The Design Space for Data Replication Algorithms in Interactive Groupware

Interactive (Synchronous) Groupware encompasses a wide range of applications, like collaborative whiteboards, text editors, engineering CAD (Computer Aided Design), Distributed Virtual Environments, and multi-player games. A very critical requirement for all these applications is the need to share data, which can be replicated to provide better responsiveness, fault-tolerance and scalability. Despite the existence of many systems and distributed algorithms for replication in interactive groupware, there is little agreement on the shared data abstraction to provide, or on the general algorithmic approach. Similarly, there is general lack of uniformity in the terminology used to describe such algorithms. This paper attempts to rectify this situation by (1) Describing the fundamental data requirements of interactive groupware, (2) Developing a data abstraction which is appropriate for meeting these requirements, (3) Developing a general algorithmic structure and terminology to express the characteristics of algorithm instances, and (4) Classifying the algorithms proposed in the research literature