FP6-511513

FP6-511513

OntoGrid: Paving the way for Knowledgeable

Grid Services and Systems

www.ontogrid.net

Sheffield, 21st February 2006

Semantic-OGSAA Reference Architecture for the Semantic Grid

Oscar CorchoThe University of Manchester

2S-OGSA

Content

What is the Grid and the Semantic Grid? S-OGSA Authorisation scenario

General architectureCollaboration diagrams

Use of S-OGSA OntoGrid-specific infrastructureVO ontology and reasoning serviceOntology service: WS-DAIOnt-RDF(S)Metadata service: Atlas

Project details: URLs, CVS, etc.

3S-OGSA

The Grid

Grid computing has emerged as an important new field, distinguished from conventional distributed computing by its focus on large-scale resource sharing, innovative applications...we [define] the "Grid problem”…as flexible, secure, coordinated resource sharing among dynamic collections of individuals, institutions, and resources - what we refer to as virtual organizations

Middleware for establishing, managing and evolving multi-organisational federations.

On-demand distributed computing

The Anatomy of the Grid: Enabling Scalable Virtual OrganizationsFoster, Kesselman and Tuecke

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Grid Computing trajectory

CPU scavenging

CPU intensive workload Grid as a utility, data Grids, robust infrastructure Intra-company, intra community

e.g. Life Science Grid

Sharing standard scientific process and data, sharing of common infrastructure

Between trusted partners

Sharing of apps and know-how

With controlled set of unknown clients

Virtual organisations with dynamic access to unlimited resources

For all

time

cost

The Semantic Grid: Myth Busting and Bridge BuildingCarole Goble. Keynote speech. ECAI04.

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Computationally intensive File access/transfer Bag of various heterogeneous protocols & toolkits Monolithic design Recognised internet, ignored Web Academic teams

Generation GameIn

crea

sed

func

tiona

lity,

stan

dard

izat

ion

Time

Customsolutions

Open GridServices

ArchitectureWeb services

Globus ToolkitCondor, Unicore

Defacto standardsGridFTP, GSI

X.509,LDAP,

FTP, …

App-specificServices

Data and knowledge intensive Open services-based architecture

Builds on Web services GGF + OASIS + W3C

Multiple implementations Global Grid Forum

Industry participation(adapted from Ian Foster GGF7 Plenary)

6S-OGSA

Open Grid Service Architecture

Categories of Services Infrastructure Data Resource Management Execution Management Security Self Management Information

Cross cutting Interoperable VO level Optimized Reliable Certain QoS Guarantee Scalable Available Extensible

XML based vocabularies & XSD based typing dominate

7S-OGSA

Grid Services

References “The Physiology of the Grid: An Open Grid Service Architecture for

Distributed Systems Integration” “The Anatomy of the Grid: Enabling Scalable Virtual Organizations”

Grid Service definition A Web service that provides a set of well-defined interfaces and that

follows specific conventions.• Interfaces: discovery, dynamic service creation, lifetime management,

notification, and manageability

• Conventions: naming and upgradeability.

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From OGSI to WSRF

OGSI (Open Grid Service Interface) fomalised these concepts... Grid service instances identified by Grid service handlers (GSH)

• A permanent network pointer to a Grid service instance.

Grid service references (GSR) used to contact Grid service instances

OGSI provides mechanisms for mapping a GSH to a GSR.

However, OGSI did not succeed Too much stuff in one specification. Does not work well with existing Web service and XML tooling. Too object oriented.

Since January 2004, WS-RF (Web Service Resource Framework) It is simply a re-factoring of OGSI.

• Inheritance is not used.

• WS-Resources instead of Grid service instances.

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WebService

WS-Resource Counter

Client

createResource

CounterResou

rce

counterID=1

CounterResource

counterID=2

add

WS-AddressingEPR

add

Destroy

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Open Grid Service Architecture

Categories of Services Infrastructure Data Resource Management Execution Management Security Self Management Information

What can semantics provide? Flexible and extensible schemas, Data fusion

support (e.g. Provided by RDF) Resistance to frequent syntactic changes Formalization & Reasoning support Eliminate chronic dependence on human-

intervention

Cross cutting Interoperable VO level Optimized Reliable Certain QoS Guarantee Scalable Available Extensible

XML based vocabularies & XSD based typing dominate

11S-OGSA

The Semantic Grid is an extension of the current Grid in which information and services are given well-defined and explicitly represented meaning, better enabling computers and people to work in cooperation

Research Agenda for the Semantic Grid: a Future e-Science InfrastructureD. De Roure, N.R. Jennings, N. Shadbolt

