Error Propagation and Recovery in Concurrent Environments

Abstract

Backward error recovery is a popular technique for recovery from unexpected system failures. In a concurrent processing environment, the synchronisation constraints and the propagation of erroneous information between processes tend to make recovery very complex and expensive. In this paper we present a detailed analysis of error propagation and introduce a new classification for variables based upon their error-propagation characteristics. Necessary and sufficient conditions to ensure a finite upper bound on the computation discarded in the course of error recovery are developed. Several other recovery-related issues are also discussed.