WS-DAIOnt: A framework of ontology access services for

1
WS-DAIOnt-RDF(S) A framework of ontology access
services for RDF(S) ontologies
Miguel Esteban Gutiérrezmesteban_at_fi.upm.esAsunci
ón Gómez-Pérezasun_at_fi.upm.esÓscar Muñoz
Garcíaomunoz_at_fi.upm.esBoris Villazón Terrazas
bvillazon_at_fi.upm.es
Ontology Engineering Group, UPM
RDF, Ontologies and Meta-Data Workshop Edinburgh,
June 7th - 9th 2006
2
Table of Contents

• Introduction
• WS-DAIOnt
• WS-DAIOnt-RDF(S)
• Workplan

3
Diversity of Ontology tools and languages

• No uniform access to ontologies implemented in
  W3C languages
• RDF(S)
• OWL
• Each language has several query languages and
  inference engines
• RDF(S) SPARQL, SeRQL, RQL, RDQL and SILRI, RIL,
  Triple
• OLW OWL-QL and FACT, Racer
• Each ontology tool and storage system has its
  own API for accessing ontologies

• Accessing RDF(S) ontologies
• Sesame
• Statements(classUri, rdfstype, rdfsclass)
  next() getObject()
• Jena
• getResource(classURI)

4
OGSA Semantic limitations

• No Grid compliant ontology access mechanisms in
  RDF(S) and OWL
• No specialized registry for localizing ontologies
• No Grid compliant instance access mechanisms in
  RDF
• SemGrid Applications access ontologies as on the
  Semantic Web

5
Adding ontologies to OGSA OGSA-ONT

• Grid compliant ontology access and querying
  mechanisms for
• RDF(S)
• OWL
• Specialized registry for localizing ontologies

6
OntoGrid, Ontologies and S-OGSA

• Architect, adapt and extend existing ontology
  services to be Grid compliant
• Access and querying
• heterogeneus and
• distributed ontology sources
• as a homogeneous logical
• resources
• Provide homogeneous
• service interfaces
• Modular design to ease
• extensibility

7
What is WS-DAIOnt?

• Web Services Data Access and Integration The
  Ontology Realization
• Specification of Grid Compliant Ontology
  Services, which
• Defines a framework for creating ontology access
  services in a Grid environment
• Is fully compliant with S-OGSA (consequently with
  OGSA)
• Is based on up-to-date Grid standards (GGF)
• WS-DAI
• Is based on Web Service standards (OASIS, W3C)
• WS-RF, WS-Addressing...
• First implementation focused on RDF(S)
  WS-DAIOnt-RDF(S)
• Sesame and Jena (Oracle RDF-store, Atlas)
• Query languages SPARQL, SeRQL, RDQL, RQL

8
Two sample implementations Architectural
implications

• Dual tier approach
• Client side single access logic
• Server side One protocol two implementations

• Monolithic approach
• Client side splitted ontology access logic
• Server side Two protocols two implementations

9
WS-DAIOnt-RDF(S) RDF(S) Ontology Access in Grids

• Our purpose
• To provide a rational access mechanism for
  RDF(S) (ontologies) in Grid environments

• Activities to carry out
• Workout a spec defining the interfaces,
  operations, messages, etc. that are to be
  provided
• Develop a system that follows the spec

• but we dont start from the scratch
• OGSA
• WS-DAI
• Globus Toolkit 4
• Different RDF(S) storages (Sesame, Jena, )

10
WS-DAIOnt-RDF(S) Implementation Architecture

• Two-tier architecture
• Web Service tier
• Upper service layer
• Intermediate service layer
• Lower service layer
• RDF(S) access tier
• RDFSConnector
• Storage layer

