This document summarizes 13 strategies for optimizing website performance: 1) adding HTTP cache headers, 2) minification, 3) GZIP compression, 4) using a CDN, 5) static site generation, 6) tuning Apache settings, 7) using opcode caching, 8) implementing Varnish, 9) leveraging Memcached, 10) improving SQL, 11) offloading tasks, 12) optimizing file handling, and 13) output buffering. Additional bonuses include using SPDY and WebSockets. Measuring performance and various Apache, PHP, and database configuration tips were also discussed.

1. “More pageviews coming up?
Improve page loading speed?
Add more boxes!”
- Anonymous developer
Thursday, January 17, 13

2. Let’s speed it up a bit
13 performance optimizing strategies[*]
Pascal de Vink (@pascaldevink)
Thursday, January 17, 13

3. About me
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4. Why does it matter?
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5. So, it hurts...
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6. So, it hurts...
• Your users
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7. So, it hurts...
• Your users
• Your search ranking
[1]
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8. So, it hurts...
• Your users
• Your search ranking
[1]
• Your profit[2]
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9. Measure it
• Request/second benchmarking with AB or
jmeter
• Page load speed with WebPageTest[3]
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10. #1 HTTP cache
headers
“If the content of the script changes only depending
on what’s in the URL, it is cacheable; if the output
depends on a cookie, authentication information or
other external criteria, it probably isn’t”[4]
- Mark Nottingham
Thursday, January 17, 13

11. #1 HTTP cache
headers
• Add:Cache-Control: public max-age=[seconds]
Last-Modified: Mon, 29 Jun 1998 02:28:12 GMT
• But, be aware of its use, eg with
authentication pages
Thursday, January 17, 13

12. #2 Minification
• Place javascript at the bottom of the html
• Place CSS at the top of the html
• Use Minify JavaScript & CSS
• Always write JavaScript & CSS in external file
• Try to reduce number of JavaScript & CSS files
• Assetic[5] can help you use tools
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13. #3 GZIP compression
<IfModule mod_deflate.c>
SetOutputFilter DEFLATE
# Don’t compress
SetEnvIfNoCase Request_URI .(?:gif|jpe?g|png)$ no-gzip dont-vary
SetEnvIfNoCase Request_URI .(?:exe|t?gz|zip|bz2|sit|rar)$ no-gzip
dont-vary
#Dealing with proxy servers
<IfModule mod_headers.c>
Header append Vary User-Agent
</IfModule>
</IfModule>
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14. #4 CDN
• Content Delivery Network
• Used for streaming video
• Based on the browser limit of 2 requests
(not applicable anymore)
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15. #4 CDN
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16. #4 CDN
• CloudFlare is a free
CDN[6]
• Amazon CloudFront is cheap [7]
• Amazon S3 works too [8]
• Roll your own
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17. #5 Static site generation
• Generate page(s) only if changed
• Hype: blogging on dropbox/github pages[9]
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18. #6 Tune apache
• KeepAlive, KeepAliveTimeout, StartServers,
MaxClients[10]
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19. #6b Get rid of apache
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20. #7 Opcode caching
• Pre-compiling PHP in memory[10]
• APC, eAccelerator, Zend server
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21. #8 Varnish
• Load balancing
• Serving assets
• Maintenance mode
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22. #9 Memcached
• In-memory object caching system[11]
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23. #10 Improve your SQL
• Use lazy-loading
• Tune MySQL [12]
• Use NoSQL
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24. #11 Load it off the request
• Message queues (ActiveMQ, RabbitMQ)
• Load off :
• Mails (notifications)
• Background changes (change of product 1
changes product 2)
• Logging (non vital)
• Cache updates
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25. #12 Improve your file
handling
• Reduce your include_path to a single entry or don't
use it at all
• Include or require absolute paths
• Ensure that each try to include a file is a hit
• Avoid file_exists(), is_file(), is_dir(), is_link() etc.
• Avoid autoloading[13]
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26. #13 Use output buffering
• Specially for huge pages
• StreamedResponse in Symfony 2.1
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27. Bonus #14 Use Google
SPDY
• Prioritizing & multiplexing
• Encryption & compression baked in
• Hint/push content
• Chromium, Firefox & Opera only
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28. Bonus #15 Use
WebSockets
• Faster then AJAX request
• Great for instant client communication
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29. In conclusion
• #1 HTTP Cache Headers • #10 Improve your SQL
• #2 GZIP Compression • #11 Load it off the request
• #3 Minification
• #12 Improve file handling
• #4 CDN
• #13 Use output buffering
• #5 Static site generation
• Bonus #14 Use Google
• #6 Tune or ditch Apache SPDY
• #7 Opcode caching
• Bonus #15 Use
• #8 Varnish websockets
• #9 Memcached
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30. One more thing
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31. One more thing
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32. One more thing
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33. Questions?
https://joind.in/talk/view/8066
@pascaldevink
Thursday, January 17, 13

34. References
• infographics: http://mashable.com/2012/11/22/slow-websites/
• varnish: http://deglos.com/blog/2010/09/22/drupal-and-varnish-quick-intro
• Webservers performance http://www.rootusers.com/web-server-performance-benchmark/
• [1] http://copperegg.com/slow-websites-hurt-search-engine-rankings/
• [2] http://econsultancy.com/nl/blog/11274-67-of-consumers-cite-slow-websites-as-the-main-cause-of-basket-abandonment
• [3] http://www.webpagetest.org
• [4] http://www.mnot.net/cache_docs/
• [5] http://symfony.com/doc/2.0/cookbook/assetic/asset_management.html
• [6] http://www.cloudflare.com/
• [7] http://aws.amazon.com/cloudfront/
• [8] http://aws.amazon.com/s3/
• [9] http://octopress.org/
• [10] http://www.bootstrappingindependence.com/technology/how-to-improve-website-performance-with-drupal-php-mysql-and-apache/
• [11] http://memcached.org/
• [12] http://www.mysqlperformanceblog.com/2006/09/29/what-to-tune-in-mysql-server-after-installation
Thursday, January 17, 13