajax Libraries API. I really like this video. It’s informative, engaging, and short. They remind me of Aza Raskin’s webcasts on Ubiquity and Jetpack. These two guys are very talented in how they convey complex information in a hands-on way. I encourage you to take a look.
OmniTI and performance koolaid
In YSlow! to YFast! in 45 minutes, Theo Schlossnagle (CEO of OmniTI) delivers a play-by-play about how he made his corporate web site 35% faster. The amazing revelation in his commentary is that he was able to complete all of these improvements while sitting in my workshop at Velocity (ahem).
OmniTI is a full service web house, specializing in web performance and scalability. The irony of the fact that their corp web site received a YSlow “F” wasn’t wasted on Theo. The cobbler’s children syndrome. (Same is true on my web site – I’ve got to optimize WordPress!)
Theo walks through his changes one-by-one: adding a far future Expires header, removing ETags, compressing text responses especially scripts and stylesheets, and moving resources to a CDN without cookies. With less than 45 minutes work, his site went from a load time of 486 milliseconds down to 315 milliseconds.
There’s more low hanging fruit – consolidating scripts, consolidating stylesheets, and CSS sprites. But it’s great to get this early case study on specific improvements and their corresponding impact on performance. I hope he’ll share the results from the next wave of optimizations.
Wikia: fast pages retain users
At OSCON last week, I attended Artur Bergman’s session about Varnish – A State of the Art High-Performance Reverse Proxy. Artur is the VP of Engineering and Operations at Wikia. He has been singing the praises of Varnish for awhile. It was great to see his experiences and resulting advice in one presentation. But what really caught my eye was his last slide:
Wikia measures exit rate – the percentage of users that leave the site from a given page. Here they show that exit rate drops as pages get faster. The exit rate goes from ~15% for a 2 second page to ~10% for a 1 second page. This is another data point to add to the list of stats from Velocity that show that faster pages is not only better for users, it’s better for business.
back in the saddle: EFWS! Velocity!
The last few months are a blur for me. I get through stages of life like this and look back and wonder how I ever made it through alive (and why I ever set myself up for such stress). The big activities that dominated my time were Even Faster Web Sites and Velocity.
Even Faster Web Sites
Even Faster Web Sites is my second book of web performance best practices. This is a follow-on to my first book, High Performance Web Sites. EFWS isn’t a second edition, it’s more like “Volume 2”. Both books contain 14 chapters, each chapter devoted to a separate performance topic. The best practices described in EFWS are completely new:
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An exciting addition to EFWS is that six of the chapters were contributed by guest authors: Doug Crockford (Chap 1), Ben Galbraith and Dion Almaer (Chap 2), Nicholas Zakas (Chap 7), Dylan Schiemann (Chap 8), Tony Gentilcore (Chap 9), and Stoyan Stefanov and Nicole Sullivan (Chap 10). Web developers working on today’s content rich, dynamic web sites will benefit from the advice contained in Even Faster Web Sites.
Velocity
Velocity is the web performance and operations conference that I co-chair with Jesse Robbins. Jesse, former “Master of Disaster” at Amazon and current CEO of Opscode, runs the operations track. I ride herd on the performance side of the conference. This was the second year for Velocity. The first year was a home run, drawing 600 attendees (far more than expected – we only made 400 swag bags) and containing a ton of great talks. Velocity 2009 (held in San Jose June 22-24) was an even bigger success: more attendees (700), more sponsors, more talks, and an additional day for workshops.
The bright spot for me at Velocity was the fact that so many speakers offered up stats on how performance is critical to a company’s business. I wrote a blog post on O’Reilly Radar about this: Velocity and the Bottom Line. Here are some of the excerpted stats:
- Bing found that a 2 second slowdown caused a 4.3% reduction in revenue/user
- Google Search found that a 400 millisecond delay resulted in 0.59% fewer searches/user
- AOL revealed that users that experience the fastest page load times view 50% more pages/visit than users experiencing the slowest page load times
- Shopzilla undertook a massive performance redesign reducing page load times from ~7 seconds to ~2 seconds, with a corresponding 7-12% increase in revenue and 50% reduction in hardware costs
I love optimizing web performance because it raises the quality of engineering, reduces inefficiencies, and is better for the planet. But to get widespread adoption we need to motivate the non-engineering parts of the organization. That’s why these case studies on web performance improving the user experience as well as the company’s bottom line are important. I applaud these companies for not only tracking these results, but being willing to share them publicly. You can get more details from the Velocity videos and slides.
