Trading Grid Services in the UK e-Science Grid

Steven Newhouse

Technical Director

London e-Science Centre

‘Marketplace for Computational Services’ project

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Market for Computational Services

• UK Core e-Science Programme project• Define interfaces & protocols to trade Grid Services• Funded by Department of Trade & Industry• Collaborators

– London e-Science Centre (LeSC)– e-Science North West (ESNW)– Southampton e-Science Centre (SeSC)– UK Grid Support Centre

Implementation of Current GESA Draft Specification

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OGSA

Infrastructure Architecture

OGSI: Interface to Grid Infrastructure

Data Intensive Applications for Science X

Compute, Data & Storage Resources

Distributed

Simulation, Analysis & Integration Technology for Science X

Data Intensive X Scientists

Virtual Integration Architecture

Generic Virtual Data Access and Integration Layer

Structured DataIntegration

Structured Data Access

Structured Data Relational XML Semi-structured-

Transformation

Registry

Job Submission

Data Transport Resource Usage

Banking

Brokering Workflow

Authorisation

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Grid Economic Services Architecture

OGSA Grid ServiceService InterfaceService Data

Service InterfaceService Data

OGSA ChargeableGrid Service

Grid EconomicService Interface

RecordResource

Usage

OGSAResource

UsageService

AgreementNegotiation

EconomicService

Data

AgreementVerification

ServiceCharging

OGSA GridPaymentService

GridUser/Actor

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Grid Economic Service Architecture

• GESA enabled client ‘obtains’ a GSH– Grid Service Handle (GSH) provides unique service ID– Represents a service & cost for use– Changes in price & status through new service & GSH

• GSH passed to an existing client– Retains existing client interface for economic services

• Key Issues:– Information needed to make the selection (SDE)– Two (Multi?) stage commit to support pricing– Enable wide ranging exploration of grid economic

models

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New Economic SDEs & Services

• Trust, Reputation & Reliability (0+)– Can I rely on this service? Will it deliver?– Has this service been audited for performance & integrity? – Allow SDE to updated by signed statements?

• Compensation & Liability (0+)– Who can I complain to and can I prosecute?– How could the contract be broken?

• Grid Payment Services (1+)– Declare which GPS are acceptable

• Resource Usage Service (1)– Declare which RUS is used by the service

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Exploratory Implementation

• Use of service specification documents developed within the project & GGF.

• Focus on core services:– Computational Grid Service (LeSC)– Resource Usage Service (eSNW)– Grid Payment Service (SeSC)

• Demonstrate through a Simple Maths service

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Simple Maths Service State diagram

SimpleMathsCGSFactory

UserAgent

RequestPricing

SDEs: Pricing, Trust,Reputation, etc.

RequestPricing

SimpleMathsCGS

SDEs: Pricing, Trust,Reputation, Cost etc.

AcceptPricing

SimpleMathsCGS

SDEs: Pricing, Trust,Reputation, Cost etc.

UseService

SimpleMathsCGS

SDEs: Pricing, Trust,Reputation, Cost etc.

TIM

E

ResourceUsage Service

Grid PaymentService

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Economically enabled Grid Service

Select a factory service to generate a service instance with which to initiate negotiations

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Examine Pricing Options

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Examine Offer

Examine the offer (‘terms & conditions’) and accept or decline.

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Browse Current Accounts…

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Use the Counter Service

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… on service destruction, cost calculated & money transferred…

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WS-Agreement Phases

• Stateless (agree on static items)– Pricing mechanisms (e.g. Fixed price)– Payment mechanism (e.g. HeyPounds on completion)

• Stateful (created by Factory)– Negotiate cost of each consumable quantity– Need ability to:

• Hold a reservation (for a specified period - negotiable)• Agree to a reservation (binding commitment)• ‘Fork’ negotiation (to explore different options)

– Support one shot or multiple iterations

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GESA Agreement Terms

• Pricing method– Enumeration of provider supported mechanisms

• Currency– Enumeration of provider supported mechanisms

• Cost– Floating point

• Consumable– Enumeration of items and their charging units– Use UR-WG quantities & rates?

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ICENI:IC e-Science Networked Infrastructure

The Iceni, under Queen Boudicca, united the tribes of South-East England in a revolt against the occupying Roman forces in AD60.

• Developed by LeSC Grid Middleware Group• Use to define and develop higher-level services• Collect and provide relevant Grid meta-data• Interaction with other frameworks: OGSI, Jxta etc.• Available under extended open source SISSL:

– http://www.lesc.ic.ac.uk/iceni

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CONTRACT CHAIN

INITIAL SERVICE LEVEL AGREEMENT

FABRIC

COMPUTERESOURCES

SOFTWARERESOURCES

STORAGERESOURCES

SERVICECONTRACT

SERVICECONTRACT

SERVICECONTRACT

CLIENTS (USERS)

Contract (SLA) Specified Services within ICENI

DefineCapability

DefineAccess

ExposeCapability

Modify, extend& restrict policy

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Information Capture & Utilisation

UserRequirements

Software & HardwareCapabilities

SoftwareComponentMeta-data

ResourceMeta-data

ApplicationStructure

SelectionPolicy

UserRights

Application asInteractive Service

Meaning

Implementation

Behaviour HardwareCharacteristics

UsagePolicy

ResourceState

CompositeApplication

Workflow Model

PerformanceModel

ExecutionPlan

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Conclusions

• Exploratory implementation of GESA– Validate use of OGSI for stateful services– Extend basic Grid Service with economic capability– Development of CGS, RUS, & GPS services

• Demonstrated use of GT3– Many problems expected from a new infrastructure

• Documentation, documentation, documentation

– See LeSC, eSNW & SeSC stands

• Next Steps– Develop & Refine current implementation– Engage in the definition & development of WS-Agreement

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Acknowledgements

• Development Teams– LeSC: Miqdad Asaria, William Lee, Anthony Mayer– eSNW: Jon MacLaren– SeSC: Kushan Nammuni

• Management Teams– LeSC: John Darlington, Steven Newhouse, Oliver Jevons– eSNW: John Brooke– SeSC: Simon Cox, Trevor Cooper-Chadwick

• http://www.lesc.ic.ac.uk/markets