Providing support for data replication protocols with multiple isolation levels

Abstract

Concurrent transaction execution with different isolation levels is an issue solved a long time ago in centralised databases. This allows an application to execute critical transactions with a high isolation level and non-critical with a weak one. In replicated databases this is still an open line, nearly virgin, with a lot of open fronts which conform the main objectives of this work. What we intend to do is a methodology to construct replication protocols supporting concurrent transaction execution with different isolation levels. As example and case of study, in this document we define the new Generalised Loose Read Committed isolation level, near to Read Committed but easier to provide in replication protocols, to study how can we apply our methodology to support GLRC and Serialisable in the weak voting replication protocol schema. © Springer-Verlag Berlin Heidelberg 2007.