Information systems slide topdowndes

Chapter 1: Introduction to Client/Server IS ❚ ❚ ❚ ❚ ❚ ❚ ❚ ❚ ❚ ❚ ❚ LAN LAN Hardware Components LAN Software Components LAN Connectivity Client/Server IS (C/S IS) Effective Analysis, Design and Implement of C/S IS C/S Connectivity and Compatibility C/S Analysis - business oriented Paradigm Shift Logical Architecture of C/S Physical Architecture of C/S Local Area Network ❚ Limited to a geographical area ❚ owned, administrated and used by a single organization (not subject to FCC regulations) ❚ support moderate data transfer rates with lower error rates ❚ supports full connectivity among WS LAN Hardware Components ❚ ❚ ❚ ❚ ❚ ❚ ❚ Network Interface Card Server - types Workstation Hub, MAU, Concentrator, Switch Connector Cable UPS LAN Software Components ❚ ❚ ❚ ❚ Network Operating System Backup Software Workstation System Software Network Application Programs LAN Connectivity Client/Server Information Systems ❚ Client/Server Information System ❙ Distributed IS ❚ Organization’s Success ❙ right information ❙ right end user ❙ right format ❙ right place and time ❙ right price Benefits of C/S IS ❚ Resource Sharing ❚ Communication ❙ GroupWare ❚ Management Control ❚ Reduced Costs - downsizing ❚ Support business environmental changes ❚ Improved Information Accessbility ❚ Faster/Better Information ❚ Open Architecture - Compatibility Issues ❚ Empowered Users Problems of C/S IS Transition Costs High cost of training, support Multivendor architecture Lack of management tools for distributed environment ❚ Lack of standards ❚ Technology not ready for missing critical application ❚ Lack of software conversion tools ❚ ❚ ❚ ❚ Effective Analysis, Design, & Implmentation of : C/S(1) Top-Down Approach BUSINESS R E Q U IR E M E N T S APPLICATION DATA NETWORK TECHNOLOGY GOLDMAN: CSIS FIG 01-03 Top-Down Approach: ❚ Business ❙ identifying business-level objectives ❙ strategic business planning ❙ BPR ❚ Application ❙ identifying information need ❙ relating information needs to business process & opportunities Characteristics of C/S IS ❚ Scalability VAX AS/400 RS/6000 Netware Mainframe UNIX Scalability: Additional clients are added to system with little or no effect on processing load owing to incremental processing power added by each client Original Clients DOS Processing OS/2 Processing Additional Clients DOS Processing OS/2 Processing Mac Processing UNIX Processing Windows Processing Enterprise Network Processing VAX GOLDMAN: CSIS FIG: 01-15 Processing AS/400 Processing Processing Processing Processing RS/6000 Netware Mainframe UNIX Characteristics of C/S IS ❚ Interprocess Communication Distributed Application Client Process CLIENT PC FRONT-END GOLDMAN: CSIS FIG 01-16 Interprocess Communication Server Process SERVER A Interprocess Communication Server Process SERVER B BACK ENDS or ENGINES Figure 1-16 Distributed Processing Requires Interprocess Communications Characteristics of C/S IS ❚ Database Distribution DOS OS/2 Mac UNIX Windows Front-end tools Front-end tools Front-end tools Front-end tools Front-end tools Database connectivity software Database connectivity software Database connectivity software Database connectivity software Database connectivity software Single Solution Gateway Universal Data Access System Enterprise Network Database Transparency Database connectivity software Database connectivity software Database connectivity software Database connectivity software Database connectivity software Database connectivity software Distributed DBMS Distributed DBMS Distributed DBMS Distributed DBMS Distributed DBMS Distributed DBMS VAX AS/400 Netware Mainframe UNIX RS/6000 GOLDMAN: CSIS FIG: 01-17 Figure 1-17 Key Components of Database Distribution Characteristics of C/S IS ❚ Distributed Transaction Processing Logical Model of Local or Nondistributed Transaction Processing Monitor Transaction Processing Monitor Logical Model of Distributed Transaction Processing Monitor Distributed Transaction Processing Monitor DTP DTP DTP API API API Local TP Monitor Local TP Monitor Local TP Monitor Distributed Processing Distributed Processing Presentation Client-Based Presentation Application Data Management Distributed Processing Distributed Data Distributed Data Distributed Data Management Management Management CLIENT All software installed on same system SERVER A SERVER B Local TP monitors ensure integrity of local transaction postings Distributed TP monitor ensures integrity of overall distributed postings Distributed TP monitor and local TP monitor communicate via DTP API GOLDMAN: CSIS FIG 01-19 Figure 1-19 Local versus Distributed Transaction Process Monitoring Application Client presentation Application rightsizing Distributed computing Distribute applications Data Distributed databases Network Enterprise networks Distributed network management Technology To be determined by physical client-server design GOLDMAN: CSIS FIG 01-20 Client/Server Architecture Increased competition on a global scale Corporate downsizing Information systems downsizing Business process redesign/reengineering Distributed Transaction Process Monitors Middleware Interprocess Communication Business Figure 1-20 The Top-Down Model and Logical Client/Server Architecture Physical/Technology Architecture ❚ Client/Server Architecture vs Mainframe/Terminal Architecture for data Data retrieval Data storage Transport of data requests Transport of actual data Mainframe - Terminal Network 3270 3270 Terminals 3270 Mainframe Mainframe Formatting of data for presentation to user Application program request for data Data retrieval Data storage Front-end processor Cluster controller Network Transport of data requests Transport of actual data Terminal Presentation of data to user GOLDMAN: CSIS FIG 01-21 Figure 1-21b Client/Server versus Mainframe-Terminal Architectures Client/Server Network Server Clients Hub Server Application program request for data Data retrieval Data storage Network Transport of data requests Transport of actual data Client Workstations Presentation of data to user Formatting of data for presentation to user Application program request for data Data retrieval Data storage Transport of data requests Transport of actual data Mainframe - Terminal Figure 1-21a Client/Server versus Mainframe-Terminal Architectures Network 3270 3270 Terminals 3270 Mainframe Front-end processor Cluster controller Internet Services Ethernet LAN Mainframe configuration router router Frame Relay WAN services router router Token-Ring LAN Minicomputer configuration GOLDMAN: CSIS FIG 01-23 Figure 1-23 Example of an Enterprise Network Physical Topology Two Tierd vs Three-Tiered CS Architecture ❚ Two-tierd ❚ Three-tierd Database Logic Database Logic Business Logic Presentation Logic Fat Client Database Logic Business Logic Business Logic Middleware Presentation Logic Presentation Logic Fat Server TWO-TIERED ARCHITECTURE THREE-TIERED ARCHITECTURES GOLDMAN: CSIS FIG 01-24 Figure 1-24 Two-Tiered versus Three-Tiered Client/Server Architecture ... Application Programs LAN Connectivity Client/Server Information Systems ❚ Client/Server Information System ❙ Distributed IS ❚ Organization’s Success ❙ right information ❙ right end user ❙ right format... Categories of Elements of Client/Server Information Systems Characteristics of C/S IS ❚ Client-based Presentation Category of Client/Server Information Systems Data Management Processing Presentation... business-level objectives ❙ strategic business planning ❙ BPR ❚ Application ❙ identifying information need ❙ relating information needs to business process & opportunities Top-Down Approach: Effective