Postmortem Simulation

BigNetSim takes a different approach by performing postmortem simulation. The BigSim emulator generates a log of tasks that were performed and their dependencies. However, the tasks in this log have not been ordered in time with respect to each other, and need to be timestamp-corrected in order to obtain performance results about the original program that was run on the BigSim emulator. To perform timestamp correction, we use a parallel discrete event simulation (PDES) environment called POSE[7][8].

BigNetSim plugs into the timestamp correction simulation and simulates the same application over a detailed network model. The behavior of the network model can be varied by its input parameters to model a variety of situations without ever needing to re-run the original simulation.