func TestGetHistogramMetrics_BucketCount(t *testing.T) {
	histBuckets := []float64{0.05, 0.1, 0.25, 0.5, 0.75}
	labels := []string{"GetObject", "PutObject", "CopyObject", "CompleteMultipartUpload"}
	ttfbHist := prometheus.NewHistogramVec(
		prometheus.HistogramOpts{
			Name:    "s3_ttfb_seconds",
			Help:    "Time taken by requests served by current MinIO server instance",
			Buckets: histBuckets,
		},
		[]string{"api"},
	)

)

var (
	httpRequestsDuration = prometheus.NewHistogramVec(
		prometheus.HistogramOpts{
			Name:    "s3_ttfb_seconds",
			Help:    "Time taken by requests served by current MinIO server instance",
			Buckets: []float64{.05, .1, .25, .5, 1, 2.5, 5, 10},
		},
		[]string{"api"},
	)
	bucketHTTPRequestsDuration = prometheus.NewHistogramVec(
		prometheus.HistogramOpts{
			Name:    "s3_ttfb_seconds",

	}
	histogram *prometheus.HistogramVec
}

var globalTierMetrics = tierMetrics{
	requestsCount: make(map[string]struct {
		success int64
		failure int64
	}),
	histogram: prometheus.NewHistogramVec(prometheus.HistogramOpts{
		Name:    "tier_ttlb_seconds",
		Help:    "Time taken by requests served by warm tier",
		Buckets: []float64{0.01, 0.1, 1, 2, 5, 10, 60, 5 * 60, 15 * 60, 30 * 60},
	}, []string{"tier"}),
}