Building Reactive Systems

This presentation was made in Brazil at DevFest XP By 99 '17 ( https://devfestxp.com/ )

Transcript

1. Building Reactive Systems @jeduardocosta
2. About me - Eduardo Costa - From São Paulo / SP - 99ner - Backend developer - Scala enthusiastic - @jeduardocosta
3. Agenda - Demystifying Reactive - Back-pressure - Circuit breaker - Event Sourcing and CQRS - How can we start?
4. Demystifying Reactive
5. What's the meaning
7. Reactive is an architectural and design principle, not just a library
8. Reactive Manifesto
9. Reactive Programming vs Reactive Systems?
10. Reactive Programming
11. Reactive Programming
12. Reactive Systems
13. They can and should be used together
14. Back Pressure
15. Back
16. Back Pressure
19. Back Pressure // Getting a stream of jobs from an imaginary external system as a Source val jobs: Source[Job, NotUsed] = inboundJobsConnector() jobs .buffer(1000, OverflowStrategy.backpressure) .map(url => pipeline(Get(url)).map((url, _))) .map(parseUrls) .runWith(Sink.foreach(println)) OverflowStrategy.dropBuffer | OverflowStrategy.dropHead OverflowStrategy.dropTail | OverflowStrategy.dropNew
21. Circuit Breaker
22. You don't need wait for failures If you're going to fail, fail fast
23. Circuit Breaker
24. Circuit Breaker class DangerousActor extends Actor with ActorLogging { import context.dispatcher val breaker = new CircuitBreaker( context.system.scheduler, maxFailures = 5, callTimeout = 10.seconds, resetTimeout = 1.minute).onOpen(notifyMeOnOpen()) def notifyMeOnOpen() = log.warning("My CircuitBreaker is now open, and will not close for one minute")
25. Event Sourcing and CQRS
26. Event Sourcing and CQRS
27. Event Sourcing
28. CQRS
29. CQRS
30. How to design domain model?
31. Domain Driven Design
32. How can we start?
33. Steps - Embrace reactive principles - Asynchronous processing with back-pressuring - Start with reactive programming - Use circuit-breaker - Events over states (Event Sourcing and CQRS)
37. References - CQRS Journey (https://msdn.microsoft.com/en-us/library/jj554200.aspx) - How Events Are Reshaping Modern Systems - Jonas Bonér (https://speakerdeck.com/jboner/how-events-are-reshaping-modern-systems) - Lessons Learned From PayPal: Implementing Back-Pressure With Akka Streams And Kafka (https://www.lightbend.com/blog/lessons-learned-from-paypal-implementing-bac k-pressure-with-akka-streams-and-kafka)
38. We're hiring Join our team carreiras.99app.com
39. @jeduardocosta