Measuring The Overhead In Conservative Parallel Simulations Of Multicomputer Programs: Detailed Measurements

In this paper we show that it is feasible to characterize the overheads present in conservative parallel simulations of multicomputer programs. We use a modified version of the parallel simulator from the Poker Programming Environment to empirically measure the overhead in two parallel algorithms which use three different interconnection structures. We discuss the sources of overhead and qualitatively discuss their relative importance. 1 INTRODUCTION There has been a great deal of interest over the past few years in comparing conservative and optimistic strategies for parallel discrete-event simulations. The work in this area can be categorized as empirical studies and analytical or formal models. In the empirical studies, specific experiments are run on both conservative and optimistic simulators to see which strategy results in a faster simulation. Fujimoto (1989) did this for closed queuing networks and found that the optimistic strategy generally outperformed the conservative str..