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

Abstract

Service Level Agreements (SLAs) are currently one of the major researchtopics in Grid Computing, as they serve as a foundation for reliableand predictable Grids. SLAs define an explicit statement of expectationsand obligations in a business relationship between provider and customer.Thus, SLAs should guarantee the desired and a-priori negotiated Qualityof Service (QoS), which is a mandatory prerequisite for the NextGeneration 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 needssophisticated mechanisms for specification and management, sub-jobmapping, data transfer optimization and fault reaction. Therefore,this book presents a system for SLA-aware Grid workflows. The maincontributions include an improved specification language for SLA-awareworkflows, three mapping and optimization algorithms for sub-jobassignment to Grid resources, an error recovery mechanism, and aprototype implementation using standard middleware.