The DeltaGrid Abstract Execution Model: Service Composition and Process Interference Handling

This paper introduces the DeltaGrid abstract execution model as a foundation for building a semantically robust execution environment for concurrent processes executing over Delta-Enabled Grid Services (DEGS). A DEGS is a Grid Service with an enhanced capability to capture incremental data changes, known as deltas, associated with service execution in the context of global processes. The abstract model contains a service composition model that provides multi-level protection against service execution failure, thus maximizing the forward recovery of a process. The model also contains a process recovery model to handle the possible impact caused by failure recovery of a process on other concurrently executing processes using data dependencies derived from a global execution history and using user-defined correctness criteria. This paper presents the abstract execution model and demonstrates its use. We also outline future directions for incorporating application exception handling and build a simulation framework for the DeltaGrid system.