This section provides more detail about what goes into each of the building blocks, the client, the server and the middleware (/) that tie...
This section provides more detail about what goes into each of the building blocks, the client, the server and the middleware (/) that ties them together.
The client building block:
This runs the client side of the application. It runs on an OS that provides a Graphical User Interface (GUI) or an Object Oriented User Interface (OOUI) and that can access distributed services, wherever they may be. The OS most often passes the responsibility to the middleware building block and lets it handle the non-local services. The client also runs a component of the Distributed System Management (DSM) element.
The server building block:
This runs the server side of the application. The server typically runs on top of some shrink-wrapped server software package. The five contending server platforms for creating the next generation of client/server applications are SQL database servers, TP Monitors, groupware servers, object servers and the web. The server side depends on the operating system to interface with the middleware building block that brings in requests for service. The server also runs a DSM component.
The middleware building block:
This runs on both the client and server sides of an application. We can break this building block into three categories – transport stacks, network operating systems (NOSs), and server specific middleware. Middleware is the nervous system of client/server infrastructure. Like the other two building blocks, the middleware also has a DSM component.
The DSM runs on every node in a client/server network. A managing workstation collects information from all its agents on the network and displays it graphically. The managing workstation can also instruct its agents to perform actions on its behalf.
Middleware does not include the software that provides the actual service, but it includes the software that is used to coordinate inter server interactions. Server to server interactions are usually client/server in nature, servers are clients to other servers however some sever to server interaction require specialized server middleware.