This document provides an overview of profiling PHP applications for performance. It begins by discussing common myths about PHP optimizations that provide little real performance benefit. Effective profiling is based on measuring actual performance results using tools. The document outlines different profiling modes for normal development and emergency situations. It then describes various tools that can be used to profile different parts of a PHP application, including the browser, web server, PHP code, database, and operating system. It emphasizes finding and addressing bottlenecks. The document concludes by offering advice like avoiding premature optimization, understanding problems fully before attempting to fix them, and asking others for help.

1. Profiling PHP
Applications
July 2011 - Justin Carmony
#uphpu
wifi: C7bluffdale -- c7dcguest

2. About Me
• CTO of Dating DNA
• CIO of CEVO LLC
• Make Websites & iPhone Apps
• Worked on Websites for Dell, nVidia,
DirectTV, and other big clients.

3. Experience
• Lots of work with “Middle-Scale” websites.
• Lucky to Work on Fun Projects
• Lots of Web Service Stuff
• Learned most of this from other really
smart people.

4. We’ll Use An Example
and an awesome one at that...

6. We Have Similar Jobs
Awesome, huh?

7. MythBusters
• They get a Myth
• Break it down to its
different parts
• They Conduct a Bunch
of Tests
• They Draw Conclusions
• and have a Fun Time

9. Developers
• We get Myths
(Hey, this is slow)
• We Break it down to
the different pieces
• We Conduct a Bunch of
Tests.
• We Draw Conclusions
(and normally make
changes)
• and Have a Fun Time...

11. So Lets Get Started!
php /lets/get/started.php now

12. First Off, Some
PHP Myths
and there are a lot of them!

13. Common Performance
Claims (Myths)
• echo instead of print() • single quotes, not double
quotes
• echo commas, not
periods • include instead of
include_once
• don’t use custom
functions/classes • === faster than ==
• pass by reference • for faster than foreach
instead of by value

14. To Quote
Derick Rethans
Author of Xdebug...

15. “I can only say one thing about this....
Complete & Utter
Bull****”

16. or in MythBusters Terminology....

17. I’m Serious, There are a
LOT of these Myths
These Example Came from Google’s Top 10 results for
“php performance tips”

18. These “Performance
Tips” Rarely Make a
Difference

19. Thats Like Debating the Windshield Wipers’s
Effect on this Car’s Performance

20. Intuition Based
Optimizations
i.e. how to not effectively
improve performance
Phrase Coined by Dave Smith
http://thesmithfam.org/blog/2011/02/

21. Your Intuitions are
WRONG
90% of the time

22. Example:
Fuel Efficiency Myths

23. MythBusters Tested
• Keeping Your AC Off vs Windows Down
• Idling Better than Stop/Start
• Magical Aerodynamics
• Dirt-Free Filters
• Special Fuel Additives to Slow Burn
All Busted! They Didn’t Make a Difference,
Or Worsened Fuel Efficiency

24. How About
Driving Angry?
After Testing, Tory & Grant Used
33% More Fule While Driving Angry

25. Effective Profiling
is based on
Actual Results

26. There are Two Types
of Profiling “Modes”

27. Normal Profiling
Lets Try this Configuration Change
and Measure the Performance Difference

28. Emergency Profiling
Aaaaaaaaaaaaah the Website is Down!!!!
Why is it so slow??? Fix it!!!!!!

29. Same Techniques
Apply to Both
• Some you’ll want to chose first depending
on your situation.
• You’ll want to be careful when profiling in
Production, you can make things worse.

30. Understanding the
Full Picture

31. Browser Static Files
Database and/or
Data Store
Web Server
PHP App
Server OS
Web Services &
Resources Hardware
Cache

32. Don’t Panic!

33. Goal: Find Slow Parts
aka Bottlenecks

34. Profiling & Testing
Different Parts

35. Tools!

36. Browser Static Files
Database and/or
Data Store
Web Server
PHP App
Server OS
Web Services &
Resources Hardware
Cache

37. FireBug

38. FireBug

39. Google Page Speed

40. Other Tools
• YSlow
http://developer.yahoo.com/yslow/
• Pingdom Tools
http://tools.pingdom.com/
• WireShark / Fiddler2

41. Browser Static Files
Database and/or
Data Store
Web Server
PHP App
Server OS
Web Services &
Resources Hardware
Cache

42. apachetop
apachetop -f /var/log/apache/example.com.access.log

43. Apachetop works
with nginx

44. Apache’s mod_status
<Location /server-status>
SetHandler server-status
Order Deny,Allow
Deny from all
Allow from 25.131.42.122
</Location>
# ExtendedStatus On

45. Apache’s mod_status

46. siege

47. siege
• Command Line Tool
• Run Concurrent HTTP Requests
• Runs on Linux & Mac OS
• Windows Users: Run a VM
• Great Way to Test End Result

