Node.Js on the JVM

Node.js on the JVM

JavaScript Evented I/O & more for the Java Enterprise Ecosystem

Niko Köbler (@dasniko) {JavaScript}Training

I'm to hire!

What is Node.js? Server-side JavaScript platform built on Google V8 engine What JavaScript has done for the webbrowser, Node.js is doing for the backend server http://nodejs.org

Asyncronous, non-blocking, evented I/O with JavaScript

var http = require('http'); http.createServer(function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }).listen(1337, '127.0.0.1'); console.log('Server running at http://127.0.0.1:1337/'); The Event Loop The cost of I/O

L1-cache 3 cycles L2-cache 14 cycles RAM 250 cycles Disk 41 000 000 cycles Network 240 000 000 cycles Why JavaScript? “ (undeﬁned is not a function!) Why Java? With Java, we have...

Longterm investments Mature solutions Complex and extensive business logic Integration of heterogeneous environments across platforms Blueprints and best-practices available Proven infrastructure and monitoring options And now, you wanna tell us about this "brave" new (Node-)world? Mostly new applications Mostly No-SQL backed New application approaches More focused silo apps "Cool stuﬀ"

~ 120.000 NPM libraries available (01/2015) No enterprise integration (yet) Infrastructure? Monitoring? Operations? Speaking JavaScript Like it or not, JavaScript is everywhere these days - from “browser to server to mobile - and now you, too, need to learn the language or dive deeper than you have. Dr. Axel Rauschmayer

http://speakingjs.com In four years ... Node.js has experienced phenomenal “ growth. Node.js is the language of choice for high performance, low latency applications and has been powering everything from robots to API engines to cloud stacks to mobile web sites. Node.js Advisory Board - October 23, 2014

Integration Integration invokedynamic Nashorn JavaScript Enginge on the JVM based on invokedynamic feature competes with Google V8 ECMAScript 5.1 compatible (ES6/ES2015 with Java 9) Seamless interoperability of Java and JavaScript Shell Scripting With Java 8u40 native execution of TypeScript Language and API Extensions closures, collections & for each, multi-line string literals, string interpolation, __noSuchProperty__, __noSuchMethod__, typed arrays, binding properties, error extensions, conditional catch clause, String functions, and many, many more... http://openjdk.java.net/projects/nashorn/ Java and JavaScript “ ...are similar than car and carpet are similar.

Nashorn Command Line Client

$ $JAVA_HOME/bin/jjs jjs> print('Hello Nashorn!');

Invoking JavaScript from Java

ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn"); engine.eval("print('Hello Nashorn!');"); engine.eval(new FileReader("scriptfile.js"));

Invocable invocable = (Invocable) engine; Object result = invocable.invokeFunction("jsSayHello", "Nashorn"); Nashorn Invoking Java from JavaScript package my.package; public class MyJavaClass { static String sayHello(String name) { return String.format("Hello %s from Java!", name); } } var MyJavaClass = Java.type('my.package.MyJavaClass'); var result = MyJavaClass.sayHello('Nashorn'); print(result); // Hello Nashorn from Java! Nashorn Listing Docker Containers via REST-Call

#!/usr/bin/jjs -fv var host = "DOCKER_HOST" var dockerUri="http://${host}:5555/containers/json"; var command = "curl ${dockerUri}"; $EXEC(command); var containers = JSON.parse($OUT); for each(container in containers){ print("${container.Image} / ${container.Names[0]} / ${container.Status}"); }

(by Adam Bien) Avatar The Oracle solution † Avatar 2.0

Inter-thread communication Message Bus Shared State (Map API: Key-Value-Store) Model-Store-API JPA (Eclipselink) / JDBC based https://avatar.java.net Avatar 2.0 The RedHat counter http://nodyn.io developed by project:odd at RedHat based on DynJS (Nashorn is on its way!) "more JavaScript than Node.js" Netty for async I/O Vert.x integration/interaction http://dynjs.org also based on invokedynamic REPL / command line Java interaction / embedding Netty

Netty is an asynchronous event-driven network “application framework for rapid development of maintainable high performance protocol servers & clients. http://netty.io Node.js Architecture Nodyn Architecture Embed in Java programs public class EmbedExample {

private static final String SCRIPT = "" + "var main = require('./project/main.js');" + "main.run();";

public void runMain(String... args) throws InterruptedException { // Use DynJS runtime RuntimeFactory factory = RuntimeFactory.init( EmbedExample.class.getClassLoader(), RuntimeFactory.RuntimeType.DYNJS);

// Set config to run main.js NodynConfig config = new NodynConfig( new String[] { "-e", SCRIPT } );

// Create a new Nodyn and run it Nodyn nodyn = factory.newRuntime(config); nodyn.setExitHandler( new NoOpExitHandler() ); try { int exitCode = nodyn.run(); if (exitCode != 0) { throw new TestFailureException(); } } catch (Throwable t) { throw new TestFailureException( t ); } } } Vert.x is a lightweight, high performance application platform“ for the JVM that's designed for modern mobile, web, and enterprise applications. http://vertx.io Polyglott* Simplicity Scalability Concurrency Distributed Event Bus**

*) Java, JavaScript, Ruby, Groovy, Python, Scala, Clojure, Ceylon **) using Hazelcast In-Memory Data Grid (hazelcast.org) vertx2-core This module exposes the vert.x 2.x eventbus to node.js clients. https://github.com/nodyn/vertx2-core

mod-nodyn This supports running Node.js workloads inside of Vert.x. https://github.com/nodyn/mod-nodyn Beer-as-a-Service https://github.com/dasniko/beer-as-a-service beer-as-a-service.js var http = require("http"); var vertx = require("vertx2-core"); var registration = vertx.eventbus.register("bar", function(message) { var amount = message.body.amount; console.log("BAR: Someone ordered " + amount + " beer(s)."); message.reply({wait_time: amount * 1.75}); }); var server = http.createServer(function(request, response) { var parts = request.url.split("/"); var amount = parts[1];

run with nodyn beer-web.js var http = require("http"); var vertx = require("vertx2-core"); var server = http.createServer(function(request, response) { var parts = request.url.split("/"); var amount = parts[1];

vertx.eventbus.send("bar", {amount: amount}, function(message) { response.write(amount + " beer(s) will be ready in " + message.body.wait_time + " minutes"); response.end(); }); }); server.listen(9000, function() { console.log( "Beer-Server is listening on port 9000" ); }); beer-bar.js var eventBus = require("vertx/event_bus"); eventBus.registerHandler("bar", function(message, replier) { java.lang.System.err.println("BAR: Someone ordered " + message.amount + " beer(s)"); replier({wait_time: message.amount * 1.75}); }); java.lang.System.err.println("The BAR is open!");

run with vertx in cluster mode

Conclusion JavaScript is an emerging language and widely adopted Node.js / IO.js is very popular Operations, monitoring and integration lacks JVM is Enterprise environment of choice (and all the above lacks are already solved) Run JavaScript on the JVM thanks to invokedynamic (Nashorn, DynJS) Re-use your infrastructures and libraries with Node Nodyn from Red Hat Re-use of Node API module, integration of Netty and Vert.x Process-bindings in Java/JavaScript Embed Node.js apps into your Java applications Thank you!

Questions?

Contact: @dasniko [email protected] http://slides.com/dasniko/nodejs-jvm