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Service Automation in Service Automation in Semantic Web, EB and GridSemantic Web, EB and Grid
Ching-Long Yeh 葉慶隆Department of Computer Science and Engineering
Tatung UniversityTaipei, Taiwan
Email: [email protected]://www.cse.ttu.edu.tw/chingyeh
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ContentContent
• Web technology evolution• Semantic Web • Semantic Web Service• Electronic Business Architecture: ebXML • Workflow Automation in Grid• Semantic Web Service Architecture• Summary
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InformationPool
WWWWWW
HTTP (Hyper Text Transport Protocol)HTML (Hyper Text Markup Language)URL (Uniform Resource Locator)
Web server
ApplicationClient
HTTP
URL
HTML Document
• Human-to-machine interaction• Information explosion
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InformationPool
Interaction Using XML
XML (eXtensible Markup Language)SOAP (Simple Object Access Protocol)
SOAP server
Application
HTTP
XML Document
• Machine-to-machine interaction • Service automation
SOAP server
Application
InformationPool
XML Document
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Web Service Architecture
Serviceregistry
Servicerequester
Serviceprovider
FindWSDL, UDDI
PublishWSDL, UDDI
Bind
Servicedescriptions
Servicedescriptions
Services
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Electronic Business
Transport, routing, packaging
Business processes,business documents
Company ACompany B
Transport, routing, packaging
Business processes,business documents
ERPERP
• Application-to-Application• Business Process Automation• RosettaNet• ebXML
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Semantic WebSemantic Web
• The Semantic Web is a vision:
• See “W3C Semantic Web Activity,” by Marja-Riitta Koivunen, for more descriptions.
the idea of having data on the web defined and linked in a way that it can be used by machines not just for display purposes, but for automation, integration and reuse of data across various applications
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Semantic WebSemantic Web
• The Semantic Web is the new generation of the World Wide Web, based on the semantic network knowledge representation formalism, which enables packaging information in the form of object-attribute-value statements, so called triplets.
• By assuming that terms used in these statements are based on the formally specified meaning (for the community of interest), i.e. ontologies, these triplets can be semantically processed by machine agents.
From: http://www2002.org/CDROM/poster/130.pdf
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The Semantic Web Layered ArchitectureThe Semantic Web Layered Architecture
(http://www.w3.org/2001/Talks/0228-tbl/slide5-0.html)
Tim Berners-Lee:“Axioms, Architecture and Aspirations”W3C all-working group plenary Meeting28 February 2001
URI Unicode
XML Namespaces
XML Schema
Sig
RDF M&S
RDF Schema
Ontology
Rules
Logic
Proof
Trust
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What Is in an Ontology?What Is in an Ontology?
• One widely cited definition of an ontology is Gruber’s [Gruber 1993] “A specification of a conceptualization”.
• An ontology is a formal explicit description of – concepts in a domain of discourse (classes (sometimes called
concepts)),
– properties of each concept describing various features and attributes of the concept (slots (sometimes called roles or properties)), and
– restrictions on slots (facets (sometimes called role restrictions)).
• An ontology together with a set of individual instances of classes constitutes a knowledge base.
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Ontology SpectrumOntology Spectrum
What is an Ontology?What is an Ontology?
Catalog/ID
GeneralLogical
constraints
Terms/glossary
Thesauri“narrower
term”relation
Formalis-a
Frames(properties)
Informalis-a
Formalinstance
Value Restrs.
Disjointness, Inverse, part-
of…
(From: http://www.ksl.stanford.edu/people/dlm/papers/ontologies-come-of-age-mit-press-(with-citation).htm)
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What is XML?What is XML?