Back in the Saddle
Over the next six months, I’ll be focusing on open sourcing many of the tools I’ve soft launched, including UA Profiler, Cuzillion, Hammerhead, and Episodes. These are already “open source” per se, but they’re not active projects, with a code repository, bug database, roadmap, and active contributors. I plan on fixing that and will discuss this more during my presentation at OSCON this week. If you’re going to OSCON, I hope you’ll attend my session. If not, I’ll also be signing books at 1pm and providing performance consulting (for free!) at the Google booth at 3:30pm, both on Wednesday, July 22.
As you can see, even though Velocity and EFWS are behind me, there’s still a ton of work left to do. We’ll never be “done” fixing web performance. It’s like cleaning out your closets – they always fill up again. As we make our pages faster, some new challenge arises (mobile, rich media ads, emerging markets with poor connectivity) that requires more investigation and new solutions. Some people might find this depressing or daunting. Me? I’m psyched! ‘Scuse me while I roll up my sleeves.
Velocity: Tim O’Reilly and 20% discount
It was great to read Tim O’Reilly’s blog post about Velocity. He tells the story about the first meeting where we talked about starting a conference for the web performance and operations community. It almost didn’t happen! The first meeting got postponed. This was at OSCON, and Tim got tied up preparing his keynote. Luckily, we were able to get together the next day.
Looking back, that seems so long ago. The excitement about web performance has skyrocketed since then, in part because of Velocity. There’s also been a lot of tool development in that space, including Firebug, YSlow, Page Speed, HttpWatch, PageTest, VRTA, and neXpert. All of these tools, and more, will be showcased at Velocity, happening this week in San Jose. The sessions take place on Tuesday, June 23 and Wednesday, June 24.
As a final nod, Tim provides a 20% discount code: VEL09BLOG. I hope to see you here!
Velocity – fully programmed
With my book and Velocity hitting in the same month, I’ve been slammed. Even though we started the Velocity planning process eleven months ago, we’ve been tweaking the program schedule up to the last minute, making room for new products and technology breakthroughs. I’m happy to say that the slate of speakers is nailed down, and it looks awesome. Here’s a rundown of the what’s happening in the Performance track, including the most recent additions.
Workshops (Mon, June 22)
At this year’s conference, we added a day of workshops. I kick things off talking about Website Performance Analysis, where I’ll take a popular, but slow, web site and show the tools used to make it faster. Nicholas Zakas is getting into deep performance optimizations with Writing Efficient JavaScript, relevant to any web site that uses JavaScript (which is every one). I’m psyched to sit in on Nicole Sullivan’s workshop, The Fast and the Fabulous: 9 ways engineering and design come together to make your site slow. We worked together at Yahoo!, so I can vouch for her guru-ness when it comes to CSS and web design. The workshops end with Metrics that Matter by Ben Rushlo from Keynote Systems. This was a topic that was brainstormed at the Velocity Summit held earlier this year – the importance of identifying the metrics that you just have to be watching to track and improve your site’s performance.
Sessions Day 1 (Tues, June 23)
We had so many good speaker proposals, we decided to kick things off a bit earlier, starting at 8:30am. We’ll cover the exciting stuff right out of the gate – new product announcements! (My lips are sealed.) One of the most important talks of the conference is The User and Business Impact of Server Delays, Additional Bytes, and HTTP Chunking in Web Search – where Eric Schurman from Live Search (‘scuse me, Bing) and Jake Brutlag from Google Search co-present the results of experiments they ran measuring the impact of latency on users. Are you kidding me?! Microsoft and Google, presenting together, with hard numbers about the impact of latency, talking about experiments run on live traffic! This is unprecedented and can’t be missed. Eric and Jake are two of the smartest and nicest guys around, so grab them afterwards and ask questions.
There’s a reprise of last year’s popular browser matchup, What Makes Browsers Performant, with representatives from Internet Explorer, Firefox, and Chrome. Doug Crockford is talking about Ajax Performance, painting the landscape of how developers should view and optimize their Web 2.0 applications. Michael Carter’s presentation on Light Speed Comet will present this newer technique for high volume, low latency Ajax communication. Other performance-related presentations include a demo of Google’s new Page Speed performance tool, A Preview of MySpace’s Open-sourced Performance Tracker, The Secret Weapons of the AOL Optimization Team, Go with the Reflow by my good buddy Lindsey Simon, and Performance-Based Design – Linking Performance to Business Metrics by Aladdin Nassar.
