Run-time selection of the checkpoint interval in Time Warp based simulations

摘要

Time warp discrete event simulators take advantage of the parallel processing of simulation events. On the other hand, they suffer from the overhead required to enforce the causality relation. This overhead consists of the time for saving the states of logical processes, the time for the rollback procedures and the wasted simulation time, that is the time spent for the processing of events which are undone because of rollback. Two techniques have been developed for state saving: periodic and incremental. In this paper we study the periodic technique, and we present an analytical model describing the simulation execution time in function of both the state saving cost and the rollback cost. Furthermore, we derive a methodology that allows each logical process to adapt its state saving period on line in order to reduce the simulation execution time. Experimental results show that, in some simulation scenarios, our methodology improves performance, in comparison to already existing proposals.