In systems consisting of multiple clusters of processors which are interconnected by relatively slow communication links and which employ space sharing for scheduling jobs, such as our Distributed ASCI1 Supercomputer (DAS), coallocation, i.e., the simultaneous allocation of processors to single jobs in different clusters, may be required. We study the performance of co-allocation by means of simulations for the mean response time of jobs depending on the structure and sizes of jobs, the scheduling policy, and the communication speed ratio. Our main conclusion is that for current communicationspeed ratios in multiclusters, coallocation is a viable option.
Anca I. D. Bucur, Dick H. J. Epema