Harnessing Domain Driven Design for Distributed Systems

These are the slides from the session Gayathri Thiyagarajan and I gave at Devoxx UK 2016

Transcript

1. @YourTwitterHandle #YourSessionHashtag Gayathri Thiyagarajan & Andrew Harmel-Law, Capgemini UK http://capgemini.github.io Harnessing Domain Driven Design for Distributed Systems @gaythu_rajan / @al94781 #harnessing_ddd
2. cc: kennyma*c - h-ps://www.flickr.com/photos/99472898@N00 @gaythu_rajan / @al94781 #harnessing_ddd Who are we?
3. Who are we? The image cannot be displayed. Your computer may not have enough memory to open the image, or the image may have been corrupted. Restart your computer, and then open the file again. If the red x still appears, you may have to delete the image and then insert it again. @gaythu_rajan / @al94781 #harnessing_ddd
4. “Microservice”? @gaythu_rajan / @al94781 #harnessing_ddd
5. “Microservice”? (cont.) @gaythu_rajan / @al94781 #harnessing_ddd
6. “Microservice”? (cont.) @gaythu_rajan / @al94781 #harnessing_ddd
7. “Microservice”? (cont.) @gaythu_rajan / @al94781 #harnessing_ddd
8. “Microservice”? (cont.) @gaythu_rajan / @al94781 #harnessing_ddd
9. “Microservice”? (cont.) @gaythu_rajan / @al94781 #harnessing_ddd
10. Microservices ROCK! cc: RaeAllen - h-ps://www.flickr.com/photos/30628871@N00 @gaythu_rajan / @al94781 #harnessing_ddd
11. Microservices are HARD @gaythu_rajan / @al94781 #harnessing_ddd
12. “Ge;ng service boundaries wrong can result in having to make lots of changes in service-service collaboraEon. An expensive operaEon.” from Sam Newman, “Building Microservices” (secEon: When shouldn’t you use Microservices) Boundaries are HARDEST @gaythu_rajan / @al94781 #harnessing_ddd
13. Microservices LOVE DDD cc: {AndreaRenee} - h-ps://www.flickr.com/photos/30282864@N02 “Despite the hype [microservices] probably giv[e] us the best environment we have ever had for doing Domain-Driven Design” (Interview with Eric Evans at 2015 DDD Exchange) @gaythu_rajan / @al94781 #harnessing_ddd
14. cc: taberandrew - h-ps://www.flickr.com/photos/88442983@N00 Unfortunately... @gaythu_rajan / @al94781 #harnessing_ddd
15. Some steps... cc: marsupium photography - h-ps://www.flickr.com/photos/43405950@N07 @gaythu_rajan / @al94781 #harnessing_ddd
16. The Core How DDD helps our CODE cc: Laurence Vagner - h-ps://www.flickr.com/photos/86078191@N00 @gaythu_rajan / @al94781 #harnessing_ddd
17. Ubiquitous Language cc: mag3737 - h-ps://www.flickr.com/photos/50318388@N00 @gaythu_rajan / @al94781 #harnessing_ddd
18. Hands-On Modellers cc: jovike - h-ps://www.flickr.com/photos/49503078599@N01 @gaythu_rajan / @al94781 #harnessing_ddd
19. The Misapplied How DDD helps our overall Architecture cc: juhansonin - h-ps://www.flickr.com/photos/38869431@N00 @gaythu_rajan / @al94781 #harnessing_ddd
20. The Important Bits •  Models •  Aggregates •  Contexts •  Bounded Contexts •  Context Maps @gaythu_rajan / @al94781 #harnessing_ddd
21. Shared Payment Services Our Case Study: cc: Khánh Hmoong - h-ps://www.flickr.com/photos/7997148@N05 @gaythu_rajan / @al94781 #harnessing_ddd
22. Shared Payment Services @gaythu_rajan / @al94781 #harnessing_ddd
23. @gaythu_rajan / @al94781 #harnessing_ddd Shared Payment Services
24. @gaythu_rajan / @al94781 #harnessing_ddd Shared Payment Services
25. @gaythu_rajan / @al94781 #harnessing_ddd Shared Payment Services
26. Models cc: Rob Swatski - h-ps://www.flickr.com/photos/50946274@N02 @gaythu_rajan / @al94781 #harnessing_ddd
27. @gaythu_rajan / @al94781 #harnessing_ddd
28. @gaythu_rajan / @al94781 #harnessing_ddd
