Trace Recovery: A Distributed Computing Application for Perturbation Tracking

Execution monitoring plays a central role in most software development tools for parallel and distributed computer systems. However, such monitoring may induce delays that corrupt event timing. In this paper we introduce a perturbation analysis-like algorithm that, given a safe timed Petri net model of the monitored software, can recover the uncorrupted event timings, i.e., those that would have been observed had the delays not been present. Monitoring conditions sufficient to ensure correct operation of the algorithm, and examples illustrating the algorithm's applicability to message-passing systems are also presented. This work is part of a larger effort aimed at identifying cost-effective software alternatives to custom hardware monitoring