1. ICE0534 – Web-based Software Development ICE1338 – Programming for WWW Lecture #11 Lecture #11 In-Young Ko iko.AT. icu.ac.kr iko.AT. icu.ac.kr Information and Communications University (ICU) - Summer 2005 -

2. Summer 2005 2 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Announcements Reading Questions #6 (for the Ph.D. lecture) is due by Tuesday August 4th Reading Questions #6 (for the Ph.D. lecture) is due by Tuesday August 4th Read the readings for Semantic Web Read the readings for Semantic Web Project Presentations Project Presentations 12 min presentation, 5 min Q&A 12 min presentation, 5 min Q&A Send your presentation material to the TA by August 10 th 5PM Send your presentation material to the TA by August 10 th 5PM All presentation and demo must be done on the machine in the classroom (please do not use your laptop computers) All presentation and demo must be done on the machine in the classroom (please do not use your laptop computers)

3. Summer 2005 3 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Last Lecture Web Services Web Services Web Services Architecture Web Services Architecture Web Services Standards Web Services Standards Technology Reviews Technology Reviews SOAP [u13: Jongwook Lee] SOAP [u13: Jongwook Lee] WSDL [u14: Hyunho Park] WSDL [u14: Hyunho Park] Technology Surveys Technology Surveys UDDI [g19: Jongha Jung] UDDI [g19: Jongha Jung] SOA (Service-oriented Architecture) [g20: Changsup Keum] SOA (Service-oriented Architecture) [g20: Changsup Keum] Web-services Platforms [g21: Youngkyu Park] Web-services Platforms [g21: Youngkyu Park]

4. Summer 2005 4 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University This Lecture Web Services Composition Web Services Composition Ph.D. Lecture Ph.D. Lecture Modeling Stateful Resource with Web Services [p1: Byung-sang Kim] Modeling Stateful Resource with Web Services [p1: Byung-sang Kim] Technology Reviews Technology Reviews BPEL4WS [u16: Sungjun Park] BPEL4WS [u16: Sungjun Park] Technology Surveys Technology Surveys Business process [g22: Kuyul Noh] Business process [g22: Kuyul Noh] Service brokering [g23: Yusik Park] Service brokering [g23: Yusik Park] (1) (3) (2) (4)

5. Summer 2005 5 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Web Services Stack http://www-306.ibm.com/software/solutions/webservices/pdf/WSCA.pdf “The service provider sends a WSDL document directly to a service requestor.” “Direct publication is useful for statically bound applications.”

6. Summer 2005 6 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Book Purchasing Process Vender Search ISBNs Business ID, Price Business ID, Items Customer Info. Business ID Book Cataloging Payment DeliveryPayment

7. Summer 2005 7 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Book Purchasing Process Vender Search ISBNs Business ID, Price Business ID, Items Customer Info. Business ID Book Cataloging Payment DeliveryPayment Web Services

8. Summer 2005 8 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Book Purchasing Process Vender Search Customer Info. Book Cataloging Payment DeliveryPayment Company A Company B Company C Company D

9. Summer 2005 9 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Software Synthesis (Composition) Assembling software components rather than constructing a system Assembling software components rather than constructing a system Software Components: Software Components: Binary (executable) units that are independently produced, acquired and deployed, and can be connected to each other to form a composite system [Szyperski 1998] Component-based Composition Paradigms Component-based Composition Paradigms Software Integration Circuits Software Integration Circuits Software Schemas Software Schemas Megaprogramming Megaprogramming Web Services Web Services

10. Summer 2005 10 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Web Services Flows Web Services enable on-the-fly software creation by utilizing loosely coupled, reusable software components Web Services enable on-the-fly software creation by utilizing loosely coupled, reusable software components Software can be developed and delivered as streams of services as opposed to packaged products Software can be developed and delivered as streams of services as opposed to packaged products Services can be decentralized and distributed over the Internet Services can be decentralized and distributed over the Internet Web Services make it possible to achieve the dynamic enterprise and dynamic value chains Web Services make it possible to achieve the dynamic enterprise and dynamic value chains [swws.semanticweb.org]

11. Summer 2005 11 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Layers for Web Services Composition Service Layer Platform Layer Web Services Platforms Abstract (Bus. Process) Layer Business Processes Application Layer Application Instances