29. @gaythu_rajan / @al94781 #harnessing_ddd
30. @gaythu_rajan / @al94781 #harnessing_ddd
31. @gaythu_rajan / @al94781 #harnessing_ddd
32. @gaythu_rajan / @al94781 #harnessing_ddd
33. Aggregates cc: J-W Brown - h-ps://www.flickr.com/photos/13797487@N00 @gaythu_rajan / @al94781 #harnessing_ddd
34. @gaythu_rajan / @al94781 #harnessing_ddd
35. Contexts cc: pe*tshoo - h-ps://www.flickr.com/photos/29426084@N00 @gaythu_rajan / @al94781 #harnessing_ddd
36. @gaythu_rajan / @al94781 #harnessing_ddd
37. @gaythu_rajan / @al94781 #harnessing_ddd
38. Bounded Contexts cc: bryce_edwards - h-ps://www.flickr.com/photos/98185064@N00 @gaythu_rajan / @al94781 #harnessing_ddd
39. @gaythu_rajan / @al94781 #harnessing_ddd
40. @gaythu_rajan / @al94781 #harnessing_ddd
41. Context Maps cc: roger4336 - h-ps://www.flickr.com/photos/24736216@N07 @gaythu_rajan / @al94781 #harnessing_ddd
42. @gaythu_rajan / @al94781 #harnessing_ddd
43. @gaythu_rajan / @al94781 #harnessing_ddd
44. Why Aggregates? @gaythu_rajan / @al94781 #harnessing_ddd
45. @gaythu_rajan / @al94781 #harnessing_ddd Aggregate == Microservice
46. @gaythu_rajan / @al94781 #harnessing_ddd Aggregate == Microservice
47. But, Aggregate != Microservice (not always) @gaythu_rajan / @al94781 #harnessing_ddd
48. @gaythu_rajan / @al94781 #harnessing_ddd But, Aggregate != Microservice (not always)
49. @gaythu_rajan / @al94781 #harnessing_ddd
50. 1.  Draw a Model and begin to implement it cc: Muffet - h-ps://www.flickr.com/photos/53133240@N00 An Approach @gaythu_rajan / @al94781 #harnessing_ddd
51. 1.  Draw a Model and begin to implement it 2.  As you draw it and code it, listen to the Language and culEvate your Model accordingly cc: Muffet - h-ps://www.flickr.com/photos/53133240@N00 An Approach @gaythu_rajan / @al94781 #harnessing_ddd
52. 1.  Draw a Model and begin to implement it 2.  As you draw it and code it, listen to the Language and culEvate your Model accordingly 3.  IdenEfy your Aggregates - these are your starter Microservices cc: Muffet - h-ps://www.flickr.com/photos/53133240@N00 An Approach @gaythu_rajan / @al94781 #harnessing_ddd
53. cc: Muffet - h-ps://www.flickr.com/photos/53133240@N00 An Approach @gaythu_rajan / @al94781 #harnessing_ddd 1.  Draw a Model and begin to implement it 2.  As you draw it and code it, listen to the Language and culEvate your Model accordingly 3.  IdenEfy your Aggregates - these are your starter Microservices 4.  When you hit pain points (indicated by the Language) split into different Bounded Contexts to resolve
54. 1.  Draw a Model and begin to implement it 2.  As you draw it and code it, listen to the Language and culEvate your Model accordingly 3.  IdenEfy your Aggregates - these are your starter Microservices 4.  When you hit pain points (indicated by the Language) split into different Bounded Contexts to resolve 5.  Revisit your Bounded Contexts now you know more about how each Aggregate - you may end up spli;ng them cc: Muffet - h-ps://www.flickr.com/photos/53133240@N00 An Approach @gaythu_rajan / @al94781 #harnessing_ddd
55. Done? cc: WarzauWynn - h-ps://www.flickr.com/photos/94246031@N00 @gaythu_rajan / @al94781 #harnessing_ddd
56. The Ignored How DDD helps our Teams Organise cc: aha42 | tehaha - h-ps://www.flickr.com/photos/31549162@N05 @gaythu_rajan / @al94781 #harnessing_ddd
57. @gaythu_rajan / @al94781 #harnessing_ddd Customer-Supplier Partnership Anti-Corruption Layer Upstream Downstream
58. Shared Kernel Separate Ways An*- Corrup*on Layer Partner- ship Conform- ist Open Host Service Customer / Supplier Control Over Associated Teams CommunicaEons Commitment / Capability of Teams @gaythu_rajan / @al94781 #harnessing_ddd