Sessions Day 2 (Wed, June 24)
We start early again, and jump right into the good stuff. Marissa Mayer starts with a keynote talking about Google’s commitment to fast web sites, followed by lightning demos of Firebug, HttpWatch, AOL PageTest, YSlow 2.0, and Visual Round Trip Analyzer. In Shopzilla’s Site Redo, Phil Dixon delivers more killer stats about the business impact of performance, such as a “5% – 12% lift in top-line revenue”. These are the numbers developers need to be armed with when debating the priority of performance improvements within their company. The morning closes with Ben Galbraith and Dion Almaer talking about the Responsiveness of web applications.
Several afternoon sessions come from Google. Kyle Scholz and Yaron Friedman present High Performance Search at Google. These guys have to build advanced DHTML that works across a huge audience; it’ll be important to find out what worked for them. Tony Gentilcore, creator of Fasterfox, gets the conference’s Sherlock Holmes award for his discoveries about why compression doesn’t happen as often as we think, in Beyond Gzipping. Brad Chen talks about a new tact on high performance applications in the browser using Google Native Client.
Matt Mullenweg is presenting some of the recent performance enhancements baked into WordPress. It’s a real treat to have Matt on the program. Developers that have to monitor performance will want to hear MySpace.com’s talk Fistful of Sand. In addition to hearing from Google Search, we’ll also get a glimpse of Frontend Performance Engineering in Facebook. Eric Mattingly is demoing a new tool called neXpert. And the day closes with me talking about the State of Performance, and a favorite from last year, High Performance Ads – Is It Possible?.
One of the most rewarding things about Velocity 2008 was the amount of sharing that took place. Everyone was talking about the pitfalls to avoid and the successes that can be had. I see that happening again this year. All of these speakers are extremely approachable. They have great experience and are smart, too, but the key for Velocity is that you can walk up to any one of them afterward and ask for more details or share what you’ve discovered. The Web is out there. Velocity is where we work together to make it faster.
See you at Velocity!
[If you haven’t registered yet, make sure to use my "vel09cmb" 15% discount code.]
Fronteers 2009
I’m psyched to be speaking at Fronteers in November – and not just because it’s one of the best conference names ever. And not just because it’s in Amsterdam – although that is a huge plus. The main reason I’m psyched is because I missed last year’s conference and regretted it. The feedback I got was that the speakers were great and so were the attendees. PPK is active in his advocacy for frontend engineering, and (from what I heard) that was apparent in the level of knowledge and participation shown throughout the talks.
Last year’s speakers included Stuart Langridge, Christian Heilmann, and Pete LePage (check out the links to their talks on YDN). PPK has announced myself and Nate Koechley as speakers for 2009, and some other web gurus I know have said they’re speaking there as well. It’s going to be another great set of speakers and sessions. I’m so glad that I’ll be there to experience it, and I hope you can make it, too.
State of Performance 2008
My Stanford class, CS193H High Performance Web Sites, ended last week. The last lecture was called “State of Performance”. This was my review of what happened in 2008 with regard to web performance, and my predictions and hopes for what we’ll see in 2009. You can see the slides (ppt, GDoc), but I wanted to capture the content here with more text. Let’s start with a look back at 2008.
2008
- Year of the Browser
- This was the year of the browser. Browser vendors have put users first, competing to make the web experience faster with each release. JavaScript got the most attention. WebKit released a new interpreter called Squirrelfish. Mozilla came out with Tracemonkey – Spidermonkey with Trace Trees added for Just-In-Time (JIT) compilation. Google released Chrome with the new V8 JavaScript engine. And new benchmarks have emerged to put these new JavaScript engines through the paces: Sunspider, V8 Benchmark, and Dromaeo.
In addition to JavaScript improvements, browser performance was boosted in terms of how web pages are loaded. IE8 Beta came out with parallel script loading, where the browser continues parsing the HTML document while downloading external scripts, rather than blocking all progress like most other browsers. WebKit, starting with version 526, has a similar feature, as does Chrome 0.5 and the most recent Firefox nightlies (Minefield 3.1). On a similar note, IE8 and Firefox 3 both increased the number of connections opened per server from 2 to 6. (Safari and Opera were already ahead with 4 connections per server.) (See my original blog posts for more information: IE8 speeds things up, Roundup on Parallel Connections, UA Profiler and Google Chrome, and Firefox 3.1: raising the bar.)
