Transaction model vs virtual synchrony model: Bridging the gap

Abstract

Two important models for building fault-tolerant applications have been independently proposed in the literature, the transaction model (developed within the context of database applications) and the virtual synchrony model (proposed initially by the Isis system to handle replication). For a better understanding of the relations between these models, we address the following question: are the basic mechanisms needed to implement both models exactly the same? The paper answers this question by denning the Dynamic-Terminating-Multicast problem, and showing that it can be seen as a generic problem, closely related to the implementation of both the transaction model and the virtual synchrony model. It is thus possible to build a system offering, in an integrated way, both the transaction model and the virtual synchrony model. Such a system could offer powerful primitives that are currently cumbersome or impossible to express in the existing systems.