statsd_exporter/exporter_test.go
Clayton O'Neill c7e76967c8
Add internal event queuing and flushing
At high traffic levels, the locking around sending on channels can cause
a large amount of blocking and CPU usage.  These adds an event queue
mechanism so that events are queued for short period of time, and
flushed in batches to the main exporter goroutine periodically.

The default is is to flush every 1000 events, or every 200ms, whichever
happens first.

Signed-off-by: Clayton O'Neill <claytono@github.com>
2019-06-04 06:57:48 -04:00

1001 lines
23 KiB
Go

// Copyright 2013 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"fmt"
"net"
"testing"
"time"
"github.com/prometheus/client_golang/prometheus"
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/statsd_exporter/pkg/clock"
"github.com/prometheus/statsd_exporter/pkg/mapper"
)
// TestNegativeCounter validates when we send a negative
// number to a counter that we no longer panic the Exporter Listener.
func TestNegativeCounter(t *testing.T) {
defer func() {
if e := recover(); e != nil {
err := e.(error)
if err.Error() == "counter cannot decrease in value" {
t.Fatalf("Counter was negative and causes a panic.")
} else {
t.Fatalf("Unknown panic and error: %q", err.Error())
}
}
}()
events := make(chan Events)
go func() {
c := Events{
&CounterEvent{
metricName: "foo",
value: -1,
},
}
events <- c
close(events)
}()
errorCounter := errorEventStats.WithLabelValues("illegal_negative_counter")
prev := getTelemetryCounterValue(errorCounter)
testMapper := mapper.MetricMapper{}
testMapper.InitCache(0)
ex := NewExporter(&testMapper)
ex.Listen(events)
updated := getTelemetryCounterValue(errorCounter)
if updated-prev != 1 {
t.Fatal("Illegal negative counter error not counted")
}
}
// TestInconsistentLabelSets validates that the exporter will register
// and record metrics with the same metric name but inconsistent label
// sets e.g foo{a="1"} and foo{b="1"}
func TestInconsistentLabelSets(t *testing.T) {
firstLabelSet := make(map[string]string)
secondLabelSet := make(map[string]string)
metricNames := [4]string{"counter_test", "gauge_test", "histogram_test", "summary_test"}
firstLabelSet["foo"] = "1"
secondLabelSet["foo"] = "1"
secondLabelSet["bar"] = "2"
events := make(chan Events)
go func() {
c := Events{
&CounterEvent{
metricName: "counter_test",
value: 1,
labels: firstLabelSet,
},
&CounterEvent{
metricName: "counter_test",
value: 1,
labels: secondLabelSet,
},
&GaugeEvent{
metricName: "gauge_test",
value: 1,
labels: firstLabelSet,
},
&GaugeEvent{
metricName: "gauge_test",
value: 1,
labels: secondLabelSet,
},
&TimerEvent{
metricName: "histogram.test",
value: 1,
labels: firstLabelSet,
},
&TimerEvent{
metricName: "histogram.test",
value: 1,
labels: secondLabelSet,
},
&TimerEvent{
metricName: "summary_test",
value: 1,
labels: firstLabelSet,
},
&TimerEvent{
metricName: "summary_test",
value: 1,
labels: secondLabelSet,
},
}
events <- c
close(events)
}()
config := `
mappings:
- match: histogram.test
timer_type: histogram
name: "histogram_test"
`
testMapper := &mapper.MetricMapper{}
err := testMapper.InitFromYAMLString(config, 0)
if err != nil {
t.Fatalf("Config load error: %s %s", config, err)
}
ex := NewExporter(testMapper)
ex.Listen(events)
metrics, err := prometheus.DefaultGatherer.Gather()
if err != nil {
t.Fatalf("Cannot gather from DefaultGatherer: %v", err)
}
for _, metricName := range metricNames {
firstMetric := getFloat64(metrics, metricName, firstLabelSet)
secondMetric := getFloat64(metrics, metricName, secondLabelSet)
if firstMetric == nil {
t.Fatalf("Could not find time series with first label set for metric: %s", metricName)
}
if secondMetric == nil {
t.Fatalf("Could not find time series with second label set for metric: %s", metricName)
}
}
}
// TestLabelParsing verifies that labels getting parsed out of metric
// names are being properly created.
func TestLabelParsing(t *testing.T) {
codes := [2]string{"200", "300"}
events := make(chan Events)
go func() {
c := Events{
&CounterEvent{
metricName: "counter.test.200",
value: 1,
labels: make(map[string]string),
},
&CounterEvent{
metricName: "counter.test.300",
value: 1,
labels: make(map[string]string),
},
}
events <- c
close(events)
}()
config := `
mappings:
- match: counter.test.*
name: "counter_test"
