private boolean failAllowedFor(NodeType nodeType) {
        return switch (nodeType) {
            case tenant, host -> true;
            case proxy, proxyhost -> nodeRepository().nodes().list(Node.State.failed).nodeType(nodeType).isEmpty();
            default -> false;
        };
    }
We can attempt to fail any number of *tenant* and *host* nodes because the operation will not be effected
unless the node is replaced.
We can also attempt to fail a single proxy(host) as there should be enough redundancy to handle that.
But we refuse to fail out config(host)/controller(host)
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeFailer.java