Flexible batching and consistency mechanisms for building interactive groupware applications

Abstract

The paper presents our state sharing support for building object oriented interactive groupware in wide area distributed environments. We motivate and present an asynchronous model for updating replicated state, which supports atomicity of updates across multiple shared objects. Coupled with our flexible marshalling framework, this model allows existing application data structure classes to be easily extended and made shareable. To solve the problem of replica consistency we use a novel combination of three mechanisms: (1) global locks, (2) detection of incorrect update ordering, and (3) cloning a subset of the shared objects and state reinitialization. Finally, to reduce network load due to fine grain user interaction, we provide a framework for application specified event batching called Late Event Modification.