Cloud Computing and SOA Convergence in Your Enterprise: A Step ...

190 Chapter 10 Defining Candidate Data, Services, and Processes for the Clouds
RIA, SOA, and Cloud Computing
A rich client, or an RIA, is a small piece of software that runs on the client to leverage
and aggregate back-end services, allowing them to appear as a single, unified,
native application. A new interface is needed as both developers and end
users begin to understand the limitations of traditional Web-based interfaces,
which are the current interfaces of choice for many distributed applications.
However, RIA is everywhere today. It is the primary interface leveraged by
Google and many other on-demand office automation systems. By leveraging
RIAs, it can offer a dynamic and reactive user interface that appears to be
native. No longer must we deal with the traditional browser interfaces where
Web pages are constantly being sent to and from the server and the user deals
more often with an hourglass than a live application.
Web interfaces in wide use within enterprises were never really designed
to support true interactive applications. The Web was built as a content provider,
serving up documents and not dynamic application services. If you
think about it, you are reloading document after document to simulate an
interactive application and always have to go to the back-end Web server to
request new content. Very little occurs at the client.
As the Web became popular and we looked to support business applications
within the enterprise using the Web interface, we began to create new
mechanisms to deliver dynamic content, including dynamic HTTP/HTML
pushers (e.g., Common Gateway Interface, Apache Server Application Programming
Interface, Internet Server Application Programming Interface) and
new browsers that supported complex dynamic behavior. We are at such an
advanced state today that entire enterprises run most of their relevant business
applications using Web interfaces.
However, with the advent of software-as-a-service (aka, application-as-aservice),
the Web 2.0, and now cloud computing, there is a need to leverage
dynamic behavior within the interfaces. Traditional browsers fall way short.
Their get/push model for driving interfaces is not as well suited to support
dynamic applications, which are, at their essence, remote functions better
suited for more visually rich types of interfaces, such as more traditional GUI
client/server interfaces that were popular a few years ago.
RIAs are not a revolution but an evolution of technology, including Asynchronous
JavaScript and XML (AJAX). Today we look to leverage dynamic
behavior and deliver that experience directly to the end user, aggregating