3-Tier Client/Server

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Case Study 1: U.K. Employment Service Rolls Out 3-Tier in Record Time

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Table of Contents

BackgroundThe Application3-Tier ArchitectureAdvice

Background

The U.K. government passed the Job Seekers Allowance legislationto encourage people to get jobs and move off benefit payments faster.To comply with this new program, the Employment Service’s staffquickly needed a top-notch application. They were new required to monitor the progress that 2.45 million unemployed people were makingtoward finding work. The IT department at Employment Service roseto this mammoth challenge. It rolled out a major new application - called the Labour Market System - in record time. It’s one of the largestoperational client/server systems in the world.

The Application : Requirements

Employment Service is an executive agency of the Department for Education and Employment in the U.K. Its branch offices are located throughout England, Scotland, and Wales. The agency’smain business is to help people without jobs find work. Currentlyabout 2.45 million people have registered as being unemployed.Before the government passed the Job Seekers Allowance(JSA)legislation, unemployed people received benefit payments if theyhad previously made unemployment insurance payments, or ifthey requested income support. JSA added additional requirements.To keep receiving benefit payments, Employment Services clientshave to sign and comply with a Job Seekers Agreement. This agreementmakes them promise to apply for a certain number of jobs within a particular time period. Staff members at the employment offices haveto log their client’s Job Seekers Agreement and job-seeking activities.As a last resort, they can recommend that benefits payments be dockedif clients aren’t making progress.

The Application : Existing Systems

OSCAR– log the meetings between the employment office

staff and the people coming in to seek jobs– have its own data locally

SVACS– show the vacancies available for jobs in the U.K.– have data in nine relational database

The Benefits Payment System– track payments of unemployment benefits and

allowances

The Application: New System

Labor Market System(LMS)– N-tier client/server application– combine OSCAR and SVACS’s local

information into global databases

Job Seekers Agreement Payment system(JSAP)– extend ‘the Benefits Payment System’– users can access it through the LMS PCs

Architecture

Physical architectureLMS server, JSA server, many LMS PCs, JSA

Payment System, LMS Database Centers, dedicated 64Kbps WAN, etc

Logical architecture– tier 1

• the client s/w and Tuxedo /WS running on the PCs in the employment offices

– tier 2• multiple LMS servers that run Tuxedo services

– tier 3• four regional Ingres database

Physical architecture

Logical architecture

Advice

Use UNIX multiprocessors so you can inexpensively increase processing power in small increments as you need it

A TP Monitor is essential when dealing with many client connections

Test, test, test at all stages of developmentPlan for the challenges of distributing s/w

remotely to a large number of usersRecognize that users will need on-going training

and mentoring to exploit a new system’s fill capabilities

Case Study 2: PeopleSoft Moves Applications to 3-Tier

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Table of Contents

BackgroundThe Application3-Tier ArchitectureAdvice

Background

With revenues of $450 million in 1996, PeopleSoft has built a successfulbusiness delivering 2-tier client/server applications that run their customers’core business functions. While these are enterprise-class applications -mostly used by Global 2000 customers - they are typically installed as departmental applications that support a few hundred concurrent users.But PeopleSoft recognized that its customers were changing the way theywere using their applications. With the arrival of the Internet, many ofPeopleSoft’s customers began launching initiatives to let all their employeesaccess the applications. In addition, many of these customers were usingseveral PeopleSoft applications together

The Application : Requirements

Instead of a few hundred users in a department accessing a particularapplication, tens of thousands of concurrent users will be using an entiresuite of applications.PeopleSoft must provides a series of integrated modules that run its customers’ core business functions. These applications will be used by Global 2000 customers that are eighty percent of PeopleSoft customers. And remaining small business, higher education institutions, and federal, state, and logical governments in US and Canada will use them.PeopleSoft have to improve performance, expand scalability, and increase the interoperability between its applications.

Architecture

Physical architectureTuxedo application server with EventBroker,

Back-end Database, remote call over WAN

Logical architecture– tier 1

• PCs running the PeopleSoft client application, Tuxedo /WS, and Jolt

– tier 2• application servers running Tuxedo services

– tier 3• broad range of databases, including Informix, Oracle,

MS-SQL server, Sybase, DB2

Physical architecture

Logical Architecture

Advice

Keep it simple, stupidClearly define your goals at project start. Make

sure you get extensive feedback from customersAdopt a gradual strategy for moving to a 3-tier

environmentUnderstand what’s flowing back and forth on the

network to make the right choices in separating client and server functionality

Take advantage of third-party products. There’s no need to spend time developing a component if someone else has one that does the job

Case Study 3: Wells Fargo Leads the Way to Internet Banking

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Table of Contents

BackgroundThe Application3-Tier ArchitectureAdvice

Background

It was once simple to understand the difference between a bank,a brokerage house, a mutual fund company, and an insurance company.They offered fundamental products, and there was little overlap. Today,the differences have become blurred as financial institutions of all typescompete for investors’ funds. Leadership in the financial services industrynow requires that an organization be able to quickly adapt to a changingmarket, offering new products and services to its customers in a timelyand efficient manner.Wells Fargo Bank has become a technology leader in banking, thanks inpart to its pioneering use of distributed object computing technology. Thistechnology has helped the company achieve several business objectives,including changing the way bank employees work with computers to becomecustomer-focused rather than account-focusedInnovations made possible through the use of this technology also enabledWells Fargo to become the first major bank to offer its customers secure on-line access to account balances through the World Wide Web.

