Re: Paxos -- It's our own implementation. Split brain is prevented by the master refusing to stand up unless a majority of configured (not just active) slaves approve its standup request. So in a 6 node deployment, 1 master and 5 slaves, 3 of the slaves would need to approve. This means one "half" would have 4 nodes, and the other would have 2 -- and the half with 2 would recognize it doesn't have quorum and thus stay idle. In a scenario where there is a split down the middle, nobody would do anything because nobody has quorum. (This is precisely why you shouldn't deploy in just 2 datacenters -- three is the magic number.)
Re: Sticky sessions -- True multi-machine consistency is impossible to guarantee and has no real practical application. The only consistency that matters is from the perspective of an observer, ensuring that it always sees a world whose time arrow progresses linearly forward. If that is what "linearizable" means, then perhaps. Sorry, my terminology could be off. Thanks for the correction!
Re: SQLite on SSD -- Sorry, I didn't mean to claim Bedrock was somehow faster than SQLite. Indeed, Bedrock adds overhead to SQLite (to do all the networking and such). My main claim is that Bedrock is faster than other databases, in particular when using C++ stored procedures for complex operations.
Thanks for the questions!