12. Summer 2005 12 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University

13. Summer 2005 13 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Web Services Orchestration and Choreography Orchestrations: a centralized control of interaction among Web services based on a business logic, etc.; making executable processes Orchestrations: a centralized control of interaction among Web services based on a business logic, etc.; making executable processes e.g., BPEL4WS (Business Process Execution Language for Web Services) e.g., BPEL4WS (Business Process Execution Language for Web Services) Choreography: a collaborative control of interaction among Web services using agents that exchange messages Choreography: a collaborative control of interaction among Web services using agents that exchange messages e.g., WSCI (Web Service Choreography Interface) e.g., WSCI (Web Service Choreography Interface) [Pel03]

14. Summer 2005 14 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Orchestration vs. Choreography Industry Acceptance Industry Acceptance BPEL4WS – IBM, Microsoft, and BEA; submitted to OASIS (Organization for the Advancement of Structured Information Standards) BPEL4WS – IBM, Microsoft, and BEA; submitted to OASIS (Organization for the Advancement of Structured Information Standards) WSCI – Sun, Intalio, and SAP; submitted to W3C WSCI – Sun, Intalio, and SAP; submitted to W3C [Pel03] Orchestration Choreography

15. Summer 2005 15 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University BPEL4WS Example <receive name="receive" partnerLink="Buyer" operation="request" variable="request" initiate="yes"> <invoke name="quote_supplier1" partnerLink="Supplier1" operation="request_quote" inputVariable="part_request" outputVariable="part_quote">

16. Summer 2005 16 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University WSCI Example <action name="Confirm" role="Agent" operation="tns:Confirm">

17. Summer 2005 17 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Technical Requirements for Web Services Composition Flexibility – Resulted from “ a clear separation between the process logic and the Web services invoked ” Flexibility – Resulted from “ a clear separation between the process logic and the Web services invoked ” Basic and structured activities – to handle business process (workflow) semantics Basic and structured activities – to handle business process (workflow) semantics Recursive composition – to support higher- level abstractions Recursive composition – to support higher- level abstractions Persistence and correlation – required to handle asynchronous Web services Persistence and correlation – required to handle asynchronous Web services Exception handling and transactions – especially important for transactions that run over a long period of time Exception handling and transactions – especially important for transactions that run over a long period of time [Pel03]

18. Summer 2005 18 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Web Services Based Application Development Models for Service & Data Descriptions Service Description Tool Describe semantic information of component services and data Service Description Tool Describe semantic information of component services and data Metadata Repository of Service and Data Descriptions Dynamic Service Coordinator Represent and control parallelism and synchronization between services Dynamic Service Coordinator Represent and control parallelism and synchronization between services Service Coordination Plan Models for Web Services Applications Web Services Based Application Composer Compose Web Services applications based on an abstract model Web Services Based Application Composer Compose Web Services applications based on an abstract model Web Services Applications Service Broker Perform reasoning on the semantic information to identify interoperable or compatible services Service Broker Perform reasoning on the semantic information to identify interoperable or compatible services Interoperable Services

19. Summer 2005 19 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University A Service-oriented Information System Service Repository: stores the descriptions about functionalities and properties of services Service Repository: stores the descriptions about functionalities and properties of services Service Broker: returns a set of candidate services that meet a set of requirements Service Broker: returns a set of candidate services that meet a set of requirements Application Composition Tool: connects services based on an abstract application model Application Composition Tool: connects services based on an abstract application model Run-time Coordinator: controls services in an application during runtime Run-time Coordinator: controls services in an application during runtime Information Retrieval Services Information Analysis Services Information Visualization Services Individual Information Services Service Access Infrastructure Service Developers An Information System System Administrators End Users Client Subsystem Application Developers Run-time Service Coordinator Application Repository Component Description Tool Application Composition Tool Service Repository Service Broker

20. Summer 2005 20 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University Problems… Hard to cope with changing user requirements and dynamic situations Hard to cope with changing user requirements and dynamic situations Hard to choose from a large and growing number of available software components and services (e.g., new component versions, new applications, Web services) Hard to choose from a large and growing number of available software components and services (e.g., new component versions, new applications, Web services) Hard to make them work together due to high complexity in interoperability relationships Hard to make them work together due to high complexity in interoperability relationships

21. Summer 2005 21 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University What we need is … Dynamic and Adaptive Software Development Framework that enables: Dynamic and Adaptive Software Development Framework that enables: Quick delivery of new applications based on new demands Quick delivery of new applications based on new demands Acquisition and adoption of new functions and services Acquisition and adoption of new functions and services Agility to adapt applications to user requirements and changing environmental conditions Agility to adapt applications to user requirements and changing environmental conditions

22. Summer 2005 22 ICE 0534/ICE1338 – WWW © In-Young Ko, Information and Communications University A Web Services Composition Tool