Although tools like Varnish can improve performance and scalability for static sites, when user-specific content is needed, a hit to the PHP/Ruby/Python/.Net backend is still required, causing scalability issues. We’ll look at a brand-new Nginx module which implements an ultra-fast and scalable solution to this problem, changing the way developers think about designing sites with user-specific content.
- 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 ;-) Language of choice :
PHP But : think Perl, Python, Ruby, Java, .Net, 3. Who am I ? Wim
Godden (@wimgtr) 4. Where I'm from 5. Where I'm from 6. Where I'm
from 7. Where I'm from 8. Where I'm from 9. Where I'm from 10. My
town 11. My town 12. Belgium the traffic 13. 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 14. Who are you ?
Developers ? System/network engineers ? Managers ? 15. To
understand the present Understand the past 16. The Stone Age New
blog post by : caveman003 17. Pre-PHP : draw it and make html 18.
The Egyptian Era 19. Old-school PHP : 'rebuild-every-time' 20. The
Industrial Revolution 21. PHP : let's cache 22. Extra ! Extra ! 23.
PHP : dynamic content in static content 24. The Modern Era 25. PHP
: multiple webservers 26. PHP : push updates to cache 27. Today 28.
Adding reverse proxy caching 29. Website with ESI Article content
page Page content Header Latest news Navigation 30. Website with
ESI Article content page Page content Top header (TTL = 2h) Latest
news Navigation (TTL = 1h) 31. Website with ESI Article content
page Page content (TTL = 30m) Top header (TTL = 2h) Latest news
(TTL = 2m) Navigation (TTL = 1h) 32. ESI how it works GET /pageGET
/page 33. ESI how it works ...
... GET /pageGET /page 34. ESI how it works
Login
GET /top 35. ESI how it works ...
... GET /pageGET /page 36. ESI how it works ...
Login
... GET /pageGET /page 37. Going to /page/id/732
38. Article content page Varnish - ESI 39. 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 40. ESI no caching on
user-specific content ? Logged in as : Wim Godden 5 messages TTL =
5minTTL=1h TTL = 0s ? 41. Nginx Web server Reverse proxy
Lightweight, fast 13.46% of all Websites 42. Nginx No threads,
event-driven Uses epoll / kqueue Low memory footprint 10000 active
connections = normal 43. ESI on Nginx Logged in as : Wim Godden 5
messages NEWSMenu 44. ESI SLIC on Nginx 45. Requesting /page (1st
time) Nginx Shared memory 1 2 3 4 /page /page 46. Requesting /page
SLIC subrequests (1st time) Nginx 1 2 3 /menu /news /top (in SLIC
session) 47. Requesting /page (next time) Nginx Shared memory 1 2
/page /menu /news /top (in SLIC session) /page 48. New message is
sent... POST /send DB insert into... set(...) top (in SLIC session)
49. 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 50. News added addnews()
method DB insert into... set(...) Memcache key /news 51. 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 52. How many
Memcached requests ? Logged in as : Wim Godden 5 messages 53. First
release : ESI Part of the ESI 1.0 spec Only relevant features
implemented Extension for dynamic session support But : unavailable
for copyright reasons 54. Rebuilt from scratch : SLIC Control
structures : if/else, switch/case, foreach Variable handling
Strings : concatenation, substring, Exception handling, header
manipulation, JSON support ! 55. SLIC code samples You are logged
in as : You are logged in as : 56. SLIC code samples
57. SLIC code samples 58. Approaches full block
You are logged in as :
You have 5 messages
Logged in as : Wim Godden 5 messages 59. Approaches individual
variables
You are logged in as :
You have messages
Logged in as : Wim Godden 5 messages 60. Approaches JSON
You are logged in as :
You have messages
Logged in as : Wim Godden 5 messages 61. Identifying the user In
Nginx configuration : slic_session_cookie Defined by language (or
configurable) slic_session_identifier Defined by you Example for
PHP : slic_session_cookie PHPSESSID slic_session_identifier UID 62.
Identifying the user Nginx + SLIC Cookie : PHPSESSID =
jpsidc1po35sq9q3og4f3hi6e2 get UID_jpsidc1po35sq9q3og4f3hi6e2432
63. Retrieving user specific content Nginx + SLIC Cookie :
PHPSESSID = jpsidc1po35sq9q3og4f3hi6e2 get userData_432 64. 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 65. What's the result ?
66. 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 380 Expected
savings : 1.5 Million per year 67. Why is it so much faster ? 68. A
real example : vBulletin 69. A real example : vBulletin Post
isModerator session variable isAdmin session variable 70. A real
example : vBulletin DB Server Load Web Server Load Max Requests/sec
(1 = 282) 0 5 10 15 20 25 30 35 Standard install With Memcached
Nginx + SCL + memcached 71. Code changes Required Template
conversion Push-to-DB Push-to-DB + Push-to-Cache Choice : If user
is logged in push updates to cache If user is not logged in warm up
cache on login 72. Availability Good news : It will become Open
Source It's solid : ESI version stable at 4 customers PHP version
(currently for dev, later for docs and learning) Bad news : First
customer holds copyrights Total rebuild Open Source release No
current projects, so spare time Anyone feel like sponsoring ? Beta
: Aug 14 (?) Stable : Oct 14 (?) - on Github 73. So... 74.
Questions ? 75. Questions ? 76. Contact Twitter @wimgtr Web
http://techblog.wimgodden.be Slides http://www.slideshare.net/wimg
E-mail [email protected]
