A Recovery Protocol for Middleware Replicated Databases Providing GSI

Middleware database replication is a way to increase availability and afford site failures for dynamic content websites. There are several replication protocols that ensure data consistency for these systems. The most attractive ones are those providing Generalized Snapshot Isolation (GSI), as read-operation never blocks. These replication protocols are based on the certification process, however, up to our knowledge, they do not cope with the recovery of a replica. In this paper we propose a recovery protocol that ensures GSI (we provide an outline of its correctness) that does not interfere with user transactions and permits the execution of transactions in the recovering node, even though the recovery process has not finished.