Software Architecture for Semantic Web Service Execution

1. Software Architecture for Semantic Web Service Execution Semantic Web Services ClusterResearch Seminar 14 February 2005, Galway Matthew Moran

2. Structure • Idea and motivation • What is the state of the art? • What’s missing and what is the contribution? • Where is the novelty? • Methodology • Current research tasks • SWS and Grid • SWS and Grounding • WSMX Invocation • Next steps

3. Idea and Motivation • A detailed architecture for a Semantic Web Services System • As a lightweight system integration platform • Provide requirements analysis for the functionality • Look beyond current components of WSMX • Can be described using an Architecture Desc. Language • Motivation • Web services: lots of specs but lack of coherence • Lack of semantics holding back Web services for business • Want to learn fundamentals of integration architectures and where other initiatives failed

4. Initial TOC • Introduction • State of the art • Web services, SWS, Software system architectures • Functional requirements for SWS Architecture • WSMX + security, reliability, transactionality, state, lifetime, … • Configuration requirements • Architectural Description Languages • Detailed description of SWS architecture • Components and interfaces • Relationship between SWS and Grid • Use case • Deployment of SWS system in real industrial environment • Analysis of design validity • Conclusions

5. State of the Art • Semantic Web Service environments • WSMX and OWL-S Virtual • Conceptual WS and SWS architectures • WSA, WSMF, Chris Preist paper, REST • Web service technology stack • Integration systems • Architectures of other software system types • Operating systems, Compilers, JVM, DBMS • Middleware and distributed computing systems

6. What is Missing • A detailed architecture for a SWS environment • Functional components • How they connect • What happens if they fail • How can they be bypassed • Non-functional properties • Reliability • Security • Adaptability • Use-case that demonstrates viability of SWS architecture design and provides metrics for analysis • A formal description of this architecture • A way to simulate different execution scenarios

7. Novelty • No requirements document exists for SWS architecture • Extend WSMF description of functionality for successful Web services to Semantic WS • No technical architecture for a coherent Semantic Web Services architecture exists (with the exception of WSMX/DIP) • No analysis of the validity of SWS technology exists for a real industrial-standard use-case • No formal model of a SWS architectural model exists

8. Methodology – Learning • Web service technology stack • Software architecture design • Patterns • Architecture Description Languages • Formal languages for semantics • RDF, OWL, Petri-Nets for execution semantics • Integration concepts • A2A, B2B, EAI • Integration systems • TP-Monitors - Cics • Middleware – Corba, COM, J2EE • Commercial – BEA WebLogic, IBM Websphere, Oracle iAS, Iona Artix, MS Biztalk, … • Grid computing

9. Methodology – Year 1 • Actively learn ‘on the job’ • WSMO and WSMX working groups • Participation in DIP and ASG projects • Organise and present at tutorials • Present at business outreach meetings • Publications (5 + tutorials) • Focus on topics • Get feedback • Learn about related research areas • Select thesis topic • Write 4 page proposal

10. Methodology – Year 2 • Finalize table of contents • Publications (focused on chapters in ToC) • Grounding • State of the art in architecture • Security and WSMX • Grid and WSMX (ii) • Continue active involvement in WSMX, WSMO & Projects • Establish suitable use-case • Through DIP or ASG use cases • Through HP • Through business outreach partner • Analyse use-case outcome • Populate thesis

11. Current Research Tasks • Service grounding at conceptual level • Mapping between WSMO and XML-Schema Conceptual Framework • Relationship between SWS and Grid • What can WSMX learn from Globus Toolkit • Service interaction (Communication Manager) • Handling different transport protocols and faults

12. Grounding at the Conceptual Level

13. Relationship between SWS and Grid SemanticWeb Services WSMO: Conceptual Model WSML: Language WSMX: Architecture & Ref. Implementation Event-basedFramework Discovery Composition Invocation Mediation

14. Relationship between SWS and Grid WSRF:WS-ResourceWS-ResourcePropertiesWS-ResourceLifetime(OASIS) SemanticWeb Services Grid WSMO: Conceptual Model WS-Addressing(W3C) WSML: Language WSMX: Architecture & Ref. Implementation SecurityGSI Dynamic EndpointAddressing Event-basedFramework Discovery Composition Service State Introspection Service Lifetime management Invocation Mediation

15. Service Interaction – Send & Receive • Use Web Service Implementation Framework (Apache WSIF) • Open source • Dynamic invocation based on WSDL • Abstracts binding details from service • Handling QoS issues at message level • Faults • Security • Reliability • Transactions • Relationship between Communication Manager and: • Choreography • Adaptors (including grounding)

16. Next Steps • Next draft of ToC • Papers • Architecture of integration systems • Invocation and grounding in WSMX • Security and WSMX • WSMX and Grid • Describing WSMX with ADL • Implementation • Communication Manager • Grounding • Use case: • Find a suitable use case • Arrange to deploy WSMX to address the problem