Real-time Web

Behind the idea of the Real-time Web is the motivation of the Web being situation-aware and in real-time. This idea was developed as a grand challenge 1 for the field of event processing. The purpose of this challenge is "to identify a single, though broad challenge that impacts society and at the same time measures the progress of research" 1. The challenge is to create a decentralized, global, Internet-like infrastructure, built upon widely-accepted open standards 1.

There are a number of terms (synonyms) given for a Web which is situation-aware. Examples are Real-time Web 2, Web of Events 3, Active Web 4, Reactive Web5 and Event Processing Fabric 1.

They have in common that data must be exchanged quickly after it is created. Moreover, Fromm 2 states that the Real-time Web (i) is a new form of communication which (ii) creates a new body of content, (iii) is real-time, (iv) is public and has an explicit social graph associated with it and (v) carries an implicit model of federation. Indeed, this work makes a contribution to the Real-time Web by enabling a new form of communication using event processing, working in real-time and supporting federated data-creation and consumption.

There are many technological developments on the Web today which can create a lot of events and thus support a Real-time Web. Such events are delivered in a push fashion as opposed to the traditional client–server Web of request and response. For one, there is the W3C Web Notification Working Group which is working on push notifications to actively notify running Web applications. Additionally, HTML5 defines two techniques to facilitate communication initiated by the server. These techniques are Server-Sent Events and WebSockets. They operate at different layers of the protocol stack to achieve push delivery to Web clients. Another approach to push-data on the Web is the Google PubSubHubbub protocol to enable mainly server-to-server notifications. It is designed to avoid inefficient polling of news feeds in Atom or RSS. Lastly, the Facebook Graph API provides an application-specific way to subscribe to Facebook real-time updates from changes to connected people’s profiles.

  1. Chandy, K. M.; Etzion, O. & von Ammon, R. (Eds.) 10201 Executive Summary and Manifesto — Event Processing Event Processing, Schloss Dagstuhl – Leibniz-Zentrum fuer Informatik, Germany, 2011 
  2. Fromm, K. The Real-Time Web: A Primer, 2009 
  3. Jain, R. Toward EventWeb IEEE Distributed Systems Online, IEEE Computer Society, 2007, 8 
  4. Ostrowski, K.; Birman, K. & Dolev, D. Live Distributed Objects: Enabling the Active Web IEEE Internet Computing, IEEE Educational Activities Department, 2007, 11, 72-78 
  5. Bry, F. & Eckert, M. Twelve theses on reactive rules for the web Proceedings of the Workshop on Reactivity on the Web, Munich, Germany, Springer, 2006