59. Shared Kernel Separate Ways An*- Corrup*on Layer Partner- ship Conform- ist Open Host Service Customer / Supplier Control Over Associated Teams CommunicaEons Commitment / Capability of Teams @gaythu_rajan / @al94781 #harnessing_ddd
60. Shared Kernel Separate Ways An*- Corrup*on Layer Partner- ship Conform- ist Open Host Service Customer / Supplier Control Over Associated Teams CommunicaEons Commitment / Capability of Teams @gaythu_rajan / @al94781 #harnessing_ddd
61. Upstream/Downstream cc: archer10 (Dennis) (73M Views) - h-ps://www.flickr.com/photos/22490717@N02 @gaythu_rajan / @al94781 #harnessing_ddd
62. Partnership cc: prac*calowl - h-ps://www.flickr.com/photos/55046645@N00 @gaythu_rajan / @al94781 #harnessing_ddd
63. @gaythu_rajan / @al94781 #harnessing_ddd Partnership
64. @gaythu_rajan / @al94781 #harnessing_ddd
65. Customer-Supplier cc: TheeErin - h-ps://www.flickr.com/photos/27073477@N00 @gaythu_rajan / @al94781 #harnessing_ddd
66. @gaythu_rajan / @al94781 #harnessing_ddd Customer-Supplier
67. @gaythu_rajan / @al94781 #harnessing_ddd @gaythu_rajan / @al94781 #harnessing_ddd
68. An*-Corrup*on Layer @gaythu_rajan / @al94781 #harnessing_ddd
69. @gaythu_rajan / @al94781 #harnessing_ddd Anti-Corruption Layer Upstream Downstream
70. @gaythu_rajan / @al94781 #harnessing_ddd
71. Done Done cc: jayneandd - h-ps://www.flickr.com/photos/8180853@N07 @gaythu_rajan / @al94781 #harnessing_ddd
72. Take Home Messages cc: Manoj Kengudelu - h-ps://www.flickr.com/photos/11767573@N02 •  Find the right Microservices - or you’ll pine for the Monolith @gaythu_rajan / @al94781 #harnessing_ddd
73. Take Home Messages cc: Manoj Kengudelu - h-ps://www.flickr.com/photos/11767573@N02 •  Find the right Microservices - or you’ll pine for the Monolith •  Don’t get confused about BCs - they will fall out if you listen to the Language @gaythu_rajan / @al94781 #harnessing_ddd
74. Take Home Messages •  Find the right Microservices - or you’ll pine for the Monolith •  Don’t get confused about BCs - they will fall out if you listen to the Language •  Organise around your services beger - apply the Strategic Pagerns cc: Manoj Kengudelu - h-ps://www.flickr.com/photos/11767573@N02 @gaythu_rajan / @al94781 #harnessing_ddd
75. Take Home Messages •  Find the right Microservices - or you’ll pine for the Monolith •  Don’t get confused about BCs - they will fall out if you listen to the Language •  Organise around your services beger - apply the Strategic Pagerns •  Be inspired to do more Domain Driven Design cc: Manoj Kengudelu - h-ps://www.flickr.com/photos/11767573@N02 @gaythu_rajan / @al94781 #harnessing_ddd
76. And Finally... cc: oatsy40 - h-ps://www.flickr.com/photos/68089229@N06 @gaythu_rajan / @al94781 #harnessing_ddd
77. Ques*ons Please cc: Derek Bridges - h-ps://www.flickr.com/photos/84949728@N00 @gaythu_rajan / @al94781 #harnessing_ddd
78. Oh, and we (Capgemini ) are hiring! (visit bit.ly/cg-jvm-jobs-ddd) cc: ptrlx - h-ps://www.flickr.com/photos/58615912@N05 @gaythu_rajan / @al94781 #harnessing_ddd
79. Read More... •  hgps://capgemini.github.io/architecture/ microservices-reality-check/ •  hgps://capgemini.github.io/architecture/ why-microservices-are-right-for-us-pt1/ •  hgps://capgemini.github.io/architecture/ microservices-like-change/ •  hgps://capgemini.github.io/architecture/ microservices-gotchas/ cc: Manoj Kengudelu - h-ps://www.flickr.com/photos/11767573@N02 @gaythu_rajan / @al94781 #harnessing_ddd