THE WHEEL QUORUM PROTOCOL: AN EFFICIENT APPROACH FOR READING REPLICATED DATA

摘要

Data is replicated in distributed systems to improve availability and performance. To keep logical data consistent, there must exist a control protocol responsible for synchronizing the access. In this paper, we present a novel and efficient distributed algorithm for managing replicated data. We impose a logical wheel structure on the set of copies of an object. The protocol ensures minimum read quorum size of one, by reading one copy of an object while guaranteeing fault-tolerance of write operations. Even in failure, read quorum remains one. Wheel structure has a wider application area as it can be imposed in a network with any number of nodes. It gives high read availability.