I gave this talk on 4/27/11 at the Boston PHP Meetup Group. It covers both server side and client side optimizations, as well as monitoring tools and techniques.

1. Web Performance, Scalability, and Testing Techniques Boston PHP Meetup Group – April 2011 Jonathan Klein jklein@csnstores.com @jonathanklein

2. What We’ll Cover Why Listen to Me? Why Performance Matters Measuring Server Side Performance Speeding up the Server Frontend Optimization Measuring Full Page Load Time Homework

3. What We’ll Cover Why Listen to Me? Why Performance Matters Measuring Server Side Performance Speeding up the Server Frontend Optimization Measuring Full Page Load Time Homework  Fun Performance Adventure!

4. Introduction Senior Software Engineer/Performance Guy at CSN Stores Organizer of the Boston Web Performance Meetup Group CSN Stores Stats: ~1400 requests/sec for static content ~400 requests/sec for dynamic content ~10 million unique visitors per month On a typical Monday we serve 75,000,000 static files

5. Currently converting all store code to PHP Windows Server  FreeBSD IIS  Lighttpd ~100,000 lines of ASP Classic  ~50,000 lines of PHP code ~5 weeks away from launch

6. Why Do We Care about Performance? A Faster Website Will Make You More Money

8. Firefox Firefox reduced the load time of their download page by 2.2 seconds Downloads went up 15.4% This could drive 60 MILLION yearly downloads

9. Google Injected a 400ms delay into search 0.44% fewer searches/user 0.76% after 6 weeks After delay was removed, 0.21% fewer searches

10. Yahoo! 400ms delay 5-9% drop in full-page traffic

11. Direct Relationship Between Speed and Dollars http://www.phpied.com/the-performance-business-pitch/

13. Server Side Monitoring Lots of Options: Paid: Coradiant dynaTrace Correlsense http://www.real-user-monitoring.com/ - Free Version Free: Access Logs Nagios Ganglia Hosted WebPagetest Selenium/dynaTrace Ajax Edition

14. Server Side Monitoring <?php $start = microtime(true); …script content… $end = microtime(true); do_stuff(‘Description’, $end - $start); ?>

15. WTH is do_stuff()? do_stuff() can do one of: Log to a database (not ideal) Write to a text file (eww) Make a StatsD call over UDP (good) -http://codeascraft.etsy.com/2011/02/15/measure-anything-measure-everything/

16. StatsD/Graphite

17. Be Careful What You Watch Averages can be misleading Better to look at percentiles

20. What Does a Scalability Problem Look Like?

21. What Does a Scalability Problem Look Like?

22. What Does a Scalability Problem Look Like?

23. Ahh, much better!

24. What can you do? Start with the Database Run a database trace Filter: Queries > 50ms Filter: Reads > 1000 Start with the worst ones and optimize

25. Okay, I’ll “Optimize” Look at execution plan Remove calls to remote servers

26. Database Optimizations Reduce Joins Select * from  Select Foo, Bar, Baz from… Minimize/consolidate subqueries Add indexes where needed We added one index: Procedure dropped from 3.5 sec & 4500 reads to .06 sec and 130 reads! Be careful with where clauses (don’t calculate stuff in them)

27. Example SELECT id, name, salary FROM employee WHERE salary < 25000; NOT SELECT id, name, salary FROM employee WHERE salary + 10000 < 35000;

28. Example SELECT id, name, salary FROM employee WHERE salary < 25000; NOT SELECT id, name, salary FROM employee WHERE salary + 10000 < 35000;

29. Caching The Fastest DB Query is the One That’s Never Made

30. Memcached Caching layer between database and webserver Can hold PHP objects and arrays

31. Memcached $m = new Memcached(); $m->pconnect(‘1.2.3.4', 11211); $m->set(‘foo’, $bar, 600); $baz = $m->get(‘foo’);

32. PHP Optimizations

33. Install APC APC – Alternative PHP Cache Opcode Cache User Cache Awesome!

34. Opcode cache

35. User Cache <?php$bar = 'BAR';apc_store('foo', $bar);var_dump(apc_fetch('foo'));?> Outputs… string(3) "BAR"

36. PHP Code Optimizations Set the max loop value before the loop: $max = count($rows); for ($i = 0; $i < $max; $i++) { echo $i; } require_once() is slow Minimize use of define() Yes, single quotes are slightly faster than double quotes

37. PHP Code Optimizations Could go on and on… http://www.wmtips.com/php/tips-optimizing-php-code.htm Minimal returns Find the hotspots in your application and fix them

38. Example… Homepage takes 5 seconds to load Optimize PHP… Reduce PHP execution time by 50%! But wait! PHP execution was only taking 100ms Saves you 50ms in load time 1% of total page load

39. HipHop for PHP Built by Facebook and Open Sourced Compiles PHP into C++ Currently supports PHP 5.2 http://developers.facebook.com/blog/post/358/ https://github.com/facebook/hiphop-php

40. Webserver Considerations

41. Webserver Optimizations Pick the right one Lighttpd/Nginx instead of Apache Designed to solve the C10K problem Lighttpd Used By: Youtube Wikipedia Meebo

43. If you are stuck on Apache… mod_deflate Gzips content for faster transfer times mod_pagespeed Automatic performance improvements KeepAlives on Server won’t create a new connection for every resource

44. Load Testing

45. JMeter

46. JMeter

47. JMeter

49. Frontend Optimization

50. Client side Optimization is Critical 80-90% of load time takes place on the client For mobile  97%

51. Best Practices Reduce HTTP Requests Combine CSS, JS Use image sprites .classname{ background: url(sprite.png) no-repeat 0 -432px; }

52. Best Practices Minify CSS/JS Strip comments and whitespace Automate this – YUI Compressor http://developer.yahoo.com/yui/compressor/ Gzip all text HTML CSS JS Optimize Images…

53. Image Optimization For graphics use PNG8 (256 color limitation) No more .gif (unless animated) JPEGs can be saved at lower quality (75%-80%) Smush all images

54. Smush Your Images! - smushit.com

55. JPEG Quality 100% 80% 182 KB 48 KB

56. Measuring Frontend Performance

57. How Do You Measure Load Time? Google Webmaster Tools WebPagetest (www.webpagetest.org) Yottaa.com Firebug YSlow PageSpeed Dynatrace Ajax Edition

61. CDN – Content Delivery Network

62. Lots of Options Amazon CloudFront MaxCDN Limelight Level3 Akamai Cotendo

64. Expires Headers Set a far future date on static resources CSS/JS/Images Release new version by changing the filename Benefits repeat visitors and repeat page views

65. Google Page Speed

67. Firebug Net Panel

72. Webmaster tools

73. Webmaster tools

77. Resources http://www.webperformancecentral.com/wiki/WebPagetest/Optimization_Help http://developer.yahoo.com/performance/ http://code.google.com/speed/ High Performance Websites (Book) Even Faster Websites (Book)

79. Conclusion “Speed is the most important feature. If your application is slow, people won’t use it. I see this more with mainstream users than I do with power users...If something is slow, they’re just gone.” - Fred Wilson (10 Golden Principles of Web Apps)

80. Conclusion “Speed is the most important feature. If your application is slow, people won’t use it. I see this more with mainstream users than I do with power users...If something is slow, they’re just gone.” - Fred Wilson (10 Golden Principles of Web Apps)

81. ?> We’re Hiring! www.csnstores.com/careers Get In Touch: www.meetup.com/Web-Performance-Boston/ jklein@csnstores.com @jonathanklein