Main Memory Commit Processing: The Impact of Priorities

Distributed transaction systems require an atomic commitment protocol to preserve ACID properties. The overhead of commit processing is a significant part of the load on a distributed database. Here, we propose approaches where the overhead is reduced by prioritizing urgent messages and operations. This is done in the context of main memory primary-backup systems, and the proposed approaches is found to significantly reduce the response time as seen by the client. Also, by piggybacking messages on each other over the network, the throughput is increased. Simulation results show that performance can be significantly improved using this approach, especially for utilizations above 50%.