Reliable Compare&Swap for fault-tolerant synchronization

Abstract

This paper presents two Compare&Swap protocols that, with respect to omission failures, are (1) fault-tolerant and (2) gracefully degrading, respectively. It shows that fault-tolerance and graceful degradation are close but distinct concepts, and that graceful degradation is inherently more costly than fault-tolerance. These Compare&Swap protocols are derived from consensus protocols proposed by Jayanti et al. (1999).