SyncSim: a synchronous simple optimistic simulation technique based on a global parallel heap event queue

We developed and implemented two highly optimized optimistic discrete event simulation techniques based on an efficient and scalable parallel heap data structure as a global event queue. The primary results are (i) the design of an optimistic simulation algorithm, namely SyncSim, which does not rely on traditional state and message saving data structures, but employs only one backup state per state variable, (ii) a demonstration, through implementation of SyncSim, of an optimistic technique which overcomes the two main mutually conflicting and unbounded overheads of the existing optimistic simulation algorithms: SyncSim bounds the additional space requirements to just one copy per state variable and drastically limits the number of rollbacks encountered. Furthermore, SyncSim beats the highly optimized traditional simulator simglobal on a wide variety of large networks on an Origin-2000 computer. The algorithm SyncSim could form a basis for a good parallelizing engine attachable relatively easily to an existing serial simulator.