This document discusses ways to improve website performance from slow "Pinto" levels to faster "Ferrari" levels. It recommends using an opcode cache like APC to speed up PHP, optimizing databases with technologies like Memcached, using caching plugins in WordPress, and considering architectures with load balancing and replication. The goal is to identify bottlenecks and apply techniques that reduce page load times through an understanding of how websites and underlying technologies work.

1. Hello

2. This Slide Intentionally
Left Blank

3. This One Too

4. Site Performance
from Pinto to Ferrari
Joseph Scott
joseph@josephscott.org
http://josephscott.org/

5. Find Me
http://josephscott.org/
joseph@josephscott.org
@josephscott

6. The Pinto

7. http://www.flickr.com/photos/autohistorian/4439476737/

8. http://www.flickr.com/photos/autohistorian/4439476737/

9. http://www.flickr.com/photos/thomashawk/2466245846/

10. http://www.flickr.com/photos/autohistorian/4439476737/

11. http://www.flickr.com/photos/autohistorian/4439476737/

12. http://www.flickr.com/photos/autohistorian/4439476737/

13. http://www.flickr.com/photos/autohistorian/4439476737/

14. http://www.flickr.com/photos/autohistorian/4439476737/

15. The Ferrari

18. Steve Souders
http://stevesouders.com/

19. 2007

20. 2009

21. Why Did I Choose This Topic?

22. I Want My Site To Be Faster

23. I Want My Site To Be Faster
Less Like A Pinto

24. I Want My Site To Be Faster
More Like A Ferrari

25. How Fast Is It Now?

26. How Fast Is It Now?
Tools For Measuring
Site Performance

27. Tools
webpagetest.org
pagespeed.googlelabs.com
Firefox & Firebug
Chrome/Safari & Dev Tools
HttpWatch

28. Where To Start?

29. Where To Start?
http://www.webpagetest.org/

30. webpagetest.org
Test Location
Browser
Connection Speed
Video

31. Browsers
IE 8 still most commonly
used browser (26.5% / 28.5%)
http://gs.statcounter.com/#browser_version-na-monthly-201106-201108-bar

32. Connection Speed
FIOS 20Mbps

33. http://www.webpagetest.org/result/110827_KZ_1EBDB/1/details/

34. Which Part?

37. The Initial Request
Get the source
for the page

38. The Initial Request
Get the source
0.113 seconds
for the page

39. The Initial Request
DNS Lookup: 5 ms
Initial Connection: 47 ms
Time to First Byte: 57 ms
Content Download: 4 ms
Bytes In (downloaded): 9.6 KB
Bytes Out (uploaded): 0.4 KB

40. Requests Per Page
November 2010: 69
August 2011: 76
http://www.stevesouders.com/blog/2011/08/17/http-archive-nine-months/

43. Thinking Clearly About
Performance
http://carymillsap.blogspot.com/2010/02/thinking-
clearly-about-performance.html

44. Average Lies
List A List B
0.924 0.796
0.928 0.798
0.954 0.802
0.957 0.823
0.961 0.919
0.965 0.977
0.972 1.076
0.979 1.216
0.987 1.273
1.373 1.320
pg3, Exhibit 1

45. Aim For Consistent Performance

47. Know Your Limits
Calculate the theoretical best performance
for your setup

48. Know Your Limits
Calculate the theoretical best performance
for your setup
What ever you actually end up with
will be slower than that

49. Moving Up The Stack

50. The Stack
Network

51. The Stack
Server Hardware
Network

52. The Stack
Operating System
Server Hardware
Network

53. The Stack
HTTP
Operating System
Server Hardware
Network

54. The Stack
HTTP PHP
Operating System
Server Hardware
Network

55. The Stack
HTTP PHP MySQL
Operating System
Server Hardware
Network

56. The Stack
WordPress
HTTP PHP MySQL
Operating System
Server Hardware
Network

57. The Stack
WordPress
HTTP PHP MySQL
Operating System
Server Hardware
Network

58. HTTP - The Web Server
Apache
remove any modules you aren’t using
turn off host name lookups
turn off FollowSymLinks
turn off .htaccess (if you can)
turn on compression (mod_deflate)
tweak MaxClients

59. HTTP - The Web Server
Apache - mod_pagespeed
http://code.google.com/speed/page-speed/docs/module.html
http://code.google.com/p/modpagespeed/

60. HTTP - The Web Server
Consider Alternatives
Nginx

61. HTTP - The Web Server
HTTP Compression
Keep-alive support
Correctly Configured Caching

62. ETag Survey
HTTP/1.1 200 OK
ETag: "cd7ac991ff11"

63. ETag Survey
If-None-Match: "cd7ac991ff11"
HTTP/1.1 304 NOT MODIFIED

64. ETag Survey
ETags used by 136 of the top
1,000 U.S. sites
http://josephscott.org/archives/2011/09/etag-survey/

65. ETag Survey
Of the 136 sites using ETags:
54 Worked Correctly (39.7%)
11 Sort of Worked (8%)
71 Broken/Useless (52.2%)

