Client/Server Technology Infsy 540 Dr. Ocker

Past centralized business computing and centralized model of organizational computing -- mainframes high degree of control for systems managers end-users not very involved barriers to information access - sharing not the norm

Now End-user computing is here to stay less control for systems managers sharing of data is the norm client-server computing is replacing the mainframe

various meanings of client/server technology One meaning: formal systems architecture describing technologies that cooperate together on a computer network users operate PCs (clients) that connect to central computers (servers) over a computer network both computers cooperate to spilt the work of performing various tasks set of management strategies for creating systems that improve org’al effectiveness strategies for distributing computing resources within an org. to support interpersonal communication, organizational coordination, and business collaboration

various meanings of client/server technology Another meaning: set of management strategies for creating systems that improve org’al effectiveness strategies for distributing computing resources within an org. to support interpersonal communication, organizational coordination, and business collaboration

Client/Server Model enterprise networking - an arrangement of the org’s HW, SW, telecommunications, and data resources to put more computing power on the desktop and create a company-wide network linking smaller networks

client/server model of computing primary way of delivering computing power to the desktop computing, data and processing power are distributed throughout the organization rather than being centrally located

client/server model of computing emphasizes the user’s interaction with the data splits processing between clients and servers

client user point of entry into a network normally a desktop computer, workstation, or laptop user generally interacts directly only with the client portion of an application

server satisfies some or all of a user’s request for data also runs the application software can be a mainframe or another desktop computer servers store and process shared data

Infrastructure c/s computing enables restructuring of information flow by distributing computing resources and allowing access to information hw and sw must function as a series of pathways/highways

Core capabilities of c/s computing users use desktop computers to do much of their work locally when they need to access shared information or to use resources of another (more powerful) machine, they connect their desktop (client) machine to the remote machine (server) using a network

Clients provide user interface - GUI - graphical user interface run stand alone applications (e.g. word processing) - these applications use entirely local resources for both processing and data storage run the client side of client-server applications

Servers shared resources that are accessible over the network;used by clients combine both hw and sw clients contact servers with requests servers process the request and return the results to the clients many clients use the server; end-users can share information by accessing a common database (stored on the client)

Networking key to c/s communications clients and servers pass information back and forth via a network

Distributing the work fig. - shows 5 different ways that components of an application can be partitioned between the client and the server applications must be written as two or more separate software components that run on different machines but that appear to operate as a single application

Payroll example client tasks could include server task could include input data submit data queries to the server display results on screen or printer server task could include fetch the entered data process the payroll control access

Business benefits of C/S computing enables new approaches to business computing by restructuring flow of communication and information within orgs. improved communication, coordination, and collaboration --> Groupware email, computer conferencing, electronic calendars, shared databases

Business benefits of C/S computing distributed data stores consist of different servers that collect and organize information corporate data warehouses can be located centrally on a mainframe; receive data extracts periodically from operational systems (e.g. TPS); serves as a repository for shared information; information can be distributed on various machines (servers)

Some Limitations more difficult to write SW that divides processing among clients and servers server can get overloaded when too many users simultaneously want service

Major influences that cause firms to shift to Client/Server technically and economically feasible to transfer computing power to desktop -- declining prices, good telecomm. capabilities knowledge-based workers create and work with information ; require easy access to information - C/S systems enhance productivity by placing information where users are

Major influences that cause firms to shift to Client/Server communication is faster, easier and less costly with C/S technology -- important in global economy flatter orgs. need more decentralized from of computing support team work through networking

Major influences that cause firms to shift to Client/Server offers flexibility to orgs. who need to change rapidly - easy to connect new clients (e.g. team members); can easily upgrade power of server without interrupting service cost savings - supposedly cheaper

key principles for managers in transition to c/s computing to achieve value from the (costly) investment in c/s computing, need to commit to process redesign two different levels of investment - infrastructure and applications

key principles for managers in transition to c/s computing need to make long-term investments in backbone communications networks; plan for ever-increasing bandwidth building the enabling infrastructure is a strategic effort building distributed applications is a tactical effort

key principles for managers in transition to c/s computing individuals and workgroups need to exploit the potential networked infrastructure enables people to work together and share information in a variety of ways