Inroduction to Client Server Computer- TCA8C23

7/31/2019 Inroduction to Client Server Computer- TCA8C23

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INTRODUCTION TO CLIENT SERVER COMPUTING

UNIT I

Introduction the business opportunitydriving forces in the 1990 s Major issues

of the 1990- client /server computing.

UNIT II

Advantages of client /server computingtechnology revolution

Connectivity ways to improve performancereduce network traffic- faster deliverysystems.

UNIT III

Components of client /server applications the client role of the client clientservicesrequest of services.

UNIT IV

Components of client /server applications- the server role of the serversever

functionality network operating system server operating system.

UNIT V

Client /server systems developmentsoftware factors of driving demandneedfor improve technology- need for platform migration client /server system development

methodologyarchitecture definitionsystem development envirommentCASE-

object oriented programming.

TEXT : 1. Client / server computing ,Patrick N.SMITH ,STEVEN L.GUENGERICH,

REF:1. Client /server computing Dawna Travis Dewire,


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The Business opportunity

We are in the midst of fundamental change in both technology and its

application. A business opportunity consists of four integrated elements all of which areto be present within the same timeframe (window of opportunity) and most often withinthe same domain or geographical location, before it can be claimed as a business

opportunity. These four elements are:

A need

The means to fulfill the need

A method to apply the means to fulfill the need and;A method to benefit

With anyone of the elements missing, a business opportunity may be developed, by

finding the missing element. The more unique the combination of the elements, the moreunique the business opportunity. The more control an institution (or individual) has over

the elements, the better they are positioned to exploit the opportunity and become a nichemarket leader.

Opportunities are available to organizations and people who are ready and able tocompete in the global market Organizations are aggressively downsizing even as they try

to expand change.

Reengineering the business process to provide information and decision making

management improves response and customer service.

Key factors in organizational philosophy, policies and practices.

Business process reengineering

Business process reengineering is one approach for redesigning the way work is done tobetter support the organization's mission and reduce costs. Reengineering starts with a

high-level assessment of the organization's mission, strategic goals, and customer needs.


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Globalization

Name for the process of increasing the connectivity and interdependence of the world's

market and businesses. This process has speeded up dramatically in the last two decadesas technological advances make it easier for people to travel, communicate, and do

business internationally.

Operational systems

The information systems organizations justify their cost. There is question if the existing

investments are return or not? To the companies.

Market driven

Market the product is very flexible. Buyers have more options and more demanding.Technology must satisfy the demand.

Downsized organizational structure

Quality and flexibility require decisions to be made by made by individuals who are in

touch with the customer. Many organizations are eliminating layers of middle

management. Technology must provide the necessary information and support to this

new structure.

Enterprise network management

If a business if run from its distributed locations the technology supporting these units

must be as reliable as the existing central systems

Information and technology
http://www.businessdictionary.com/definition/process.htmlhttp://www.businessdictionary.com/definition/connectivity.htmlhttp://www.businessdictionary.com/definition/connectivity.htmlhttp://www.businessdictionary.com/definition/process.html


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Information is very important to communicate. we can use technology today to provideSingle system image to provide information.

Cost Competitive

Competion is driving innovation.Organization use architectures that take advantage of

cost effective offferings as new offer.

Increasing power and capacity of workstations.

Desktop workstations provide the power and capacity to create solutions to real business

problems.

Growing importance of workgroup coputing

Access information and work collectively.

Decision are made in the work place not in head office

Expanded network access

Computer networking is a large and technically very complex topic upon which a

great deal of online information is widely available. The scope of this section is

therefore constrained to a largely non-technical overview of the practicalities

involved in connecting computers together to form a local area network (LAN) or a

personal area network (PAN) using the most commonly available wired and wireless

technologies. Connecting a computer to the Internet is covered separately in the

internet pages, whilst networking-related security issues receive attention in the

security pages.

OPEN SYSTEMS

Open system, a system where matter or energy can flow into and/or out of the

system, in contrast to a closed system, where energy can enter or leave but matter

may notOpen system, in management science system that is capable of self-maintenance

on the basis of throughput of resources from the environment

Client server computing

To truly understand how much of the Internet operates, including the Web, it is important

to understand the concept of client/server computing. The client/server model is a form ofdistributed computing where one program (the client) communicates with another

program (the server) for the purpose of exchanging information.


