James Padgett

Brokering of risk-aware service level agreements in grids

Service level agreements (SLAs) are facilitators for widening the commercial uptake of Grid technology. They provide explicit statements of expectation and obligation between service consumers and providers. However, without the ability to assess the probability that an SLA might fail, commercial uptake will be restricted, since neither party will be willing to agree. Therefore, risk assessment mechanisms are critical to increase confidence in Grid technology usage within the commercial sector. This paper presents an SLA brokering mechanism with risk assessment support, which evaluates the probability of SLA failure. WS‐Agreement and risk metrics are used to facilitate SLA creation between service consumers and providers within a typical Grid resource usage scenario. An evaluation is conducted to examine risk models, the performance of the brokers implementation as well as a comparison of its capabilities against similar SLA‐based solutions from the literature. Copyright

Grid-Based SLA management

This paper presents an architecture for specifying, monitoring and validating Service Level Agreements (SLA) for use in Grid environments. SLAs are an essential component in building Grid systems where commitments and assurances are specified, implemented and monitored. Targeting compute resources, an SLA manager reserves resources for user applications requiring resources on demand. Methods for automated monitoring and violation capture are discussed showing how Service Level Objectives (SLO) can be validated. A SLA for a compute service is specified and experiments carried out on the White Rose Grid. Results are presented in the form of a SLA document and show the violations that were captured during task execution.

Reliability and risk in grid resource brokering

If grid computing is to experience widespread commercial adoption, then incorporating risk assessment and management techniques is essential, both during negotiation between service provider and service requester and during run-time. This paper focuses on the role of a resource broker in this context. Specifically, techniques for evaluating the reliability of risk information received from resource providers is discussed. The performance of three algorithms are compared through simulation, showing than an odds betting-based algorithm performs better in identifying providers with highly variable risk assessments.

SLA management in a service oriented architecture

This paper presents a Service Level Agreement (SLA) management architecture for the Grid. SLAs are an essential component in building Grid systems where commitments and assurances are specified, implemented and monitored. Targeting CPU type resources, we show how a SLA manager is able to interface with a broker designed for user applications that require resources on demand. The broker uses a novel three-phase commit protocol which provides the means to secure resources that meet the applications requirements through SLAs. Experiments are carried out on a Grid testbed to show how a SLA for a compute service is specified. Experimental results show that the broker provides performance enhancement in terms of the time taken from submission of application requirements until a job begins execution.

Assessgrid, economic issues underlying risk awareness in grids

In order to improve the attractiveness and drive the commercial uptake of Grid technologies, the establishment of Service Level Agreements (SLAs) is required. The AssessGrid project contributes to this aim by introducing risk-aware Grid architectural components. Grid service users, brokers and providers benefit from risk assessment functionalities in all phases of service provisioning and utilisation. This paper focuses on the economic issues which result from this new risk-aware approach to Grid computing. Multiple open economic research questions are discussed from the perspective of users, brokers and providers, which point out the potential impact of AssessGrid in this area.

Evaluating Provider Reliability in Grid Resource Brokering

If Grid computing is to experience widespread commercial adoption, then incorporating risk assessment and management techniques is essential,both during negotiation between service provider and service requester and during run-time. This paper focuses on the role of a resource broker in this context. Specifically, an approach to evaluating the reliability of risk information received from resource providers is presented, using historical data to provide a statistical estimate of the average integrity of their risk assessments, with respect to systematic overestimation or underestimation of the probability of failure. Simulation results are presented, indicating the effectiveness of this approach.

Risk-Aware SLA Brokering Using WS-Agreement

Service Level Agreements (SLAs) are facilitators for widening the commercial uptake of Grid technology. They provide explicit statements of expectation and obligation between service consumers and providers. However, without the ability to assess the probability that an SLA might fail, commercial uptake will be restricted, since neither party will be willing to agree. Therefore, risk assessment mechanisms are critical to increase confidence in Grid technology usage within the commercial sector. This paper presents an SLA brokering mechanism including risk assessment techniques which evaluate the probability of SLA failure. WS-Agreement and risk metrics are used to facilitate SLA creation between service consumers and providers within a typical Grid resource usage scenario.