There's no theoretical reason why multipaxos can't be implemented hierarchically in order to increase throughput or expand the key space beyond what a small num

There's no theoretical reason why multipaxos can't be implemented hierarchically in order to increase throughput or expand the key space beyond what a small number of machines can handle. But paxos itself is complicated enough to deter almost all implementers, so add two additional levels of complexity? I don't think I'm surprised no one has tried. Paxos: Agree on a value. Multipaxos: Agree on a Leader, who will coordinate a set of values. Hierarchical Multipaxos: Agree on a Leader, who will coordinate a set of Leaders, who will each coordinate a set of values. If you squint hard enough, this looks almost like a B-Tree.