Accelerating Distributed Discrete Event Simulation through Exchange of Conditional Look-Ahead

Distributed discrete event simulation is a very important method today to analyze the behavior of large models. We investigate the practical implementation of distributed discrete event simulation with conservative synchronization and its acceleration through dynamic estimation of process-to-process look-ahead. Since the dynamic look-ahead changes with time, we have to face the situation, that the look-ahead between some logical processes is decreased temporarily. The shortened lookahead has a very negative influence to the performance of the simulation and it is hard to avoid. However, this effect can be reduced by introducing some extra mechanisms in the simulation. In this paper, we present a mechanism to optimize the simulation for the situation that the look-ahead between some processes is very short. This mechanism is based on exchange of conditional look-ahead and broadcast of invalidation announcement. Our evaluation shows reduction of the execution time of a majority of distributed simulations, especially when the estimated look-ahead is stochastically too conservative.