The Semantic Grid

Scale of data and computation

Sca

le o

f In

tero

pera

bilit

y

SemanticWeb

ClassicalWeb

SemanticGrid

ClassicalGrid

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Service Oriented Knowledge Utilities

Converged vision of Next Generation Grids and Service Oriented Knowledge Utilities

Service Oriented –services may be instantiated and assembled dynamically

Knowledge –knowledge-assisted to facilitate automation, and processing and delivering knowledge

Utility –directly and immediately useable service with established functionality, performance and dependability

Ecosystem of Dependable, Knowledge-aware, Societal,Autonomic, Stateful services

Next Generation Grids Expert Group Report 3 (NGG3). January 2006D. De Roure (ed)

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Content





14S-OGSA

Desiderata – a thing of elegance and beauty

Architecture as lightweight as possible: minimise the impact

Extensible and customisable as opposed to complete and generic architecture

Everything is OGSA compliant

Mixed ecosystem of Grid andSemantic Grid services

Straightforward migration pathAny resource can have multiple descriptions andany description can be in different formalisms

Conceptual: reference architecture that can be applied to any grounding (GT4, etc.)

15S-OGSA

S-OGSA

Semantic-OGSA (S-OGSA) is...Our proposed Semantic Grid reference architectureA low-impact extension of OGSA

• Mixed ecosystem of Grid and Semantic Grid servicesServices ignorant of semanticsServices aware of semantics but unable to process themServices aware of semantics and able to process (part of) them

• Everything is OGSA compliant

Defined by • Information model• Capabilites• Mechanisms

Model

Capabilities Mechanisms

provide/consume

expose

use

16S-OGSA

S-OGSA Model and Capabilities

Semantic ProvisioningService

Knowledge Resource

Grid Entity

Semantic Binding

Grid ServiceIs-a

0..m0..m

1..m1..m

Semantic aware Grid Service

consume

produce

0..m0..m

1..m1..m

uses

VOMS

SAML

DFDL file

JSDL file

Is-a

Knowledge Entity

Is-a

Ontology Service

Is-a

Reasoning Service

Semantic BindingProvisioning Service

Annotation Service

Metadata Service

Grid Resource

IDT

AtlasIs-a Is-a

Is-a

Is-a

KnowledgeProvisioning

Service

Is-a

Ontology

Rule set

Knowledge Semantic Grid Grid

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METADATAas SemanticAnnotations

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Optimization

Execution Management

Resourcemanagement

Data

Security

Information Management

Infrastructure Services

Application 1 Application N

OG

SA

Sem

antic

-OG

SA

Semantic Services

From OGSA to the S-OGSA

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Optimization

Execution Management

Resourcemanagement

Data

Security

Information Management

Infrastructure Services

Application 1 Application N

OG

SA

Sem

antic

-OG

SA

Semantic Services

From OGSA to the S-OGSA

Ontology

ReasoningKno

wle

dge

Metadata

Annotation

Sem

antic

bin

ding

Semantic Provisioning Services

20S-OGSA

S-OGSA Mechanisms: S-StatefulServices

Lifetime

Notification

State/properties metadata

. . .

•WSRF defined operations

•getProperties

•queryProperties

Service

Resource

Client

3

1

2

Semantic Binding IdsRetrieval Request

Semantic Binding Ids

Metadata Retrieval/Query Request

4 Query/Retrieval Result

5 Obtain schema for Semantic Bindings

MetadataService

MetadataService

OntologyService

OntologyService

Metadata can be distributed(and may be inconsistent)

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OntoKit: Refactored and additional components

Coordinationand

negotiation

IntelligentDebugging

Coordinationand

negotiation

IntelligentDebugging

Semantically Aware

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Content





23S-OGSA

getInsurancePolicy

Driver John Doe

Business scenario – supporting the authorization model

InterInsurance Portal

BestInsurer PortalgetInsurancePoli

cy

getInsurancePolicy

DENY ACCEPTINDETERMINATE

OntoKitInfrastructurefor authorisation

InterInsuranceCarFraudService

(PEP)

Common objective: improve operations and prevent fraudsCommon objective: improve operations and prevent frauds

Partial sharing of customer information (previous insurance details, claims, etc.)