11
Implementation and Specification
12
RDFSRepositorySelectorService
13
RDFSRepositorySelectorService sample message
getRepositoryFactory message
Returns an EPR for a given repository
ltxsdelement name"getRepositoryFactory"gt
ltxsdcomplexTypegt ltxsdsequencegt
ltxsdelement name "id" minOccurs"1"
maxOccurs"1" ref"tnsrepositoryId"/gt
lt/xsdsequencegt lt/xsdcomplexTypegt lt/xsdelemen
tgt ltxsdelement name"getRepositoryFactoryResponse
"gt ltxsdcomplexTypegt ltxsdsequencegt
ltxsdelement name "epr" minOccurs"1"
maxOccurs"1" ref"wsaEndpointReference"/gt
lt/xsdsequencegt lt/xsdcomplexTypegt lt/xsdelemen
tgt
14
RDFSRepositoryService
15
RDFSRepositoryService sample messages (I)
getClassFactory message
Returns the EPR for a given class
ltxsdelement name"getClassFactory"gt
ltxsdcomplexTypegt ltxsdsequencegt
ltxsdelement name"classUri" maxOccurs"1"
minOccurs"1" ref"tnsUri"/gt
lt/xsdsequencegt lt/xsdcomplexTypegt lt/xsdelemen
tgt ltxsdelement name"getClassFactoryResponse"gt
ltxsdcomplexTypegt ltxsdsequencegt
ltxsdelement name"epr" ref"wsaEndpointReference
"/gt lt/xsdsequencegt lt/xsdcomplexTypegt lt/
xsdelementgt
16
RDFSRepositoryService sample messages (II)
query message
Performs a SELECT or CONSTRUCT query to the
repository in a given QL and returns the result
as a table of string values
ltxsdelement name"query"gt ltxsdcomplexTypegt
ltxsdsequencegt ltxsdelement
name"queryString" maxOccurs"1" minOccurs"1"
ref"tnsQuery"/gt ltxsdelement
name"queryLanguage" maxOccurs"1" minOccurs"1"
ref"tnsLanguage"/gt lt/xsdsequencegt
lt/xsdcomplexTypegt lt/xsdelementgt ltxsdelement
name"queryResponse"gt ltxsdcomplexTypegt
ltxsdsequencegt ltxsdelement
name"resourceSet" minOccurs"0"
maxOccurs"unbounded" ref"tnsRow"/gt/gt
lt/xsdsequencegt lt/xsdcomplexTypegt lt/xsdelemen
tgt
17
RDFSClassService
18
RDFSClassService sample messages (I)
getSubclasses message
Returns all the subclasses of the class
ltxsdelement name"getSubClasses"gt
ltxsdcomplexType/gt lt/xsdelementgt ltxsdelement
name"getSubClassesResponse"gt
ltxsdcomplexTypegt ltxsdsequencegt
ltxsdelement name"classes" minOccurs"0"
maxOccurs"unbounded" ref"tnsUri"/gt
lt/xsdsequencegt lt/xsdcomplexTypegt lt/xsdelemen
tgt
19
RDFSClassService sample messages (II)
getSuperClasses message
Returns all the superclasses of the class
ltxsdelement name"getSuperClasses"gt
ltxsdcomplexType/gt lt/xsdelementgt ltxsdelement
name"getSuperClassesResponse"gt
ltxsdcomplexTypegt ltxsdsequencegt
ltxsdelement name"classes" minOccurs"0"
maxOccurs"unbounded" ref"tnsUri"/gt
lt/xsdsequencegt lt/xsdcomplexTypegt lt/xsdelemen
tgt
20
RDFSRepository.rdfs Structure
Configuring the system
RDFSRepository
RDFSNamespace uri
has

• More RDF(S) Repositories here to be added
• For example
• Jena RDF(S) storage
• Oracle-RDF
• RDF distributed systems (ATLAS)

21
RDFSRepository.rdf example
Sample configuration

• lt?xml version"1.0" encoding"WINDOWS-1252"?gt
• ltrdfRDF xmlnsrdfs_repos"http//wsdaiordfs.eu.is
  t.ontogrid/RDFSRepository" xmlnsrdf"http//www.
  w3.org/1999/02/22-rdf-syntax-ns"
  xmlnsrdfs"http//www.w3.org/2000/01/rdf-schema"
  gt
• ltrdfDescription
• rdfabout"http//wsdaiordfs.eu.ist.ontogr
  id/RDFSRepositorycivil_file"gt
• ltrdfscommentgtA testing filelt/rdfscommentgt
• ltrdfslabelgtcivil_filelt/rdfslabelgt
• ltrdfs_reposhas
• rdfresource"http//wsdaiordfs.eu.
  ist.ontogrid/RDFSRepositorycivil"/gt
• ltrdfs_reposfilegt/etc/ws-daio-rdfs/Civil_Persona
  lity.rdfslt/rdfs_reposfilegt
• ltrdftype rdfresource"http//wsdaiordfs.eu.ist
  .ontogrid/
• 
  RDFSRepositoryRDFSSesameFileRepository"/gt
• lt/rdfDescriptiongt
• ltrdfDescription rdfabout"http//wsdaiordfs.eu.
  ist.ontogrid/RDFSRepositorycivil"gt
• ltrdfscommentgtAn example namespace.lt/rdfscommen
  tgt
• ltrdfslabelgtcivillt/rdfslabelgt
• ltrdfs_reposurigthttp//webode.dia.fi.upm.es/RDFS
  /Civil_Personalitylt/rdfs_reposurigt
• ltrdftype
• rdfresource"http//wsdaiordfs.eu.
  ist.ontogrid/RDFSRepositoryRDFSNamespace"/gt
• lt/rdfDescriptiongt

22
Where we are moving to
23
Access to WS-DAIOnt-RDF(S) implementation

• Publications
• WS-DAIOnt Ontology Access Provisioning in Grid
  Environments. Esteban Gutiérrez M, Gómez-Pérez A,
  Bechhofer S. Knowledge and Data Management in
  Grids (Springer CoreGRID Series). In press.
• Source code
• http//www.ontogrid.net/, For Downloading
  Distributions
• Access to CVS
• Connection type pserver
• user ontogrid
• password not needed
• Host rpc262.cs.man.ac.uk
• Port 2401
• Repository path /local/ontogrid/cvsroot
• module prototype/ws-daio-rdfs

24
Ongoing development workplan in OntoGrid

• First spec for WS-DAIOnt
• Ontogrid deliverable d3.1
• WS-DAIOnt-RDF(S) implementation
• access to RDF(S) ontologies
• stored in Sesame (download it !!)
• stored in Jena (July 2006)
• Update the Spec at the end of (Sept 2006)
• WS-DAIOnt-OWL
• spec first implementation (Sept 2007)

25
GGF activities

• BoF discussion in GGF16 and GGF17
• Chartering the RDF(S) access initiative as part
  of the DAIS WG
• Joint collaboration OntoGrid (UPM) AIST
• DAIS RDF F2F Breakout session on friday

26
Use WS-DAIOnt-RDF(S)! available
atwww.ontogrid.net
Feedback to mesteban_at_fi.upm.es
omunoz_at_fi.upm.es
Acknowledgements to the OntoGrid consortium