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Get info about the Encyclopedia of Networking and Telecommunicatons, 3rd edition (2001)
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Note: Many topics at this site are reduced versions of the text in "The Encyclopedia of Networking and Telecommunications." Search results will not be as extensive as a search of the book's CD-ROM.
An application server is a server that runs programs in a network environment. The applications may be network versions of commercial, off-the-shelf software that allow multiple users to access and run the program. This avoids loading the program on each user's computer and allows central updates to take place on the server. Custom-built or off-the-shelf client/ server applications may run on application servers as well. A client/server application distributes processing between the client and the server, with the server handling file and data access and the client handling presentation and user input. A database server is also an application server, but is optimized for disk I/O (input/output) and may include attached servers that contain replicas of the data for fault tolerance.
Application servers have more recently become middleware servers. More specifically, they are "middle servers" in a three-tiered architecture (an evolution of the two-tiered client-server model). Application servers interface with databases and information systems on the back end. On the front end, application server interface with clients, usually Web server clients. The servers may perform relatively simple functions such as building Web pages on the fly with data obtained from back-end servers. The servers may also provide more sophisticated functions, such as transaction processing in electronic commerce applications.
Application servers provide a variety of functions. They serve as a central hub for running services such as message routing, object exchange, transaction processing, and data transformation. They also may support CORBA, Microsoft COM/DCOM, and Enterprise JavaBeans. Additional features include the ability to connect with a variety of back-end database services and to load balance the traffic between the servers and users. The servers are also a logical place to implement advanced sercurity services.
See the related entries for more information.
Copyright (c) 2001 Tom Sheldon and Big Sur Multimedia.