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OLTP

Online transaction processing, or OLTP, refers to a class of systems that facilitate and

manage transaction-oriented applications, typically for data entry and retrieval transaction

proceesing. The term is somewhat ambiguous; some understand a "transaction" in the

context of computer or database transaction.OLTP has also been used to refer toprocessing in which the system responds immediately to user requests. An automatic

teller machine (ATM) for a bank is an example of a commercial transaction processingapplication.

EIS

An Executive Information System (EIS) is a type of management information system

intended to facilitate and support the information and decision making needs of seniorexecutives by providing easy access to both internal and external information relevant to

meeting the strategic goals of the organization. It is commonly considered as a

specialized form of a (DSS) The emphasis of EIS is on graphical displays and easy-to-useuser interfaces. They offer strong reporting and drill down capabilities. In general, EIS

are enterprise-wide DSS that help top-level executives analyze, compare, and highlight

trends in important variables so that they can monitor performance and identify

opportunities and problems.

DSS

A decision support systems (DSS) is a computer-based information system that supportsbusiness or organizational decision making activities. DSSs serve the management,

operations, and planning levels of an organization and help to make decisions, which may

be rapidly changing and not easily specified in advance.

DSSs include knowledge based systems. A properly designed DSS is an interactive

software-based system intended to help decision makers compile useful information froma combination of raw data, documents, personal knowledge, or business models to

identify and solve problems and make decisions.

Enterprise solutions

Enterprise Solutions provide for a scalable, easy to manage programmingsolution to providing business management and information accessability forinternal and external clients. Enterprise solutions deal with the problem of

providing information to clients both externally and internally. It deals withprogramming and databases. The main problem being how to most efficiently getour data accessable to those we want to access it.


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Single System Image

In distributed computing, a single system image (SSI) cluster is a cluster of machines

that appears to be one single system. The concept is often considered synonymous with

that of a distributed operating system, but a single image may be presented for more

limited purposes, just job scheduling for instance, which may be achieved by means of anadditional layer of software over conventional operating system images running on each

node. The interest in SSI clusters is based on the perception that they may be simpler touse and administer than more specialized clusters. Different SSI systems may provide a

more or less complete illusion of a single system.

Islands of automation

CLIENT/SERVER MODEL OF COMPUTING

This is client/server computing described.

To truly understand how much of the Internet operates, including the Web, it is important

to understand the concept of client/server computing. The client/server model is a form of

distributed computing where one program (the client) communicates with anotherprogram (the server) for the purpose of exchanging information.

The client's responsibility is usually to:

1. Handle the user interface.2. Translate the user's request into the desired protocol.3. Send the request to the server.4. Wait for the server's response.5. Translate the response into "human-readable" results.6. Present the results to the user.


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The server's functions include:

1. Listen for a client's query.2. Process that query.3. Return the results back to the client.

A typical client/server interaction goes like this:

1. The user runs client software to create a query.2. The client connects to the server.3. The client sends the query to the server.4. The server analyzes the query.5. The server computes the results of the query.6. The server sends the results to the client.7. The client presents the results to the user.8. Repeat as necessary.

A typical client/server interaction

This client/server interaction is a lot like going to a French restaurant. At the restaurant,you (the user) are presented with a menu of choices by the waiter (the client). After

making your selections, the waiter takes note of your choices, translates them into

French, and presents them to the French chef (the server) in the kitchen. After the chef

prepares your meal, the waiter returns with your diner (the results). Hopefully, the waiterreturns with the items you selected, but not always; sometimes things get "lost in the

translation."

Flexible user interface development is the most obvious advantage of client/servercomputing. It is possible to create an interface that is independent of the server hosting

the data. Therefore, the user interface of a client/server application can be written on a

Macintosh and the server can be written on a mainframe. Clients could be also written forDOS- or UNIX-based computers. This allows information to be stored in a central server

and disseminated to different types of remote computers. Since the user interface is the

responsibility of the client, the server has more computing resources to spend onanalyzing queries and disseminating information. This is another major advantage of


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client/server computing; it tends to use the strengths of divergent computing platforms to

create more powerful applications. Although its computing and storage capabilities aredwarfed by those of the mainframe, there is no reason why a Macintosh could not be used

as a server for less demanding applications.

