Using Multicast to Reduce Deadlock in Replicated Databases

Abstract

Obtaining good performance from a distributed replicated database that allows update transactions to originate at any site while ensuring one-copy serializability is a challenge.   A popular analysis of deadlock probabilities in replicated databases shows that the deadlock rate for the system is high and increases as the third power of the number of replicas.  We show how a replica management protocol that uses atomic broadcast for replica update reduces the occurrence of deadlocks and the dependency on the number of replicas.  The rate of deadlock is shown to be a function of both the number of sites as well as the cost of broadcast.  The analysis is confirmed by simulation experiments.
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