Conquer the Network - Techorama 2017

Session delivered at Techorama 2017 in Antwerp. This session is about patterns and components that can be used to make your Xamarin app more resilient against network hiccups, low bandwidth, etc.

1. conquer network the
2. conquer network the
3. HI. I’M ROY @roycornelissen blog.roycornelissen.com
5. 8 fallacies of distributed computing
6. ESPECIALLY ON MOBILE, THIS IS CHALLENGING http://blog.davidsingleton.org/mobiletcp $
7. roycornelissen/ConquerTheNetwork SAMPLE REPO
8. ARCHITECTURE
9. OUR GOALS 1.Do less coding 2.Speed! 3.Prioritize requests 4.Work offline 5.Deal with errors
10. TIP KNOW YOUR TOOLS
11. CHARLES / FIDDLER or any network monitor NETWORK LINK CONDITIONER https://developer.apple.com/download/more/?q=Additional%20Tools ANDROID EMULATOR
12. GOAL #1 be a lazy dev (do less coding)
13. > Install-Package Refit (thanks Paul Betts!) be a lazy dev
14. GOAL #2 speed!
15. STEP 1 use native stack speed!
16. speed! Core OS layer OS API layer Mono stack Application layer
17. speed! Core OS layer OS API layer Mono stack Application layer Native HttpClientHandler
18. STEP 2 cache data locally speed!
19. > Install-Package Akavache (thanks again Paul Betts!) speed!
20. GOAL #3 all requests are equal (but some are more equal than others)
21. WHAT IF §… the user Pulls-to-Refresh immediately after the screen is opened? §… or Pulls-to-Refresh many times consecutively? §… the same screen requests the same image multiple times? §… the user navigates away from the screen before loading completes? §… a screen does many requests? some requests are more equal than others
22. > Install-Package Fusillade (thanks AGAIN Paul Betts!) some requests are more equal than others
23. GOAL #4 work offline
24. > Install-Package Xam.Plugin.Connectivity (thanks James Montemagno!) work offline
25. GOAL #5 deal with errors
26. WHAT COULD GO WRONG? deal with errors
27. WHAT DO YOU DO? deal with errors How often? At what interval? What if the server is already busy? Fail fast in case of downstream errors RETRY CIRCUIT BREAKER
28. > Install-Package Polly (thanks Michael Wolfenden & the Polly Project!)
29. DON’T LOSE USER DATA deal with errors this also applies to the server! 1. RETRY 2. SAVE DATA LOCALLY 3. RETRY LATER
30. yay! ü Less coding: Refit ü Speed: § Native network stack § Local caching: Akavache ü Work offline: Connectivity Plugin ü Prioritize requests: Fusillade ü Deal with errors: Polly
31. recommended reading Improving HTTP Performance in Xamarin Applications Jonathan Peppers http://jonathanpeppers.com/Blog/improving-http-performance-in-xamarin-applications Disconnected Mobile Device Seminar Frank Krueger https://blog.xamarin.com/the-disconnected-mobile-device-seminar Resilient Network Services with Mobile Xamarin Apps Rob Gibbens http://arteksoftware.com/resilient-network-services-with-xamarin Eight Fallacies of Distributed Computing Gareth Wilson https://blog.fogcreek.com/eight-fallacies-of-distributed-computing-tech-talk
32. thanks! @roycornelissen blog.roycornelissen.com
33. thanks! @roycornelissen blog.roycornelissen.com pages.xpirit.com/magazine2017