Computer Network Questions and Answers Part 5,

What is Client/Server?
Clients and Servers are separate logical entities that work together over a network to accomplish a task. Many systems with very different architectures that are connected together are also called Client/Server.

What is a File server?
File servers are useful for sharing files across a network. With a file server, the client passes requests for file records over nerwork to file server.

What are called Fat clients and Fat servers?
If the bulk of the application runs on the Client side, then it is Fat clients. It is used for decision support and personal software.
If the bulk of the application runs on the Server side, then it is Fat servers. It tries to minimize network interchanges by creating more abstract levels of services.

What is Remote Procedure Call (RPC)?
RPC hides the intricacies of the network by using the ordinary procedure call mechanism familiar to every programmer. A client process calls a function on a remote server and suspends itself until it gets back the results. Parameters are passed like in any ordinary procedure. The RPC, like an ordinary procedure, is synchoronous. The process that issues the call waits until it gets the results.
Under the covers, the RPC run-time software collects values for the parameters, forms a message, and sends it to the remote server. The server receives the request, unpack the parameters, calls the procedures, and sends the reply back to the client. It is a telephone-like metaphor.

What are the building blocks of Client/Server?
The client ,The server and Middleware.

What is a TP Monitor?
There is no commonly accepted definition for a TP monitor. According to Jeri Edwards’ a TP Monitor is “an OS for transaction processing”.
TP Monitor does mainly two things extremely well. They are Process management and Transaction management.
They were originally introduced to run classes of applications that could service hundreds and sometimes thousands of clients. TP Monitors provide an OS - on top of existing OS - that connects in real time these thousands of humans with a pool of shared server processes.

What are Super servers?
These are fully-loaded machines which includes multiprocessors, high-speed disk arrays for intervive I/O and fault tolerant features.

What is a Web server?
This new model of Client/Server consists of thin, protable, “universal” clients that talk to superfat servers. In the simplet form, a web server returns documents when clients ask for them by name. The clients and server communicate using an RPC-like protocol called HTTP.

What is a Database Server?
With a database server, the client passes SQL requests as messages to the database server. The results of each SQL command are returned over the network. The server uses its own processing power to find the request data instead of passing all the records back to the client and then getting it find its own data. The result is a much more efficient use of distributed processing power. It is also known as SQL engine.

What is an Object server?
With an object server, the Client/Server application is written as a set of communicating objects. Client object communicate with server objects using an Object Request Broker (ORB). The client invokes a method on a remote object. The ORB locates an instance of that object server class, invokes the requested method and returns the results to the client object. Server objects must provide support for concurrency and sharing. The ORB brings it all together.