Transparent Implementation of Conservative Algorithms in Parallel Simulation Languages

Parallel discrete event simulation offers significant speedup over the traditional sequential event list algorithm. A number of conservative and optimistic algorithms have been proposed and studied for parallel simulation. We examine the problem of transparent execution of a simulation model using conservative algorithms, and present experimental results on the performance of these transparent implementations. The conservative algorithms implemented and compared include the null message algorithm, the conditional-event algorithm, and a new algorithm which is a combination of these. We describe how dynamic topology can be supported by conservative algorithms. Language constructs to express lookahead are discussed. Finally, performance measurements on a variety of benchmarks are presented, along with a study of the relationship between model characteristics like lookahead, communication topology and the performance of conservative algorithms.