Group transactions: an integrated approach to transactions and group communication
Ricardo Jiménez, Marta Patiño-Martı́nez, Sergio Arévalo Viñuales · 2000
Transactions and group communication are two techniques to build fault-tolerant distributed applications. They have evolved separately during a long time. It has been in the last years when researchers have proposed an integration of both techniques. Transactions were developed in the context of database systems to provide data consistency in the presence of failures and concurrent accesses. On the other hand, group communication was proposed as a basic building for reliable distributed systems, and it deals with consistency in the delivery of multicast messages. The difficulty of the integration stems from the fact that the two techniques provide very different kinds of consistency. This work addresses the following questions: Is it possible to build a system providing both models? Is it possible to propose an integrated model? This work discusses how applications using group communication can benefit from transactions and vice versa. Groups of processes can deal with persistent data in a consistent way with the help of transactions and transactional applications can take advantage of group communication to build distributed cooperative servers as well as replicated ones. An additional advantage of an integrated approach is that it can be used as a base for building transactional applications taking advantage of computer clusters. In this paper we address the integration of transactions and group communication proposing a new transaction model, GroupTransactions, where transactional servers can be groups of processes. This research has been partially funded by the Spanish National Research Council CICYT under grant TIC98-1032-C03-01.