Amadeus: A Holistic Service-oriented Environment for Grid Workflows

In this paper, we present Amadeus, which is a holistic service-oriented environment for QoS-aware grid workflows. Amadeus considers user´s requirements, in terms of QoS constraints, during workflow specification, planning, and execution. Within the Amadeus environment, workflows and the associated QoS constraints are specified at a high-level using an intuitive graphical notation. A set of QoS-aware service-oriented components is provided for workflow planning to support automatic constraint-based service negotiation and workflow optimization. For improving the efficiency of workflow planning, we introduce a QoS-aware workflow reduction technique. By following either a static or a dynamic planning strategy the workflow is executed using the selected services in the manner that the specified user´s requirements are met. For each phase of the workflow lifecycle we experimentally evaluate the corresponding Amadeus components