> Since Schemaless uses MySQL asynchronous replication, the write will be lost if a master receives a write request, persists the request, and then fails before

> Since Schemaless uses MySQL asynchronous replication, the write will be lost if a master receives a write request, persists the request, and then fails before it has replicated the write to the minions (e.g., in a hard drive failure). To solve this problem we use a technique called buffered writes. Buffered writes minimize the chance of losing data by writing it to multiple clusters. If a master is down, the data is not readily available for subsequent reads but has nevertheless been persisted. Postgres has the same replication semantics as MySQL async replication. So yes, if you want to build something like this, you could. However, the question you should be asking yourself isn't "could you" but "should you". The answer is probably not. Multi-master setups are extremely difficult to build reliably and unless you understand them extremely well you can frequently shoot yourself in the foot with something that seems right but really is only right for a handful of use cases.