Harness: adaptable virtual machine environment for heterogeneous clusters

This paper describes ongoing work on the Harness system for next-generation heterogeneous distributed computing. Harness is an adaptable, reliable virtual machine environment being built as a follow-on to PVM. The three fundamental concepts presented here are parallel plugins, fault-tolerant distributed control, and dynamically merging and splitting virtual machines. The distributed control mechanisms provide the support framework necessary for coordinating and applying parallel plugins that allow applications to customize or tune their operating environment on-the-fly. In the spirit of CUMULVS, Harness applications can plug into each other to couple for collaborative computing. Virtual machines that merge and split can assist applications in dynamically utilizing different computing resources to suit changing computational needs.