Case study: parallelizing a sequential simulation model

Most successful examples of parallel simulation models were developed for parallel execution, from the beginning. A number of simulation models are designed only for sequential simulation, even in languages like PARSEC, that support both sequential and parallel simulation algorithms. Converting such simulation models to a form that yields good performance with a parallel implementation can be non-trivial. We describe a case study showing this conversion process for a simulation model of replicated file systems. The details of the major steps taken in converting the simulation into a parallel simulation are presented: correctness changes; performance changes such as communication topology simplification and lookahead specification; and modeling changes to eliminate performance bottlenecks. The details and performance improvements of each step are presented