1. Computing Resource Paradigms CS3353

2. Computing Resource Paradigms Centralized Computing Distributed Computing

3. Early Centralized Computing Paradigm Characterized by one central computer. Housed in a limited access, climate controlled room. A shared resource – users connect through dumb-terminals. Limited interactive access. Jobs are submitted through batch job- queues.

5. Centralized Computing There remain highly specialized computer systems of this type: Supercomputers designed for special resource intensive problem solving.

6. Cray T3E/512-PE Supercomputer Mainframe

7. Centralized Computing Advantages Ideal for maintaining a high level of security. Climate controlled environment is equipment friendly. Reduces maintenance costs.

8. Distributed Paradigm Demand driven by departments wanting access to more computing resources beyond the confines of centrally controlled systems. Unix becomes a popular operating system for this paradigm. HP, Sun, SGI, and others ride this wave during the 1980’s.

9. DEC Micro-VAX

10. Client-Server The spread of networks and low cost network hardware led to the client-server computing paradigm. This successfully merges the two central and distributed paradigms. Computers are interconnected by a network. The computers are classified as either clients or servers in the network.

11. Server A powerful computer configured to provide services to other computers within a computing system environment. Example Services: –Disk –Printer –Application –E-mail –etc

12. Server The server is typically a powerful computer configured with: Fast processors (1 or more) Fast and reliable disk storage Memory rich

13. Server Central location for the server allows ease of maintenance and high levels of security. Simplifying the maintenance of the system helps control costs. Small operations (businesses) can put a powerful central computing system in a small room. There it can be relatively secure and easy to maintain.

14. Server Rack

15. Behind the Server Rack

16. The Client A client is configured to access specific services within the boundary of the defined computing system environment. Client classifications: –Fat client: fully functional workstation –Thin client: a dumb terminal or graphical display –Hybrid client: between thin and fat.

17. Client Fat clients are fully functional computers with local storage and computing capability. Thin clients rely on a server to provide storage and computing resources. Characterized as diskless and without a processor. Hybrid clients provide some computing resources independent of a server; storage is provided by a server.

18. Client Thin/Hybrid clients can cost less than fat-clients to purchase and maintain when carefully chosen. Work well for: –public access areas –high security environments –When full function workstations are unnecessary. –Reduces maintenance for cost conscious businesses.

19. $300 client