In short, client/server computing provides a mechanism for disparate computers tocooperate on a single computing task.

Introduction to Client/Server Architecture

Numerous applications run in a client/server environment, this means that client

computers (computers forming part of the network) contact a server, generally a very

powerful computer in terms of input/output, which provides services to the client

computers. These services are programmes which provide data such as the time, files, aconnection, etc.

The services are used by programs client programs which run on client computers. Thisis why the term "client" is applied FTP client,email client, etc.), where a program is

designed to run on a client computer, capable of processing data received from a server

(in the case of the FTP client we are dealing with files whereas for the email client we

deal with email email).

Advantages of Client/Server Architecture

The client/server model is particularly recommended for networks requiring a high

degree of reliability, the main advantages being:


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centralised resources: given that the server is the centre of the network, it can

manage resources that are common to all users, for example: a central databasewould be used to avoid problems caused by redundant and inconsistent data

improved security: as the number of entry points giving access to data is not so

important

server level administration: as clients do not play a major role in this model,they require less administration

scalable network: thanks to this architecture it is possible to remove or add

clients without affecting the operation of the network and without the need formajor modification

Disadvantages of the client/server model

Client/Server architecture also has the following drawbacks:

increased cost: due to the technical complexity of the server

a weak link: the server is the only weak ling in the client/server network, giventhat the entire network is built around it! Fortunately, the server is highly fault

tolerant (primarily thanks to the RAID System)

Client/Server system operation

A client/server system operates as outlined in the following diagram:

The client sends a request to the server using its IP address and the Port, which isreserved for a particular service running on the server.

The server receives the request and responds using the client IP address and port


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Electronic data interchange (EDI) is the structured transmission of data between

organizations by electronic means. It is used to transfer electronic documents or businessdata from one computer system to another computer system, i.e. from one trading partner

to another trading partner without human intervention.

It is more than mere e-mail; for instance, organizations might replace bills of lading andeven cheques with appropriate EDI messages. It also refers specifically to a family of

standards, e.g. UN/EDIFACT, ANSI X12.

The National Institute of Standards and Technology in a 1996 publication defines

electronic data interchange as "the computer-to-computer interchange of strictlyformatted messages that represent documents other than monetary instruments. EDI

implies a sequence of messages between two parties, either of whom may serve as

originator or recipient. The formatted data representing the documents may be

transmitted from originator to recipient via telecommunications or physically transportedon electronic storage media.". It goes on further to say that "In EDI, the usual processing

of received messages is by computer only. Human intervention in the processing of areceived message is typically intended only for error conditions, for quality review, andfor special situations. For example, the transmission of binary or textual data is not

EDI as defined here unless the data are treated as one or more data elements of an

EDI message and are not normally intended for human interpretation as part of

online data processing."

Desktop application integration

A workflow is a model to represent real work for further assessment, e.g., for describing

a reliably repeatable sequence of operations. More abstractly, a workflow is a pattern ofactivity enabled by a systematic organization of resources, defined roles and mass, energy

and information flows, into a work process that can be documented and learned

In, intelligent character recognition (ICR) is an advanced optical character recognition(OCR) or - rather more specific handwriting recognition system that allows fonts and

different styles of handwriting to be learned by a computer during processing to improveaccuracy and recognition levels.

Most ICR software has a self-learning system referred to as a neural network, which

automatically updates the recognition database for new handwriting patterns. It extends

the usefulness of scanning devices for the purpose of document processing, from printed

character recognition (a function of OCR) to hand-written matter recognition. Becausethis process is involved in recognising hand writing, accuracy levels may, in some

circumstances, not be very good but can achieve 97%+ accuracy rates in reading

handwriting in structured forms. Often to achieve these high recognition rates several

read engines are used within the software and each is given elective voting rights todetermine the true reading of characters. In numeric fields, engines which are designed to


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read numbers take preference, while in alpha fields, engines designed to read hand

written letters have higher elective rights.

