Extending JMS to Web Devices over HTML5 WebSockets - JavaOne 2011

Agenda l  HTML5 WebSockets vs. HTTP l  Java Message Service l  Implementing JMS over WebSockets l  Demos and code examples l  Kaazing WebSocket Gateway, JMS Edition l  Questions2 JavaOne 2011 © 2011 – Kaazing Corporation

HTML5 WebSocket l  Extends TCP across the web l  Full-duplex, single socket, very low overhead l  Shares port with HTTP (80/443) Enables new classes of networked apps l  l  W3C API (JavaScript) l  IETF Protocol Full duplexWebSocket Browser Back-end server 6 JavaOne 2011 © 2011 – Kaazing Corporation

HTTP vs. WebSocket HTTP WebSocket Overhead 1000s of bytes (headers) 2-6 bytes/frame (typical) Latency New connection each time None: Reuses existing connection Latency (polling) Must wait for next request No waiting Latency (long polling) None, if server is holding No waiting a pending request (+ time to set up new connection) 7 JavaOne 2011 © 2011 – Kaazing Corporation

Overheard… "Reducing kilobytes of data to 2 bytes… and reducing latency from 150ms to 50ms is far more than marginal. In fact, these two factors alone are enough to make WebSocket seriously interesting to Google." Ian Hickson (Google, HTML5 Spec Lead) 8 JavaOne 2011 © 2011 – Kaazing Corporation

Using the WebSocket API Java //Create and connect new WebSocket WebSocket mySocket = new WebSocket(); // Associate listener webSocket.addWebSocketListener( new WebSocketListener() { @Override public void onMessage(WebSocketEvent event) { alert(event.getData()); } @Override public void onClose(WebSocketEvent closedEvent) {} }; mySocket.connect(new URI("ws://www.WebSocket.org")); mySocket.send("Hello world!"); 9 JavaOne 2011 © 2011 – Kaazing Corporation

WebSocket Browser SupportBrowser native support §  Chrome §  Firefox (need to turn on) §  Opera 10.7 (need to turn on) §  Safari §  Internet Explorer 9+ Beta 10 JavaOne 2011 © 2011 – Kaazing Corporation

Why JMS? l  WebSocket is a good start but doesnt offer much help to the application developer l  JMS well established standard, widely available l  Offers important features over pure WebSocket: l  Publish and subscribe (Topics) for broadcast l  Point to point (Queues) for command processing l  Transactions l  Guaranteed delivery l  Structured data 14 JavaOne 2011 © 2011 – Kaazing Corporation

Why JMS over WebSocket?Typical Current JMS Architecture Firewall J2EE Applica+on Server Web Container EJB Container SOAP over HTTP JMS Web Service EJB WEB JSP Message Broker HTTP (JMS Provider) 15 JavaOne 2011 © 2011 – Kaazing Corporation

Why JMS over WebSocket?Typical Current JMS Architecture Firewall J2EE Applica+on Server Web Container EJB Container SOAP over HTTP JMS Web Service EJB WEB JSP Message Broker HTTP (JMS Provider)New WebSocket-based Architecture Firewall JMS Over WebSocket 16 JavaOne 2011 © 2011 – Kaazing Corporation

JMS Client Library ●  Implements the JMS objects and API l  Initiate WebSocket connection l  Encode outgoing JMS messages in STOMP l  Decode and deliver incoming messages ●  Manage connections and sessions, stop and start, message listeners, reconnect ●  A single WebSocket connection suffices (full duplex, asynchronous receive) 19 JavaOne 2011 © 2011 – Kaazing Corporation

The Protocol l  STOMP l  Text-based wire encoding, so suitable for multiple client languages (Java, JavaScript, ...) l  http://stomp.codehaus.org & http://stomp.github.com! l  Wireline encoding into STOMP: l  CONNECTnNAME:namen PASS:password (once) l  Encode JMS properties as key-value pairs: SENDnprop1:valuenprop2 -  -  MESSAGEnprop1:valuenprop2 l  SUBSCRIBEndestination:/topic/stock l  BEGIN, COMMIT, ABORT 20 JavaOne 2011 © 2011 – Kaazing Corporation

JMS Client Library ●  session.createConsumer l  → SUBSCRIBE destination:xxx l  Await RECEIPT ●  producer.send l  → SEND prop1:val1... <text> l  Await RECEIPT ●  Separate thread(s): read MESSAGEs l  Route to appropriate MessageListener l  Send ACK 21 JavaOne 2011 © 2011 – Kaazing Corporation

JMS Client Library ●  Transactions l  Group message sends and Acks l  Single unit of work ●  Auto-reconnect l  For resilience to network failures l  Reissue SUBSCRIBEs ●  Other client languages: l  Javascript, Flash, .Net 22 JavaOne 2011 © 2011 – Kaazing Corporation