The Application : Requirements

In the 1980s, competition for investors’ funds - traditionally kept in banks - expanded to include brokerage and insurance companies. To remain competitive, banks began offering products such as mutual funds and brokerage accounts - products historically outside the purview of traditional banking. By the late 1980s, a growing trend wad compound statement banking, where customers expected to receive a single, unified statement listing the balances and transactions for all of their accounts - including checking and savings, mortgage, credit card, brokerage, and retirement accounts. Customers wanted their banking activities to be structured in terms of their overall relationship with the bank instead of a single account.

The Application : Existing Systems

Direct deposit accounts in mainframeMutual funds in Digital VAX/VMS systemBrokerage account processing in Tandem

How can we combine all these information seamlessly and correctly ?

The Application: New System

Customer Relationship System(CRS)– use BEA’s ORB, ObjectBroker– customers can retrieve overall relationship with

the bank, including all accounts owned and their balances and statues by using SSN or EIN

Applications– Wells Fargo’s Internet Banking Solution– Interactive Voice Response Unit(IVRU)– Automated Teller Machine(ATM)– A Stock market data application

Architecture

Physical architectureBack-end mainframe application servers,

Middle-tier ObjectBroker, client PCs

Logical architecture– tier 1

• windows-based client application to provide GUI

– tier 2• Digital’s ObjectBroker using CORBA object model

– tier 3• several legacy application systems

Client PC(Windows)

HP 9000(HP-UX)

IBM(MVS) IBM(MVS) IBM(MVS)HP 9000(HP-UX)

Digital(VAX/VMS)

Interactive VoiceResponse Unit

Sun(SunOS)

ObjectBroker ObjectBroker

ObjectBroker

ObjectBrokerObjectBroker

Customer

Container Account

Account

Bill Pay Service

Credit

On-line Service

Deposit

Service

ProductUses

Business Object Model

Advice

Transform your organization into a group that can effectively develop component-based,

Include users and business participants in the design and development processes

Understand the business process - both the existing and the desired one

Invest time and energy in developing an object model that truly represents the business process

Provide sufficient funding to maintain and enhance your object model

Case Study 4: Apple Improves Ordering With 3-Tier Upgrade

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Table of Contents

BackgroundThe Application3-Tier ArchitectureAdvice

Background

Apple computer relies on its electronic ordering systems to give itsauthorized resellers and service providers an easy way to order computersand parts. This lets the resellers have greater control over the orderingprocess, and it offers Apple cost savings by minimizing administrative tasks.But when Apple decided to move to an SAP-based solution for all itscorporate functions, it found that it also had to replace the existing orderingsystems with a new one that could interoperate with SAP R/3.To accomplish this, Apple developed a new worldwide ordering systembased on a 3-tier architecture. The new system - called AppleOrder Global -serves as a font-end to SAP for processing electronic orders. It provides thescalable, on-line performance needed to service thousands of resellers around the world. AppleOrder Global is now up and running in Canada andEurope; U.S. resellers are due to come on-line in 1998.

The Application : Requirements

To develop and roll out an electronic ordering system that would garner internal acclaim - at least from Apple’s resellers - we need as follows.First, to develop a scalable system with interactive interfaces.Next, to support an international production environment. That is, we must provide real-time performance on a global scale.Last, to ensure that all the functionality of existing systems are offered.

The Application

Existing system– five different electronic ordering systems in

different regions around the world

New system– AppleOrder Global

• electronic ordering system• use SAP R/3 modules• users can get information about the status of

pending orders and shipments and access their account and invoice information and up-to-date product and pricing information. etc…

Architecture

Physical architectureMacintosh computers, Leased line, AppleOrder

Global RS/6000 application server, SAP RS/6000 Order management server

Logical architecture– tier 1

• AppleOrder Global GUI and Tuxedo /WS

– tier 2• AppleOrder Global application server

– tier 3• SAP R/3 Order Management application server

Reseller’sMacintosh

Reseller’sMacintosh

DedicatedNetwork

AppleOrder GlobalRS/6000

Application Server

SAP RS/6000Order Management

Server

Dial-up orLeased-lineConnection

T1 Line

RFCs overHigh-speed LAN

Physical Architecture

AppleOrderGlobal GUI

MacAppFramework

Application Layer API

Application Objects

Order Management API

Loca DataAPI

AppleOrderGlobal API

MiddlewareAPI

Tuxedo /WS

CTreeDatabase

CustomOrder

ManagementABAP/4Routines

SAPR/3

Application

RemoteFunction

Calls

Application Objects

Order Management API

LocalDataAPI

OracleRemoteFunction

Calls

AppleOrderGlobal API

MiddlewareAPI

TuxedoWorkstation

Handler

SAPAPI

Tier 1Client

Tier 2Application Server

Tier 3Order Management Server

(acting as SAP client)

Logical architecture

Advice

Take time in designing the system. Once you begin development, it’s hard to go back and revise the design

Make sure you have a specialist in each technology

Be sure to have people from the business side of the house participate as you design and develop the system

If possible, reuse work you’ve already completed