private static int calculateNodesAboveLimit(Optional<ClusterStateBundle.FeedBlock> feedBlock) {
        if (feedBlock.isEmpty()) return 0;

        var exhaustions = feedBlock.get().getConcreteExhaustions();
        return (int) exhaustions.stream().map(resource -> resource.node).distinct().count();
    }
Represents resource usage stats for the cluster that are exposed as metrics.
clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ResourceUsageStats.java