Julien Ponge Thomas Segismont @jponge @tsegismont

Shameless plug

Reactive? (because resources are scarce)

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Application

Reactive systems Reactive streams Reactive programming Reactive “Responding to stimuli” Manifesto, Actor, Messages Resilience, Elasticity, Scalability, Asynchronous, non-blocking Data flow Back-pressure Non-blocking Data flow Events, Observable Spreadsheets Akka, Vert.x Akka Streams, RxJava, Reactor, Vert.x Reactor, Reactive Spring, RxJava, Vert.x

while (isRunning) { String line = bufferedReader.readLine(); switch (line.substring(0, 4)) { case "ECHO": bufferedWriter.write(line); break // ... // other cases ( ...) // ... default: bufferedWriter.write("UNKW Unknown command"); } }

x 1000 = !

Virtual machines, Containers, etc

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Vert.x? (async all the things!)

Eclipse Vert.x Open source project started in 2012 Eclipse / Apache licensing A toolkit for building reactive applications for the JVM 7K ⋆ on # Built on top of $ https://vertx.io % @vertx_project

& ' & Http server verticle Database client verticle  Event Bus ) ' “Details for user 1234?” “{data}” 4 instances 1 instance

Events Thread Event Loop & & & & &

(demo) Hello Vert.x

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foo.a(1, res1 -> { if (res1.succeeded()) { bar.b("abc", 1, res2 -> { if (res.succeeded()) { baz.c(res3 -> { dosomething(res1, res2, res3, res4 -> { // (...) }); }); } }); } }); “Callback hell”

Callbacks RxJava 1 + 2 Quasar (vertx-sync) Kotlin coroutines (core) (codegen)

Boiler Vroom (in the mix)

(demo)

* ) WebMidi JSON / Event Bus

const eventBus = new EventBus("/eventbus") traktorIn.addListener("controlchange", 5, (event) => { eventBus.publish("boilervroom.vu-meter", { type: "volume-level", value: event.value }) }) eventBus.publish("boilervroom.fromtraktor", { type: "filter", number: 1, value: (event.value !== 0) }) Event Bus

+ , - . IceCast VLC * Chrome / DJ Booth app Clients / NuProcess MIDI Event Bus Event Bus

SockJSHandler sockJSHandler = SockJSHandler.create(vertx); PermittedOptions permittedOptions = new PermittedOptions() .setAddressRegex(“boilervroom\\ ..+”); BridgeOptions bridgeOptions = new BridgeOptions() .addInboundPermitted(permittedOptions) .addOutboundPermitted(permittedOptions); sockJSHandler.bridge(bridgeOptions); router.route("/eventbus /*").handler(sockJSHandler);

+ , - . IceCast VLC Clients / OGG/Vorbis OGG/Vorbis MP3 MP3 HTTP 1.0 HTTP 1.1 HTTP Client Event bus → Chunked HTTP

router.get("/audiostream").handler(context -> { HttpServerResponse response = context.response(); response.setStatusCode(200); response.setChunked(true); response.putHeader("Content-Type", "audio/mpeg"); MessageConsumer consumer = eventBus.consumer("boilervroom.audiostream"); consumer.bodyStream().handler(buffer -> { if (!response.writeQueueFull()) { response.write(buffer); } }); response.endHandler(v -> { consumer.unregister(); }); response.exceptionHandler(t -> { consumer.unregister(); }); });

Outro

Unified end-to-end reactive model + ecosystem (not just APIs…) For all kinds of distributed applications (even the small-scale ones) Flexible toolkit, not a framework (your needs, your call)

https: //youtu.be/ZkWsilpiSqw 0 Applications réactives avec Eclipse Vert.x 1 Building Reactive Microservices in Java https: //goo.gl/ep6yB9 1 Guide to async programming with Vert.x for Java developers https: //goo.gl/AcWW3A

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