"Skalowalna architektura na przykładzie soccerway.com" - Adam Brodziak - Global Sports Media b.v.

1. Scalable architecture
By Adam Brodziak
Global Sports Media b.v.

2. Abstract
 Adam Brodziak
An overview of modern web-based application
architecture - from hardware infrastructure,
through PHP/SQL code, HTML/CSS markup
distribution. All of this spiced up by cache,
loadbalancing and CDN.

3. Who is this guy?
 Lead developer at Global Sports Media
 GSM collects and process sports data
 GSM owns soccerway.com portal
 Linux user
 Interested in frameworks, design patterns
 Semantic Web enthousiast
 Football (soccer) fan

4. Topics
 The Challenge
 Infrastructure
 Code
 Cache
 CDN

5. Topics
 The Challenge
 Infrastructure
 Code
 Cache
 CDN

6. Raw numbers
 7 millions visits / month
 52 millions pageviews / month
 1 billion request / month
 6TB of traffic / month
 300k users at peak time
 Quite a few clients using the same hardware

7. Not so much, but...
 700 leagues
 Livescores
 Game events
 Match statistics
 Rankings
 Editorials

8. Traffic growth

9. The Challenge
 Loads of data to process
 Scores
 Events
 Stats
 In real-time (livescores)
 Growing number of visitors
 13K hits/sec at peak-time

10. 10 servers to run it all

11. Topics
 The Challenge
 Infrastructure
 Code
 Cache
 CDN

12. It starts with one

13. Load balancing

14. Loadbalancing caveats
 Don't relay on the local filesystem
 Temporary files, session, logs
 Avoid assuming exclusive/single cache
 APC, Zend Cache
 Use distributed session storage
 Memcache, database
 Encalsulate above

15. Separate database server

16. DB replication

17. Replicaton caveats
 Writes only on master
 Reads from slaves
 Data consistency
 Replication lag
 Don't do
$master->query('UPDATE session SET logged = 1');
$slave->query('SELECT logged FROM session');

18. Whole image

19. Topics
 The Challenge
 Infrastructure
 Code
 Cache
 CDN

20. PHP is slow!
 Yes, but it does not matter!
 Database access is slower
 Cache over network is slower
 Disk access is slower
 HTTP requests are slower
 Webservice calls are slower
 Discover bottlenecks before blaming PHP

21. It's about architecture
 Heavy tasks in background
 CRON, Gearman
 Pregenerate stuff
 Move some code to SQL
 Calculations in queries
 Stored procedures
 Triggers
 C/C++ or Java for heavy computation
 Use PHP to glue it together

22. PHP Frameworks
 Hundreds of others
 Which one to choose?

23. Framework? Think again!
 Raw performance matters
 Support for master-slave replication
 Multiple layers of cache
 Working with accelerators (HipHop!)
 Beware of bottlenecks
 i.e. core part of framework is slow
 Designed to scale

24. Topics
 The Challenge
 Infrastructure
 Code
 Cache
 CDN

25. Cache is everywhere
 CPU: L1, L2
 Disk buffer
 Linux filesystem
 MySQL
 PHP (APC)
 Smarty
 HTTP Proxy
 Browser cache

26. Where to cache?

27. Memory is cheap
 Pre-generate stuff
 Store results in memory
 APC, memcached
 App config in memory
 APC with stat=off
 Increase RAM for MySQL
 Disk is the new tape

28. Memcached for the rescue!
 Dead simple
 Key-value
 Distributed storage pool
 Automatic invalidation after X sec
 No garbage collecting invoked
 Store arrays, objects, simple values
 Easy integration

29. Topics
 The Challenge
 Infrastructure
 Code
 Cache
 CDN

30. Reverse-proxy
 First line of cache
 Returns content if resource is up-to-date
 Works on HTTP level
 Can be integrated into existing infrastructure
 Can do load balancing
 In-memory cache storage
 Squid, Nginx, Varnish

31. Content Delivery Network
 Network of servers
 Worldwide
 Automatic loadbalancing
 Fast access (low ping time)
 Data redundancy gratis
 Ideal for static resources
 But not only
 Must-have for worldwide websites

32. CDN as reverse-proxy
 HTTP request / response chain
 Embraces REST architecture
 Requests are distributed
 Reduces latency
 Lowers traffic volume
 Increases availability
 i.e. Akamai Edge Suite

33. CDN at soccerway.com
 All of the content is served via CDN
 Images, CSS, JS
 Generated HTML
 JSON for Ajax
 90% of traffic via CDN
 Origin requests only from Europe
 Site online even if servers are down
 Can't live without ;)

34. Thank you for listening
Questions?

35. Interested?
 Contact me:
 adam@globalsportsmedia.com
 www.goldenline.pl/adam-brodziak
 www.linkedin.com/in/adambrodziak
 We're hiring!
 Web developers
 Football / sport fans