Dr Ioannis Kotsiopoulos The University of Manchester [email protected]
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Transcript of Dr Ioannis Kotsiopoulos The University of Manchester [email protected]
An overview of Semantic Interoperability Challenges related to Resource Provisioning in Business Grids
Dr Ioannis KotsiopoulosThe University of Manchester
Workshop Semantic Interoperability: A Practical Approach
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Resource Provisioning in Business Grids
• Business Grids: today’s landscape– Service and resource providers– Desiderata
• From Grid to Semantic Grid– The S-OGSA approach– SOKU
• Resource and Grid Service Semantic Descriptions – Grid Resource Ontology– GRIP– Standardisation– BREIN Semantic Initiatives
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Service and Resource Providers
• Resource Providers– Amazon EC2 and S3– SUN Utility Computing – Academic Centres:
• Barcelona Supercomputing, Manchester Northwest Grid, HLRS• Service Providers
– Sun Grid Middleware– IBM Grid: Grid Middleware and Hardware– Amazon Web Services
• Hybrid– CDO2: Delivering financial grid solutions on a compute utility
service– ANSYS: Engineering Simulation Software
• Virtual Organisations– Stuttgart Airport: Resources offered by companies operating at the
airport
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Desiderata for seamless resource provisioning
• Desiderata for Service and Resource Providers– Maximize Resource Usage– Maximize Profit– Minimize Penalties– Increase Client Base– Increase Automation– Improve Brand Name– Improve Security– Create New Business
Opportunities
• Desiderata for Clients– Ease of use– Greater choice– Lower prices– Better QoS– More QoS Guarantees
Common Desiderata–Flexibility–Extensibility–Performance–Scalability
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So where do we need semantics?
• Service Providers use different vocabularies (semantic heterogeneity) for describing what they offer:– Resource types– Service Level Agreements
• Performance• QoS• Penalties• Small Print
• Dynamic formation of a VO is still a very complex task– Security Policies– Software incompatibilities
• Heterogeneous platforms• Heterogeneous Middleware
• Web Services have addressed only part of the problem• Who is managing all the metadata? What do they mean? Are they
still valid?
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Semantic Grid?…because metadata matters!
• Driven from the need to manage and understand the metadata
• Metadata concern all aspects of VO formation– Describing and asserting policy
• Flexible and extensible schemas, transparency
– Can you be a member of this VO? • Matching task, integration
– How do we set your roles so you can be? • Configuration
– Are these set of policies mutually consistent?• Configuration and verification
– Service Level Agreements• Matching provides and expects clauses
– Authentication & Authorisation• Reconcile diverse policies
Intelligent decision making and operations
Static and dynamic VO
model
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“To realise the Next Generation Grid requires semantically rich information representation, the exploitation of knowledge, and
co-ordination and orchestration that is aware of context and task”
David Snelling, NextGRID, Fujitsu, GGFOntologist
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OGSA: A Reference Architecture for the Grid
Characteristics•Service Based Virtualisation•Manageable Resources•Addressing•State•Lifetime•Eventing. . . . .
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Semantic OGSA: A Framework for Exposing and Managing Metadata in the Grid
• The Reference Semantic Grid Architecture : Semantic OGSA– Entities in the Semantic Grid– Core Services, Spectrum of capabilities– Patterns & Profiles of use, re-factoring, use-cases
Model
Capabilities Mechanisms
Provide Consume
Expose
use
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S-OGSA Model
Knowledge Entity
Grid Entity Semantic Binding
Is-a
0..m0..m
1..m
Grid Resource
Is-a
Grid Service
Is-a
Is-a
1..m
Knowledge Resource
Knowledge Service
Is-a
Is-a
Is-a
VOOntology
Rule-Base
Is-a
Satellite Image File
A Grid Identity/Person
Is-a
• Journal of Web Semantics, Vol.4, June 2006, “An overview of S-OGSA: A Reference Semantic Grid Architecture” Ó. Corcho et. al.
A Resource in its own right!
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Optimization
Execution Management
Resourcemanagement
Data
Security
Information Management
Infrastructure Services
Application X Application Y
OG
SA
Sem
antic
-OG
SA
Semantic Provisioning
Services
S-OGSA Capabilities
Middleware
Ontology
Reasoning
Metadata
Annotation
Semantic Provisioning Services
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S-OGSA Mechanisms:Middleware for Managing Metadata
• Semantic Binding as a resource deployed in a WSRF compliant manner
•ONTOKIT available for download
SB Factory
Client
Semantic Binding
Metadata Query
SBSB
SB
create
Query w/o Inference, UpdateContent
Query( over unified view)
WS-RP: Get/Set/Query Properties
WS-Addressing: epr
RDFRDF
create
query
Inspect-props . . .
query
Semantic Binding Service Suite
WS-RL: Destroy , SetTerminationTime
WS-RL ++: archive
WS-Notif: Subscribe / Notify
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SOKU
• Explicit Semantics!– Semantically Described– Semantic Aware
• Mixed Economy• Creating an abstraction for metadata Semantic Binding
• Multiform metadata with introspectable properties• Management interfaces for metadata
• “S-OGSA--OntoKit, a first SOKU implementation” **
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Resource and Grid Service Semantic Descriptions
Grid Service
Person View
Machine View
Person View??
Machine View
Grid Resource
Grid Resource Ontology
Specific Application Ontology
GridService Ontology
Functional
Non-Functional
Specific Application Ontology
State State
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Grid resource ontology
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Unicore GLUE
http://www.grid-interoperability.org/
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Can Standardization help?
• Standardization is as crucial as creating an Ontology and can be seen as the first task of knowledge elicitation
• The process requires the agreement of the community • Relevant approaches from OGF:
– Information Modeling for Computing Resources(OGSA Modeling Activities)
• Reference Model Working Group (RM-WG) (chaired by Paul Strong - e-Bay)– OGSA Resource Selection Services WG (OGSA-RSS-WG)( Donal Fellows -
UMAN/BREIN)• Knowledge Engineers can encode this knowledge in order to create the
appropriate ontologies– The objective is to increase re-usability of software– Make semantics explicit (and machine understandale)– Increase interoperability between heterogeneous Grid middleware
• Businesses are actively involved in this process– E-Bay has already encoded part (?) of the Information Model for internal resource
management (Demo shown in last GGF)• Software and Services Technical Group on Ontologies TG2
– New wiki, mailing list, draft of White Paper
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BREIN Semantic Initiatives
• Resource Broker– Dynamic Resource Provisioning – Complete Outsourcing of Grid Infrastructure - Financial Grid
scenario– Extend capabilities during peak periods (load balancing) -
ANSYS scenario• Related Components using Semantic Technologies
– Intelligent Scheduling – Semantic Annotation of Service Level Agreements (SASLA)– Intelligent Negotiation using SASLA– Dynamic Workflow Adaptation using Agent technologies
• Modeling– Domain/Application Specific Resource Modeling– BREIN Upper Business Grid Ontology– Extension of Grid Resource Ontology
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Acknowledgements
• Thank You!• Questions...• Acknowledgements
– Carole Goble– Pinar Alper– Oscar Corcho– OntoGrid Consortium– John Brooke– Donal Fellows– BREIN Consortium