1. Lecture 2: Service Oriented Computing

2. Enter 21 st Century!

3. Our Information Landscape Image from: http://www.socialmedia.biz/images/masssocialmedia.png

4. The Future of Information Image from: http://novaspivack.typepad.com/nova_spivacks_weblog/metaweb_graph.JPG

5. What is 21st Century Business? Buyers and sellers who are: Effective Learners Effective Collaborators Effective Creators Image from: http://www.uniquecare.org/Collaborate%20250.jpg What do you think?

6. 21st Century Learners: Lifelong learners Can learn how to learn Independent learners Metacognitive Intrinsically motivated Focus on self improvement Image from: http://flickr.com/photos/akaicker/38149570/

7. 21st Century Collaborators: Are effective communicators. Are socially and culturally aware. Take responsibility for their role. Are flexible. Image from: http://flickr.com/photos/wainwright/351684037/.

8. 21st Century Collaborators: Are able to delegate or share responsibility when necessary. Are equally comfortable as either leaders or participants. Appreciate and internalize the essential interdependence of being part of society. Image from: http://flickr.com/photos/pedrosimoes7/1301014184/

9. 21st Century Creators: Effectively analyze and synthesize. Originality, innovative and creative contributors to society. “think outside the box”. Systems thinkers. Goal oriented and productive. Demonstrate ethical responsibility. Image from: http://flickr.com/photos/jimfrazier/525695141/

10. Why Go Global? “The World is Flat” We are no longer bound by four walls of classroom Authentic development experiences Image from: http://www.csupomona.edu/~sfenglehart/%20Hst%20Images%20/Berlin%20Wall.JPEG

11. Why Go Global? Learning (and life) is networked, digital, connected. Create an authentic classroom environment. Image from: http://www.psychologicalscience.org/observer/2006/0306/images/old_classroom.jpg

12. Why Go Global? Power of networks Screen Shot from: Chrissy Hellyer @ Teaching Sagittarian: http://teachingsagittarian.edublogs.org/

13. New Interfaces? Tap into the energy that people are bringing through new interfaces. Image from: http://flickr.com/photos/bigduke6/90086641/

14. The Technology Toolbox How to pick the right tools for the job Image from: http://flickr.com/photos/mamabarns/747588843/

15. The Technology Toolbox

16. ToolBox: Blogs When to use a blog: individual reflection seeking feedback Grade 5 Student Blog: http://heejae.learnerblogs.org/

17. ToolBox: Blogs Features of a blog: Entries posted in consecutive order, newest on top Comments from readers extend classroom learning Personal journal Grade 5 Student Blog: http://heejae.learnerblogs.org/

18. ToolBoox: Wikis When to use a wiki collaborative knowledge building Grade 6 Student Wiki: http://ancientafricah.wikispaces.com

19. ToolBox: Social Networking When to use Social Networks Connecting students and teachers Grade 4 Flat Classroom Project: http://connectedclassroom.ning.com/

20. Collaborative Multimedia creative representation of ideas Sample VoiceThread: http://voicethread.com/#home.b6073.i45532

21. ToolBox: VoIP When to use VoIP Communicating with personal learning network Connecting on a personal level

22. ToolBox: VoIP Features of VOIP Audio/video e-mail Audio/video chat Recording discussions 7th Grade YackPack

23. The Ultimate Goal Learning anytime, anywhere. Develop a global Personal Learning Network Communicate, Connect and Collaborate Image from: http://prblog.typepad.com/strategic_public_relation/images/2007/06/22/simple_social_network.png

25. Chapter 1 25Service-Oriented Computing: Semantics, Processes, Agents - Munindar Singh and Michael Huhns Highlights of this Chapter Visions for the Web Open Environments Services Introduced The Evolving Web Standards Bodies

26. The Web As It Is Not easy to program Designed for people to get information Focuses on visual display (as in HTML) Lacks support for meaning Supports low-level interactions HTTP is stateless Processing is client-server Creates avoidable dependencies among what should be independent components

27. The Web As It Is Becoming Enable interactions autonomous, heterogeneous parties (information providers and users) Go beyond visual display to capture meaning  Semantic Web Support standardized interfaces  Web services Support complex activities  processes Support rich interactions among autonomous parties  agents

28. Historical View of Services over the Web GenerationScopeTechnologyExample FirstAllBrowserAny HTML page SecondProgrammaticScreen scraper Systematically generated HTML content ThirdStandardizedWeb servicesFormally described service FourthSemanticSemantic Web services Semantically described service

29. Viewpoints on Services Traditionally, a capability that is provided and exploited, often but not always remotely Networking: bundle of bandwidth-type properties Telecom: features (caller ID, forwarding) Systems: operational functions (billing, storage); parceled up into operation-support systems Web or Grid: Web pages or Grid resources Wireless: Wireless access; messaging By contrast, we treat services as resembling real-life services or business partners

30. What is a Web Service? A piece of business logic accessible via the Internet using open standards (Microsoft) Encapsulated, loosely coupled, contracted software functions, offered via standard protocols (DestiCorp) A set of interfaces providing a standard means of interoperating between different software applications, running on a variety of platforms and frameworks (W3C) Our working definition: A service is functionality that can be engaged

31. Scope Includes wherever Internet and Web technologies are employed Internet Intranet: network restricted within an enterprise Extranet: private network restricted to selected enterprises Virtual Private Network (VPN): a way to realize an intranet or extranet over the Internet

32. Service Composition Vision Specify and provide services independently, hiding implementations Use services in combination in novel ways Going beyond the idea of a passive object Obviously desirable and challenging But is this what we want? Can or should implementations be hidden? What about organizational visibility? How to assess risk? How to handle exceptions?

