When dynamic becomes static: the next step in web caching techniques
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The document discusses advancements in web caching techniques, focusing on the transition from dynamic to static content in PHP. It outlines the benefits and configurations of using tools like Varnish and Nginx for efficient content delivery, including details on ESI (Edge Side Includes) for managing dynamic content. Additionally, it highlights performance improvements and cost savings achieved by reducing server loads and streamlining architecture.
When dynamic becomes static: the next step in web caching techniques
- 1. When dynamic becomes static – the next step in web caching techniques Wim Godden Cu.be Solutions
- 2. Disclaimer The next step as in : what you will be doing in the future Not as in : go home and run it ;-)
- 3. Who am I ? Wim Godden (@wimgtr) Founder of Cu.be Solutions (http://cu.be) Open source developer since 1997 Developer of OpenX, PHPCompatibility, ... Speaker at PHP and Open Source conferences
- 4. Who are you ? Developers ? System/network engineers ? Managers ?
- 5. To understand the present Understand the past
- 6. The Stone Age New blog post by : caveman003
- 7. Pre-PHP : draw it and make html
- 9. Old-school PHP : 'rebuild-every-time'
- 11. PHP : let's cache
- 12. Extra ! Extra !
- 13. PHP : dynamic content in static content
- 14. The Modern Era
- 15. PHP : multiple webservers
- 16. PHP : push updates to cache
- 17. Today
- 18. Adding reverse proxy caching
- 19. Website X with ESI Header Latest news Article content page Navigation Page content
- 20. Website X with ESI Header (TTL = 2h) Latest news Article content page Navigation (TTL = 1h) Page content
- 21. Website X with ESI Header (TTL = 2h) Latest news (TTL = 2m) Article content page Navigation (TTL = 1h) Page content (TTL = 30m)
- 22. Going to /page/id/732 <esi:include src="/header"/> <esi:include src="/nav"/> <esi:include src="/latest-news"/> <esi:include src="/article/id/732"/>
- 23. Varnish - ESI Perfect for caching pages <esi:include src="/top"/> <esi:include src="/news"/> Article content page <esi:include src="/nav"/> <esi:include src="/article/732"/> In your Varnish config : sub vcl_fetch { if (req.url == "/news") { esi; /* Do ESI processing */ set obj.ttl = 2m; } elseif (req.url == "/nav") { esi; set obj.ttl = 1m; } elseif …. …. }
- 24. A simple benchmark – 2KByte JPEG Apache 2.2 4210 IIS 7.5 3960 Varnish 3.0 11400
- 25. A dynamically generated, but static page Apache 2.2 + PHP (3 DB queries) 18 IIS 7.5 + .Net (3 DB queries) 16 Varnish 3.0 11400
- 26. Varnish - what can/can't be cached ? Can : Static pages Images, js, css Static parts of pages that don't change often (ESI) Can't : POST requests Very large files (it's not a file server !) Requests with Set-Cookie User-specific content
- 27. ESI → no caching on user-specific content ? Logged in as : Wim Godden TTL = 0s ? TTL=1h 5 messages TTL = 5min
- 28. Nginx Web server Reverse proxy Lightweight, fast 12.81% of all Websites
- 29. Nginx No threads, event-driven Uses epoll / kqueue Low memory footprint 10000 active connections = normal
- 30. ESI on Nginx Logged in as : Wim Godden 5 messages Menu NEWS
- 31. ESI SCL on Nginx <scl:include key="top" src="/top" session="true" ttl="1h" /> <scl:include key="menu" src="/menu" ttl="1h" /> <scl:include key="news" src="/news" ttl="5m" />
- 32. Requesting /page (1st time) Nginx 1 Shared memory /page 4 /page 3 2
- 33. Requesting /page ESI subrequests (1st time) Nginx 1 2 3 /menu /news /top (in ESI session)
- 34. Requesting /page (next time) Nginx Shared memory 1 /page 2 /page /menu /news /top (in ESI session)
- 35. New message is sent... POST /send o i nt rt e ins ... se t (.. .) DB top (in ESI session)
- 36. Advantages No repeated GET hits to webserver anymore ! At login : POST → warm up the cache ! No repeated hits for user-specific content Not even for non-specific content
- 37. News added addnews() method o i nt rt e ins ... se t (.. .) DB Memcache key /news
- 38. Advantages No repeated GET hits to webserver anymore ! At login : POST → warm up the cache ! No repeated hits for user-specific content Not even for non-specific content No TTLs for non-specific content
- 39. How many Memcache requests ? Logged in as : Wim Godden <scl:include key="top" src="/top" session="true" ttl="1h" /> 5 messages <scl:include key="menu" src="/menu" ttl="1h" /> <scl:include key="news" src="/news" ttl="5m" />
- 40. First release : ESI Part of the ESI 1.0 spec Only relevant features implemented Extension for dynamic session support But : unavailable for copyright reasons
- 41. Rebuilt from scratch : SCL Session-specific Caching Language Language details : Control structures : if/else, switch/case, foreach Variable handling Strings : concatenation, substring, ...
- 42. SCL code samples You are logged in as : <scl:session_var("person_name") /> You are logged in as : <@s("person_name") />
- 43. SCL code samples <scl:switch var="session_var('isAdmin')"> <scl:case value="1"> <scl:include key="admin-buttons" src="/admin-buttons.php" /> </scl:case> <scl:default> <div id="just-a-user"> <scl:include key="user-buttons" src="/user-buttons.php" /> </div> </scl:default> </scl:switch>
- 44. SCL code samples <scl:foreach item="messageId" src="global_var('thread' + query_var('threadId'))"> <scl:include key="'thread-message_' + messageId" src="'/thread/message.php?id=' + messageId" /> </scl:foreach>
- 45. ESI code samples <esi:foreach items="message" collection="$(ESIGLOBAL{'thread_' + $(QUERY_STRING{'threadId'})})"> <esi:include key="'thread-message' + $message" src="'/thread/message.php?id=' + $message" /> </esi:foreach>
- 46. Why Nginx ? Native Memcached support Excellent and superfast subrequest system Including parallel subrequests Handles thousands of connections per worker With minimal memory footprint Integrates with php-fpm Additional features (chroot, slow request log, offline processing, ...) Graceful rolling upgrades
- 47. What's the result ?
- 48. Figures 2nd customer : No. of web servers : 72 → 8 No. of db servers : 15 → 4 Total : 87 → 12 (86% reduction !) Last customer : No. of total servers : +/- 1350 Expected reduction : 1350 → 300 Expected savings : €1.6 Million per year
- 49. Why is it so much faster ?
- 50. A real example : vBulletin
- 51. A real example : vBulletin isAdmin session variable Thread isModerator session variable
- 52. A real example : vBulletin 35 30 25 20 Standard install With Memcached Nginx + SCL + memcached 15 10 5 0 DB Server Load Web Server Load Max Requests/sec (1 = 282)
- 53. Availability Good news : It will become Open Source It's solid : ESI version stable at 4 customers Bad news : First customer holds copyrights Total rebuild → Open Source release No current projects, so spare time Beta : Dec-Jan Final : Q1-Q2 (on Github !)
- 54. So...
- 55. Questions ?
- 56. Questions ?
- 57. Contact Twitter Web Slides E-mail @wimgtr http://techblog.wimgodden.be http://www.slideshare.net/wimg wim.godden@cu.be Please rate my talk : http://joind.in/9568
- 58. Thanks ! Please rate my talk : http://joind.in/9568
Editor's Notes
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