This blog discusses Asynchronous versus Synchronous MySQL replication for MySQL clustering. Synchronous replication is viewed as the ‘holy grail’ of clustering. But unfortunately, when something is too good to be true, it often is. Before the Tungsten cluster solution Continuent built two synchronous replication cluster solutions (m/cluster, uni/cluster), but we abandoned those for good reasons.
MySQL Clustering with Asynchronous versus Synchronous Replication
Advanced Replication, Geographic Distribution and Geo-Scale, Performance