Waterfall Anti-Patterns - Web Performance Analysis (Boston)

777
-1

Published on

You've been asked to investigate why your web site is loading slowly. You've heard of WebPagetest.org so you enter the URL and run a test. What appears next is a colorful chart that looks like a Dr. Seuss illustration. Some bars are long, some are short. Some bars are blue, some are green. "That's nice," you say to yourself, wondering what to do next. It looks benign, innocently simple. But you know it holds many secrets.

The waterfall chart is a mysterious force to some developers. Performance gurus seem to be able to divine the ailments of a slow site at one quick glance. "How?" you wonder. The reality is that anyone can read a waterfall chart - if they know that they are looking for.

This presentation will bestow upon you the ability to recognize specific patterns in a waterfall chart, patterns which are the signs of a slow site. Using these newfound skills, you will become that performance guru and everyone will rejoice.

Presented to the Boston Web Performance Group on April 11, 2013.
http://www.meetup.com/Web-Performance-Boston/events/108633052/

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
777
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
23
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Waterfall Anti-Patterns - Web Performance Analysis (Boston)

  1. 1. Waterfall AntiPatterns Rick Viscomi Performance EngineerBoston Web Performance Group April 11, 2013
  2. 2. About Me● Performance Engineer Scripps Networks Interactive ○ Food Network ○ Travel Channel ○ HGTV● Open source developer ○ trunk8 ○ red dwarf
  3. 3. Web Performance
  4. 4. Waterfall
  5. 5. Waterfall Slope
  6. 6. Waterfall AntiPatterns
  7. 7. Anatomy of a Request● DNS Lookup● Initial Connection● SSL Negotiation● TTFB● Content Download
  8. 8. HTTP Responses● 301 Moved Permanently● 302 Found
  9. 9. HTTP Responses ● 304 Not Modified ● Cache static content with long TTL ○ Cache-Control: max-age=31536000 Last-Modified: Thu, 11 Apr 2013 15:17:34 GMT ● Cache busting ○ style_20130412.css
  10. 10. HTTP Responses● 404 Not FoundExtra Credit: What happened here?
  11. 11. Canceled RequestsInternet Explorer only »
  12. 12. Navigation Timing● domContentLoaded* (document.ready)● Start Render (first paint)● loadEvent* (onload)● Document Complete (loadEventStart)* Chrome and Firefox only
  13. 13. Navigation Timing
  14. 14. Navigation Timing
  15. 15. Navigation Timing
  16. 16. Request Serialization ● "stair step" pattern ● many requests ● few connections ○ 2-6 ● HTTP 2.0?
  17. 17. Request Serialization Connection View cssjavascriptimagesflash
  18. 18. Request Serialization Connection View cssjavascript imagesflash
  19. 19. Closed Connections ≈● TCP overhead● Enable Keep-Alive
  20. 20. Network Silence● bandwidth utilization low● CPU utilization high ○ why?Demo
  21. 21. Summary● waterfall slope● request components● HTTP responses ○ redirects ○ conditional GETs ○ errors● page load events● request concurrency● network utilization
  22. 22. Thank You Rick Viscomi jrvis.com @rick_viscomiComing Soon: Hands-On Web Performance Optimization Workshop June 18, 2013 Santa Clara, CA
  23. 23. Preview: Worst of WebPagetest www.aplia.com ● 46 requests ○ 5 successful ● 21 seconds to Start Render ● 30% gzip savings
  24. 24. Preview: Worst of WebPagetest coder143.com ● 443 requests ● 8,000 DOM elements ● 1.6 MB of JavaScript
  25. 25. Preview: Worst of WebPagetest www.taboradelaide.edu.au/ ● 2 MB page weight ● 26 second load time ● 17 second repeat view
  26. 26. Thank You Rick Viscomi jrvis.com @rick_viscomiComing Soon: Hands-On Web Performance Optimization Workshop June 18, 2013 Santa Clara, CA
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×