Enhancing the availability of networked database services by replication and consistency maintenance

We describe a middleware platform for maintaining the consistency of replicated data called COPla (Common Object Platform). The purpose of replication is to enhance the availability of data and services in distributed database networks. That is orthogonal to recovery strategies of backed-up snapshots, logs and other measures to alleviate database downtimes. A range of different consistency modes ensures the correctness of replicated data.