• Extensible Markup Language• A Syntax for Documents • A Meta-Markup Language• A Structural and Semantic Language, not a Formatting
Language• Not just for Web pages
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XML StandardsXML Standards
• DTD• Namespace• Schema• DOM• CSS, XSL-T, XSL-FO• XLink• XPointer
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RDF M&SRDF M&S• RDF (Resource Description Framework)
– Beyond Machine readable to Machine understandable
• RDF consists of two parts– RDF Model (a set of triples)– RDF Syntax (different XML serialization syntaxes)
• RDF Schema for definition of Vocabularies (simple Ontologies) for RDF (and in RDF)
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RDF Data ModelRDF Data Model• Resources
– A resource is a thing you talk about (can reference)– Resources have URI’s– RDF definitions are themselves Resources (linkage, see
requirement 1)
• Properties – slots, define relationships to other resources or atomic values
• Statements– “Resource has Property with Value”– (Values can be resources or atomic XML data)
• Similar to Frame Systems
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A Simple ExampleA Simple Example• Statement
– “Ora Lassila is the creator of the resource http://www.w3.org/Home/Lassila”
• Structure– Resource (subject) http://www.w3.org/Home/Lassila– Property (predicate) http://www.schema.org/#Creator– Value (object) "Ora Lassila”
• Directed graph
http://www.w3.org/Home/Lassilas:Creator
Ora Lassila
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OWLOWLW3C Web Ontology LanguageW3C Web Ontology Language
• OWL provides three increasingly expressive sublanguages: OWL Lite, OWL DL, and OWL Full.
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OWLOWLW3C Web Ontology LanguageW3C Web Ontology Language
OWL Lite language constructs
RDF Schema Features: Class rdf:Property rdfs:subClassOf rdfs:subPropertyOf rdfs:domain rdfs:range Individual
(In)Equality: equivalentClass equivalentProperty sameAs differentFrom allDifferent
Property Characteristics: inverseOf TransitiveProperty SymmetricProperty FunctionalProperty InverseFunctionalProperty
Property Type Restrictions: allValuesFrom someValuesFrom
Restricted Cardinality: minCardinality (only 0 or 1) maxCardinality (only 0 or 1) cardinality (only 0 or 1)
Header Information: ontology imports
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Some Motivating TasksSome Motivating Tasks
• The kinds of task we expect OWL-S to enable:– Automatic Web service discovery – Automatic Web service invocation – Automatic Web service composition and interoperation – Automatic Web service execution monitoring
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High-level View of the Service OntologyHigh-level View of the Service Ontology
ServiceProfile
ServiceModel
ServiceGrounding
ServiceResourceprovides
presents
describedBy
supports
What the service does
How it works
How toAccess it
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Top Level of the Process OntologyTop Level of the Process Ontology
Process Profile
AtomicProcess Composite
ProcessSimpleProcess
ControlConstruct
SequenceRepeatUntil
ProcessComponent=Process U ControConstruct
ProcessComponent=Process U ControConstruct
ProcessComponent=Process U ControConstruct
hasProcesshasProfile
computedInputcomputedOutputcomputedEffect
computedPreconditioninvocab
compsedBy
expandcollapserealizes
realizedBy
hasGrounding
InputPrecondition
Outputeffect
Condition
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Grounding a Service to a Concrete Realization Grounding a Service to a Concrete Realization
Process Model
Atomic Process
Operation
DL-Based Types
Inputs/Outputs
Message
Binding to SOAP, HTTP, etc.
WSDL
OWL-S
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The ebXML Framework at WorkThe ebXML Framework at Work
Customer
Supplier
ebXMLRegistry
ProfilesProcessSpecifications
Registry Host1
2
Impl
emen
tatio
n
3
4
5
6
Intermediaries
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Components of the ebXML FrameworkComponents of the ebXML Framework
• Defining how public business-process must be described using the ebXML BPSS standard.
• Defining the semantics of business documents that are exchanged in public processes using ebXML’s Core Component (ebCC) standard.
• Definition of services and the constraints in using the services using Collaboration Protocol Profile (CPP) defined in the ebXML CPPA standard.
• Description of the mutual agreement between the business partners – Collaboration Protocol Agreement (CPA) – to carry out the public business process. The schema for a CPA is also defined by ebXML CPPA standard.
• Protocols for registering, storing, and retrieving public business processes and associated business documents, and CPPs using the ebXML Registry standard.
• A standard way to send and receive messages between business partners, as defined in the ebXML Message specification.
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IntroductionIntroduction
• Grid technologies are changing the way scientists conduct research, fostering large-scale collaborative endeavors where scientists share their resources, data, applications, and knowledge to pursue common goals.
• Collaborations, – Virtual Organizations (VOs), LIGO and GEO– Virtual Data, first introduced within the GriPhyN project,
• The Grid applications are no longer monolithic codes, rather they are being built from existing application components. – In general, we can think of applications as being defined by
workflows, where the activities in the workflow are individual application components and the dependencies between the activities reflect the data and/or control flow dependencies between the components.
