Hybrid Approaches to Loosely-Synchronized Parallel Discrete-Event Simulation

该项目探索了通过结合保守和乐观同步策略的特点来提高并行离散事件模拟性能的方法。而不是试图避免回滚，这是通过减慢模拟的最快组件来实现的，策略是避免状态检查点，这应该会加快最慢的组件的速度。这个项目是试验性的。一个单一的实现将允许人们在纯保守同步和混合方法的性能之间进行公平的比较。此外，通过添加在纯乐观和混合情况下限制乐观程度的机制，可以验证或驳斥这样的假设：与状态检查点的开销相比，乐观回滚的开销是二阶效应。在成功验证这一假设的前提下，本研究将继续使用启发式方法，在模拟执行过程中动态调整乐观程度。

This project explores methods for improving the performance of parallel discrete-event simulation by combining features of both conservative and optimistic synchronization strategies. Rather than attempting to avoid rollback, which is accomplished by slowing down the fastest components of the simulation, the strategy is to avoid state checkpointing, which should speed up the slowest components. The project is experimental in nature. A single implementation will allow one to make fair comparisons between the performance of pure conservative synchronization, and a hybrid method. Furthermore, by adding a mechanism for limiting the degree of optimism in both the pure optimistic and the hybrid cases, it will be possible to verify or refute the hypothesis that the overhead of optimistic rollback is a second-order effect compared to the overhead of state checkpointing. Subject to the successful verification of this hypothesis, this research will continue with heuristics for dynamically adapting the degree of optimism in a simulation during its execution.