MySQL Cluster over WAN: Best Architecture Options?
For high-latency the main choice is between Percona XtraDB Cluster (Galera+InnoDB-based) or the new WAN replication in MySQL Cluster 7.2 (NDB-based). The downside of NDB is greatly increased complexity and application changes; it is NOT a drop-in replacement for your existing system.  Percona XtraDB Cluster has only a few small differences, e.g. locking is pessimistic on the local node (as currently) but optimistic cluster-wide, so if there are conflicting changes on a remote node you won't find out until you commit. (If there are conflicting changes, the commit will fail and roll back; you can't break the cluster as you can with standard MySQL replication.)