Location Independent Remote Execution in NEST

We consider a computing environment consisting of a network of autonomous, yet cooperating personal computer workstations and shared servers. Computing cycles in such an environment can be shared by creating a pool of compute servers in the network that may be used by the workstations to supplement their computing needs. Some processors may be permanently designated to be the compute servers. In addition, through an advertisement mechanism, any workstation may make itself temporarily available for a specific duration of time to be used as a compute server. In this paper, we present the design and implementation of a scheme for augmenting the UNIX® operating system with the location independent remote execution capability. This capability allows processes to be offloaded to the compute servers and preserves the execution environment of these processes as if they were still executing locally at the originating machine. Our model provides execution location independence of processes by preserving the process view of the file system, parent-child relationships, process groups, and process signaling across machine boundaries in a transparent way. We also present our scheme that allows processors to advertise themselves as available to some or all nodes in the network and withdraw as a compute server in a distributed manner. The scheme is robust in presence of node failures.