Result or Exception

Insurance DB federation

getInsurancePolicy



BestInsurerCarFraudService

(PEP)Result or Exception


……

24S-OGSA


(PEP)

getInsurancePolicy

Driver John Doe

Policy Enforcement Point (according to GT4)



cy

getInsurancePolicy




(PEP)


Result or Exception


getInsurancePolicy






……

25S-OGSA


(PEP)

getInsurancePolicy

Driver John Doe

Policy Decision Point (OntoKit infrastructure)



cy

getInsurancePolicy




Result or Exception


getInsurancePolicy






……

26S-OGSA

WS-DAIOnt

XACML_AuthZService(PDP)

CarFraudService (PEP)

XACML AuthZ Request

getInsurancePolicy

VO Ontology Class Hierarchy -RDFS

RDF

RDF

John Doe has had 2 distinct accidents

Role OpMapping

Pellet Reasoner

Obtain Semantic Bindings of John Doe

Obtain all classes that are subclass of ROLE

Classify John Doe wrt VO ont

Lookup whether the ROLE that is inferred permits or not

XACML AuthZ Response

1

2

3

4

5

6

7

Atlas

PIPProxy

PDPProxy

VO OntologyOWL

Demonstrator. Collaboration Diagram

8 Result or Exception

27S-OGSA

WS-DAIOnt



XACML AuthZ Request

getInsurancePolicy


RDF

RDF


Role OpMapping

Pellet Reasoner






1

2

3

4

5

6

7

Atlas

PIPProxy

PDPProxy

VO OntologyOWL



Ignorant of semantics

Semantic aware but unable to process semantics

Semantic aware and able to process semantics

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WS-DAIOnt



XACML AuthZ Request

getInsurancePolicy


RDF

RDF


Role OpMapping

Pellet Reasoner






1

2

3

4

5

6

7

Atlas

PIPProxy

PDPProxy

VO OntologyOWL


8 Result or Exception/C=GB/O=PERMIS/CN=User0

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WS-DAIOnt



XACML AuthZ Request

getInsurancePolicy


RDF

RDF


Role OpMapping

Pellet Reasoner






1

2

3

4

5

6

7

Atlas

PIPProxy

PDPProxy

VO OntologyOWL



30S-OGSA

WS-DAIOnt



XACML AuthZ Request

getInsurancePolicy


RDF

RDF


Role OpMapping

Pellet Reasoner






1

2

3

4

5

6

7

Atlas

PIPProxy

PDPProxy

VO OntologyOWL



...

...

...

...

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WS-DAIOnt



XACML AuthZ Request

getInsurancePolicy


RDF

RDF


Role OpMapping

Pellet Reasoner






1

2

3

4

5

6

7

Atlas

PIPProxy

PDPProxy

VO OntologyOWL



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WS-DAIOnt



XACML AuthZ Request

getInsurancePolicy


RDF

RDF


Role OpMapping

Pellet Reasoner






1

2

3

4

5

6

7

Atlas

PIPProxy

PDPProxy

VO OntologyOWL



...

...

...

...

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Content


General architectureCollaboration diagram



34S-OGSA

WS-DAIOnt



XACML AuthZ Request

getInsurancePolicy


RDF

RDF


Role OpMapping

Pellet Reasoner






1

2

3

4

5

6

7

Atlas

PIPProxy

PDPProxy

VO OntologyOWL

The VO ontology and the reasoning service. Configuration

Configurable pieces


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The VO ontology and the reasoning service (I)

VO ontology based on...• KaOS ontologies (Actors, Groups and Actions)• UNICORE ontology (Entities, Identities and Roles)

Joint development between NextGrid, UniGrids and OntoGrid

Policy definitionRole-based

• Actors or groups of actors have a set of roles in the VO • Tasks:

Extend ontology with domain-specific classes and propertiesDefine roles wrt these extensions

E.g., a blacklistedDriver is a driver that has had at least 3 accident claims in the past

E.g., a goodReputationDriver is a driver that has been insured at least by one trusted company and that has had at most 2 accident claims

• PDP uses a DL classifier to obtain roles of a subjectMapping roles-operations

• Available in a lookup table

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The VO ontology and the reasoning service (II)

37S-OGSA

S-OGSA Model and Capabilities (reminder)


Knowledge Resource

Grid Entity

Semantic Binding

Grid ServiceIs-a

0..m

0..m

1..m

1..m


consume

produce 0..m

0..m

1..m

1..m

uses

VOMS

SAML

DFDL file

JSDL file

Is-a

Knowledge Entity

Is-a

Ontology Service

Is-a

Reasoning Service


Annotation Service

Metadata Service

Grid Resource

IDT

AtlasIs-a Is-a

Is-a

Is-a


ServiceIs-a

Ontology

Rule set


38S-OGSA

Ontology services

Adapt and extend ontology services to be Grid compliant

Access heterogeneus and distributed ontology sources as a homogeneous logical resources