Downsizing and client/server computing

Down Sizing is nothing but The Process of mo

ving an application from a {main frame ) to cheaper

system, typically a (client-server) system.

Downsizing is a process of moving an application from a mainframe system to clent sever system.

Perserving your mainframe applications investment through porting

Though different legacy environments and modernization strategies require different sets of tools,

most projects need to address existing COBOL, CICS, and JCL applications. Software tools and run-time environments are available from various ISV for those companies wishing to continue support

of these applications on the Windows and Microsoft .NET platform.

Alchemy Solutions

The Alchemy software solutions are designed to revitalize as you migrate. The Neo suite of products

(NeoKicks, NeoBatch, and NeoSort) along with NetCOBOL automate the migration of CICS COBOL,

batch COBOL, and JCL to the Microsoft .NET Framework, with minimum change to the COBOL and

JCL code, while fully enabling the applications for the new environment. For example, CICS BMS

screens are transformed to ASP.NET Web pages.

Anubex

Anubex is an important player in the mainframe modernization market and has one of the largest

sets of tools available to automate the transformation and modernization of mission-critical

applications. Anubex specializes in IBM zSeries and Siemens BS2000/OSD application porting and

targets .NET and other modern platforms. With over 15 years' experience in building such tools for

its customers, Anubex succeeds in generating maintainable, compact, and functionally auditable

software from applications with even many millions of lines of code.

Anubex offers a comprehensive solution to applications created with proprietary 4GLs and

development tools: database modernization including the automated migration from prerelational

databases to RDBMSs; automated translation of COBOL, Natural, ADS, JCL, and other languages;

and screen modernization through the conversion to nonproprietary mainframe alternatives or the

latest in graphical .NET user interfaces.

Asysco

Asysco is the leading migration technology provider for the Unisys mainframe environment. We help

our customers protect and enhance their investments in mission-critical enterprise applications. The

Asysco Migration Technology (AMT) provides our customers with all the tools they need to migrate

their legacy applications to an open systems environment. Our technology solutions, AMT-LION and

AMT-VS (Visual Studio), allow companies to choose their path away from the mainframe. Both


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technologies lower the costs of maintaining existing enterprise applications and speed up the

development and the time to market of new applications. At the same time, our customers are able

to continue to enjoy the unparalleled robustness, security and availability of the traditional

mainframe environment in an open environment.

.

Enterprise InformaticsEnterprise Informatics Inc. is a leading provider of enterprise information management solutions

that vastly improves the integrity, visibility, and access to all relevant information at the time it is

neededreducing the cost of meeting compliance requirements, minimizing business risk, and

optimizing process efficiency. As one of 400 Microsoft Gold Managed Partners, Enterprise

Informatics has been an early adopter of the latest Microsoft technologies. The company's flagship

product eB (enterprise bridge) is Certified for the Windows Vista logo and for Microsoft Windows

Server 2008. eB is built on the Microsoft .NET Framework and extends the document management

capabilities of Microsoft Office SharePoint Server 2007 to the enterprise.

Language conversion

Technology changement

Custom developments

Software management analysis and assessment

APM (application portfolio management)

Tools to convert ALGOL libraries to Windows-compatible languages

ClientView Builder tool that modernizes legacy applications by creating a web-based GUI using

Visual Studio and Microsoft ASP.NET

Idea has revolutionized the industry with our innovative tools and key partnerships. If you need an

affordable migration tailored to your needs, choose Idea Legacy.

Treehouse software,

Treehouse Software, Inc. (TSI) is a global leader in mainframe integration, offering the most

complete and flexible portfolio of solutions available anywhere for integration, replication and

migration of data between mainframe sources and any target, application or platform. Using ETL,

CDC and SQL/XML technologies, we connect your enterprise--from anything to anything.

Hundreds of customers worldwide benefit from TSIs industry-leading products and outstanding

support. Traditionally, the company has focused on software that was complementary to the

Software AG mainframe product line (ADABAS database management system and NATURAL

programming language) in the areas of security, control, auditing, performance enhancement, etc.

The primary TSI focus today is software and services that enable mainframe customers to leverage


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their investments in legacy systemsemploying virtually any data sourcewith data integration,

data warehousing, modernization and conversion, Service-Oriented Architectures, and other new

technologies.

