In: Int. Workshop on Petri Nets and Performance Models, Madison, Wisconsin, pages 84-92. Washington: IEEE Computer Society Press, 1987.
Also in: IEEE, Transactions on Software Engineering, Vol. 15, No. 4, pages 394-401. April 1989.
Abstract: The authors present a stochastic Petri net model of a replicated file system in a distributed environment where replicated files reside on different hosts and a voting algorithm is used to mantain consistency. Witnesses, which simply record the status of the file but contain no data, may be used to reduce overhead. The model is sufficiently detailed to include file status as well as failure and repair of hosts where copies or witnesses reside. Two different majority protocols are examined, one where a majority of all copies and witnesses is necessary to form a quorum, and the other where only a majority of the copies and witnesses on operational hosts is needed.
Keywords: stochastic net; voting algorithm; replicated file system; majority protocol.