Web Applications

Constantinos Phanouriou

Imagine a computing environment where your wordprocessor software does not reside on your PC's hard disk. Instead, the executable code sits on a remote server. That server might be owned by your corporation or government agency, and might only be a short walk from your desk. Or the server could be owned by the developer of the wordprocessor software and might be physically located hundreds, even thousands of miles away. Imagine that the wordprocessor works equally well on your Intel-based PC or your Macintosh, is always the newest version, and costs the same regardless of the operating system. In a sense the network is the operating system, and your enterprise network is the part of the World-Wide-Web that's behind your firewall.

Vision propounded by Scott MacNealy, CEO of Sun Microsystems

The Web Environment

The Web, while providing significant benefits, introduces new technical challenges with respect to scalability, and management of session, state, transactions and security. These challenges are as follows:

• Web applications can face unpredictable and potentially enormously peak loads. This demands a high performance architecture that is extremely scalable.
• The Web is a stateless environment, in which the client and server are loosely coupled. Applications must keep state information from one page to another if they are to avoid requiring users to re-enter information such as user name and password from page to page.
• The Web presents new security issues for companies wishing to make internal databases accessible to external users. User authorization and authentication are more challenging in the Web environment because of the large number of potential users.
• The Web is changing rapidly and standards are still evolving.

Advantages

• Platform independent
• Always get the latest version
• No setup time for new applications
• Better monitoring of usage
• Remote user evaluation
• Reduce cost for client hardware
• Distribute load on mulitple machines transparently
• Reduces deployment costs and overcomes performance limitations of client/server applications
• Enables companies to provide new services and reach new customers

Tools for generating Web Application

• WebObjects
• NetDynamics
• Javamatic

• Leveraging their investments in existing applications and data
• Integrating with complementary technologies, web-based and others
• Deploying robust, dynamic web solutions in a timely fashion

Future

• Proprietary GUI interfaces replaced by Web interfaces
• Web browsers that manage intranets, hubs, routers, printers, workstations, PCs and numerous other networked devices
• Web-based systems that leverage existing application resources and data stores