1 / 19

Software Architecture in Practice

Software Architecture in Practice. RiSE’s Seminars Bass’s at all Book :: Chapters 13 Fred Durão. Summary. The world wide web – A case study in Interoperability (Chapter 13) The original requirements Architectural Solution The evolution of web based e-commerce architecture

jin
Download Presentation

Software Architecture in Practice

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Software Architecturein Practice RiSE’s Seminars Bass’s at all Book :: Chapters 13 Fred Durão

  2. Summary • The world wide web – A case study in Interoperability (Chapter 13) • The original requirements • Architectural Solution • The evolution of web based e-commerce architecture • The architectural business cycle today

  3. The word wide web – A case study in Interoperability

  4. The World Wide Web :: Chapter 13 History • Tim Berners Lee and CERN members seen the need of creating a information network; • In 1989, Tim Berners Lee created a document named “Information Management: A proposal”; • In 1990, a reformulated version of his document became a project named World Wide Web

  5. The World Wide Web :: Chapter 13 The www original requirements • Remote access across networks • Heterogeneity • Noncentralization • Access to existing data • Ability for users to add data • Private links • Bells and whistles – the data display was on 24 x 80 character ASCII Terminal • Data analysis • Live links – given that information changes all the time • Some non requirements became requirements like SSL (Secure Socket Layer) and HTTPS (HttpSecure)

  6. The World Wide Web :: Chapter 13 Internet Statistics Source: Used with permission of Matthew Gray of the Massachusetts Institute of Technology

  7. The World Wide Web :: Chapter 13 Internet Growth Internet Backbones in the USA 1996 • Web has been doubling in size every 3 to 6 year months • From 130 sites in 6/1993 to more that 230.000 sites in mid-1996 • and 27 million in early 2001

  8. The World Wide Web :: Chapter 13 Architectural Solution • Based on client and servers and wwwLibs • - compact, portable library that can be built on to create Web-based applications such as clients, servers, databases, and Web Spiders

  9. The World Wide Web :: Chapter 13 libWWW layers Support a set of application functionalities for writing applications Support a set of network-protocol-aware modules, like HTTP, FTP, TELNET Provides the abstraction of stream of all data transported Provides standard interfaces to Web Applications Portability layer that provide platform-independent function

  10. The World Wide Web :: Chapter 13 Lessons learned from libWWW • Formalized application programming interfaces (APIs) are required; • Functionality and the API’s that present it must be layered; • The library must support a dynamic, open-ended set of features; • Processes built on the software must be thread safe;

  11. The World Wide Web :: Chapter 13 An Early Client-Server Architecture using libWWW • WWW Client • External Viewer • HTTP Client • UI Manager, Cache Manager and more… • WWW Server • CGI • HTTP Server • Stream Manager, Access Control and more…

  12. The World Wide Web :: Chapter 13 Common Gateway Interface - CGI • CGI is one of the most important requirement driving the evolution of Web software • CGI scripts allowed dynamic request information to be returned to clients • The most common use of CGI were create dynamic HTML document and return it to users • CGI allowed users “put” information into the web, in contrast to “get” operation that servers normally provide. E.g. add info on databases by filling out a form

  13. The World Wide Web :: Chapter 13 How the WW Achieved Quality Goals

  14. The World Wide Web :: Chapter 13 The Evolution of Web-Based E-Commerce Architectures • The new requirements: • High performance • Customer will not tolerate the site simply refusing their requests; • High availability • The Web Sites have to be available 24/7; • Scalability • Possibility of growth to maintain acceptable levels of customer service. • Security • Adapt mechanisms for avoiding stealing or modifying data. • Modifiability • Ability for changes Customer

  15. The World Wide Web :: Chapter 13 A typical e-commerce system

  16. The World Wide Web :: Chapter 13 E-Commerce Architecture achieving qualities • Web Browsers claim forMODIFIBILITY • HTTPS claims forSECURITY • Proxy Servers claim forPERFORMANCE • Reuters and Firewalls claim forSECURITY • Load Balancing claims forSCALABILITY and AVAILABILTY

  17. The World Wide Web :: Chapter 13 E-Commerce Architecture achieving qualities • Web Servers claim forPERFORMANCE • Databases claim forPERFORMANCE, SCALABILITY and AVAILABILITY • Application Servers claim forPERFORMANCE, MODIFIABILITY and SCALABILITY

  18. The World Wide Web :: Chapter 13 The Architecture Business Cycle Today • Several types of organization provide the technical environment: Service providers and Data providers • A number of open-source projects have increased • E.g. Apache Project • Web-enable languages, particularly Java, are changing the way functionality is developed over the Web • The emergence of the Web as a distributed development environment has given rise to several new organizations and products

  19. The World Wide Web :: Chapter 13 References • Bass L., Clements P. and Kazman R. Software Architecture in Practice. Second Edition, 2003. “o mundo pode esperar”

More Related