A fault tolerant replicated storage system

Abstract

One way of achieving high availability of data in a distributed system is to replicate the data on several nodes. We present an algorithm for a replicated storage system which takes advantage of the high reliability of ETHERNET local area networks and their broadcast capability. The algorithm is both simple and efficient. It does not use reliable communication protocols and does not require a separate recovery procedure or knowledge of the current status (up or down) of the other nodes in the network. It guarantees that all transactions will be completed within a finite time and that no record will be locked indefinitely. We discuss the properties of the algorithm and some extensions to it. We also compare it with some other methods of managing replicated storage systems.