Modelling the Performance of Distributed Database Protocols for Real Time Environments

Distributed database management protocols are usually based on the assumption that data consistency is paramount. However, this assumption is invalid for distributed real-time applications such as ship combat systems and air traffic control, where data availability is crucial and may need to be achieved at the expense of guarantees of data consistency. Two protocols designed for real-time combat systems which achieve availability by relaxing consistency restraints are ADDAM (ARE (Admiralty Research Establishment) Distributed Database Manager) and ALDM (ADDAM Like Distributed Database Manager). In this paper, the performance of these protocols is compared with the well-known TwoPhase Commit (2PC).