The design and implementation of an active replication scheme for distributing services in a cluster of workstations

Replication is the key to providing high availability, fault tolerance, and enhanced performance in a cluster of workstations (COWs). However, buildin g such a system remains as a difficult and challenging task, mainly due to the difficulty of maintaining data consistency among replicas and the lack of easy and efficient tools supporting the development procedure. In this p aper we propose an active replication scheme in which data consistency can be maintained. Based on the active replication scheme, we present an object -oriented design pattern and a constructing tool to simplify the design and implementation of service replications in COWs. (C) 2001 Elsevier Science Inc. All rights reserved.