On the Use of Service Level Agreements in AssessGrid.

On the Use of Service Level Agreements in AssessGrid

Dominic Battré - On the Use of SLAs in AssessGrid 2

Overview

• Motivation AssessGrid

• Negotiation Scenarios

• End-user Layer

• Broker Layer

• Grid Fabric Layer

Dominic Battré - On the Use of SLAs in AssessGrid 3

Motivation AssessGrid

• AssessGrid Aim- integrate a risk-aware Service Level Agreement model

into current Grid technology

• Risk awareness incorporated across three layers

Dominic Battré - On the Use of SLAs in AssessGrid 4

What is risk?

• Risk:Combination of the probability of an event and its consequences

Dominic Battré - On the Use of SLAs in AssessGrid 5

What is risk?

• Risk as a negative force …- Avoid it using risk management

• Risk as a positive force …- Opportunities may be created as a result of risk

taking

- Potential benefits when taking certain risk

• Risk management- Identification and treatment of risk

Dominic Battré - On the Use of SLAs in AssessGrid 6

Why risk management?

low riskmiddle riskhigh risk

• Grid Resource Provider- estimates the risk for agreeing an SLA

- considers risk of resource failure for scheduling

- initiates precautionary fault-tolerance mechanisms

Dominic Battré - On the Use of SLAs in AssessGrid 7

Why risk management?

• Grid Resource Broker- Published PoF enables to compare different offers

• Risk, QoS, charge, and penalty fee

- Reliability measure will classify trustful providers

- Estimates risks for building workflows

PoF PoF PoF

Dominic Battré - On the Use of SLAs in AssessGrid 8

Why risk management?

• End User?!?

• is happy…- Knows its risks.

- Can pick most suitable provider!

Dominic Battré - On the Use of SLAs in AssessGrid 9

Scenario 1: User – Provider Neg.

Get Template

Fill Template- Job description- Max. PoF- Min. Penalty

Create Offer- Set Price

SLA Request

SLA Offer

CommitContract

Dominic Battré - On the Use of SLAs in AssessGrid 10

Scenario 2a: Broker = Mediator

Template Subscription

Get Templates

Dominic Battré - On the Use of SLAs in AssessGrid 11

Scenario 2a: Broker = Mediator

SLA Request

SLA Offer

Evaluate Reliability

Medium PoF Low PoF1000 EUR, 1% 1000 EUR, 1.5%

Dominic Battré - On the Use of SLAs in AssessGrid 12

Scenario 2a: Broker = Mediator

Commit

Timeout

Dominic Battré - On the Use of SLAs in AssessGrid 13

Scenario 2b: Broker = Contractor

Dominic Battré - On the Use of SLAs in AssessGrid 14

Architectural Overview

• End-user- Portal

• Broker- Risk Assessor

- Confidence Service

- Workflow Assessor

• Provider- Negotiator

- Scheduler

- Risk Assessor

- Consultant Service

Dominic Battré - On the Use of SLAs in AssessGrid 15

End-User Layer – Portal Architecture

• Presentation- of SLA templates, requests, offers

- of PoF and reliability information

- of status of executing and pending jobs

- SLA violations and compensation (penalties)

- specific to user role (end user, administrator)

• Follows the MVC (Model View Controller) design pattern

• Based on GridSphere portal architecture

Dominic Battré - On the Use of SLAs in AssessGrid 16

Broker Layer

• Inspired by GridWay scheduler

• SLA Processor: Agreement and AgreementFactory WebService

• Resource Filter:find suitable resources that are likely to respond

• Offer Manager:Used if broker acts as provider

Scenario 2b

Dominic Battré - On the Use of SLAs in AssessGrid 17

Grid Fabric Layer

• NegotiationManager

- Agr./Agr.Fact. WS

- checks whether offer complies to template

- initiation of file transfers

• Scheduler

- creates tentative schedules for offers

• Risk Assessor

• Consultant Service

- records data

- builds models

Dominic Battré - On the Use of SLAs in AssessGrid 18

Summary

• Motivation AssessGrid

• Negotiation Scenarios

• End-user Layer

• Broker Layer

• Grid Fabric Layer

• Questions

Dominic Battré - On the Use of SLAs in AssessGrid 19

Questions?

I will not ask questions about the math involved. I will not ask questions about the math involved. I will not ask questions about the math involved. I will not ask questions about the math involved.