> what you're describing isn't a quorum read/write scenario -- what do you mean by "a wins"? Also where is the prepare phase for 2 phrase commit/any consensus a

> what you're describing isn't a quorum read/write scenario -- what do you mean by "a wins"? Also where is the prepare phase for 2 phrase commit/any consensus algo? There is no consensus; that requires a leader system. The paper you link appears to require a multi-phase lock; the quorum itself does not guarantee serializability. Explicit preparation via quorum can guarantee serializability (but not strict serializability, I don't think), but cleanup of locks is a big performance problem in practice. > Replica A shouldn't be reporting an unacknowledged transaction to coordinators -- the write hasn't been quorum acknowledged. Acknowledged by who? The replicas can't block on the other replicas; they just tell the coordinator when they applied the write. This is worth a blog post.