Treffer: Reversible Languages and Incremental State Saving in Optimistic Parallel Discrete Event Simulation

Optimistic parallel discrete event simulation (PDES) requires to do a distributed rollback if conflicts are detected during a simulation due to the massively parallel optimistic execution approach. When a rollback of a simulation is performed each node that is determined to be in a wrong state must be restored to one of its previous states. This can be achieved through reverse computation or by restoring a previous checkpoint. In this paper we investigate and compare both approaches, reverse computation and a variant of checkpointing, incremental state saving (also called incremental checkpointing), to restore a previous program state as part of an optimistic parallel discrete event simulation. We present a benchmark model that is specifically designed for evaluating the performance of approaches to reversibility in PDES. Our benchmarking model has mathematical properties that allow to tune the amount of arithmetic operations relative to the amount of memory operations. These tuning opportunities are the basis for our systematic performance evaluation.