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EMBEDDED SYSTEMS n-FORMATION

Implementing an n-Tiered Client-Server
by Ian Agranat

Start ý Database ý n-Tiered Implementation ý Sources and PDF

As the structure and relationships of information in the corporate environment become more complex, it is becoming increasingly more important to design systems that support access to the ever-growing diversity of resources. People now have significant computing power available to them on their desktops.

Technological advances have enabled professionals of all disciplines to use systems developed for their particular needs, from standard PCs running Windows to high-end graphics workstations running Unix. These powerful systems, combinations of sophisticated hardware and software, emphasize the importance of information in todayýs corporate environment. In such an environment, the goal is to provide individuals with easy access to the necessary set of resources and information.

With the evolution of the worldwide web, corporations are taking advantage of web technology to provide distributed access to enterprise data. Corporate networks connect a wide range of resources, including desktop notebooks, PCs, workstations, as well as database and corporate-application systems.

Web browsers on desktop systems provide access to information on internal corporate networks and the Internet. This flexibility gives individuals significant resources to accomplish a wide variety of tasks.

Web-based architecture has evolved out of the generic client-server architecture. This architecture provides a model for network applications that is flexible, powerful, and takes advantage of Internet technology.

The model is the basis for the significant increase in the number of web applications, providing access to massive online databases through online magazines, newspapers, catalogs, and other information-related applications. The structure for this architecture is referred to as n-tiered, which is loosely defined as the separation of the user interface, the application, and the database components.

Embedded systems are becoming part of the critical path for web business. Therefore, the corporate network topography must include these resources. To accomplish this, the solution must use the existing, available technology of choice and apply the n-tiered architecture to an embedded-system environment. The task presents significant challenges, but the solution provides easy integration of embedded systems into the corporate network environment.

n-TIERED ARCHITECTURE

The software applications available for common corporate-environment systems are sophisticated and powerful, complementing the potential inherent in evolving Internet/Intranet technologies.

The technology of distributed computing has evolved to the point that end-user systems now support a standardized user-interface that provides remote access to data from a wide variety of resources. Web browsers, standardized on the hypertext markup language (HTML) and the hypertext transport protocol (HTTP), provide a graphical user interface for locating and displaying data distributed across the network.

As shown in Figure 1, the client tier encapsulates user interface functions. The application tier supports data processing associated with client requests, and provides the connection between the client tier and the database tier. And last, the database tier provides data storage.

Figure 1ýThe n-tiered architecture defines the functional separation of user interface and data in general terms, dividing a network-based application into client, application, and database tiers.

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