What is Node.js?

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

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?

Why Java?

With Java, we have...

And now, you wanna tell us
about this

Node.js Advisory Board - October 23, 2014

Atwood's Law

http://blog.codinghorror.com/the-principle-of-least-power/

Integration

Integration

Integration

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
• Language and API Extensions

http://openjdk.java.net/projects/nashorn/​

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...

Java and JavaScript

...are similar than car and carpet are similar.

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!

by project:odd @RedHat

http://nodyn.io

• http://dynjs.org
• also based on invokedynamic
• REPL / command line
• Java interaction / embedding

http://netty.io

Netty

Node.js Architecture

Nodyn Architecture

• 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)

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];

  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-as-a-service.js

run with nodyn

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-web.js

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

https://github.com/nodyn/nodyn

We are always mindful where we invest our resources and focus our efforts, and believe the Node.js Foundation has an important role to play in helping to make Node.js successful, as well as the developers using the technology to deploy Node.js applications. We look forward to working alongside our colleagues in the Foundation to help guide the project in the future.

Rich Sharples, senior director, Product Management, Red Hat

https://www.redhat.com/en/about/press-releases/red-hat-joins-nodejs-foundation