On the time-complexity of robust and amnesic storage

Dobre, D. and Majuntke, M. and Suri, Neeraj (2008) On the time-complexity of robust and amnesic storage. In: Principles of Distributed Systems. Springer, pp. 197-216. ISBN 9783540922209

Abstract

We consider wait-free implementations of a regular read/ write register for unauthenticated data using a collection of 3t∈+∈k base objects, t of which can be subject to Byzantine failures. We focus on amnesic algorithms that store only a limited number of values in the base objects. In contrast, non-amnesic algorithms store an unbounded number of values, which can eventually lead to problems of space exhaustion. Lower bounds on the time-complexity of read and write operations are currently met only by non-amnesic algorithms. In this paper, we show for the first time that amnesic algorithms can also meet these lower bounds. We do this by giving two amnesic constructions: for k∈=∈1, we show that the lower bound of two communication rounds is also sufficient for every read operation to complete and for k∈=∈t∈+∈1 we show that the lower bound of one round is also sufficient for every operation to complete. © 2008 Springer Berlin Heidelberg.