September 2007
Intermediate to advanced
170 pages
4h 24m
English
Content preview from High Performance Web Sites
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Yahoo!
Figure 17-23. http://www.yahoo.com
Yahoo! (http://www.yahoo.com) is the fourth-heaviest page in total bytes among the ones examined in this chapter, but second in response time and YSlow grade. The Yahoo! home page team has been engaged with my performance team for years, and is constantly tracking and working to improve response times. As a result, their YSlow scores are high, and they are able to squeeze more speed out of their page.
Yahoo!'s home page has four CSS sprite images. It has been using sprites for years and was the first web site in which I encountered the use of sprites. One of these sprites is icons_1.5.gif. Looking at the list of components, we see that this image is downloaded twice. On further investigation, the issue is that two URLs reference the exact same image:
http://us.js2.yimg.com/us.js.yimg.com/i/ww/sp/icons_1.5.gif http://us.i1.yimg.com/us.yimg.com/i/ww/sp/icons_1.5.gif
How does a mistake like this happen? Template variables are most likely used to build these URLs. The CSS rules that include this background image are both inlined in the HTML document, so presumably both had access to the same template variables. The us.js2.yimg.com hostname is used for all of the scripts, and us.i1.yimg.com is used solely for images and Flash. Most likely, the "JavaScript" hostname, us.js2.yimg.com, was accidentally used for this CSS background image.
This look at the ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.