| "My take on RAFT is that it's basically Paxos" You're right that Raft is Paxos for the leader election phase, in the same way that VR is Paxos for the view change phase, or that Paxos is basically VR's view change but for deciding a value. But a better way of saying this would be that Raft is Multi-Paxos (https://news.ycombinator.com/item?id=23123701), because Raft is much more than Paxos (in the same way that VR is more than Paxos because it not only decides on a value/leader but is also a protocol for replication). I think this is where our misunderstanding came in. Yes, I've read the linked "Vive La Difference" paper. As the excerpt makes clear, one of the key differences is active replication (Paxos: with multiple concurrent processes that want to decide on a value) vs passive replication (Multi-Paxos variants: VR and Raft and ZAB all protocols with a single leader elected for a given term/view during which multiple rounds of replication take place). The name Multi-Paxos just means that the first round of Paxos for leader election is reused for multiple rounds of replication, driven by a single leader instead of competing processes always using the minimum two-phase Paxos. "I have this thing for underdogs" Yes, me too, and that's why I tried to show that VR is no less than Multi-Paxos in my original comment, and that Raft is not newer than Multi-Paxos in my follow-up. It would be great for VR to receive the recognition it deserves. |
That functionally M-Paxos and Raft are equivalent does not make them the equivalent. RAFT uses a protocol that looks awfully like Paxos for election of a single leader - so it has nothing to do with multi-Paxos (as I understand it). But that L.E. phase + the interim regime gives you functional equivalence to Multi-Paxos.