Modern app programming

Size: px

Start display at page:

Download "Modern app programming"

Amber Gordon
5 years ago
Views:

1 Modern app programming with RxJava and Eclipse Vert.x

2 Who am I? Vert.x core team member since 2016 Working at since 2012 Contributing specifically to monitoring and

3 Eclipse Vert.x A toolkit to build reactive applications on the JVM Started in 2O12 Eclipse / Apache licensing 7K on Built on top of

5 Pay the right price Tiny footprint Do one thing and do it well Modular set of extensions

6 Why going reactive?

7 A hotel room booking startup story

8 20 00

10 20 02

12 20 03

14 20 06

16 20 09

18 20 11 NoSQL

21 1/ Many channels 2/ Lots of I/O

22 while (isrunning) { String line = bufferedreader.readline(); switch (line.substring(0, 4)) { case "ECHO": bufferedwriter.write(line); break; //... // other cases (...) //... } }

23 x 1000 =

24 But I don t do Internet scale. I do enterprise!

25 2018 server: 28 cores, 512 GB memory

26 Microservices

27 Your container share: 2 vcpu, 512 MB memory

28 1/ Keep the number of threads to a minimum 2/ Keep them busy

29 Thread Events Event-loop

30 Event loops in Vert.x project

31 2 event-loops per core

32 class HttpServerVerticle extends AbstractVerticle { public static void main(string[] args) { Vertx vertx = Vertx.vertx(); vertx.deployverticle(httpserververticle.class.getname()); public void start() throws Exception { vertx.createhttpserver().requesthandler(req -> { req.response().end("hello world!"); }).listen(8080); } Verticles }

33 DeploymentOptions options = new DeploymentOptions().setInstances(3); vertx.deployverticle(httpverticle, options); Load-balancing

34 Communication between verticles?

35 Multi-paradigm EventBus Messaging passing, not shared data Standalone or clustered Browser and mobile bridges

36 EventBus eventbus = vertx.eventbus(); eventbus.<string>consumer("greeting").handler(msg -> { String name = msg.body(); msg.reply(string.format("hello %s!", name)); }); 2 1 EventBus eventbus = vertx.eventbus(); eventbus.<string>send("greeting", "QConSP", ar -> { if (ar.succeeded()) { System.out.println(ar.result().body()); } else { ar.cause().printstacktrace(); } });

37 Bridge Verticle

38 Distributed EventBus demo

39 Reactive Programming with RxJava

40 Everything is a stream: data or events

41 Java 8 streams on steroids

42 Observable Observer Subscription Lazy and push based

43 Request Observable Observer Subscription Backpressure

44 Different flavors None One Many Completable Single<T> Observable<T> * plus Maybe<T> and Flowable<T> in RxJava 2

45 Composing data flows

47 Great to deal with failures and latencies in distributed systems

51 Observable<String> loadpostsfromrdbms(localdate date); Observable<Comment> loadfromdocumentstore(string postid); Composition loadpostsfromrdbms(date).concatmap(postid -> loadfromdocumentstore(postid)).retry(4).timeout(500, TimeUnit.MILLISECONDS).subscribe();

52 No need to create your own Observables with Vert.x

53 Rxified APIs import io.vertx.ext.web.router; import io.vertx.reactivex.ext.web.router;

54 Rxified APIs void listen(int port, Handler<AsyncResult<HttpServer>> handler); Single<HttpServer> rxlisten(int port);

55 Rxified ReadStream<T> class AsyncFile implements ReadStream<Buffer> { //... // RxJava1 Observable<Buffer> toobservable(); // RxJava2 Flowable<Buffer> toflowable(); //... }

56 Music Store demo

57 Mongo Postgres Cover Art Archive

58 Learning

59 Learning

60 Thank you! More questions? Come to the Red Hat booth!

High performance reactive applications with Vert.x

High performance reactive applications with Vert.x Tim Fox Red Hat Bio Employed By Red Hat to lead the Vert.x project Worked in open source exclusively for the past 9 years Some projects I've been involved