ASSIGNMENT 4

TASK 4

1.      What is a client-server?

Client server is a program relationship in which one program where client request a service or resource from another program where it is server. In the easy term, server will serve request from a client. Client will establish a connection to the server over local area network(LAN) or wide area network(WAN), such as the internet. Once the server has fulfilled the client’s request, the connection is terminated. Web browser is a client program that has requested service from a server in fact the service and resource that the server provide is the delivery of this Web page.

2.      How does it works?

The client–server model of computing is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients. Often clients and servers communicate over a computer network on separate hardware, but both client and server may reside in the same system. A server host runs one or more server programs which share their resources with clients. A client does not share any of its resources, but requests a server's content or service function. Clients therefore initiate communication sessions with servers which await incoming requests.

Examples of computer applications that use the client–server model are email ,network printing, and the World Wide Web.

3.      Why is a client server good?

The client–server characteristic describes the relationship of cooperating programs in an application. The server component provides a function or service to one or many clients, which initiate requests for such services. Whether a computer is a client, a server, or both, is determined by the nature of the application that requires the service functions. For example, a single computer can run web server and file server software at the same time to serve different data to clients making different kinds of requests. Client software can also communicate with server software within the same computer. Communication between servers, such as to synchronize data, is sometimes called inter-server or server-to-server communication

4.      What are the drawback to the client-server model.

The drawback of client server model are stated as below:

1)Congestion in Network: Too many requests from the clients may lead to congestion, which rarely takes place in P2P network. Overload can lead to breaking-down of servers. In peer-to-peer, the total bandwidth of the network increases as the number of peers increase. 
2) Client-Server architecture is not as robust as a P2P and if the server fails, the whole network goes down. Also, if you are downloading a file from server and it gets abandoned due to some error, download stops altogether. However, if there would have been peers, they would have provided the broken parts of file. 
3) Cost: It is very expensive to install and manage this type of computing.
4) You need professional IT people to maintain the servers and other technical details of network.

5.      What are the correlation the thin and thick client to this topic

Thin client-

                       

A thin client (sometimes also called a lean, zero or slim client) is a computeror a computer program that depends heavily on another computer (its server) to fulfill its computational roles. This is different from the traditional fat client, which is a computer designed to take on these roles by itself. The specific roles assumed by the server may vary, from providing data persistence (for example, for diskless nodes) to actual information processing on the client’s behalf.

Thin clients occur as components of a broader computer infrastructure, where many clients share their computations with the same server. As such, thin client infrastructures can be viewed as providing some computing service via several user interfaces. This is desirable in contexts where individual fat clients have much more functionality or power than the infrastructure requires.

Thick client-

In contrast, a thick client (also called a fat client) is one that will perform the bulk of the processing  in client/server applications. With thick clients, there is no need for continuous server communications as it is mainly communicating archival storage information to the server. As in the case of a thin client, the term is often used to refer to software, but again is also used to describe the networked computer itself. If your applications require multimedia components or that are bandwidth intensive, you'll also want to consider going with thick clients. One of the biggest advantages of thick clients rests in the nature of some operating systems and software being unable to run on thin clients. Thick clients can handle these as it has its own resources.