Diese Präsentation wurde erfolgreich gemeldet.
Die SlideShare-Präsentation wird heruntergeladen. ×

Weitere Verwandte Inhalte

Ähnliche Bücher

Kostenlos mit einer 30-tägigen Testversion von Scribd

Alle anzeigen

Ähnliche Hörbücher

Kostenlos mit einer 30-tägigen Testversion von Scribd

Alle anzeigen

05

  1. 1. Understanding Networked Applications: A First Course Chapter 5 by David G. Messerschmitt
  2. 2. Understanding Networked Applications A First Course2 Client host Server host Client host
  3. 3. Understanding Networked Applications A First Course3 Part of the rationale • Specialization: – Clients specialize in user interface – Servers specialize in managing data and application logic • Sharing: – Many clients can be supported by few servers – Often data and logic are shared among applications and users
  4. 4. Understanding Networked Applications A First Course4 Client/server Peer-to-peerServer “I want to access some information” “I want to collaborate with my colleague” Client
  5. 5. Understanding Networked Applications A First Course5 Distinctions • Client-server – Asymmetric relationship – Client predominately makes requests, server makes replies • Peer-to-peer – Symmetric relationship
  6. 6. Understanding Networked Applications A First Course6 Client Server Client Email client sends message to server Message is stored on POP server Later, recipient’s email client retrieves message from server Email application
  7. 7. Understanding Networked Applications A First Course7 Client Server Client Chat clients send user’s typing to server Chat server aggregates typing from all users and sends to all clients Other user’s clients display aggregated typing from chat server Chat application
  8. 8. Understanding Networked Applications A First Course8 Presentation Application logic Shared data Local-area network Note: many clients per application server, several application servers per data server Three-tier client/server
  9. 9. Understanding Networked Applications A First Course9 Client Web browser Web server Application logic Databases and DBMS Common gateway interchange Host architecture Application partition
  10. 10. Understanding Networked Applications A First Course10 Practice in defining tiers • Online bookseller (e.g. amazon.com) • Stock trading system (e.g. Schwab or E- trade)
  11. 11. Understanding Networked Applications A First Course11 amazon.com
  12. 12. Understanding Networked Applications A First Course12 Schwab
  13. 13. Understanding Networked Applications A First Course13 Question • What types of social applications would be appropriate for a client/server architecture?
  14. 14. Understanding Networked Applications A First Course14 Departments Enterprise Commerce Enterprise-to-enterprise Consumer
  15. 15. Understanding Networked Applications A First Course15 Customers Consumer Enterprise Customer-service department Technical-support department software4u.com
  16. 16. Understanding Networked Applications A First Course16 Web server Customer logic Customer audit Software documentation Web browser Problem knowledge base Databases Agent logic Consumer application Enterprise application Technician logic Web server Web browser Web server Web browser Customercare
  17. 17. Understanding Networked Applications A First Course17 Accounts Products Orders Customer logic Databases Agent logic Customers Agents Technicians Technician logic
  18. 18. Understanding Networked Applications A First Course18 Book distribution centers books4u.com Customers Financial institution Consumer Enterprise Inter-enterprise
  19. 19. Understanding Networked Applications A First Course19 Web server Customer logic Customers Merchandise Web browser Orders Acquirer bank Book distributors Databases Outside links Fullfillment logic Consumer e-commerce Inter-enterprise e-commerceBookmerchant
  20. 20. Understanding Networked Applications A First Course20 Clients Customers Merchandise Acquirer bank Book distributorsOrders Customer logic Databases Fullfillment logic
  21. 21. Understanding Networked Applications A First Course21 Stock market stocks4u.com Customers Information providers Consumer Enterprise Inter-enterprise
  22. 22. Understanding Networked Applications A First Course22 Web server Customer logic Accounts Products Web browser Orders Information providers Financial markets Databases Outside links Trading logic Consumer e-commerce Inter-enterprise e-commerceStocktrader
  23. 23. Understanding Networked Applications A First Course23 Clients Accounts Products Information providers Financial marketsOrders Customer logic Databases Trading logic
  24. 24. Understanding Networked Applications A First Course24 Local florists flowers4u.com Customers Financial institution Consumer Enterprise Inter-enterprise
  25. 25. Understanding Networked Applications A First Course25 Web server Customer logic Accounts Products Web browser Orders Acquirer bank Databases Outside link Fullfillment logic Consumer e-commerce Inter-enterprise e-commerce Push client Push server Floristdelivery
  26. 26. Understanding Networked Applications A First Course26 Accounts Products Acquirer bank Orders Customer logic Databases Fullfillment logic Customers Florists
  27. 27. Understanding Networked Applications A First Course27 Shortcomings of client/server • Departmental solution • Proliferates non-interoperable technologies and applications • Hardwired applications lose flexibility What are some goals and likely characteristics of future enterprise architectures?

Hinweis der Redaktion

  • Copyright 1999, University of California Jul 29, 2013
  • Copyright 1999, University of California Jul 29, 2013
  • Copyright 1999, University of California Jul 29, 2013
  • Copyright 1999, University of California Jul 29, 2013
  • Copyright 1999, University of California Jul 29, 2013 What is presentation, application logic, shared data? Presentation: Web browser Application logic Shared data
  • Copyright 1999, University of California Jul 29, 2013 What is presentation, application logic, shared data?
  • Copyright 1999, University of California Jul 29, 2013 Deferred applications need a server -- you wouldn’t want communication to fail because a client was turned off, and there is often a “consolidation” function (example chatroom) Immediate applications can be done peer-to-peer -- if a client is turned off, no point to the application anyway. Also avoids server bottlenecks. Server may still have a role is filtering or consolidation.
  • Copyright 1999, University of California Jul 29, 2013 Major goal: flexibility to meet new business opportunities and new organizational structures More tiers to logically decouple roles Away from stovepipe: horizontal as well as vertical structure

×