Publication Abstract

Khazan, R. I., Lynch, N. A., An Algorithm for an Intermittently Atomic Data Service Based on Group Communication, Proceedings of the International Workshop on Large-Scale Group Communication, Florence, Italy, pp. 25-30, October 2003.

Abstract

Group communication provides a convenient mechanism for building applications that maintain a replicated state of some sort. Such applications typically implement certain consistency properties regarding how different application clients perceive the replicated state. One of the well-understood and often preferred consistency properties is strong consistency or atomicity, which creates a perception of the replicated state as being non-replicated. However, in large-scale wide-area settings, providing atomicity may result in prohibitive levels of overhead and sometimes, during network partitions, in blocking the applications until partitions repair. Thus, weaker consistency properties may be more appropriate in such settings. A key question is which weaker consistency properties are still coherent and acceptable to the application clients. In this paper, we propose one way to weaken the atomicity property and illustrate the resulting property, intermittent atomicity, with a simple application.