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![What is reactive programming? Reactive programming - is a declarative programming paradigm concerned with data streams, the propagation of change [1] Reactive programming - is about non-blocking, event-driven applications that scale with a small number of threads [2] 1. https://en.wikipedia.org/wiki/Reactive_programming 2. https://spring.io/blog/2016/07/28/reactive-programming-with-spring-5-0-m1](https://image.slidesharecdn.com/whatarethebenefitsofreactiveprogramminginjava-191027213021/75/What-are-the-benefits-of-reactive-programming-in-java-18-2048.jpg)
What are the benefits of reactive programming in java
- 1. What are thebenefits of reactive programming in Java? Dmytro Melnychuk
- 2. Bio Software Engineer ● 7years experience in JVM languages twitter.com/meldmy github.com/meldmy
- 3. Agenda ● Synchronous vsasynchronous programming ● The key reactive programming concepts ● Current state of Java-based reactive frameworks and toolkits
- 4. Have you everstayed in such long queue? The first McDonald's in Moscow opened in 1990
- 5. When can ithappen?
- 6. When can ithappen? When too many clients need to wait for finalization of their orders!
- 7. What is theproblem with simple order system? We need to stay in queue until all previous orders complete * https://www.vintag.es/2016/03/old-mcdonalds-historical-photos-of.html
- 8. How they resolveda problem with a long queue? * https://www.calvertjournal.com/images/uploads/thumbnails/McDonalds/LON29289.jpg * https://external-preview.redd.it/x0cIVo6wWlM8ryudtVHhMmPwvnUkZxOg1_izN5fgwZ8.jpg?auto=webp&s=209c2937112562108309eb5b4b59165bc46c0fb9
- 9. The same problemwith synchronous blocking I/O Blocking is waiting! Let’s remember! Waiting is doing nothing!
- 10. Let’s avoid doingnothing!
- 11. Freezing UI andour backend use blocking I/O
- 12. Let’s increase thenumber of server threads?
- 13. Let’s increase thenumber of server threads?
- 14. What's wrong withincreasing threads and blocking I/O? ➢ Thread-per-connection approach ➢ Thread Context Switching
- 15. Thread-per-connection approach * http://www.coralblocks.com/index.php/thread-concurrency-vs-network-asynchronicity/ 1.Thread creating 2. Thread per connection 3. Waiting thread per Keep-Alive connection 4. Context Switching
- 16. Context Switching -cores switch between processes * http://www.coralblocks.com/index.php/thread-concurrency-vs-network-asynchronicity/
- 17. What about reactiveprogramming?
- 18. What is reactiveprogramming? Reactive programming - is a declarative programming paradigm concerned with data streams, the propagation of change [1] Reactive programming - is about non-blocking, event-driven applications that scale with a small number of threads [2] 1. https://en.wikipedia.org/wiki/Reactive_programming 2. https://spring.io/blog/2016/07/28/reactive-programming-with-spring-5-0-m1
- 19. How we candouble every int in the array in Java? Imperative approach
- 20. How we candouble every int in the array in Java?
- 21. How we candouble every int in the array in Java? Imperative approach Declarative approach
- 22. Imperative vs declarativeprogramming Imperative programming Declarative programming How you want to do What you want to do
- 23. Reactive programming is programmingwith data streams
- 24. Reactive programming concernedwith data streams Data streams Non-blocking I/OBlocking I/O Synchronous Asynchronous java.util.stream.* java.util.concurrent.Flow (JDK 9)
- 25. Understand the termof propagation of change var A = 1, B = 2; var C = A + B; A = 3; print(C); //=> 5 What should we know about C behavior? ● C is automatically updated when values of A or B change ● C is a observer that subscribes to an observable A and B
- 26. Observable needs asmall number of threads to scale
- 28. The reactor pattern(single-threaded event loop)
- 29. Is reactor patternfaster than one-thread-per-connection model?
- 30. Why do youthink this happens? *https://dzone.com/articles/spring-boot-20-webflux-reactive-performance-test Spring MVC Spring WebFlux Embedded Tomcat (maxThreads 10000) Netty framework
- 31. Reactor pattern makesbetter use of threads/cores! *https://dzone.com/articles/spring-boot-20-webflux-reactive-performance-test Spring MVC Spring WebFlux Embedded Tomcat (maxThreads 10000) Netty framework Thread-Based Architecture Event-driven architecture
- 32.
- 33. Reactive Java frameworksand toolkits Project Reactor
- 36.