&gt; <i>Both PostgreSQL and Cassandra have mature replication frameworks</i><p>Speaking of Postgres - master&#x2F;slave replication is fairly easy and seems to work well. But trying to implement master&#x2F;master replication is painful. There are some external solutions like Bucardo, which is basically a Perl-based service that handles replication outside of PG (yikes!); there&#x27;s BDR which is integrated with the main PG daemon, but it&#x27;s not production ready. And this is only asynchronous replication.<p>Any suggestions for sane, reliable master&#x2F;master replication with PG that simply works?