Methods of conducting database transactions. One such method comprises receiving data to be written to a database; identifying a set of shard replicas corresponding to the database to which the data is to be written; transmitting, to each of the replicas in the set, a request to write the data thereto; receiving votes back from the replicas in the set, each vote representing whether the respective replica commits to a writing of the data thereto; determining whether to commit to the writing of the data to the database according to whether a majority of the replicas of every shard having replicas in the set has transmitted a vote committing to the writing of the data thereto; and transmitting an outcome of the determining to each of the replicas in the set.