stat, err := p.Stat()
	if err != nil {
		metricsLogIf(ctx, err)
	} else {
		loadProcStatMetrics(ctx, stat, m)
	}

	io, err := p.IO()
	if err != nil {
		metricsLogIf(ctx, err)
	} else {
		loadProcIOMetrics(ctx, io, m)
	}

	l, err := p.Limits()
	if err != nil {
		metricsLogIf(ctx, err)
	} else {
		if l.OpenFiles > 0 {

//
// This is a `MetricsLoaderFn`.
func loadClusterUsageObjectMetrics(ctx context.Context, m MetricValues, c *metricsCache) error {
	dataUsageInfo, err := c.dataUsageInfo.Get()
	if err != nil {
		metricsLogIf(ctx, err)
		return nil
	}

	// data usage has not captured any data yet.
	if dataUsageInfo.LastUpdate.IsZero() {
		return nil
	}

	var (
		clusterSize               uint64

)

// loadMemoryMetrics - `MetricsLoaderFn` for node memory metrics.
func loadMemoryMetrics(ctx context.Context, m MetricValues, c *metricsCache) error {
	memMetrics, err := c.memoryMetrics.Get()
	if err != nil {
		metricsLogIf(ctx, err)
		return err
	}

	m.Set(memTotal, float64(memMetrics.Total))
	m.Set(memUsed, float64(memMetrics.Used))
	usedPerc := float64(memMetrics.Used) * 100 / float64(memMetrics.Total)
	m.Set(memUsedPerc, usedPerc)

func (p promLogger) Println(v ...interface{}) {
	s := make([]string, 0, len(v))
	for _, val := range v {
		s = append(s, fmt.Sprintf("%v", val))
	}
	err := fmt.Errorf("metrics handler error: %v", strings.Join(s, " "))
	metricsLogIf(GlobalContext, err)
}

type metricsV3Server struct {
	registry *prometheus.Registry
	opts     promhttp.HandlerOpts
	authFn   func(http.Handler) http.Handler

	metricsData *metricsV3Collection
}

	logger.LogOnceIf(ctx, "etcd", err, id, errKind...)
}

func subnetLogIf(ctx context.Context, err error, errKind ...interface{}) {
	logger.LogIf(ctx, "subnet", err, errKind...)
}

func metricsLogIf(ctx context.Context, err error, errKind ...interface{}) {
	logger.LogIf(ctx, "metrics", err, errKind...)
}

func s3LogIf(ctx context.Context, err error, errKind ...interface{}) {

}

// loadDriveMetrics - `MetricsLoaderFn` for node drive metrics.
func loadDriveMetrics(ctx context.Context, m MetricValues, c *metricsCache) error {
	driveMetrics, err := c.driveMetrics.Get()
	if err != nil {
		metricsLogIf(ctx, err)
		return nil
	}

	for _, disk := range driveMetrics.storageInfo.Disks {
		labels := []string{
			driveL, disk.DrivePath,
			poolIndexL, strconv.Itoa(disk.PoolIndex),

		// metrics pertinent to site replication - overall roll up.
		if globalSiteReplicationSys.isEnabled() {
			m, err := globalSiteReplicationSys.getSiteMetrics(GlobalContext)
			if err != nil {
				metricsLogIf(GlobalContext, err)
				return ml
			}
			ml = append(ml, MetricV2{
				Description: getRepReceivedBytesMD(clusterMetricNamespace),
				Value:       float64(m.ReplicaSize),
			})