A middleware database replication protocol providing different isolation levels

Database replication protocols have been usually designed in order to support a single isolation level. This paper proposes a middleware protocol able to manage three different isolation levels over multi-version DBMSs: GSI, SI, and serializable. This ensures a better support for applications that demand different isolation levels for their transactions. Additionally, this protocol is also able to merge the coordination of the replicas for each isolation level, using a weak voting approach for all of them, whilst other recent protocols need a certifying technique for GSI and SI, or a 2PC rule for serializable level