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IntroductionIntroduction
• Although Grid middleware allows for discovery of the available resources and of the locations of the replicated data, users are currently responsible for carrying out all of these steps manually.
• Automating this process is desirable and necessary because of– Usability
– Complexity
– Solution cost
– Global cost
– Reliability
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Architecture of the planning system and itsinteractions with other Grid-based services.
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Application Example
• The GriPhyN Virtual Data System (VDS) that consists of Chimera, Pegasus and DAGMan has been used to execute both large workflows with an order of 100,000 jobs with relatively short runtimes and workflows with small number of long-running jobs.
Components of a Workflow Generation, Mapping and Execution System.
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Application Example
A simple example of partial workflow descriptions expressed in Chimera’s Virtual Data Language (VDL)
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IntroductionIntroduction
• Develop architectural and protocol abstractions forming a reference architecture to support Semantic Web Service technologies
• The support functions the architecture will cover– Dynamic Service Discovery– Service Process Enactment and Management– Negotiation and Contracting– Semantic Web Community Support Services– Semantic Web Service Lifecycle and Resource
Management Services– Cross-cutting Issues
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IntroductionIntroduction
• Semantic Web Services are viewed as a way to extend the capabilities of web services in the direction of dynamic interoperability.– Commercial web services, in both B2B and B2C applications– Grid computing– Ubiquitous computing– Information Services
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Functional AreasFunctional Areas
Dynamic Service Discovery B2B B2C Ubiq Grid Info
Advertising of Service Descriptions
Candidate Service Query Formulation
Candidate Service Matchmaking
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Functional AreasFunctional Areas
Service Process Enactment and Management B2B B2C Ubiq Grid Info
Candidate Service Selection
Service request formation and response interpretation
Request and Response Translation
Choreography interpretation and execution
Process mediation and delegation
Dynamic Service Composition
Process status monitoring and event notification
Service failure handling and compensation
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Functional AreasFunctional Areas
Negotiation and Contracting B2B B2C Ubiq Grid Info
Service contract negotiation
Dispute Resolution and Compliance
Non-Repudiation/Audit Tracking/Explanation
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Functional AreasFunctional Areas
Semantic Web Community Support Services B2B B2C Ubiq Grid Info
Ontology Management and Mapping Services
Service catalog and Information brokering Services
Membership and Authority Services
Security (identification/authentication, authorization, delegation)
Privacy Services
Reputation Services
Policy and Protocol Management Services
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Functional AreasFunctional Areas
Service Lifecycle Support B2B B2C Ubiq Grid Info
Executable process management services
Resource Allocation and Provisioning services
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SummarySummary
• Abstractions of services on emerging technological architectures
• The Semantic Web Service Architecture is probably an integration of the abstractions of services for various functional areas.
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ReferencesReferences
• W3C Semantic Web Activity, http://www.w3.org/2001/sw/• Semantic Web Specifications, http://www.w3.org/2001/sw/#spec• N. F. Noy and D. L. McGuinness. ``Ontology development 101: a guide to creating your first
ontology''. Stanford Knowledge Systems Laboratory Technical Report KSL-01-05 and Stanford Medical Informatics Technical Report SMI-2001-0880, March 2001.
• D. L. McGuinness. "Ontologies come of age". In D. Fensel, J. Hendler, H. Lieberman, and W. Wahlster (eds.) Spinning the Semantic Web: Bringing the World Wide Web to Its Full Potential. MIT Press, 2002.
• ebXML Technical Architecture Project Team, ebXML Technical Architecture Specification v1.0.4, http://www.ebxml.org/specs/ebTA.pdf
• J. Blythe, E. Deelman, and Y. Gil, “Automatically composed Workflows for Grid Environments,” IEEE INTELLIGENT SYSTEMS, July/August, 2004.
• Y. Gil, E. Deelman, J. Blythe, C. Kesselman, and H. Tangmunarunkit, “Artificial intelligence and Grids: workflow planning and beyond,” IEEE INTELLIGENT SYSTEMS, Jan/Feb, 2004.
• E. Deelman, et al, "Pegasus : mapping scientific workflows onto the Grid ," Across Grids Conference 2004, Nicosia, Cyprus, 2004.
• Mark Burstein (ed.), Semantic Web Services Architecture Requirements• Version 1.0 (1 June 2004), http://www.daml.org/services/swsa/swsa-requirements.html