For MySQL, for smaller deployments, I've found Galera to really be a handy HA system to get going: > Galera Cluster is a synchronous multi-master database clus

For MySQL, for smaller deployments, I've found Galera to really be a handy HA system to get going: > Galera Cluster is a synchronous multi-master database cluster, based on synchronous replication and MySQL and InnoDB. When Galera Cluster is in use, database reads and writes can be directed to any node. Any individual node can be lost without interruption in operations and without using complex failover procedures. * https://galeracluster.com/library/documentation/overview.html https://galeracluster.com/library/documentation/overview.htm... * https://packages.debian.org/search?keywords=galera https://packages.debian.org/search?keywords=galera The closest out-of-box solution that I know of for Postgres is the proprietary BDR: * https://www.enterprisedb.com/docs/pgd/4/bdr/ https://www.enterprisedb.com/docs/pgd/4/bdr/ * https://wiki.postgresql.org/wiki/BDR_Project https://wiki.postgresql.org/wiki/BDR_Project There are systems like Bucardo, but they are trigger-based and external to the Postgres software: * https://www.percona.com/blog/multi-master-replication-solutions-for-postgresql/ https://www.percona.com/blog/multi-master-replication-soluti... Having a built-in 3-node MMR (or 2N+1arb[0]) solution would solve a bunch of 'simple' HA situations. [0] https://packages.debian.org/search?keywords=galera-arbitrator https://packages.debian.org/search?keywords=galera-arbitrato...