On Deadlock Detection in Distributed Systems

A hierarchically organized and a distributed protocol for deadlock detection in distributed databases are presented in [1]. In this paper we show that the distributed protocol is incorrect, and present possible remedies. However, the distributed protocol remains impractical because "condensations" of "transaction-wait-for" graphs make graph updates difficult to perform. Delayed graph updates cause the occurrence of false deadlocks in this as well as in some other deadlock detection protocols for distributed systems. The performance degradation that results from false deadlocks depends on the characteristics of each protocol.