The Server ●  Bridge between Web and Message Broker l  Accepts WebSocket connections l  Connects to JMS provider ●  Converts incoming STOMP frames to JMS API calls ●  Routes messages from provider back to clients ●  Must manage flow control 23 JavaOne 2011 © 2011 – Kaazing Corporation

The Server l  Simplest implementation: l  Each client connection → 1 broker Connection and Session l  Each client subscription (message consumer) → 1 consumer in broker l  More scalable: l  1 connection for many clients l  Single topic subscription for many clients 24 JavaOne 2011 © 2011 – Kaazing Corporation

Portfolio Demo ●  "stock" topic for stock price updates l  MessageConsumer stockConsumer! l  MessageListener: portfolioModel.updateStock()! ●  Temporary queue for command responses l  responseQueue = session.createTemporaryQueue()! ●  "command" queue to send commands l  producer.send (replyTo=responseQueue) l  command property (get_portfolio, get_balance, buy, sell)26 JavaOne 2011 © 2011 – Kaazing Corporation

Code Examples l  Creating a connection (omitting exception handling) env.put(Context.INITIAL_CONTEXT_FACTORY, StompInitialContextFactory.class.getName()); env.put(Context.PROVIDER_URL, “ws://myhost:80/stomp.jms”); InitialContext ctx = new InitialContext(env); ConnectionFactory cf = (ConnectionFactory)ctx.lookup(“ConnectionFactory”); Connection connection = cf.createConnection(); l  Destination look up Topic stockTopic = (Topic)ctx.lookup(“/topic/stock”);27 JavaOne 2011 © 2011 – Kaazing Corporation

Code Examples l  From there its all just standard JMS API Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); MessageConsumer stockConsumer = session.createConsumer(stockTopic); // Listen for stock price changes stockConsumer.setMessageListener(new MessageListener() { @Override public void onMessage(Message message) { try { String stockData = ((TextMessage)message).getText(); portfolioModel.updateStock(new Stock(stockData)); } catch(JMSException e) { } } } connection.start(); 28 JavaOne 2011 © 2011 – Kaazing Corporation

WebSocket EmulationEmulation for browsers with no native WebSocket support: l  Kaazing WebSocket Gateway: makes WebSocket work in all browsers today: l  Internet Explorer 6, 7, 8 l  Firefox 3.6 l  And more . . . 31 JavaOne 2011 © 2011 – Kaazing Corporation

Kaazing JMS Edition l  Messages traverse firewalls and proxies l  Fast, secure communication over the Internet l  Message distribution to massive numbers of clients thanks to resource offloading (fan-out) 32 JavaOne 2011 © 2011 – Kaazing Corporation

Resource Offloading ●  Connection + Session offload (fan out) l  Reduces broker resource usage l  Minimal connections, sessions to broker ●  Java NIO (Apache Mina framework) ●  Subscription offload l  Multiplexed over shared connection, single message consumer l  Gateway tracks subscribed topics and queues from all connected clients l  Gateway handles individual client acknowledgments33 JavaOne 2011 © 2011 – Kaazing Corporation

JMS Gateway Features ●  “stomp.jms” service l  Clients speak STOMP to the service. l  Service uses vendors JMS API to talk to broker l  Connection, session and subscription offload ●  “stomp.proxy” service l  Clients speak STOMP to the service l  Service uses STOMP to talk to “stomp.jms” service running on another Gateway l  Further offload ●  Gateway clusters for High Availability35 JavaOne 2011 © 2011 – Kaazing Corporation

Using Multiple Gateways ●  Hundreds of thousands of clients or more can be supported by using a network of gateways ●  “stomp.proxy” gateways at the edge (near users) l  Route messages to central gateway running “stomp.jms” service l  Connection offloading (single connection to central gateway) ●  Most network traffic is local ●  Use gateway clusters for HA36 JavaOne 2011 © 2011 – Kaazing Corporation

Writing Applications l  JMS API is available to code running within the browser or mobile device l  Gateway provides client libraries l  Written like a Java JMS client l  Similar concepts and APIs for each client technology (JavaScript, Flash, .Net) l  Application needs to include Kaazing JMS library files (jars, .js)38 JavaOne 2011 © 2011 – Kaazing Corporation

Take-aways l  HTML5 WebSockets offers a paradigm shift for highly interactive and scalable Web applications l  High level protocols can be extended beyond the firewall all the way to Web devices: l  JMS l  XMPP l  AMQP l  Production solution with live customers available today40 JavaOne 2011 © 2011 – Kaazing Corporation

Conclusion“We’re committed to providing real-timeaccess to critical management informationacross the enterprise...Kaazing solves the industry’s fundamental issueswhich have kept yesterday’s web architecturefrom meeting these needs.” Quintin Gomez, CTO of ITRS Group, 28 Sep 1141 JavaOne 2011 © 2011 – Kaazing Corporation

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Extending JMS to Web Devices over HTML5 WebSockets - JavaOne 2011

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