Transcript A Software Architecture for SWS - Research Seminar

Software Architecture for
Semantic Web Service
Execution
Semantic Web Services Cluster
Research Seminar
14 February 2005, Galway
Matthew Moran
14/02/2005
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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
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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
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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
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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
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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
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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
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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
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Methodology – Year 1
• Actively learn ‘on the job’
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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
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Methodology – Year 2
• Finalize table of contents
• Publications (focused on chapters in ToC)
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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
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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
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Grounding at the Conceptual
Level
XML Schema
Conceptual
Framework
XML Schema
XML Data Instance
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Bidirectional mappings
at conceptual level
Rules based on
conceptual mappings
Rules based on
conceptual mappings
WSMO Ontology
Metamodel
WSMO Ontology
WSML Data Instance
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Relationship between SWS and Grid
Semantic
Web Services
WSMO: Conceptual Model
WSML: Language
WSMX: Architecture & Ref. Implementation
Event-based
Framework
Discovery
Invocation
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Composition
Mediation
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Relationship between SWS and Grid
Semantic
Web Services
WSRF:
WS-Resource
WS-ResourceProperties
WS-ResourceLifetime
(OASIS)
Grid
WSMO: Conceptual Model
WS-Addressing
(W3C)
WSML: Language
Security
GSI
WSMX: Architecture & Ref. Implementation
Dynamic Endpoint
Addressing
Event-based
Framework
Discovery
Invocation
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Composition
Service State
Introspection
Service Lifetime
management
Mediation
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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
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Faults
Security
Reliability
Transactions
• Relationship between Communication Manager and:
– Choreography
– Adaptors (including grounding)
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Next Steps
• Next draft of ToC
• Papers
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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
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