The promise of all cloud vendors out there is they can run your applications without changes. While that claim is true, it’s better to optimize existing software or design specifically for the cloud when moving or building an application. Architectural optimization will speed up your application, make it more scalable and even will make it cheaper to run on Windows Azure. This session will take you along some common patterns that are easy to implement and will make your cloud more sunny. The promise of all cloud vendors out there is they can run your applications without changes. While that claim is true, it’s better to optimize existing software or design specifically for the cloud when moving or building an application. Architectural optimization will speed up your application, make it more scalable and even will make it cheaper to run on Windows Azure. This session will take you along some common patterns that are easy to implement and will make your cloud more sunny.

1. Architectural Patterns for the Cloud
Maarten Balliauw
@maartenballiauw
RealDolmen

2. Who am I?
• Maarten Balliauw
• Antwerp, Belgium
• www.realdolmen.com
• Focus on web
– ASP.NET, ASP.NET MVC, PHP, Azure, …
– MVP Windows Azure (formerly ASP.NET)
• http://blog.maartenballiauw.be
• @maartenballiauw
• Author: Pro NuGet - http://amzn.to/xrzS6j

3. Agenda
• Quick recap: Windows Azure
• What’s different in the cloud?
• Rethinking apps
• Conclusion

4. Quick recap
Windows Azure

5. Windows Azure is a cloud platform
• On-demand
• Self-service
• Pay per use
• Highly automated

6. Windows Azure Components
Compute Storage SQL Azure Service Bus Connect
BI Marketplace CDN Caching ACS
Application Services Storage Services Foundation Services

7. What’s different
in the cloud?

8. Differences with your infrastructure
• Uniform
• Automated
• Designed for failure
• Designed for scale
• It’s not in your datacenter

9. Uniform
• Every machine +/- the same
• No specialized hardware
• No specialized OS*

10. DEMO the Windows Azure virtual machine
Customizing

11. Automated
• Makes decisions on provisioning & updating
• Monitors health
• The platform knows what’s best
– Not necessarily for your app…

12. Designed for failure
UD 1
UD 2

13. Designed for scale
• Scale out
• Stateless

14. It’s not in your datacenter
• Integration
• Authentication

15. Rethinking apps
What do I have to think about?

16. Scenario: Newspaper website
• National & International
• Sudden spikes in usage
• Dynamic content
• Static content

17. Current architecture
• Will work on the cloud!
• Will fail on the cloud!

18. Design for failure

19. Assume everything will fail
• Automated service maintenance
• Compute node crash
• Storage throttling
• SQL Azure throttling
• Connectivity
• Your code

20. Retry everything
SQL Azure Error 40501
The service is currently busy. Retry the
request after 10 seconds.
Retry against anything that might be external
SQL Azure, Windows Azure Storage, Service Bus, …
http://windowsazurecat.com/2011/02/transient-fault-
handling-framework/

21. The entire datacenter fails!
• Run in 2+ datacenters
• Keep data synchronized
– All data
– or limit scope

22. Refactoring the architecture

23. Windows Azure Data Centers
100ms
50ms

24. Windows Azure Traffic Manager

25. Windows Azure Traffic Manager
• Strategies
– Round-robin
– Fail-over
– Performance (geo)
• Solves datacenter outage

26. Are we there yet?

27. Solutions to a SPOF being down
• Set a monitoring endpoint for TM
• Take the entire datacenter out of the loop
• Take the SPOF out of the story
• Degrade gracefully

28. Refactoring our architecture

29. Design for scale
and failure

30. Belgians are not used to snow
What will happen to our
architecture?

31. Here’s what will happen…

32. Solution: scale out!
• Add more VM’s!
• Autoscaling (WASABi)
– Windows Azure Autoscaling Application Block
– Enterprise Library
– http://entlib.codeplex.com/wikipage?title=WASABiBetaRel
easeNotes&referringTitle=EntLib5Azure

33. Solution: scale out!
• Add more VM’s!
• Autoscaling (as-a-Service)
– www.opstera.com

34. Here’s what will happen…

35. SQL Azure
• Monitored by the platform
• The platform does not like high DB traffic
– Throttling & retries

36. Caching
• Most of our users are doing reads
• Cache content near where it’s needed
• Windows Azure Caching
• Blob Storage

37. Refactoring our architecture

38. Caching
• How do you populate it?
• When do you populate it?
• When do you invalidate it?

39. Work asynchrounously
• Read from cache
• Present? Use cache
• Not present? Ask to cache it & read from DB

40. Refactoring our architecture

41. A typical web request…
• 1 request is dynamic
• 493 requests are static*
• Get that static content out of your servers!
– Cache content near where it’s needed

42. Windows Azure CDN

43. Refactoring our architecture

44. Conclusion

45. Key takeaways
• Cloud is different
• Design for failure
• Design for scale
• Work asynchronously
• Cache close to where it’s needed
• Also think price vs. Allowed outage

46. One more… Learn from others!
• Amazon - http://slidesha.re/AlaHIG
• Trello - http://bit.ly/xO5G9e
• YouPorn - http://bit.ly/yUSanQ
• StackOverflow - http://bit.ly/xkLvH9
• InstaGram - http://bit.ly/xbWuzx
• … (highscalability.com)

47. http://blog.maartenballiauw.be
@maartenballiauw
THANK YOU! http://amzn.to/xrzS6j
#tdarc