Client-Server models

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Types of Client Server Models


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Agenda

Introduction

Logical Layers

Presentation layer

Application layer

Data layer

Client / Server Models

Distributed presentation

Remote presentation

Distributed logic

Remote data

Distributed data


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Introduction

The Client-Server model is the most prevalent

model for distributed computing protocols.

It is the basis of all distributed computing

paradigms at a higher level of abstraction.

It is service-oriented, and employs a request-

response protocol.


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Introduction

ClientA client is an individual user's computer or a user

application that does a certain amount of

processing on its own. It also sends and receives

requests to and from one or more servers for otherprocessing and/or data.

Server

A server consists of one or more computers thatreceive and process requests from one or more

client machines. A server is typically designed with

some redundancy in power, network, computing

and file storage.


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The Client / Server Model

A server process, running on a server host,provides access to a service.

A client process, running on a client host,

accesses the service via the serverprocess.

The interaction of the process proceeds

according to a protocol.An application based on the client-server

model is a client-server application.


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Logical Layers

In general, application software can be

divided into 3 logical layers:

Presentation layer

Application layer

Data layer


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Presentation Layer

Presentation layer is responsible fordisplaying the information and interacting with

the user .

It must make the information available in a

suitable form to the user and must respond

appropriately to input from the user.


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Application Layer

Application layer processes commands,makes logical decisions, performs

calculations, and coordinates the application

It also moves and processes data between

the presentation layer and data layer


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Data Layer

Data layer refers to the management ofunderlying databases

It is responsible for storing and retrieving thedata according to the requirements of the

application layer.


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Client Server Models

Distributed presentation

Remote presentation

Distributed logic

Remote data

Distributed data


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Distributed Presentation

Only presentation management functionshared between client and server everything

else remains on the server

Dummy terminals GUI placed in front of existing character

based interface, E.g. Windows 3.1.


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Presentation

Layer

Application Layer Data Layer

Client Side Server Side


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Remote presentation

Presentation manager entirely on client

Application layer, data layer and data

manager on server

Web applications where clients are Webbrowsers, Unix through Putty


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Presentation

Layer




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Distributed Logic

Application is split into presentation layer anddata layer component

All presentation management activities on

clientAll data management activities on the server


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Presentation

Layer




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Presentation

Layer


Client Side Server

Side


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Distributed Data

Portions of the database reside on client

Portions of the database reside on server

DBMS manages communication involved

Limited implementation of full-fledged DDBMSfunctionality


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Presentation

Layer


Client Side Server

Side


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THANK YOU

Documents

Client-Server models