"Count of offline nodes in the cluster")
	healthNodesOnlineCountMD = NewGaugeMD(healthNodesOnlineCount,
		"Count of online nodes in the cluster")
)

// loadClusterHealthNodeMetrics - `MetricsLoaderFn` for cluster health node
// metrics.
func loadClusterHealthNodeMetrics(ctx context.Context, m MetricValues,
	c *metricsCache,
) error {
	nodesUpDown, _ := c.nodesUpDown.Get()

			healthCapacityRawTotalBytesMD,
			healthCapacityRawFreeBytesMD,
			healthCapacityUsableTotalBytesMD,
			healthCapacityUsableFreeBytesMD,
		},
		JoinLoaders(loadClusterHealthDriveMetrics,
			loadClusterHealthNodeMetrics,
			loadClusterHealthCapacityMetrics),
	)

	clusterUsageObjectsMG := NewMetricsGroup(clusterUsageObjectsCollectorPath,
		[]MetricDescriptor{
			usageSinceLastUpdateSecondsMD,
			usageTotalBytesMD,