advantages and disadvantages

hi all.....

today i will continued the last session of my blog..

Clients characteristics:-

-Always initiates requests to servers.
- Waits for replies.
- Receives replies.
- Usually connects to a small number of servers at one time.
- Usually interacts directly with end-users using any user interface such as graphical user interface.



Server characteristics:-

- Always wait for a request from one of the clients.
- Serve clients requests then replies with requested data to the clients.
- A server may communicate with other servers in order to serve a client request.



Advantages:-

- A client-server architecture enables the roles and responsibilities of a computing system to be distributed among several independent computers.
- Greater ease of maintenance.

- All the data is stored on the servers, generally have much security controls than most clients. Servers can better control access and resources to guarantee that only those clients with the appropriate permissions may access and change data.

- Updates data are much easier to administrators than what would be possible under a P2P architecture.

- Under a P2P architecture, data updates may need to be distributed and applied to each peer in the network, which is both time-consuming and error-prone as there can be thousands or even millions of peers.

- Many advanced clients server technologies are already available which were designed to ensure security, user friendly interfaces and ease of use.



Disadvantages :-

- Networks traffic blocking is one of the problems related to the client-server model. Number of simultaneous client requests to a given server increases, the server can become overloaded.

- Contrast that to a P2P network, where its bandwidth actually increases as more nodes are added, since the P2P networks overall bandwidth can be roughly computed as the sum of the bandwidths of every node in that network.

- Compare client-server model with the P2P model, if one server fail, clients requests cannot be severd but in case of P2P networks, servers are usually distributed among many nodes. Even if one or more nodes fail, for example if a node failed to download a file the remaining nodes should still have the data needed to complete the download.


http://simple.wikipedia.org/wiki/Client-server