AN ANALYSIS OF THE AVERAGE MESSAGE OVERHEAD IN REPLICA CONTROL PROTOCOLS

Management of replicated data has received considerable attention in t he last few years. Several replica control schemes have been proposed which work in the presence of both node and communication link failure s. However, this resiliency to failure inflicts a performance penalty in terms of the communication overhead incurred. Though the issue of p erformance of these schemes from the standpoint of availability of the system has been well addressed, the Issue of message overhead has bee n limited to the analysis of worst case and best case message bounds. In this paper we derive expressions for computing the average message overhead of several well known replica control protocols and provide a comparative study of the different protocols with respect to both ave rage message overhead and system availabilities.