Dependable execution of workflow activities on a virtual private grid middleware

In this paper we relate QoS management to Workflow management and discuss dependable execution on a middleware layer, named Virtual Private Grid (VPG), of sets of processes performing a workflow activity. We propose two patterns of interaction between a Workflow Management System and the distributed workflow management support. The patterns monitor resource availability & connectivity, and, in case of fault of any resource, ensure job completion by re-mapping a process graph and restarting it. We also describe current implementation of the patterns and of the run-time support.