private static void warnWhenMinNodeRatioLowAndManySmallGroups(ContentCluster cluster, DeployState deployState) {
            var minNodeRatioPerGroup = cluster.getClusterControllerConfig().tuning().minNodeRatioPerGroup();
            StorageGroup rootGroup = cluster.getRootGroup();
            List<StorageGroup> subgroups = rootGroup.getSubgroups();
            if (subgroups.isEmpty()) return;

            int numberOfNodes = subgroups.get(0).getNodes().size();
            var numberOfLeafGroups = rootGroup.getNumberOfLeafGroups();
            if (numberOfLeafGroups >= 3
                    && numberOfNodes <= 3
                    && (minNodeRatioPerGroup.isEmpty() || minNodeRatioPerGroup.get() < 1.0)) {
                deployState.getDeployLogger().logApplicationPackage(INFO, "In cluster '" + cluster.getName() +
                        "': min-node-ratio-per-group should be set to 1 when there are 3 or more groups (" +
                        numberOfLeafGroups + ") and there are 3 or fewer nodes in the group (" + numberOfNodes + ")" +
                        ". See https://docs.vespa.ai/en/reference/services-content.html?mode=cloud#min-node-ratio-per-group");
            }
        }
Returns of memory reserved on a host. Memory is reserved for the jvm if the cluster is combined
config-model/src/main/java/com/yahoo/vespa/model/content/cluster/ContentCluster.java