A Framework for SLA-aware Execution of Grid-based Workflows

Service Level Agreements (SLAs) are currently one of the major research topics in Grid Computing as they serve as a foundation for reliable and predictable Grids. SLAs define an explicit statement of expectations and obligations in a business relationship between provider and customer. Thus SLAs should guarantee the desired and a-priori negotiated Quality of Service (QoS) which is a mandatory prerequisite for the Next Generation Grids. The complexity of an SLA-based workflow grows significantly as characteristics of correlated sub-jobs the data transfer phases the deadline constraints and possible failures have to be considered. Thus an architect for an SLA-aware workflow implementation needs sophisticated mechanisms for specification and management sub-job mapping data transfer optimization and fault reaction. Therefore this book presents a system for SLA-aware Grid workflows. The main contributions include an improved specification language for SLA-aware workflows three mapping and optimization algorithms for sub-job assignment to Grid resources an error recovery mechanism and a prototype imple­mentation using standard middleware.