vendor: update github.com/VictoriaMetrics/metrics from v1.8.2 to v1.8.3

go.mod

@@ -4,7 +4,7 @@ require (
 	cloud.google.com/go v0.49.0 // indirect
 	cloud.google.com/go/storage v1.4.0
 	github.com/VictoriaMetrics/fastcache v1.5.2
-	github.com/VictoriaMetrics/metrics v1.8.2
+	github.com/VictoriaMetrics/metrics v1.8.3
 	github.com/aws/aws-sdk-go v1.25.37
 	github.com/cespare/xxhash/v2 v2.1.1
 	github.com/golang/groupcache v0.0.0-20191027212112-611e8accdfc9 // indirect

go.sum

@@ -24,8 +24,8 @@ github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAE
 github.com/OneOfOne/xxhash v1.2.5/go.mod h1:eZbhyaAYD41SGSSsnmcpxVoRiQ/MPUTjUdIIOT9Um7Q=
 github.com/VictoriaMetrics/fastcache v1.5.2 h1:Erd8iIuBAL9kke8JzM4+WxkKuFkHh3ktwLanJvDgR44=
 github.com/VictoriaMetrics/fastcache v1.5.2/go.mod h1:+jv9Ckb+za/P1ZRg/sulP5Ni1v49daAVERr0H3CuscE=
-github.com/VictoriaMetrics/metrics v1.8.2 h1:Oa+u0XlcofYfPDAPTgKObyangxbp+vVGkjSwARtObFQ=
-github.com/VictoriaMetrics/metrics v1.8.2/go.mod h1:LU2j9qq7xqZYXz8tF3/RQnB2z2MbZms5TDiIg9/NHiQ=
+github.com/VictoriaMetrics/metrics v1.8.3 h1:5eVP1tVjnSao/YVMIQiWrQkEJ6nzQq7IANbNniVu4cI=
+github.com/VictoriaMetrics/metrics v1.8.3/go.mod h1:LU2j9qq7xqZYXz8tF3/RQnB2z2MbZms5TDiIg9/NHiQ=
 github.com/allegro/bigcache v1.2.1-0.20190218064605-e24eb225f156 h1:eMwmnE/GDgah4HI848JfFxHt+iPb26b4zyfspmqY0/8=
 github.com/allegro/bigcache v1.2.1-0.20190218064605-e24eb225f156/go.mod h1:Cb/ax3seSYIx7SuZdm2G2xzfwmv3TPSk2ucNfQESPXM=
 github.com/aws/aws-sdk-go v1.25.37 h1:gBtB/F3dophWpsUQKN/Kni+JzYEH2mGHF4hWNtfED1w=

vendor/github.com/VictoriaMetrics/metrics/README.md

@@ -14,6 +14,7 @@
 * Easy to use. See the [API docs](http://godoc.org/github.com/VictoriaMetrics/metrics).
 * Fast.
 * Allows exporting distinct metric sets via distinct endpoints. See [Set](http://godoc.org/github.com/VictoriaMetrics/metrics#Set).
+* Supports [easy-to-use histograms](http://godoc.org/github.com/VictoriaMetrics/metrics#Histogram), which just work without any tuning.
 
 
 ### Limitations
@@ -39,6 +40,9 @@ var (
 	queueSize = metrics.NewGauge(`queue_size{queue="foobar",topic="baz"}`, func() float64 {
 		return float64(foobarQueue.Len())
 	})
+
+	// Register histogram with a single label.
+	responseSize = metrics.NewHistogram(`response_size{path="/foo/bar"}`)
 )
 
 // ...
@@ -50,6 +54,9 @@ func requestHandler() {
 	processRequest()
 	// Update requestDuration summary.
 	requestDuration.UpdateDuration(startTime)
+
+	// Update responseSize histogram.
+	responseSize.Update(responseSize)
 }
 
 // Expose the registered metrics at `/metrics` path.
@@ -86,3 +93,11 @@ exposed from your application.
 
 Just use [GetOrCreateCounter](http://godoc.org/github.com/VictoriaMetrics/metrics#GetOrCreateCounter)
 instead of `CounterVec.With`. See [this example](https://godoc.org/github.com/VictoriaMetrics/metrics#example-Counter--Vec) for details.
+
+
+#### Why [Histogram](http://godoc.org/github.com/VictoriaMetrics/metrics#Histogram) buckets contain `vmrange` labels instead of `le` labels like in Prometheus histograms?
+
+Buckets with `vmrange` labels occupy less disk space comparing to Promethes-style buckets with `le` labels,
+because `vmrange` buckets don't include counters for the previous ranges. [VictoriaMetrics](https://github.com/VictoriaMetrics/VictoriaMetrics) provides `prometheus_buckets`
+function, which converts `vmrange` buckets to Prometheus-style buckets with `le` labels. This is useful for building heatmaps in Grafana.
+Additionally, its' `histogram_quantile` function transparently handles histogram buckets with `vmrange` labels.

