Grid Quality of Service and Service Level Agreements

1. Grid Quality of Service and Service Level Agreements Karim Djemame University of Leeds

2. Outline • SLA: What is in it? • SLA Management Architecture • Example: SLA for a Compute Service • Need for Resource Brokering • Conclusion and Future Work

3. A description of the service being provided Names of the provider, consumer and 3rd A definition of the domains in which the SLA is valid Levels of service (guarantees) agreed on Describes the SLA state What is not covered by the SLA Service Level Agreements (SLA) • A Service Level Agreement is • “…an explicit statement of expectations and obligations that exist in a business relationship between two organisations: the service provider and the customer.” • Formalises requirements and specifies behaviours • SLA Model: SLA Root Purpose Provider 3rd Parties Parties Consumer Scope SLIndicator SLObjectives Measurement State Violations Exclusions Policing

4. User wants access to computational resources on the Grid GSx GSx GSx dB HPCx Portal access over internet Grid resource access via Grid Services and the Globus Toolkit DAME Problem Scenario HTTPS Globus GT 3 Internet Specialist Resources HTTPS Consumer Provider Resources + Grid Services White Rose Grid

5. Provides access to service functions Provides meta-data relating to the service eg. state Selects resources and submits the execution Negotiates SLA between the user and provider Monitors Service Level Objectives and records violations Reacts to violations by adapting managed grid service execution Proposed SLA Management Architecture

6. Capture user requirements Negotiate SLA Sign SLA Launch managed grid service Reserve resources Monitor and record violations Adapt to violations SLA Management Interaction Interface

7. SLA Management • Automated management will provide autonomic self-optimisation without the need for user intervention • Outcome: for each Grid Execution instance, an SLA Manager will provide: • SLA • resource reservation • job monitoring • job adaptation • violation log

8. Example: SLA for a Compute Service

9. SLA Specification using XML • Grid Task requirements represented in an SLA content tree (JAVA) • SLA content tree converted to XML using Java Architecture for XML Binding (JAXB) • SLA XML document created to interact with external resource brokers and pass user requirements

10. Co-ordinater Resource gatherer Decision maker Dispatcher Grid middleware TSLA Portal Portal Matchmaker Knowledge bank RSLA R R R R R R R R BSLA Grid Resources SNAP Resource Broker Architecture TSLA: Task Service Level Agreement RSLA: Resource Service Level Agreement BSLA: Bind Service Level Agreement MatchMaker Co-Ordinator Dispatcher Decision Maker Resource Gatherer Grid Middleware SNAP: Service Negotiation and Acquisition Protocol

11. Current and Future Work • Implementation • Produced a basic implementation of an SLA Manager to accept user requirements, embed them within an SLA (XML) document and report them back to the user • SNAP-based resource broker being deployed on the WRG • Automated Monitoring • Engineering automated monitoring within the SLA Manager • Enable subscriptions to an external Grid Monitoring Service depending on the SLA guarantees • Adaptation Algorithm • Investigate an adaptation algorithm that is suitable for use within a Service Oriented Architecture • Integration with SLA Manager

12. References • SLA Management in a Service Oriented Architecture. K. Djemame, M. Haji and J. Padgett. ICCSA’2004, Assissi, Italy, May 2004 • A SNAP-based Community Resource Broker using a Three-Phase Commit Protocol. M. Haji, P. Dew, K. Djemame and I. Gourlay. IPDPS’2004, Santa Fe, New Mexico, April 2004