Improving performance by replicating simulations with alternative synchronization approaches

Parallel and distributed simulation facilitates the construction of a simulation application (i.e., federation in HLA terminology) with a number of simulation components (federates). Recently, an approach based on active replication technique has been proposed to improve the performance of simulations by exploring software diversity. To guarantee the correctness of the approach, all replicas of the same federate are required to be Piece-Wise-Deterministic (PWD). However, the PWD restriction will not be satisfied if the replicas achieve software diversity by employing different kinds of synchronization approaches. A replication structure is proposed in this paper, which can transparently handle the federate replicas that use either conservative or optimistic synchronization approach. The execution speed of the federation is increased by always choosing the fastest replica to represent the federate in the federation. Besides presenting the implementation details, we also report the experimental results to demonstrate the performance improvement of the replication structure.