The Architecture of StackOverflow - QCon China 2014

The Architecture of Stack OVerflow - Slides updated for QCon China 2014 including data for April 2014, new slides on garbage collection and China-specific content.

Transcript

1. The Architecture Of Marco Cecconi @sklivvz sklivvz@stackoverflow.com
4. #49 network for traffic* *source: Quantcast, Alexa
5. #49 network for traffic* …and #7 in China! *source: Quantcast, Alexa much successful very traffic 谢谢 wow
6. 561,027,840 pageviews in the last 30 days* (~100% growth year over year) *source: Quantcast
7. 561,027,840 pageviews in the last 30 days* (~100% growth year over year) *source: Quantcast
9. web servers load balancers redis search database http(s) http rest http protobuf sql sql protobuf tag engine
11. We are still scaling up, yo!
12. BATCAVE
13. BATCAVE DEV.SO
14. BATCAVE DEV.SO META.SO
15. BATCAVE DEV.SO META.SO
16. BATCAVE DEV.SO META.SO NETWORK
17. Move fast and break things
18. Move fast and break things* * Not the home page or question page :-)
19. Move fast and break things* * Not the home page or question page :-)
20. Network Level Caches (CDN, etc.) Server Level Cache (HttpRuntime.Cache) Site Level Cache (Redis) SQL Server Database Cache (384 gigs of RAM!) Solid State Disk
25. Too Many Allocations This is really the most basic thing that can go wrong. Too Many Pointers If you create a data structure that is a large mesh of pointers you'll have two problems. First, there will be a lot of object writes […] and, secondly, when it comes time to collect that data structure, you will make the garbage collector follow all those pointers and if necessary change them all as things move around. […] But if you create such a structure on a transitory basis, […], then you will pay the cost much more often. http://msdn.microsoft.com/en-us/library/ms973837.aspx#dotnetgcbasics_topic2
26. Too Many Allocations This is really the most basic thing that can go wrong. Too Many Pointers If you create a data structure that is a large mesh of pointers you'll have two problems. First, there will be a lot of object writes […] and, secondly, when it comes time to collect that data structure, you will make the garbage collector follow all those pointers and if necessary change them all as things move around. […] But if you create such a structure on a transitory basis, […], then you will pay the cost much more often. http://msdn.microsoft.com/en-us/library/ms973837.aspx#dotnetgcbasics_topic2
31. Too Many Allocations This is really the most basic thing that can go wrong. Too Many Pointers If you create a data structure that is a large mesh of pointers you'll have two problems. First, there will be a lot of object writes […] and, secondly, when it comes time to collect that data structure, you will make the garbage collector follow all those pointers and if necessary change them all as things move around. […] But if you create such a structure on a transitory basis, […], then you will pay the cost much more often. http://msdn.microsoft.com/en-us/library/ms973837.aspx#dotnetgcbasics_topic2
32. IRepository<Order> orderRepository = container.Resolve<IRepository<Order>>(); Order order = orderRepository.Get(35); This is what you think you are doing…
33. …but if you think about it a bit more…
34. ...this is what you are actually doing! IRepository<Order> repository = new ValidatingOrderRepository ( new SecurityRepository<Order> ( new LoggingRepository<Order> ( new CachingRepository<Order> ( new NHibernateRepository<Order> () ) ) ) ); Order order = repository.Get(35);
38. 馄饨！
39. Few projects :-)
40. Few projects :-) Few lines of code :-)
41. Few projects :-) Few lines of code :-) Eeek! very few tests :-S
42. Few projects :-) Few lines of code :-) Awesome community to help :-D Eeek! very few tests :-S
43. YAGNI*. It works. * You Ain’t Gonna Need It!
44. * Source http://bit.ly/1eSLr8Z
48. Write libraries & open them to the world
52. DEEP DIVES
53. OPINIONATED HIRING
54. REMOTE WORK
55. • Performance is a feature • Always. Be. Shipping. • Use your circumstances. • Open source your libraries • 3 obscenely big monitors. CONCLUSION
56. $_='@mk=uf=radimdp1Z--&ewxuhhl';tr/=1m-za-l@&Z/ !a-zP@\n/&print; Marco Cecconi @sklivvz sklivvz@stackoverflow.com