A Token-Based Synchronization Scheme Using Epsilon-Serializability and Its Performance for Real-Time Distributed Database Systems

Schedulers for real-time distributed replicated databases must satisfy timing constraints of transactions and preserve data consistency. In this paper, we present a replication control algorithm, which integrates real-time scheduling and replication control. The algorithm adopts a token-based scheme for replication control and attempts to incorporate the urgency of real-time transactions into the conflict resolution policies. The algorithm employs epsilon-serializability, new correctness criterion which is less stringent than conventional one-copyserializability. The performance of the algorithm is evaluated using a simulation environment.