Velocity Session on ShowSlow, Compression and BrowserMob

Keeping Track of Your Performance Using Show Slow

Sergey Chernyshev (truTV)
4:35pm Wednesday, 06/23/2010
Web Performance 209/210
Sergey Chernyshev will talk about the importance of web site performance and a way to keep track of performance metrics using Show Slow, open source tool developed to simplify metrics gathering and reporting.

The goal of the project is to give a high level picture of the state of performance for your web site so your business as well as development teams can make decisions about performance optimization efforts.

Measuring web site performance becomes a standard practice for web developers, designers and product managers. Fast web sites attract user, keep their attention and provide better overall experience. Major web companies like Google, Amazon and Yahoo were able to do a research and connect performance to the money bottom line and emphasizes practical importance of web performance optimization.

Unfortunately, just measuring performance during development is not enough – keeping track of day-to-day changes and incorporating performance measurement into testing process ensures that business and developers can make important decisions based on the history of performance for the web site.

Featured by Steve Souders at Velocity Fall 2009, Show Slow is an open source tool that helps keeping track of performance metrics gathered over time using Yahoo’s YSlow and Google’s Page Speed Firefox extensions as well as other custom measurement applications using web-based RESTful beacons. It provides easy to understand graphical representation of metric changes over time that makes decision making quick and easy.

Notes on the Session

Show Slow

Wow…this session was clearly put in the wrong sized room. They should have put us in the ballrooms.

Souders kicked off talking about IE9 web timing previews. Definitely something we need to look into.

Sergey leads the NY Web Performance Meetup group. He’s a web technologist at trueTV.

  • ShowSlow integrates with YSlow, PageSpeed, dynaTrace and NeExpert.
  • Also, httpwatch, myspace perf tracker and Microsoft VRTA
  • Omniture, Google Analytics

Basically works from Beacons…load your site and then sync the data to ShowSlow.

Forcing Gzip Compression

Andy Martone (Google)
4:48pm Wednesday, 06/23/2010
Web Performance 209/210
Tony Gentilcore’s Beyond Gzipping presentation at Velocity 2009 ( identified that ~15% of Internet users receive uncompressed responses. This is mostly due to proxies or client security software stripping or mangling the Accept-Encoding header from the web browser.

RFC 2616 states: If no Accept-Encoding field is present in a request, the server MAY assume that the client will accept any content coding. In this case, if “identity” is one of the available content-codings, then the server SHOULD use the “identity” content-coding, unless it has additional information that a different content-coding is meaningful to the client.

Google web search now tests these browsers’ ability to understand compressed content. If the test is successful, Google serves gzipped content. This has significantly lowered latency for users at the tail end of the latency distribution.

Notes on this Session

Andy works on the search team. GZip is awesome. A smaller payload means lower latency. He used the term Captain Obvious. GZip has been around for ages. Claims that this was by far the single most important optimization made by Google Search.

Who Are the Users without Compression Being Allowed

  • Higher percentage of IE users
    • IE6 has lower success rate of passing forced compression
  • More likely behind a known proxy
  • Traffic tends to be more corporate as traffic is low on weekend

What Not to Do

  • IFrame must end .html, served with Content-Type of text/html

Continuous Performance Optimization

Patrick Lightbody (BrowserMob)
5:01pm Wednesday, 06/23/2010
Web Performance 209/210
Learn how open source tools and new standardization efforts make it easier to continuously measure your site’s page performance. Get the latest info on a new collaboration between BrowserMob,, ShowSlow, WebMetrics, PageSpeed, and others as they create standard components and APIs for sharing and reporting on performance data.

People planning to attend this session also want to see:
Keeping Track of Your Performance Using Show Slow
Forcing Gzip Compression
Building Performance Into the New Yahoo! Homepage
Stupid Web Caching (and Other Intermediary) Tricks
Patrick Lightbody

Patrick is the founder and CEO of BrowserMob, which provides low-cost, self-service, cloud-based products that help monitoring and test the performance of modern web sites.

Patrick is an avid open source contributor, having founded OpenQA, created Selenium Remote Control, and co-created Struts 2. Prior to founding BrowserMob, he was the senior Product Manager at Gomez, running the QA Solutions product group. Before that, he founded HostedQA, an automated web-testing platform acquired by Gomez in 2007. Patrick has held management and software engineering positions with Jive Software, Spoke Software, and Cisco Systems.

Notes on this Session

All about integrating continuous performance into the development process. He calls it CPO that runs regularly after every commit or daily. Opensourced a tool called PagePerf (only supported on Firefox). Simple REST API for posting HAR data for query purpose. We should look into this to understand more about how Selenium can be tied to data capture.

—HAR Data
—–Selenium Automation
——-Native Chrome HAR
——-PagePerf/NetExport (Firefox)
——-WebPage Test and Native IE9 HAR
———BrowserMob Proxy/Fiddler


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