@Override
    protected Move suggestedMove(Node node, Node fromHost, Node toHost, NodeList allNodes) {
        NodeList clusterNodes = clusterOf(node, allNodes);
        NodeList clusterHosts = allNodes.parentsOf(clusterNodes);
        if (onExclusiveSwitch(node, clusterHosts)) return Move.empty();
        if (!increasesExclusiveSwitches(clusterNodes, clusterHosts, toHost)) return Move.empty();
        return new Move(node, fromHost, toHost);
    }
Ensure that nodes within a cluster a spread across hosts on exclusive network switches.

@author mpolden
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/SwitchRebalancer.java