Internet and Technology

The Rich Internet Application reflects the gradual but inevitable transition of Web applications from the simple thin-client model of a traditional Web browser to a richer distributed-function model that behaves more like the desktop in a client/server model. Today these richer user experiences are being implemented with technologies such as Flash, Ajax, and Java, using standard Internet and Web protocols to take web performance to the next level.

Because RIAs are significantly more complex than traditional browserbased Web applications, they pose new design, measurement, and management challenges. To implement RIAs successfully, enterprises must re-evaluate their approaches to service level management (SLM) and consider several new challenges including:

• how to measure an RIA user’s experience of response time;

• how to break apart into meaningful components the time it takes to complete a business transaction;

• how to monitor the performance of a production application, and alert when its behavior is abnormal;

• how to change development and systems management processes to ensure successful implementations.

The Evolution of the Web Page

The Web was originally intended to help researchers share documents as static pages of linked text formatted in HTML. From there, Web pages quickly evolved to include complex structures of text and graphics, with plug-in programs to play audio and video files or to stream multimedia content. Web developers supplement the basic browser function of rendering HTML by invoking code (scripts) on the user’s computer (the client). These scripts can create interface elements such as rollover effects, custom pull-down menus, and other navigation aids. These script capabilities, while they enhance a user’s interaction with individual Web pages, do not change the fundamental model in which application logic runs on the server and executes between Web pages after the user clicks. This behavior is said to be synchronous, that is, after each click the user waits while the server handles the input and the browser downloads a response page.

From Web Pages to Rich Internet Applications

In a traditional Web application, all processing is done on the server, and a new Web page is downloaded each time the user clicks. Recently, Web developers have been evolving a new model—the Rich Internet Application (RIA), which is “a cross between Web applications and traditional desktop applications, transferring some of the processing to a Web client and keeping (some of) the processing on the application server”.

As with most computing advances, several technologies are vying for acceptance as the de facto standard way to build RIAs. The main contenders are Adobe’s Flash suite, Java applets, and the collection of Web technologies known as Ajax, a term coined in 2005 by Adaptive Path’s Jesse James Garrett. Garrett explained that Ajax is “really several technologies, each flourishing in its own right, coming together in powerful new ways.

Ajax incorporates:

• standards-based presentation using XHTML and CSS;

• dynamic display and interaction using the Document Object Model;

• data interchange and manipulation using XML and XSLT;

• asynchronous data retrieval using XMLHttpRequest;

• JavaScript binding everything together.”

In practice, we can think of Ajax as a development concept or approach, as various technologies can substitute for those specified by Garrett. Some developers even claim that “Flash is Ajax”, and others advocate using them together. viz., AFLAX. All having their hand in website performance complicating any analysis of RIA technology is the massive amount of hype surrounding both “Web 2.0” (a superset of RIA) and Ajax (a subset of RIA).