Welcome!

SOA & WOA Authors: Bernard Golden, Elizabeth White, Carmen Gonzalez, Ivan Antsipau, Paul Speciale

Related Topics: Web 2.0

Web 2.0: Article

Is Web 2.0 Possible with Existing Open Source Technologies?

AJAX Pushed

If you Google "AJAX Web 2.0" you'll get over eight million hits, but what technologies will you find in that mix that can truly deliver on the promises of Web 2.0 today? While there's no single definition of Web 2.0, at its heart lays the Internet acting as a platform for social networks, where information can be created and shared in a community of interest. Rich Internet Applications (RIAs) relate to Web 2.0 concepts only in that they enhance the platform by providing a more effective user interface. AJAX relates to Web 2.0 only in that it provides a lightweight approach for developing RIAs that execute through a single ubiquitous interface, the Web browser.

An examination of the interaction models for existing social networking platforms like wikis and blogs reveals that they lack the instantaneous nature of true human interaction. This is an artifact of the synchronous Web model that must be overcome when we consider next-generation platforms envisioned in the Web 2.0 spectrum. Internet-based chat is the most basic example of the near-instantaneous interaction that Web 2.0 demands, but even delivering these basic capabilities in a scalable, lightweight, browser-based mechanism is beyond the scope of most AJAX technologies. In fact, if you sift through those eight million Google hits, you'll find only a handful of open source technologies that address the problems associated with pushing content asynchronously to the user through standard browser mechanisms. We'll provide an overview of those technologies later, but first some basics.

The Basics of Web-based Push
Industry has not standardized on a mechanism or a name for asynchronous data push to the browser. In the AJAX realm the technique goes by a variety of names including AJAX Push, Comet, and Reverse AJAX, but regardless of what you call it, the various approaches share a common characteristic. The only lightweight communication mechanism available to the browser is the HTTP protocol, but HTTP only facilitates standard request/response communication initiated from the browser to the server. To deliver responses asynchronously, it's necessary to invert the HTTP protocol by holding an open request at the server, and fulfilling that request when an update is available. The differences between standard AJAX request processing and the inverted mechanism required for push are illustrated in Figure 1.

To support asynchronous push we need to hold a browser connection open in anticipation of a server-based event that will result in presentation changes in the browser. Intuition suggests that there are issues with this approach and in this case intuition serves us well, since we face connection-related problems at both the browser and the server.

Browser Connection Limit
One of the main difficulties faced by asynchronous Web techniques is caused by the typical browser "two-connection limit." To reduce server load, the HTTP specification recommends that user agents establish at most two connections per server, but asynchronous techniques consume one of these connections as a notification channel. Considering the case where multiple browser windows are open to the same Web page, if each window attempts to establish its own connection, we quickly saturate the available connections. To work within these limitations, a single connection must be shared, but the scripting environments of distinct browser windows are isolated for security reasons, making it difficult to coordinate a shared connection. One technique that can be applied is to make use of a shared HTTP cookie, which is associated with all HTTP interaction with a given server. The cookie is shared across windows and, by manipulation through JavaScript, can be used for cross-window communication.

The problem is amplified in portal environments because legacy portal engines don't support the necessary asynchronous communication path. For push to work in multiple portlets it's not only necessary to share the browser connection, but a single shared server connection is required to marshal asynchronous responses. If portlets are deployed from multiple WARs, there's an additional complication in that the sharing mechanism must coordinate between multiple Web applications and will require some IPC mechanism to do so.

More Stories By Ted Goddard

Ted Goddard is the senior architect of the ICEfaces AJAX framework. Following a Ph.D. in mathematics, he proceeded with postdoctoral research in component and Web-based collaborative technologies. He currently participates in the JavaServer Faces and Servlet expert groups.

More Stories By Steve Maryka

Stephen Maryka is CTO at ICEsoft Technologies Inc., and leads the ICEfaces open source project. He has been involved in Java-based AJAX techniques since 2003 - a time before the term "AJAX" was even coined. Prior to joining ICEsoft, Steve was co-founder of AudeSi Technologies where he served as VP of Technology and led Java product development for Internet appliances. After AudeSi was acquired by Wind River Systems in 2000, he served as a principle technologist there until joining ICEsoft.

