The Architecture of Stack Overflow - Merge Lisbon 2014

The Architecture of Stack Overflow slides from Merge Lisbon 2014

Transcript

1. The  Architecture  Of   Marco Cecconi @sklivvz http://sklivvz.com
2. Sizing  up  the  problem  
6. *source: Quantcast, Alexa #50-­‐ish  network  for  traffic*   (between imdb.com and t.co)
7. #50-­‐ish  network  for  traffic*   …and  #17  in  Portugal!?     *source: Quantcast, Alexa   much successful very traffic obrigado, yo!
8. 543,255,552  pageviews  in  the  last  30  days*   *source: Quantcast
9. Our  datacenter?  
11. web servers load balancers redis search database http(s) http rest http protobuf sql sql protobuf tag engine
13. We  are  sNll  scaling  up!  
14. Our  development  cycle  
15. BAT!CAVE Code-build-test cycle running on home machine feature requests
16. BAT!CAVE DEV.SO Test on the real servers git push
17. BAT!CAVE DEV.SO META.SE 1-click deploy Users test on meta.stackexchange.com (“baking”) git push
18. BAT!CAVE DEV.SO META.SE 1-click deploy HALP! git revert git push
19. BAT!CAVE DEV.SO NETWORK META.SE 1-click deploy git push 1-click deploy It’s live! Tons of users use it…
20. BAT!CAVE DEV.SO NETWORK META.SE 1-click deploy git push 1-click deploy …and provide new feature requests
21. Move  fast  and  break  things*   * Not the home page or question page :-)
22. Move  fast  and  break  things*   * Not the home page or question page :-)
23. Abusing  caching  
24. 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
28. RisoQo  &  SpagheS  
34. Throwing away risotto… one grain at a time!
35. Abuse  caching  for  GC   performance  
36. IRepository<Order>  orderRepository  =            container.Resolve<IRepository<Order>>();     Order  order  =  orderRepository.Get(35); This is what you think you are doing…
37. …but if you think about it a bit more…
38. ...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);
39. Throwing away spaghetti… one strand at a time!
40. Dependency  InjecNon  is  our   version  of  spagheS  code  
41. Our  source  code  
42. Few projects :-)
43. Few projects :-) Few lines of code :-)
44. Few projects :-) Few lines of code :-) Eeek! very few tests :-S
45. Few projects :-) Few lines of code :-) Awesome community to help :-D Eeek! very few tests :-S
46. YAGNI*   * You Ain’t Gonna Need It!
47. Libraries  and  open  source  
51. Wrap  code  in  libraries     and  open  source  it  
55. “SUPERHERO” CODING
56. HIRE “NINJA” CODERS
57. TOOLS LEVEL: “NINJA”
58. •     Performance  is  a  feature   •     Always.  Be.  Shipping.   •     Use  your  circumstances.   •     Open  source  your  libraries   •     3  obscenely  big  monitors.     KEY TAKEAWAYS
60. Marco Cecconi @sklivvz http://sklivvz.com we are hiring new ninjas from anywhere in the world!