Distributed slicing and partial re-execution for distributed programs

Abstract

We present a parallel algorithm to compute dynamic slices for distributed programs. Dynamic slices are used in debugging to re-execute only those statements of the original program that actually influenced an observed erroneous result. We introduce the notion of a Distributed Dependence Graph (DDG) as the graphical representation of the relevant dependencies among statements that arise during execution of a distributed program. Based on the DDG, we developed a parallel and fully distributed slicing algorithm, where each process determines its local section of the global slice. The potential for non-determinism in distributed programs is addressed by constructing a slice such that non-deterministic selections that were made during execution of the original program are reproduced when re-executing the program slice.