- Velocity
- Velocity 2008, the first conference focused on web performance and operations, launched June 23-24. Jesse Robbins and I served as co-chairs. This conference, organized by O’Reilly, was densely packed – both in terms of content and people (it sold out!). Speakers included John Allspaw (Flickr), Luiz Barroso (Google), Artur Bergman (Wikia), Paul Colton (Aptana), Stoyan Stefanov (Yahoo!), Mandi Walls (AOL), and representatives from the IE and Firefox teams. Velocity 2009 is slated for June 22-24 in San Jose and we’re currently accepting speaker proposals.
- Jiffy
- Improving web performance starts with measuring performance. Measurements can come from a test lab using tools like Selenium and Watir. To get measurements from geographically dispersed locations, scripted tests are possible through services like Keynote, Gomez, Webmetrics, and Pingdom. But the best data comes from measuring real user traffic. The basic idea is to measure page load times using JavaScript in the page and beacon back the results. Many web companies have rolled their own versions of this instrumentation. It isn’t that complex to build from scratch, but there are a few gotchas and it’s inefficient for everyone to reinvent the wheel. That’s where Jiffy comes in. Scott Ruthfield and folks from Whitepages.com released Jiffy at Velocity 2008. It’s Open Source and easy to use. If you don’t currently have real user load time instrumentation, take a look at Jiffy.
- JavaScript: The Good Parts
- Moving forward, the key to fast web pages is going to be the quality and performance of JavaScript. JavaScript luminary Doug Crockford helps lights the way with his book JavaScript: The Good Parts, published by O’Reilly. More is needed! We need books and guidelines for performance best practices and design patterns focused on JavaScript. But Doug’s book is a foundation on which to build.
- smush.it
- My former colleagues from the Yahoo! Exceptional Performance team, Stoyan Stefanov and Nicole Sullivan, launched smush.it. In addition to a great name and beautiful web site, smush.it packs some powerful functionality. It analyzes the images on a web page and calculates potential savings from various optimizations. Not only that, it creates the optimized versions for download. Try it now!
- Google Ajax Libraries API
- JavaScript frameworks are powerful and widely used. Dion Almaer and the folks at Google saw an opportunity to help the development community by launching the Ajax Libraries API. This service hosts popular frameworks including jQuery, Prototype, script.aculo.us, MooTools, Dojo, and YUI. Web sites using any of these frameworks can reference the copy hosted on Google’s worldwide server network and gain the benefit of faster downloads and cross-site caching. (Original blog post: Google AJAX Libraries API.)
- UA Profiler
- Okay, I’ll get a plug for my own work in here. UA Profiler looks at browser characteristics that make pages load faster, such as downloading scripts without blocking, max number of open connections, and support for “data:†URLs. The tests run automatically – all you have to do is navigate to the test page from any browser with JavaScript support. The results are available to everyone, regardless of whether you’ve run the tests. I’ve been pleased with the interest in UA Profiler. In some situations it has identified browser regressions that developers have caught and fixed.
2009
Here’s what I think and hope we’ll see in 2009 for web performance.
- Visibility into the Browser
- Packet sniffers (like HTTPWatch, Fiddler, and WireShark) and tools like YSlow allow developers to investigate many of the “old school” performance issues: compression, Expires headers, redirects, etc. In order to optimize Web 2.0 apps, developers need to see the impact of JavaScript and CSS as the page loads, and gather stats on CPU load and memory consumption. Eric Lawrence and Christian Stockwell’s slides from Velocity 2008 give a hint of what’s possible. Now we need developer tools that show this information.
- Think “Web 2.0”
- Web 2.0 pages are often developed with a Web 1.0 mentality. In Web 1.0, the amount of CSS, JavaScript, and DOM elements on your page was more tolerable because it would be cleared away with the user’s next action. That’s not the case in Web 2.0. Web 2.0 apps can persist for minutes or even hours. If there are a lot of CSS selectors that have to be parsed with each repaint -Â that pain is felt again and again. If we include the JavaScript for all possible user actions, the size of JavaScript bloats and increases memory consumption and garbage collection. Dynamically adding elements to the DOM slows down our CSS (more selector matching) and JavaScript (think getElementsByTagName). As developers, we need to develop a new way of thinking about the shape and behavior of our web apps in a way that addresses the long page persistence that comes with Web 2.0.
- Speed as a Feature
- In my second month at Google I was ecstatic to see the announcement that landing page load time was being incorporated into the quality score used by Adwords. I think we’ll see more and more that the speed of web pages will become more important to users, more important to aggregators and vendors, and subsequently more important to web publishers.
