A Database Replication Protocol Where Multicast Writesets Are Always Committed

Database replication protocols based on a certification approach are usually the best ones for achieving good performance. The weak voting approach achieves a slightly longer transaction completion time, but with a lower abortion rate. So, both techniques can be considered as the best ones for replication when performance is a must, and both of them take advantage of the properties provided by atomic broadcast. We propose a new database replication strategy that shares many characteristics with such previous strategies. It is also based on totally ordering the application of writesets, using only an unordered reliable broadcast, instead of an atomic broadcast. Additionally, the writesets of transactions that are aborted in the final validation phase are not broadcast in our strategy. Thus, this new approach reduces the communication traffic and also achieves a good transaction response time (even shorter than those previous strategies in some system configurations).