Rethinking Reactive Architectures

Transcript

1. Rethinking Reactive Architectures YA!VACONF Remote, June 2021

2. @duffleit @duffleit david.leitner@squer.at David Leitner Coding Architect

3. Reactive? Programming with, or designing upon, asynchronous data streams.

4. asynchronous data streams. Space Time Collections Iterator Generator Value Getter

   Setter Promise Deferred Resolver Stream Reader Emitter

5. The relationship between them is implicit, an idea that only

   exists in the mind of the programmers. It should be explicit, a part of the language, and existing for all time. Counter and doubled should be bound.

6. The relationship between them is implicit, an idea that only

   exists in the mind of the programmers. It should be explicit, a part of the language, and existing for all time. Counter and Double should be bound. = the Destiny Operator

7. The relationship between them is implicit, an idea that only

   exists in the mind of the programmers. It should be explicit, a part of the language, and existing for all time. Counter and Double should be bound. = the Destiny Operator 1 map(x => x*2) 2 3 6

8. The relationship between them is implicit, an idea that only

   exists in the mind of the programmers. It should be explicit, a part of the language, and existing for all time. Counter and Double should be bound. = the Destiny Operator

9. The relationship between them is implicit, an idea that only

   exists in the mind of the programmers. It should be explicit, a part of the language, and existing for all time. Counter and Double should be bound. = the Destiny Operator

10. Stream Caller Receiver Caller Receiver propagate change observe change trigger

    change directly The reactive programming paradigm is based on asynchronous streams which propagate change. This differs from imperative programming, where statements are used to change a program’s state.

11. YAMS — Yet Another Mail Service NEW 2021-04-11 — An

    important Email 2021-04-09 — Another important Email 2021-04-08 — Do you want to join my network? 2021-04-05 — Nigerian prince wants to send you money X your inbox contains 4 mails 1 NEW Mail Reload Controller Rest Client update UI Element update UI update UI

12. YAMS — Yet Another Mail Service NEW 2021-04-11 — An

    important Email 2021-04-09 — Another important Email 2021-04-08 — Do you want to join my network? 2021-04-05 — Nigerian prince wants to send you money X your inbox contains 4 mails 1 NEW Mail Reload Websocket Client Email Email count() count() collect() filter() subscribe Email map()

13. YAMS — Yet Another Mail Service NEW 2021-04-11 — Hello

    YA!VACONF! 👋 2021-04-09 — Another important Email 2021-04-08 — Do you want to join my network? 2021-04-05 — Nigerian prince wants to send you money X your inbox contains 5 mails 2 NEW Mail Websocket Client Email Email count() count() collect() filter() subscribe Email NEW 2021-04-11 — An important Email map()

14. We move from a pull-based design, to an asynchronous push-based

    design.

15. Reactive Programming ✅ Reactive Architectures 🥺 We take the same

    concepts from reactive programming and move them up to the system architecture. 🤞

16. Internet has 4.7 Billion users. Facbook has 2.8 Billion users.

    Youtube has 2.1 Billion users. 2010 2020 The Internet has 1.4 Billion users. A single website may now handle twice as much traffic as the entire internet did a decade ago.
17. None

18. The Reactive Manifesto Message Driven Responsive Elastic Resilient NFR Supported

    by Enabled by Scalability Extendibility

19. Microservice A Microservice B Message Driven Responsive Elastic Resilient Value

    Form Means

20. Microservice A Microservice B Message Driven Responsive Elastic Resilient Value

    Form Means Microservice B

21. Microservice A Microservice B Message Driven Responsive Elastic Resilient Value

    Form Means Microservice B Stream

22. Microservice A Microservice B Message Driven Responsive Elastic Resilient Value

    Form Means

23. Message Driven Responsive Elastic Resilient Value Form Means Microservice A

    Stream Microservice B

24. We support Back-Pressure Stream Provider Consumer events are stored until

    consumed Stream Provider Consumer A Consumer C Consumer B scaling out consumers We can scale-out by Location Transparency

25. We move from a synchronous pull-based architecture, to an asynchronous

    push-based architecture.

