The important design issue about building active-active multi-master on the base of raft protocol is about being able to apply changes locally without immediately putting them into a log (without sacrificing durability). MySQL implements a binlog, which is separate from a log, to ensure durability. OrioleDB implements copy-on-write checkpoints and row-level WAL. That gives us a chance to implement MM and durability using a single log.
yeah, fair shout
`columnar index` for hybrid analytical workloads and `multi-master` roadmap items haven't been put in an order on the schedule yet so maybe multi-master makes sense to do first. Both align with webscale requirements though. Columnar would move into the AlloyDB space and multi-master would be more like PlanetScale (although not quite the same audience in the latter case)
It's motivated by liking of reliable systems that keep working when a node fails.
There are a bunch of non-webscale companies that pick mysql over postgresql because they can use either percona xtradb cluster or galera cluster.
Having an open source multi-master solution would mean that postgresql could finally be used over there as well.