Comments (2)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


@ThingsExpo Stories
Samsung VP Jacopo Lenzi, who headed the company's recent SmartThings acquisition under the auspices of Samsung's Open Innovaction Center (OIC), answered a few questions we had about the deal. This interview was in conjunction with our interview with SmartThings CEO Alex Hawkinson. IoT Journal: SmartThings was developed in an open, standards-agnostic platform, and will now be part of Samsung's Open Innovation Center. Can you elaborate on your commitment to keep the platform open? Jacopo Lenzi: Samsung recognizes that true, accelerated innovation cannot be driven from one source, but requires a...
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at Internet of @ThingsExpo, James Kirkland, Chief Architect for the Internet of Things and Intelligent Systems at Red Hat, will describe how to revoluti...
The Internet of Things will greatly expand the opportunities for data collection and new business models driven off of that data. In her session at Internet of @ThingsExpo, Esmeralda Swartz, CMO of MetraTech, will discuss how for this to be effective you not only need to have infrastructure and operational models capable of utilizing this new phenomenon, but increasingly service providers will need to convince a skeptical public to participate. Get ready to show them the money! Speaker Bio: Esmeralda Swartz, CMO of MetraTech, has spent 16 years as a marketing, product management, and busin...
SYS-CON Events announced today that Red Hat, the world's leading provider of open source solutions, will exhibit at Internet of @ThingsExpo, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Red Hat is the world's leading provider of open source software solutions, using a community-powered approach to reliable and high-performing cloud, Linux, middleware, storage and virtualization technologies. Red Hat also offers award-winning support, training, and consulting services. As the connective hub in a global network of enterprises, partners, a...
P2P RTC will impact the landscape of communications, shifting from traditional telephony style communications models to OTT (Over-The-Top) cloud assisted & PaaS (Platform as a Service) communication services. The P2P shift will impact many areas of our lives, from mobile communication, human interactive web services, RTC and telephony infrastructure, user federation, security and privacy implications, business costs, and scalability. In his session at Internet of @ThingsExpo, Robin Raymond, Chief Architect at Hookflash Inc., will walk through the shifting landscape of traditional telephone a...
BSQUARE is a global leader of embedded software solutions. We enable smart connected systems at the device level and beyond that millions use every day and provide actionable data solutions for the growing Internet of Things (IoT) market. We empower our world-class customers with our products, services and solutions to achieve innovation and success. For more information, visit www.bsquare.com.
SYS-CON Events announced today that Matrix.org has been named “Silver Sponsor” of Internet of @ThingsExpo, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Matrix is an ambitious new open standard for open, distributed, real-time communication over IP. It defines a new approach for interoperable Instant Messaging and VoIP based on pragmatic HTTP APIs and WebRTC, and provides open source reference implementations to showcase and bootstrap the new standard. Our focus is on simplicity, security, and supporting the fullest feature set.
How do APIs and IoT relate? The answer is not as simple as merely adding an API on top of a dumb device, but rather about understanding the architectural patterns for implementing an IoT fabric. There are typically two or three trends: Exposing the device to a management framework Exposing that management framework to a business centric logic • Exposing that business layer and data to end users. This last trend is the IoT stack, which involves a new shift in the separation of what stuff happens, where data lives and where the interface lies. For instance, it’s a mix of architectural style...
SYS-CON Events announced today that SOA Software, an API management leader, will exhibit at SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. SOA Software is a leading provider of API Management and SOA Governance products that equip business to deliver APIs and SOA together to drive their company to meet its business strategy quickly and effectively. SOA Software’s technology helps businesses to accelerate their digital channels with APIs, drive partner adoption, monetize their assets, and achieve a...
From a software development perspective IoT is about programming "things," about connecting them with each other or integrating them with existing applications. In his session at @ThingsExpo, Yakov Fain, co-founder of Farata Systems and SuranceBay, will show you how small IoT-enabled devices from multiple manufacturers can be integrated into the workflow of an enterprise application. This is a practical demo of building a framework and components in HTML/Java/Mobile technologies to serve as a platform that can integrate new devices as they become available on the market.
SYS-CON Events announced today that Utimaco will exhibit at SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Utimaco is a leading manufacturer of hardware based security solutions that provide the root of trust to keep cryptographic keys safe, secure critical digital infrastructures and protect high value data assets. Only Utimaco delivers a general-purpose hardware security module (HSM) as a customizable platform to easily integrate into existing software solutions, embed business logic and build s...
Connected devices are changing the way we go about our everyday life, from wearables to driverless cars, to smart grids and entire industries revolutionizing business opportunities through smart objects, capable of two-way communication. But what happens when objects are given an IP-address, and we rely on that connection, sometimes with our lives? How do we secure those vast data infrastructures and safe-keep the privacy of sensitive information? This session will outline how each and every connected device can uphold a core root of trust via a unique cryptographic signature – a “bir...
Internet of @ThingsExpo Silicon Valley announced on Thursday its first 12 all-star speakers and sessions for its upcoming event, which will take place November 4-6, 2014, at the Santa Clara Convention Center in California. @ThingsExpo, the first and largest IoT event in the world, debuted at the Javits Center in New York City in June 10-12, 2014 with over 6,000 delegates attending the conference. Among the first 12 announced world class speakers, IBM will present two highly popular IoT sessions, which will take place November 4-6, 2014 at the Santa Clara Convention Center in Santa Clara, Calif...
Almost everyone sees the potential of Internet of Things but how can businesses truly unlock that potential. The key will be in the ability to discover business insight in the midst of an ocean of Big Data generated from billions of embedded devices via Systems of Discover. Businesses will also need to ensure that they can sustain that insight by leveraging the cloud for global reach, scale and elasticity.
WebRTC defines no default signaling protocol, causing fragmentation between WebRTC silos. SIP and XMPP provide possibilities, but come with considerable complexity and are not designed for use in a web environment. In his session at Internet of @ThingsExpo, Matthew Hodgson, technical co-founder of the Matrix.org, will discuss how Matrix is a new non-profit Open Source Project that defines both a new HTTP-based standard for VoIP & IM signaling and provides reference implementations.