66. Understanding PHP

67. Understanding PHP
Lifespan
.php
Read Parse Compile Execute Output

68. Understanding PHP
Lifespan
.php
Read Parse Compile Execute Output
Apache / mod_php

69. Understanding PHP
.php
Lifespan
Read Parse Compile Execute Output
FastCGI
Nginx

70. Reading
Open Read Close

71. Reading
Open Read Close
Avoid co$tly services like NFS

72. Parse
hello.php
<?php
echo "Hello, World!n"
Parse error: syntax error, unexpected $end,
expecting ',' or ';' in /tmp/hello.php on line 3

73. Tokens
<?php echo
$tokens = token_get_all( '
"Hello, World!";' );

74. foreach ( $tokens as $token ) {
if ( is_array( $token ) ) {
echo token_name( $token[0] ) . " ( {$token[2]} ) -
{$token[1]}n";
} else {
echo "{$token}n";
}
}

75. T_OPEN_TAG ( 1 ) - <?php
T_ECHO ( 1 ) - echo
T_WHITESPACE ( 1 ) -
T_CONSTANT_ENCAPSED_STRING ( 1 ) - "Hello,
World!"
;

76. Compile

77. Branch analysis from position: 0
Return found
filename: /tmp/hello.php
function name: (null)
number of ops: 3
compiled vars: none
line # op fetch ext return operands
-------------------------------------------------------------------------------
2 0 ECHO 'Hello%2C+World%21%0A'
3 1 RETURN 1
2* ZEND_HANDLE_EXCEPTION

78. Execute
Deceptively Simple Term
•Includes all sorts of activity
•Database / remote requests

79. Output
•PHP can buffer output
•Don’t forget about compression

80. Making PHP Faster

81. Making PHP Faster
.php
Read Parse Compile Execute Output

82. Making PHP Faster
.php
Read APC
Parse Compile Execute Output

83. Making PHP Faster
.php
Read APC
Parse Compile Execute Output
opcode cache

84. PHP - opcode caching
APC
requests per second - increased 4x
time per request - decreased 4x

85. Use An Opcode Cache
(APC)

86. Use An Opcode Cache
(APC)!

87. APC == Free Money

88. APC == Free Money

89. PHP
use an opcode cache (APC)
use newer versions
don’t use on static files (unless you really need to)
consider output buffering
be careful with preg_* functions
profile your running code (Xdebug, VLD)
don’t re-invent native PHP functions, they are likely
faster than yours

90. The Stack
WordPress
HTTP PHP MySQL
Operating System
Server Hardware
Network

91. MySQL
use InnoDB table type (unless you have a
really good reason not to)
use the slow query log
use EXPLAIN on queries, learn
what the output means
double triple check your indexes
learn about quirks

92. The Stack
WordPress
HTTP PHP MySQL
Operating System
Server Hardware
Network

94. Memcached
“Free & open source, high-performance,
distributed memory object caching
system”
in memory only, won’t survive a reboot
key/value data store
http://memcached.org/

95. WordPress + Memcached
Memcached Object Cache
Persistent data store for WordPress objects
Reduces the number of database queries
http://wordpress.org/extend/plugins/memcached/

96. I’m Batcache

97. WordPress + Memcached
Batcache
Persistent data store for rendered pages
http://wordpress.org/extend/plugins/batcache/

98. WordPress Caching - Alternatives
WP Super Cache
http://wordpress.org/extend/plugins/wp-super-cache/
W3 Total Cache
http://wordpress.org/extend/plugins/w3-total-cache/

99. But Wait, There’s More!

100. MySQL Replication
Master / Slave
one way, asynchronous
send writes to the master
send reads to the slave
supports multiple slaves, and chaining

101. WordPress + HyperDB
Drop in replacement for default DB class
distributed reads and writes
partition data
http://wordpress.org/extend/plugins/hyperdb/

102. What Could This Look Like?

103. What Could This Look Like?
Net
web & database

104. What Could This Look Like?
Net db
web

105. What Could This Look Like?
db
Net
web
memcached

106. What Could This Look Like?
db db
Net
web
memcached memcached

107. What Could This Look Like?
web db db
load web
balancer
web memcached memcached

108. Variations
slave just for backups
multiple data centers
task specific web servers

109. When Things Go Wrong

110. Hire an Amazing SysAdmin

111. Questions?

112. Find Me
http://josephscott.org/
joseph@josephscott.org
@josephscott