vendor/github.com/VictoriaMetrics/metrics/histogram.go

@@ -37,14 +37,16 @@ import (
 //     - <start> and <end> - start and end values for the given bucket
 //     - <counter> - the number of hits to the given bucket during Update* calls.
 //
-// Only non-zero buckets are exposed.
+// Histogram buckets can be converted to Prometheus-like buckets with `le` labels
+// with `prometheus_buckets(<metric_name>_bucket)` function in VictoriaMetrics:
 //
-// Histogram buckets can be converted to Prometheus-like buckets in VictoriaMetrics
-// with `prometheus_buckets(<metric_name>_bucket)`:
-//
-//     prometheus_buckets(rate(request_duration_bucket[5m]))
+//     prometheus_buckets(request_duration_bucket)
 //
 // Histogram cannot be used for negative values.
+//
+// Time series produced by the Histogram have better compression ratio comparing to
+// Prometheus histogram buckets with `le` labels, since they don't include counters
+// for all the previous buckets.
 type Histogram struct {
 	buckets [bucketsCount]uint64
 
@@ -89,6 +91,10 @@ func GetOrCreateHistogram(name string) *Histogram {
 //
 // v cannot be negative.
 func (h *Histogram) Update(v float64) {
+	if math.IsNaN(v) || v < 0 {
+		// Skip NaNs and negative values.
+		return
+	}
 	idx := getBucketIdx(v)
 	if idx >= uint(len(h.buckets)) {
 		panic(fmt.Errorf("BUG: idx cannot exceed %d; got %d", len(h.buckets), idx))
@@ -106,13 +112,60 @@ func (h *Histogram) UpdateDuration(startTime time.Time) {
 	h.Update(d)
 }
 
+// VisitNonZeroBuckets calls f for all buckets with non-zero counters.
+func (h *Histogram) VisitNonZeroBuckets(f func(vmrange string, count uint64)) {
+	for i, v := range h.buckets[:] {
+		if v == 0 {
+			continue
+		}
+		vmrange := getRangeForBucketIdx(uint(i))
+		f(vmrange, v)
+	}
+}
+
+func getRangeForBucketIdx(idx uint) string {
+	bucketRangesOnce.Do(initBucketRanges)
+	return bucketRanges[idx]
+}
+
+func initBucketRanges() {
+	start := "0"
+	for i := 0; i < bucketsCount; i++ {
+		end := getRangeEndFromBucketIdx(uint(i))
+		bucketRanges[i] = start + "..." + end
+		start = end
+	}
+}
+
+var (
+	bucketRanges     [bucketsCount]string
+	bucketRangesOnce sync.Once
+)
+
+func getTagForBucketIdx(idx uint) string {
+	bucketTagsOnce.Do(initBucketTags)
+	return bucketTags[idx]
+}
+
+func initBucketTags() {
+	for i := 0; i < bucketsCount; i++ {
+		vmrange := getRangeForBucketIdx(uint(i))
+		bucketTags[i] = fmt.Sprintf(`vmrange=%q`, vmrange)
+	}
+}
+
+var (
+	bucketTags     [bucketsCount]string
+	bucketTagsOnce sync.Once
+)
+
 func (h *Histogram) marshalTo(prefix string, w io.Writer) {
 	count := atomic.LoadUint64(&h.count)
 	if count == 0 {
 		return
 	}
 	for i := range h.buckets[:] {
-		h.marshalBucket(prefix, w, i)
+		h.marshalBucket(prefix, w, uint(i))
 	}
 	// Marshal `_sum` and `_count` metrics.
 	name, filters := splitMetricName(prefix)
@@ -127,17 +180,12 @@ func (h *Histogram) marshalTo(prefix string, w io.Writer) {
 	fmt.Fprintf(w, "%s_count%s %d\n", name, filters, count)
 }
 
-func (h *Histogram) marshalBucket(prefix string, w io.Writer, idx int) {
+func (h *Histogram) marshalBucket(prefix string, w io.Writer, idx uint) {
 	v := h.buckets[idx]
 	if v == 0 {
 		return
 	}
-	start := "0"
-	if idx > 0 {
-		start = getRangeEndFromBucketIdx(uint(idx - 1))
-	}
-	end := getRangeEndFromBucketIdx(uint(idx))
-	tag := fmt.Sprintf(`vmrange="%s...%s"`, start, end)
+	tag := getTagForBucketIdx(idx)
 	prefix = addTag(prefix, tag)
 	name, filters := splitMetricName(prefix)
 	fmt.Fprintf(w, "%s_bucket%s %d\n", name, filters, v)

vendor/modules.txt

@@ -12,7 +12,7 @@ cloud.google.com/go/storage
 github.com/BurntSushi/toml
 # github.com/VictoriaMetrics/fastcache v1.5.2
 github.com/VictoriaMetrics/fastcache
-# github.com/VictoriaMetrics/metrics v1.8.2
+# github.com/VictoriaMetrics/metrics v1.8.3
 github.com/VictoriaMetrics/metrics
 # github.com/aws/aws-sdk-go v1.25.37
 github.com/aws/aws-sdk-go/aws