Service solutions

System integrators with dedicated modernization practices can provide the skills, expertise, and

staffing necessary to plan and execute on a modernization practice. The integrators often work with

Microsoft consultants to build the best solution for the customer.

Accenture

Many organizations have accumulated technology that impedes business productivity and flexibility.

According to Accenture research, more than half of all business applications are between 5 and 20

years old. Accenture can help clients obtain more value out of existing investments by re-

platforming, decommissioning, remediating, and reverse engineering existing or legacy technologies

and applications. The result is increased stability and flexibility, decreased cost, and an extended life

of current IT assets.

Anuberx

Anubex provides solutions for the modernization of large and complex legacy applications for

business and government organizations alike. Anubex exclusively applies a proven, iterative process

and specialized software to optimally re-use the value in existing applications while automatically

transforming them to use the most leading-edge technologies. A core part of Anubex's offering is its

ability to tailor the standard transformation behavior of the tools to satisfy the coding guidelines and

environment parameters of each individual customer.

A recent addition to the core Anubex modernization services is a framework for automating the

testing of interactive (online) applications. Using the Anubex automated testing framework,

companies have been able to reduce the amount of time users spend testing and accepting the

converted software by as much as 90%.

Several of Anubex's customers are ranked among the Fortune Global 500. Anubex operates

internationally and often collaborates with systems integrators to manage modernization projects

and minimize risk.

Asyco

Asysco is the leading migration technology and service provider for the Unisys mainframe

environment. We help our customers protect and enhance their investments in mission-critical

enterprise applications. Our technology solutions, AMT-LION and AMT-VS (Visual Studio), allow

companies to choose their path away from the mainframe. Before, during, and after a migration

project, Asysco provides services to their customers, including, but not limited to, migration project

management, software installations and upgrades, new development projects assistance,

outsourcing resources, and training.

Treehouse software

Treehouse Software, Inc. (TSI) is a global leader in mainframe integration, offering the most

complete and flexible portfolio of solutions available anywhere for integration, replication and

migration of data between mainframe sources and any target, application or platform. Using ETL,


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CDC and SQL/XML technologies, we connect your enterprise--from anything to anything.

Hundreds of customers worldwide benefit from TSIs industry-leading products and outstanding

support. Traditionally, the company has focused on software that was complementary to the

Software AG mainframe product line (ADABAS database management system and NATURAL

programming language) in the areas of security, control, auditing, performance enhancement, etc.

Today, TSI consulting services include: modernization of mainframe data sources into state-of-the-

art RDBMSs, and support for extracting, propagating, and integrating that mainframe data;

complementary rehosting, transformation and modernization services for NATURAL and other

applications; ADABAS and NATURAL technical consulting, project management and training for

application development, software installation, change management, database design, security and

audit implementation and performance and tuning analysis; and remote and on-site DBA services

for outsourcing and staff augmentation.

Qualified TSI personnel are familiar with many programming languages, operating systems,

databases and platforms, and they are available for short- and long-term consulting assignments.

Real world tools

A tool for the development of multiple-table database applications for client/serverenvironments automates both capture of system requirements and code production. A

client portion of a multiple-table, client/server database application for processing

requests against a server database, is developed by first storing in a repository a

description of the server database describing database entities within the server databaseand relationships between those database entities. Representations of the database entities

are displayed, and an application drawing window is provided. The user drags and drops

within the application drawing window one of said representations that represents aparticular database entity. The tool then creates within the repository an entry for the

particular database entity, and draws within the drawing window a representation of the

particular database entity. For each database entity for which an entry within the

repository has been created, the tool checks the description of the server database storedin the repository to determine whether a relationship exists between the particular

database entity and the database entity being checked. If a relationship does exist between

the particular database entity and the database entity being checked, the tool then createswithin the repository an entry for that relationship, and draws within the drawing window

a connector representing that relationship. The foregoing drag-and-drop sequence is

repeated multiple times. When the design is complete, the tool, using information stored

in the repository, automatically generates the client portion of the multiple-table,client/server database application

Inroduction to Client Server Computer- TCA8C23

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