SLAs and Negotiation in Ontogrid:

Scenarios and Requirements

Shamima PauroballyUniversity of Westminster

S.Paurobally@westminster.ac.uk

Michael Wooldridge, Valentina Tamma

University of Liverpool

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Overview of Talk

Motivation of negotiation for SLAs Two scenarios Requirements from scenarios An overview of Ontogrid’s implementation Some results

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Dynamic Provisioning of Grid services

Grid + Semantic Web + P2P + MAS have much in common in terms of high-level vision• Cooperation is a recurring theme

• Resource owners may (or not) choose to charge for their resources.

SLAs state the terms of the agreements between the consumer and the provider as a contract for the provider to perform a task or to provide agreed resources.

Agreements on resource provisioning:• the provider’s commitment to execute a task or provide the

resources.

• terms about performance levels and penalties (provisioning).

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Negotiation for Dynamic SLAs

Reconciliation between preferences and constraints through the negotiation of SLAs.

SOA, VOs, enterprise Grids which can support

commercial applications

• Optimal allocation of resources to grid users while

assuring some specific quality of service for all

• Negotiation Protocols, Contract Definitions, Utilities

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Agreements in Cooperation Lifecycle

Grid Services(=resources+constraints)

VO FormationAgreement on who will participate in VO, who will work with each other

Virtual Organisations(=sets of services)

Team formationAgreement on who does which task with which resource

Teams(=subsets of VOs)

SchedulingAgreement on how to dynamically coordinate

TIM

E

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Scenario 1: InsuranceGrid

Y’All B.V. and Boyd International, Netherlands Traditional ways of handling claims in the

insurance sector• Slow and costly because of inter-dependency between

many parties

• Every aspect of claim is dealt by a different department

• Need for chain integration

• Exchange large amount of data and maintain long term relationships

• Human translation from one domain to another

• Needs automation!

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The Insurance Grid Facts

DamageSecure looks after and controls all businesses involved in dealing with car damage claims for a number of insurance companies.• To enhance the quality and efficiency of the total

damage claims handling process

Every year, ~100,000 damages are reported to DamageSecure• 40% repairs, 60% replacement

• Automation could save 172Million Euros

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Repair Grid Scenario

Expert Services

Customer

DamageSecure

Insurance Services

Repair Services

i1

i2

i5

i3

i4

Negotiation

Long-termContracts

With repairservices

Contracts,Insurance

policies

SLAs(dynamic)

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Front End of the Insurance Grid

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InsuranceGrid Contracts

http://www.insurancegrid.org Insurance companies Repair companies Contracts between insurance and repair companie

s Contracts between customers and insurance com

panies All policies in Aksa insurance All damage reports are Aksa All insured vehicles at Aksa

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Car Fraud Grid1. When a customer wishes to become a client2. When an insurance service receives a claim

FraudGridManager

Search reports, SLAs for suspicious cases

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Goal for Negotiation in Insurance Grid

Add web services negotiation to the insurance repair process between repair services and DamageSecure

Advantages: • More efficient than the current manual settlement process

• Provides a more healthy market for claim settlement

• Repair prices will drop

• Quality of repairs will increase because of open competition

“Web Services Negotiation in an Insurance Grid”

S.Paurobally, C. van Aart, V.Tamma, M. Wooldridge, P. van Hapert. Proceedings of AAMAS 2007, Industrial Track

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Negotiation for SLAs in the Middleware: VO Authorisation

User: authorisation request reflecting demand of the tasks Users have:

• Digital certificates that attest to their attributes• Membership in VO• Requirements for resource

Resource owners have:• Access policies for resource• Resource sharing constraints

Different goals: • a client might want to get access the resource ASAP

• Resource owner want to collect as much information about the client’s attributes before granting access

Negotiation on cost and security demands Client trusts the server apriori but the server does not trust the

client

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Example of Negotiation for Authorisation

Olson, Winslett et. al. ICDEW 06

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Using Bilateral Negotiation

ResourceOwneroffer({Ca,Cd,Cc})

offer({Ca,Cb,Ce,Cf})

User

NegotiationService

NegotiationServiceaccept({Cd,Ce,Cg})

Repeat until deadline or received counter offer is better than generated offer

Advertise(Ca, Cb, Cc, Cd, Ce, Cf,Cg)

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Trust Negotiation in VO

SLAs consisting of certificates, and indicate level of

trustworthiness

• Trust is established between parties based on their properties

proved through credential disclosure.

Negotiation allows credentials and policies to be

disclosed between parties in a bilateral and iterative

manner that incrementally establishes trust.

Parties iteratively disclose more sensitive credentials

until the authorisation policy is satisfied or one party

gives up.

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Requirements from Scenarios Chain Integration (translation of contracts and SLAs) Automation to draft SLAs Multi-issues in SLA and relative importance of issues Quantitative and qualitative issues (negotiation about information

exchange) 1-many and many-many negotiation Competition between self-interested parties Protocols and strategies Preferences and their ontology Trust and security in a VO Business process monitoring 3rd party surveyor/authority Counter malicious behaviour Verification and validation: Prove properties of the negotiation

protocols

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Architecture of the Negotiation Service

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Ontogrid’s Negotiation Service

1. Messages that can be exchanged • Port-type of web service e.g. offer, bid, accept, cfp,

propose, submit_bid

2. Negotiation protocols (Business Logic)• Sequence of invoking the methods e.g. provider cfp

consumer propose provider accept consumer inform

3. Preferences Ontology• To decide what makes a good deal e.g. reserve prices

4. Decision strategies • To evaluate and generate the content of the messages

e.g. time dependent concession

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Representing SLAs in Speech Act Subject Type

<xsd:element name="Speech_Act_Subject"> <complexType name="Speech_Act_Sub"> <sequence> <element name="sender" type="wsa:EndpointReferenceType"/> <element name="context_job" type="xsd:string"/> <xsd:element ref="tns:IssuesList"/> <element name="bid_number" type="xsd:int"/> <element name="deadline" type="xsd:int"/> </sequence> </complexType> </xsd:element>

IssuesList is a list of tuple issues {(name, value, isNegotiable),….}Example (EPR of provider, JobID YU7,

{(price,£20,true), (response,20ms,false)}, bidNo 3, 1000ms)

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Evaluating the Negotiation

Negotiation issues on: price of repair, speed of repair, location of repair service, colour of vehicle, method of repair

Evaluating the SLAs reached• From provider’s or consumer’s viewpoint

• Using preferences and strategy

How long to achieve SLA Evaluating each offer

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Convergence towards AgreementContract Net Protocol

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Utility of Deals with Varying DeadlineBilateral Negotiation

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Comparing Various Strategies

Thank You