Provide homogeneous service interfaces

Modular design to ease extensibility WS-DAI

Message PatternsBehavioural Properties

WS-DAIOnt WS-DAIXXML

WS-DAIRRelational

WS-DAIOnt-RDFRDF Specific

WS-DAIOnt-OWLOWL specific

WS-RDF

Jena Sesame

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RDFS model

rdfs:Class

rdfs:Resource

rdfs:Containerrdf:List rdf:Property rdfs:Classrdf:Statement

rdfs:Datatype

rdfs:Literal

rdf:XMLLiteralrdf:Bag rdf:Seq rdf:Alt

rdf:nil

rdfs:ContainerMembershipProperty

rdf:_1 rdf:_2 rdf:_3

rdfs:memberrdfs:seeAlsordfs:isDefinedByrdfs:value“property”

rdfs:labelrdfs:comment

rdf:subjectrdf:predicaterdf:object rdf:type

rdfs:subclassOf

rdfs:domainrdfs:range

rdfs:subPropertyOf

rdf:first

rdf:rest

RDF(S)

rdf:XMLLiteralrdfs:member

rdfs:Class

rdfs:Resource

rdfs:Containerrdf:List rdf:Property rdfs:Classrdf:Statement

rdfs:Datatype

rdfs:Literal

rdf:XMLLiteralrdf:Bag rdf:Seq rdf:Alt

rdf:nil

rdfs:ContainerMembershipProperty

rdf:_1 rdf:_2 rdf:_3

rdfs:memberrdfs:seeAlsordfs:isDefinedByrdfs:value“property”

rdfs:labelrdfs:comment

rdf:subjectrdf:predicaterdf:object rdf:type

rdfs:subclassOf

rdfs:domainrdfs:range

rdfs:subPropertyOf

rdf:first

rdf:rest

RDF(S)

rdf:XMLLiteralrdfs:member

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Component Description

Jena ....

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S-OGSA Model and Capabilities (reminder)


Knowledge Resource

Grid Entity

Semantic Binding

Grid ServiceIs-a

0..m

0..m

1..m

1..m


consume

produce 0..m

0..m

1..m

1..m

uses

VOMS

SAML

DFDL file

JSDL file

Is-a

Knowledge Entity

Is-a

Ontology Service

Is-a

Reasoning Service


Annotation Service

Metadata Service

Grid Resource

IDT

AtlasIs-a Is-a

Is-a

Is-a


ServiceIs-a

Ontology

Rule set


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Atlas

Atlas is a P2P system for the distributed storage and querying of RDF(S) data using DHTs.

State of implementationBase technology: Bamboo DHT (http://bamboo-dht.org)Model: RDF (eventually RDFS as well)Query and update languages: RQL (subset of data queries)

and RUL (not yet implemented)Functionality: one-time queries (implemented),

publish/subscribe (under development).

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Atlas and the Metadata Service

ATLAS

METADATA SERVICE INTERFACE

I want to publish

information about a resource

I want to discover a

resource that meets my needs

METADATA SERVICE INTERFACE

Web service protocols

Web service protocols

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Content


General architectureCollaboration diagram



45S-OGSA

Project details

OntoGridPublications at http://www.ontogrid.net/

• CTWatch• Journal of Web Semantics (Special issue on Semantic Grid)• GGF16 Semantic Grid Workshop (http://www.semanticgrid.org/)

Source code• http://www.ontogrid.net/, Downloads

Not very user-friendly yet

• Access to CVSConnection type: pserveruser: ontogridpassword: not neededHost: rpc262.cs.man.ac.ukPort: 2401Repository path: /local/ontogrid/cvsrootmodule: prototype

46S-OGSA

Acknowledgements

The OntoGrid team at ManchesterPinar Alper, Ioannis Kotsiopoulos, Paolo Missier,

Sean Bechoffer, Carole Goble The OntoGrid team at other sites

UPM: WS-DAIOnt-RDF(S)NKUA: Atlas

Others already acknowledged in the slides

47S-OGSA

More References

http://www.globus.org/wsrfModeling Stateful Resources with Web ServicesThe WS-Resource FrameworkFrom Open Grid Services Infrastructure to WS-Resource

Framework: Refactoring and Extension WSRF OASIS working group

http://www.oasis-open.org/committees/tc_home.php?wg_abbrev=wsrf

WS-Notification OASIS working grouphttp://www.oasis-open.org/committees/tc_home.php?

wg_abbrev=wsn

FP6-511513

OntoGrid: Paving the way for Knowledgeable

Grid Services and Systems

www.ontogrid.net

Sheffield, 21st February 2006

Semantic-OGSAA Reference Architecture for the Semantic Grid

Oscar CorchoThe University of Manchester

FP6-511513

Documents

Transcript of FP6-511513