48. siege
• Create txt file with lists of URLs to hit
• Run Command:
siege -c 10 -r 10 -f urls.txt
• c = concurrent
r = # of requests
f = path to URL file

49. siege

50. siege

51. Other Tools
• nginx stub status (similar to mod_status)
http://wiki.nginx.org/HttpStubStatusModule
• Apache Bench & http_load -- CLI
• JMeter -- Java Desktop App

52. Browser Static Files
Database and/or
Data Store
Web Server
PHP App
Server OS
Web Services &
Resources Hardware
Cache

53. My Favorite New Tools:
XHProf & XHGui

54. XHProf
• Developed by Facebook
• Works well for both Development
& Production* Profiling
• pecl extension
• Decent UI for viewing Results
* - Use Sampling & Special CPU Flags for Production
http://mirror.facebook.net/facebook/xhprof/doc.html

55. XHGui
• Improved GUI
• Easy to Setup
• Built In Sampling
• Advanced Configuration
• MySQL Backend
• I recommend using this!
https://github.com/preinheimer/xhprof

56. More Fun to Show
Demo Time

57. Xdebug Profiler
• Install Xdebug
• Enable Xdebug Profiling
• Outputs a Cachegrind Log
• Use KCachegrind / WinCachegrind /
Webgrind to view
• For the Rich, MacCallGrind for $150

58. Enabling Xdebug
Profiling
xdebug.profiler_enable=1
xdebug.profiler_output_dir=/tmp
xdebug.profiler_output_name=cachegrind.out.%p
Xdebug Profiling Not for Production
(unless you have a 100TB HDD laying around)

59. Webgrind

60. Timing Points
• Most Frameworks have Built-In Profiling /
Timing Points
• Most ORMs have them as well
• You can do them yourself
• A must for Database Queries

61. Timing Points
$start = microtime(true); // true to get as float
/* Do your Crazy Code, i.e. query */
$end = microtime(true);
$time = round($end - $start, 4);

62. Other Tools
• Inclued
http://php.net/manual/en/book.inclued.php
• Memtrack
http://php.net/manual/en/
book.memtrack.php

63. Browser Static Files
Database and/or
Data Store
Web Server
PHP App
Server OS
Web Services &
Resources Hardware
Cache

64. Databases
• Typically, First Thing to Slow Down
• Things to that will Kill the DB:
• Missing Indexes
• Nested Queries
• Large Joins
• Locked Queries

65. Jet Profiler
• MySQL Profiler
• Free Version (Okay) & Paid (Awesome)
• Not Cheap ($399)
• But Worth It
• Analytics Over Time

66. Jet Profiler

67. MySQL Commands
• explain <query>
• show processlist
• show variables
• show status

68. mtop

69. Browser Static Files
Database and/or
Data Store
Web Server
PHP App
Server OS
Web Services &
Resources Hardware
Cache

70. vmstat
command: vmstat 1

71. vmstat
• swap > 0 means swapping
Memory Issue
• cpu sys + us really high
CPU / Code / PHP Problem
• cpu wa > 10
Disk IO Problem*
* - Technically could be Network IO as well, but typically
one of the last and more rare bottlenecks to hit

72. vnstat
command: vnstat -l -i eth0

73. top

74. htop

75. strace

76. iotop

77. Other Tools
• netstat
• iostat
• mpstat
• pidstat
• (on ubuntu, install via sysstat package)

78. Other Tools
• grep, awk, sed
• IPs Connected:
netstat -plan | grep :80 | awk '{print $5}' |
sed 's/::ffff://g' | awk -F: '{print $1}' | sort |
uniq -c | sort -n

79. Monitoring
Munin
http://munin-monitoring.org/

80. Monitoring
Wormly
http://wormly.com/

81. Whew, Lots of Tools
and a lot more out there not in this talk
Find any cool ones, let me know!

82. Normal Profiling
• Start with XHProf/XHGui and FireBug
• Avoid Premature Optimization
• Complicated Change
• Little Reward
• Use siege, or alternative, to simulate load.

83. Emergency Profiling
• Start with OS Level Testing Tools (htop,
vmstat, vnstat) to check Server
Performance
• Determine which Resource(s) are being
over utilized
• Finding the bottleneck is key

84. Emergency Profiling
• What Changed?
• Increased Traffic?
• New Feature?
• Something Failed/Down?
• Don’t Panic & Start Wildly Guessing

85. Few Final Thoughts

86. The Better You
Understand
The Problem
The Better You Can
Fix It

87. Don’t
Put Off Profiling
Until there is an
Emergency

88. You Can Throw
Hardward at the
Problem, but Avoid IT

89. Ask Others for Ideas
aka
Brainstorming

90. Good Luck!

91. Questions?

92. Thanks!
Twitter: JustinCarmony
IRC: carmony
#uphpu #phpc #joind.in
Website:
http://www.justincarmony.com/blog
Email:
justin@justincarmony.com