An Introduction to Client Server Computing

1 This pageintentionally leftblankCopyright 2009, New Age International (P) Ltd., PublishersPublished by New Age International (P) Ltd., PublishersAll rights part of this ebook may be reproduced in any form, by photostat, microfilm,xerography, or any other means, or incorporated into any information retrievalsystem, electronic or mechanical, without the written permission of the inquiries should be emailed to FOR ONE WORLDNEW AGE INTERNATIONAL (P) LIMITED, PUBLISHERS4835/24, Ansari Road, Daryaganj, New Delhi - 110002 Visit us at (13) : 978-81-224-2861-2In recent years there have been significant advances in the development of high performancepersonal computer and networks.

2 There is now an identifiable trend in industry towarddownsizing that is replacing expensive mainframe computers with more cost-effectivenetworks of personal computer that achieve the same or even better results. This trendhas given rise to the architecture of the Client / Server term Client / Server was first used in the 1980s in reference to personal computerson a network. The actual Client / Server model started gaining acceptance in the late term Client / Server is used to describe a Computing model for the development ofcomputerized systems. This model is based on the distribution of functions between twotypes of independent and autonomous entities: Server and Client .

3 A Client is any processthat request specific services from Server processes. A Server is process that providesrequested services for Clients. Or in other words, we can say A Client is defined as arequester of services and a Server is defined as the provider of services. A single machinecan be both a Client and a Server depending on the software configuration. Client andServer processes can reside in same computer or in different computers linked by a general, Client / Server is a system . It is not just hardware or software. It is notnecessarily a program that comes in a box to be installed onto your computer s hard is a conglomeration of computer equipment, infrastructure, and softwareprograms working together to accomplish Computing tasks which enable their users to bemore efficient and productive.

4 Client / Server applications can be distinguished by the natureof the service or type of solutions they provide. Client / Server Computing is new technologythat yields solutions to many data management problems faced by modern Computing : An Introduction , features objective evaluations and details ofClient/ Server development tools, used operating system , database management system andits mechanism in respect of Client / Server Computing and network components used inorder to build effective Client / Server but not the least, this work is primarily a joint work with a number of fellowteacher who have worked with us.

5 My parents, wife Meera, and our children, Akankshaand Harsh. I am particularly grateful to Dr. A. P. Singh, Principal, Udai Pratap Inter College,Varanasi; Dr. D. S. Yadav, Sr. Lecturer, Department of Computer Science and Engineering,IET, Lucknow; Dr. A. K. Naiyak, Director IIBM, Patna, former President of IT and ComputerScience Section of Indian Science Congress Association; Prof. A. K. Agrawal, Professorand Ex-Head of Department, Computer Science and Engineering IT, BHU, Varanasi andMr. Manish Kumar Singh, Sr. Lecturer, Rajarshi School of Management and Technologyfor providing the necessary help to finish this and comments about the book are most welcome and can be sent by e-mailto Chandra YadavPrefaceviPrefacev1 INTRODUCTION1 What is Client / Server Computing ?

6 A Server for Every : Fat or : Stateless or and Client / Server Integration with distributed to Client / Server Classification of Client / Server Client / Server Client / Server Processing with Message with an Application with an ORB Architecture and Client / Server Clients/ Server Advantages and Misconceptions About Client / Server Computing22 Exercise 123 ContentsContentsviii2 DRIVING FORCES BEHIND Client / Server COMPUTING25 Driving Technology Development of Client / Server Development Client / Server Client / Server Client / Server Security to

7 Server Organizational Improving Performance of Client / Server Single system Downsizing and Client / Server Methodology39 Exercise 2403 ARCHITECTURES OF Client / Server SYSTEMS41 between the Client / Server principles behind Client / Server Client Server Complexity of Communications Middleware Architecture for Business Information Three-Layer General Existing Client / Server Environment60 Exercise 362 Contentsix4 Client / Server AND DATABASES63 Client / Server in Respect of Client / Server Client / Server Database Client / Server Database Database Middleware Access to Multiple distributed Client / Server Database distributed Web/database system for Client / Server Web/database Vs Traditional Database77 Exercise 4785 Client / Server APPLICATION COMPONENTS79 Technologies for Client / Server Service of a Client / Server Categories of Client / Server Client Inter Process Remote Window Dynamic Data Exchange (DDE) Object Linking and Embedding (OLE) Common Object Request Broker Architecture (CORBA)

8 Print/Fax Database Server Client / Server Application: Role and Mechanism of Client / Server Application: Layered Design Interface in Three Layers103 Exercise 5104 Contentsx6 system DEVELOPMENT105 Hardware PC Level Processing Protection Specific Software Network Communication Interface Technology Interface Token SMTP136 Exercise 61377 TRAINING AND TESTING139 Technology Behind Training Training (OTJ) Groups and Event Web-based Management Systems (LMS) Performance Support Systems (EPSS)143 To Whom Training is Required?

9 Administrator Administrator and Technical Staff Applications Administration and Training Impact of Technology on Administration and Client / Server Testing Testing Testing of Testing Client / Server Application153 Exercise 71568 Client / Server TECHNOLOGY AND WEB SERVICES157 What are Web Services? Web Services Web Server Web Web Server Role of Java for Client / Server on Web Services and Client / Server /Browser Server Client / Server Technology and Web Balanced Computing and the Server s Changing Role171 Exercise 81729 FUTURE OF THE Client / Server COMPUTING173 Technology of the Next Development and Enabling Expert Client / Server Computing and the Is the Intranet Killing Client / Server ?

10 Future Transformational and User Technology: Data Interchange192 Exercise 9193 References195 197 Index199 WHAT IS Client / Server Computing ?According to MIS terminology, Client / Server Computing is new technology that yieldssolutions to many data management problems faced by modern organizations. The termClient/ Server is used to describe a Computing model for the development of computerizedsystems. This model is based on distribution of functions between two types of independentand autonomous processes: Server and Client . A Client is any process that requests specificservices from the Server process.