public static double skew(NodeResources totalHostCapacity, NodeResources freeHostCapacity) {
        NodeResources all = totalHostCapacity.justNumbers();
        NodeResources allocated = all.subtract(freeHostCapacity.justNumbers());

        return new Mean(allocated.vcpu() / all.vcpu(),
                        allocated.memoryGiB() / all.memoryGiB(),
                        allocated.diskGb() / all.diskGb())
                       .deviation();
    }
Computes the allocation skew of a host node
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/Node.java