1. Client/Server Technology
Infsy 540
Dr. Ocker

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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)

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

16. 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

17. 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

18. 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
, computer conferencing, electronic calendars, shared databases

19. 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)

20. 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

21. 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

22. 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

23. 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

24. 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

25. 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

26. 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