- Performance Standards
- As the industry becomes more focused on web performance, a need for industry standards is going to arise. Many companies, tools, and services measure “response time”, but it’s unclear that they’re all measuring the same thing. Benchmarks exist for the browser JavaScript engines, but benchmarks are needed for other aspects of browser performance, like CSS and DOM. And current benchmarks are fairly theoretical and extreme. In addition, test suites are needed that gather measurements under more real world conditions. Standard libraries for measuring performance are needed, a la Jiffy, as well as standard formats for saving and exchanging performance data.
- JavaScript Help
- With the emergence of Web 2.0, JavaScript is the future. The Catch-22 is that JavaScript is one of the biggest performance problems in a web page. Help is needed so JavaScript-heavy web pages can still be fast. One specific tool that’s needed is something that takes a monolithic JavaScript payload and splits into smaller modules, with the necessary logic to know what is needed when. Doloto is a project from Microsoft Research that tackles this problem, but it’s not available publicly. Razor Optimizer attacks this problem and is a good first step, but it needs to be less intrusive to incorporate this functionality.
Browsers also need to make it easier for developers to load JavaScript with less of a performance impact. I’d like to see two new attributes for the SCRIPT tag: DEFER and POSTONLOAD. DEFER isn’t really “new” – IE has had the DEFER attribute since IE 5.5. DEFER is part of the HTML 4.0 specification, and it has been added to Firefox 3.1. One problem is you can’t use DEFER with scripts that utilize document.write, and yet this is critical for mitigating the performance impact of ads. Opera has shown that it’s possible to have deferred scripts still support document.write. This is the model that all browsers should follow for implementing DEFER. The POSTONLOAD attribute would tell the browser to load this script after all other resources have finished downloading, allowing the user to see other critical content more quickly. Developers can work around these issues with more code, but we’ll see wider adoption and more fast pages if browsers can help do the heavy lifting.
- Focus on Other Platforms
- Most of my work has focused on the desktop browser. Certainly, more best practices and tools are needed for the mobile space. But to stay ahead of where the web is going we need to analyze the user experience in other settings including automobile, airplane, mass transit, and 3rd world. Otherwise, we’ll be playing catchup after those environments take off.
- Fast by Default
- I enjoy Tom Hanks’ line in A League of Their Own when Geena Davis (“Dottie”) says playing ball got too hard: “It’s supposed to be hard. If it wasn’t hard, everyone would do it. The hard… is what makes it great.” I enjoy a challenge and tackling a hard problem. But doggone it, it’s just too hard to build a high performance web site. The bar shouldn’t be this high. Apache needs to turn off ETags by default. WordPress needs to cache comments better. Browsers need to cache SSL responses when the HTTP headers say to. Squid needs to support HTTP/1.1. The world’s web developers shouldn’t have to write code that anticipates and fixes all of these issues.
Good examples of where we can go are Runtime Page Optimizer and Strangeloop appliances. RPO is an IIS module (and soon Apache) that automatically fixes web pages as they leave the server to minify and combine JavaScript and stylesheets, enable CSS spriting, inline CSS images, and load scripts asynchronously. (Original blog post: Runtime Page Optimizer.) The web appliance from Strangeloop does similar realtime fixes to improve caching and reduce payload size. Imagine combining these tools with smush.it and Doloto to automatically improve the performance of web pages. Companies like Yahoo! and Google might need more customized solutions, but for the other 99% of developers out there, it needs to be easier to make pages fast by default.
This is a long post, but I still had to leave out a lot of performance highlights from 2008 and predictions for what lies ahead. I look forward to hearing your comments.
Velocity 2009: Call for Participation
Velocity 2009 is officially open! This is the conference that Jesse Robbins and I co-chair. Velocity 2009 is scheduled for June 22-24 at the Fairmont in San Jose. Checkout the new site. Most importantly, submit your speaking proposals on the Call for Participation page. We’ve provided some suggested topics. My favorites:
- How to tie web performance and operations to the bottom line
- Profiling JavaScript, CSS, and the network
- Managing web services – flaming disasters you survived and lessons learned
- The intersection between performance and design
- Ads, ads, ads – the performance killer?
Last year’s event sold out with popular sessions that included:
- members from the IE and Firefox teams talking about browser performance tradeoffs
- demos of web development tools: Firebug, Fiddler, AOL PageTest, and HTTPWatch
- case studies from top web apps including Wikipedia, Hotmail, Netflix, Live Search
- performance optimizations for Ajax and images
- open source product launches including Jiffy and EUCALYPTUS
Velocity 2009 is going to be even bigger and better. This year’s conference includes an extra day focused on workshops where experts will get into the details of their best practices for performance and operations. More time, more talks, more experts, more people, more takeaways to apply when you get back home. I can’t wait. See you there!