SUNNYVALE, Calif., Oct. 20, 2014 /PRNewswire/ -- Spansion Inc. (NYSE: CODE), a global leader in embedded systems, today added 96 new products to the Spansion® FM4 Family of flexible microcontrollers (MCUs). Based on the ARM® Cortex®-M4F core, the new MCUs boast a 200 MHz operating frequency and support a diverse set of on-chip peripherals for enhanced human machine interfaces (HMIs) and machine-to-machine (M2M) communications. The rich set of periphera...

SYS-CON Events announced today that Aria Systems, the recurring revenue expert, has been named "Bronze Sponsor" of SYS-CON's 15th International Cloud Expo®, which will take place on November 4-6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Aria Systems helps leading businesses connect their customers with the products and services they love. Industry leaders like Pitney Bowes, Experian, AAA NCNU, VMware, HootSuite and many others choose Aria to power their recurring revenue business and deliver exceptional experiences to their customers.
The Internet of Things (IoT) is going to require a new way of thinking and of developing software for speed, security and innovation. This requires IT leaders to balance business as usual while anticipating for the next market and technology trends. Cloud provides the right IT asset portfolio to help today’s IT leaders manage the old and prepare for the new. Today the cloud conversation is evolving from private and public to hybrid. This session will provide use cases and insights to reinforce the value of the network in helping organizations to maximize their company’s cloud experience.
The Internet of Things (IoT) is making everything it touches smarter – smart devices, smart cars and smart cities. And lucky us, we’re just beginning to reap the benefits as we work toward a networked society. However, this technology-driven innovation is impacting more than just individuals. The IoT has an environmental impact as well, which brings us to the theme of this month’s #IoTuesday Twitter chat. The ability to remove inefficiencies through connected objects is driving change throughout every sector, including waste management. BigBelly Solar, located just outside of Boston, is trans...
SYS-CON Events announced today that Matrix.org has been named “Silver Sponsor” of Internet of @ThingsExpo, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Matrix is an ambitious new open standard for open, distributed, real-time communication over IP. It defines a new approach for interoperable Instant Messaging and VoIP based on pragmatic HTTP APIs and WebRTC, and provides open source reference implementations to showcase and bootstrap the new standard. Our focus is on simplicity, security, and supporting the fullest feature set.