In: Proceedings of the Seventh International Workshop on Petri Nets and Performance Models, June 3-6, 1997, Saint Malo, France, pages 205-216. Los Alamitos, California: IEEE Computer Society, June 1997.
Abstract: The unthrottled optimism underlying the Time Warp (TW) parallel simulation protocol can lead to excessive aggressiveness in memory consumption due to saving state histories and waste of CPU cycles due to overoptimistically progressing simulations that eventually have to be ``rolled back''. Furthermore, in TW simulation executing in distributed memory environments, the communication overhead induced by the rollback mechanism can cause pathological overall simulation performance. In this work direct optimism control mechanisms are used to overcome these shortcomings by probabilistically controlling simulation progression based on the forecasted time stamp of forthcoming messages. Several forecast methods are presented and their performance is compared for very large Petri net simulation models executed with the TW protocol on the Meiko CS-2.