33. Applications of Composable Services Portals Legacy system interoperation E-commerce Virtual enterprises Grid computing

34. Autonomy Independence of business partners (users and organizations) Political reasons Ownership of resources Control, especially of access privileges Payments Technical reasons Opacity of systems with respect to key features, e.g., precommit in distributed databases

35. Heterogeneity Independence of component designers and system architects Political reasons Ownership of resources Technical reasons Conceptual problems in integration Fragility of integration Difficult to guarantee behavior of integrated systems

36. Dynamism Independence of system administrators Needed because the parties change Architecture and implementation Behavior Interactions Make configurations dynamic to improve service quality and maintain flexibility

37. Locality: How to Handle the Above Reduce sharing of data and metadata to reduce inconsistencies and anomalies Reduce hard-coding, which reflects out-of- band agreements among programmers Bind dynamically to components Use standardized formats to express data Express important knowledge as metadata Use standardized languages to express metadata Relax consistency constraints Obtain remote knowledge only when needed Correct rather than prevent violations of constraints: often feasible

38. System Architectures: Centralized Mainframe Terminal3270 Terminal

39. System Architectures: Client-Server E-Mail Server Web Server Database Server PC Client PC Client PC Client Workstation Client Master-Slave

40. System Architectures: Peer-to-Peer E-Mail System Web System Database System Application

41. System Architectures: Cooperative E-Mail System Web System Database System Application (Mediators, Proxies, Aides, Wrappers) Agent

42. An Introduction to Web Services

43. Objectives Discuss distributed computing Explain web services and their characteristics Discuss the generic architecture of web services Describe the life cycle of a web service Identify the requirements for a web service Explain the working of a web service Discuss the advantages and disadvantages of web services

44. Component Architecture Components Method 1…… User submits parameters Appropriate Method called Returns the result Application Method 2……

45. Application Computing Over the Years (1) Database Stand-alone Computers

46. Client-Server Computing Server Clients: Smart terminals PC Computing Over the Years (2)

47. Distributed Computing Smart terminals Network Distributed Computing Component A Windows OS Component B Component F Linux OS Component CComponent D Component E

48. Distributed Component Architectures  The three main Distributed Component Architectures are: CORBA Developed by OMG DCOM Developed by Microsoft RMI Developed by SUN. Uses CORBA for Heavy-Duty Distributed Systems

49. Inter-Module Communication Application developed using C# Application developed using VB.net Inter-Module communication needs: 1. Set of rules for communication 2. Standard Language for interfaces 3. Interfaces for the modules

50. Web-based Applications Must be simple, self explanatory and easy to use Services Offered e-mail, browsing, searching the net, chat applications Devices Used to Access the Web

51. Web Services Network Network may be LAN, WAN, MAN or Internet  Web Services: Internet based modular applications Web Service

52. Web Services Solutions Two of the most popular Web Services Solutions SUN TM OPEN NET ENVIRONMENT (SUN ONE)

53. Web Service Example EMI Calculator Web Service Loan Application Using Web Service Running on Another Web Service

54. Characteristics of Web Services Should be registered Uses XML Uses standard web protocols Accessed over the web Web Services Has a service interface Supported by loosely coupled applications Integrated Just In Time

55. Important Components Service Broker Service Requestor Service Provider Service Registry Publish Find Bind

56. Web Services: Generic Architecture

57. Life Cycle 1. Create a web service 2. Define service interface, invocation methods for the web service 3. Publish the web service on the Internet or Intranet 5. Invoke the web service 6. Unpublish the web service when not needed 4. Search for the web service

58. Requirements for a Web Service XML: Represent data in a standard format SOAP: Common extensible message format WSDL: Common, extensible, service description language UDDI: Maintains registries storing information about service providers and their services

59. Working of a Web Service Soap Protocol XML over HTTP Parameters Return Value Get Type info (XML Schema) Service Description Web Server (With Web Service) Client Application

60. Accessing Web Services over HTTP HTTP GET operation HTTP POST operation SOAP

61. Business Process Web Service Organization A Organization B Advantages of Web Services  Cross business integration  Improved efficiency  Closer customer relationships  Facilitates just-in-time integration  Reduces complexity  Legacy applications

62. Constraints Businesses not willing to expose the functionalities The only technology that forms the base is XML, that means we cannot do without XML The cost involved is very high

63. How it works? Consider a simple account-management and order -processing system. The accounting personnel use a client application built with Visual Basic or JSP to create new accounts and enter new customer orders. The processing logic for this system is written in Java and resides on a Solaris machine, which also interacts with a database to store the information. The steps illustrated above are as follows: 1. The client program bundles the account registration information into a SOAP message. 2. This SOAP message is sent to the Web Service as the body of an HTTP POST request. 3. The Web Service unpacks the SOAP request and converts it into a command that the application can understand. The application processes the information as required and responds with a new unique account number for that customer. 4. Next, the Web Service packages up the response into another SOAP message, which it sends back to the client program in response to its HTTP request. 5. The client program unpacks the SOAP message to obtain the results of the account registration process. For further details regarding the implementation of Web Services technology, read about the Cape Clear product set and review the product components.