OWLS: As a Semantic Markup Language for Grid Services

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OWL-S As a Semantic Mark-up Language for Grid
Services
By Narendranadh.J
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Topics

• Objective
• Introduction
• Current Scenario
• Motivation
• Semantics
• OWL-S Relevance to Grid Services
• Previous Work
• Why GWSDL2OWL-S
• How To Migrate From GWSDL2OWL-S
• Solution Space/Implementation
• What needs to be done/Challenges
• Conclusions
• Future Work

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Objective

• To propose a suitable semantic description
  language for grid services

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Introduction

• What is a Grid Service
• Any Physical or logical resource
• e.g. A collection of computers or A Complex
  Software Program
• What is a Semantic Description Language
• Represents resources in terms of their
  meaning rather than syntax.
• e.g. A UNIX machine is either Solaris, LINUX
  etc.

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Current Scenario

• Grid Services are Represented Syntactically.
  OGSI Spec.
• Uses GWSDL Extension of WSDL
• The Extensions are for
• State Fullness Service Data
• Service Description
• Life Cycle Management

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Motivation

• According to OGSI
• The service description is meant to capture
  both interface syntax, as well as (in a very
  rudimentary, non-normative fashion) semantics.
• Concise semantics can be associated with each
  of these names in specification documentsand
  perhaps in the future through Semantic Web or
  other more formal descriptions.

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Motivation (contd)

• Semantic Grid
• Visions for an e-science environment
• Demands
• Dynamic Info.
• QoS of Grid services
• Versioning and Dynamic Policy Changes
• Multi Party Negotiation
• Interoperability
• Also, Demands a More Expressive Language for Grid
  Service Publishing, Discovery and Composition.

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Semantics

• OWL-S Ontology Web Language for Web Services
• Claims
• 1) Automatic Web Service Discovery
• 2) Automatic Web Service Invocation
• 3) Automatic Web Service Composition and
  Interaction
• 4) Automatic Web Service Execution Monitoring
  Currently not Supported

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Semantics contd

• OWL-S uses OWL classes to represent resources,
  properties and the relationships between
  different classes
• OWL reasoners infer semantics from these
  properties and relationships
• OWL-S include
• Service Profile service desc. for humans
• Service Model IOPEs
• Service Grounding Concrete Specification

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OWL-S Relevance to Grid Services

• Service Profiles Can be Used in Dual Ways
• Representing Service Capabilities
• Representing Service Needs
• Service Model Allows
• Resource Analysis, Service Composition,
  Coordination and Execution Monitoring

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Previous Work

• G-QoSM Grid Service Discovery Using QoS
  Properties, Rashid etal
• Ontology-based Resource Matching in the Grid
  The Grid meets the Semantic Web
  Hongsuda Tangmunarunkit etal
• A Grid Service Discovery Matchmaker based on
  Ontology Description, Simone A. Ludwig etc.
• Autonomic Service Adaptation in ICENI using
  Ontological Annotation, Jeffrey Hau etal.

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Why GWSDL2OWL-S

• GWSDL is Based on WSDL, Which is Syntactic
  Representation of Web Services
• Will Revolutionize Grid Resource Utilization by
  Introducing Semantics in GWSDL Extensions Like
• Service Data, Service Description, Life Cycle
  Management, Fault Management and Change Management

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How to Migrate from GWSDL2OWL-S

• Both Use Abstract Types and Concrete Types

GWSDL Abstract Types Concrete Types
OWL-S Abstract Types Concrete Types
GWSDL2OWL-S
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Contd

• GWSDL Uses Semantically Poor WSDL XSD Types to
  Represent Abstract Types and Has a Good Grounding
  Specification
• OWL-S Uses Semantically Rich OWL-S Classes and
  Is Not Yet Well Defined In Service Grounding
• So, The Reference Architecture Will Include OWL
  Abstract Types and WSDL/GWSDL Concrete Types

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Solution Space/Implementation
Globus Resource Management Architecture Using
OWL-S
OWL-S
Brokers
Queries Info
Application
Info. Service
Co-allocator
Ground OWL-S
WSDL/GWSDL
GRAM
GRAM
GRAM
LSF
Condor
NQE
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Challenges

• Defining Name Spaces for GWSDL to OWL-S
• OWL-S Editor for Grid Consumers
• Tool for Automatic Transformation From
  GWSDL2OWL-S

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Conclusions

• Semantic Grid Requires An Expressive Language For
  Grid Services and OWL-S Suitably Fits Into The
  Requirement
• But, To Be Effective OWL-S Must Be Supported By
  Domain Ontology

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Future Work

• Defining Example Grid Service Using OWL-S and
  GWSDL
• Developing GWSDL2OWL-S Tool Kit

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