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> A Raft cluster must have an odd number of nodes. what about a 7 to 3 / 3 / 1 split?
by Flenser 12y ago
> A Raft cluster must have an odd number of nodes.
what about a 7 to 3 / 3 / 1 split?
- Muzzaf 12y agoNot sure I understand. A node in each split cluster would need at least 4 votes to be elected leader. Hence no node can be elected leader since all split clusters have strictly fewer than 4 nodes. Theorem. With 2n + 1 nodes, there can not be two separate majorities after a net split. Proof. By way of contradiction, assume there are two separate majorities. Each separate majority would contain at least ceil((2n + 1)/2) = n + 1 nodes. This implies that there are in total at least 2(n + 1) = 2n + 2 nodes in the system, contradiction.