Felipe Knop

Checkpoint and recovery methods in the ParaSol simulation system

State-saving operations are a major source of overheads in optimistic and adaptive parallel discreteevent simulations. We present some techniques for saving state in the the context of the PARASOL multithreaded parallel simulation system. In this system, threads are used to implement both logical processes and active transactions which access passive simulation objects. Hence, system state is a combination of thread-state and object-state. We introduce a new save-if-modified method for incremental checkpointing of threads and objects. Because of the PARASOL system’s domain-oriented support, checkpointing is transparent to the user. Application-level objects that are foreign to a domain may be saved via invocations to primitives in the system’s ParaState module.

Minimum cost adaptive synchronization: experiments with the ParaSol system

We present a novel adaptive synchronization algorithm, called the minimum average cost (MAC) algorithm, in the context of the PARASOL parallel simulation system. PARASOL is a multithreaded system for parallel simulation on shared- and distributedmemory environments, designed to support domainspecific Simulation Object Libraries. The proposed MAC algorithm is based on minimizing the cost of synchronization delay and rollback at a process, whenever its simulation driver must decide whether to either proceed optimistically or to delay processing. In the former case the risk is rollback cost, in the event of a straggler’s arrival. In the latter case the risk is unnecessary delay, in the event a late-comer is not a straggler. In addition to the MAC algorithm and an optimal delay computation model, we report on some early experiments comparing the performance of MAC-based adaptive synchronization to optimistic synchronization.

Minimum Cost Adaptive Synchronization: Experiments With The System

We present a novel adaptive synchronization algorithm, called the minimum average cost (MAC) algorithm, in the context of the PARASOL parallel simulation system. PARASOL is a multithreaded system for parallel simulation on sharedand distributedmemory environments, designed to support domainspecific Simulation Object Libraries. The proposed MAC algorithm is based on minimizing the cost of synchronization delay and rollback at a process, whenever its simulation driver must decide whether to either proceed optimistically or to delay processing. In the former case the risk is rollback cost, in the event of a straggler’s arrival. In the latter case the risk is unnecessary delay, in the event a late-comer is not a straggler. In addition to the MAC algorithm and an optimal delay computation model, we report on some early experiments comparing the performance of MAC-based adaptive synchronization to optimistic