26. Microservice A Microservice B Microservice C Web Application Microservice C

    with high latency First Generation MicroServices Synchronous and without Backpressure Support

27. Microservice A Microservice B Microservice C Web Application Microservice C

    with high latency Second Generation MicroServices Partially asynchronous with Queues Queue isolates bottleneck Queue

28. Web Application Stream Microservice usually Backend-For-Frontend (BFF) Microservice A Microservice

    B Microservice C Third Generation MicroServices Fully asynchronous & stream-centric

29. Events as the System State Stream of Transactions Max sent

    David 100€ Max sent Maria 70€ David sent Maria 25€ User Balance David + 75 € Max - 170 € Maria + 95 € ➡ Event Sourcing 100% reliable audit log.

30. Web Application Stream Microservice usually Backend-For-Frontend (BFF) Microservice A Microservice

    B Microservice C

31. Web Application Eventstore Microservice usually Backend-For-Frontend (BFF) Microservice A Microservice

    B Microservice C

32. Web Application Eventstore Microservice usually Backend-For-Frontend (BFF) Lambda A Lambda

    B Lambda C Forth Generation MicroServices EventSourced with FaaS

33. Lambda A Web Application Lambda B Lambda C Eventstore Microservice

    often Backend-For-Frontend (BFF) HTTP Streaming Request/Response

34. Microservice A Web Application Microservice B Microservice C Stream Microservice

    often Backend-For-Frontend (BFF) HTTP Streaming Request/Response

35. GraphQL ✅ Consumer Driven APIs ✅ Native Schema Support ✅

    Streaming Support

36. Streaming with GraphQL ➡

37. Lambda A Web Application Lambda B Lambda C Eventstore Microservice

    often Backend-For-Frontend (BFF) HTTP Streaming Request/Response

38. Lambda A Web Application Lambda B Lambda C Eventstore GraphQL

    Streaming Request/Response

39. Lambda A Web Application Lambda B Lambda C Eventstore GraphQL

    Microservice A Microservice B Microservice C Web Application ➡ pull-based push-based

40. Realtime Insurance Calculation Real World Example

41. GraphQL Step 1 Step 2 Step 2 Car Brand Build

    Year Car Model Insurance Agent Customer ✅ This Is Correct Alfra Romeo Giulia, 2020 110PS, Diesel Step 1 Step 2 Step 2 Coverage 200 € 🏁 Sign Digital Do you accept 70% coverage for 200€? Lambda A Lambda B Lambda C Eventstore GraphQL Customers expect realtime syncronisation between channels. car brand has changed

42. GraphQL Step 1 Step 2 Step 2 Car Brand Build

    Year Car Model Lambda A Insurance Agent Lambda B Lambda C Eventstore GraphQL Customer ✅ This Is Correct Alfra Romeo Giulia, 2020 110PS, Diesel Step 1 Step 2 Step 2 Coverage 250 € 🏁 Sign Digital Do you accept full coverage for 250€?

43. Resilient Banking with Projections Real World Example

44. Mobile Banking Usage Show balance & last transactions: 93% Initiate

    new payment: 3% Any other functionality: 4%

45. Microservice A Web Banking Microservice B Microservice C Stream GraphQL

    Projection Projections 1⃣ Projections act as read-models for a specific client. 2⃣ They subscribe to events & hydrate the projection. 3⃣ The client only reads from the projection.

46. There are only two core issues in Computer Science: •

    cache invalidation, • and naming things.

47. There are only two core issues in Computer Science: •

    unused potential of reactive systems, • and naming things.

48. Microservice A Web Banking Microservice B Microservice C Stream GraphQL

    Projection Projections 1⃣ Projections act as read-models for a specific client. 2⃣ They subscribe to events & hydrate the projection. 3⃣ The client only reads from the projection.

49. GraphQL Mobile Client Projection Microservice A Web Banking Microservice B

    Microservice C Eventstore GraphQL Projection Projections 1⃣ Projections act as read-models for a specific client. 2⃣ They subscribe to events & hydrate the projection. 3⃣ The client only reads from the projection. Show balance & last transactions: 93%

50. The Reactive Manifesto Message Driven Responsive Elastic Resilient NFR Supported

    by Enabled by Scalability Extendibility

51. This stuff is cool, but think twice, & ensure that

    reactive architectures really fit your problem at hand (aka. NFRs).

52. Architectural Styles buy you options Reactive Architectures buy you mainly

    Resilience, Realtime Capabilities, Elasticity, & Extendibility. you pay by complexity. 💵

53. Maybe start small, and shift to reactive systems once needed.

54. by: twitter.com/swardley

55. Let’s talk about Reactive Systems: www.vyte.in/davidleitner @duffleit squer.at/slides this presentation