}

func (t *tierMetrics) logSuccess(tier string) {
	t.Lock()
	defer t.Unlock()

	stat := t.requestsCount[tier]
	stat.success++
	t.requestsCount[tier] = stat
}

func (t *tierMetrics) logFailure(tier string) {
	t.Lock()
	defer t.Unlock()

	stat := t.requestsCount[tier]
	stat.failure++
	t.requestsCount[tier] = stat
}

var (
	// {minio_node}_{tier}_{ttlb_seconds_distribution}

	expSuccess := 10
	expFailure := 5
	for i := 0; i < expSuccess; i++ {
		globalTierMetrics.logSuccess(tier)
	}
	for i := 0; i < expFailure; i++ {
		globalTierMetrics.logFailure(tier)
	}
	metrics := globalTierMetrics.Report()
	var succ, fail float64
	for _, metric := range metrics {
		switch metric.Description.Name {
		case tierRequestsSuccess:
			succ += metric.Value

			op.TimeToResponseNS = since.Nanoseconds()
			globalTierMetrics.Observe(tier, since)
			globalTierMetrics.logSuccess(tier)
		} else {
			op.Error = err.Error()
			globalTierMetrics.logFailure(tier)
		}

		logger.GetReqInfo(ctx).AppendTags("tierStats", op)
	}
}

// getTransitionedObjectReader returns a reader from the transitioned tier.