labels:
code: $1
`
testMapper := &mapper.MetricMapper{}
err := testMapper.InitFromYAMLString(config, 0)
if err != nil {
t.Fatalf("Config load error: %s %s", config, err)
}
ex := NewExporter(testMapper)
ex.Listen(events)
metrics, err := prometheus.DefaultGatherer.Gather()
if err != nil {
t.Fatalf("Cannot gather from DefaultGatherer: %v", err)
}
labels := make(map[string]string)
for _, code := range codes {
labels["code"] = code
if getFloat64(metrics, "counter_test", labels) == nil {
t.Fatalf("Could not find metrics for counter_test code %s", code)
}
}
}
// TestConflictingMetrics validates that the exporter will not register metrics
// of different types that have overlapping names.
func TestConflictingMetrics(t *testing.T) {
scenarios := []struct {
name string
expected []float64
in Events
}{
{
name: "counter vs gauge",
expected: []float64{1},
in: Events{
&CounterEvent{
metricName: "cvg_test",
value: 1,
},
&GaugeEvent{
metricName: "cvg_test",
value: 2,
},
},
},
{
name: "counter vs gauge with different labels",
expected: []float64{1, 2},
in: Events{
&CounterEvent{
metricName: "cvgl_test",
value: 1,
labels: map[string]string{"tag": "1"},
},
&CounterEvent{
metricName: "cvgl_test",
value: 2,
labels: map[string]string{"tag": "2"},
},
&GaugeEvent{
metricName: "cvgl_test",
value: 3,
labels: map[string]string{"tag": "1"},
},
},
},
{
name: "counter vs gauge with same labels",
expected: []float64{3},
in: Events{
&CounterEvent{
metricName: "cvgsl_test",
value: 1,
labels: map[string]string{"tag": "1"},
},
&CounterEvent{
metricName: "cvgsl_test",
value: 2,
labels: map[string]string{"tag": "1"},
},
&GaugeEvent{
metricName: "cvgsl_test",
value: 3,
labels: map[string]string{"tag": "1"},
},
},
},
{
name: "gauge vs counter",
expected: []float64{2},
in: Events{
&GaugeEvent{
metricName: "gvc_test",
value: 2,
},
&CounterEvent{
metricName: "gvc_test",
value: 1,
},
},
},
{
name: "counter vs histogram",
expected: []float64{1},
in: Events{
&CounterEvent{
metricName: "histogram_test1",
value: 1,
},
&TimerEvent{
metricName: "histogram.test1",
value: 2,
},
},
},
{
name: "counter vs histogram sum",
expected: []float64{1},
in: Events{
&CounterEvent{
metricName: "histogram_test1_sum",
value: 1,
},
&TimerEvent{
metricName: "histogram.test1",
value: 2,
},
},
},
{
name: "counter vs histogram count",
expected: []float64{1},
in: Events{
&CounterEvent{
metricName: "histogram_test2_count",
value: 1,
},
&TimerEvent{
metricName: "histogram.test2",
value: 2,
},
},
},
{
name: "counter vs histogram bucket",
expected: []float64{1},
in: Events{
&CounterEvent{
metricName: "histogram_test3_bucket",
value: 1,
},
&TimerEvent{
metricName: "histogram.test3",
value: 2,
},
},
},
{
name: "counter vs summary quantile",
expected: []float64{1},
in: Events{
&CounterEvent{
metricName: "cvsq_test",
value: 1,
},
&TimerEvent{
metricName: "cvsq_test",
value: 2,
},
},
},
{
name: "counter vs summary count",
expected: []float64{1},
in: Events{
&CounterEvent{
metricName: "cvsc_count",
value: 1,
},
&TimerEvent{
metricName: "cvsc",
value: 2,
},
},
},
{
name: "counter vs summary sum",
expected: []float64{1},
in: Events{
&CounterEvent{
metricName: "cvss_sum",
value: 1,
},
&TimerEvent{
metricName: "cvss",
value: 2,
},
},
},
}
config := `
mappings:
- match: histogram.*
timer_type: histogram
name: "histogram_${1}"
`
for _, s := range scenarios {
t.Run(s.name, func(t *testing.T) {
testMapper := &mapper.MetricMapper{}
err := testMapper.InitFromYAMLString(config, 0)
if err != nil {
t.Fatalf("Config load error: %s %s", config, err)
}
events := make(chan Events)
go func() {
events <- s.in
close(events)
}()
ex := NewExporter(testMapper)
ex.Listen(events)
metrics, err := prometheus.DefaultGatherer.Gather()
if err != nil {
t.Fatalf("Cannot gather from DefaultGatherer: %v", err)
}
for i, e := range s.expected {
mn := s.in[i].MetricName()
m := getFloat64(metrics, mn, s.in[i].Labels())
if m == nil {
t.Fatalf("Could not find time series with metric name '%v'", mn)
}
if *m != e {
t.Fatalf("Expected to get %v, but got %v instead", e, *m)
}
}
})
}
}
// TestEmptyStringMetric validates when a metric name ends up
// being the empty string after applying the match replacements
// tha we don't panic the Exporter Listener.
func TestEmptyStringMetric(t *testing.T) {
events := make(chan Events)
go func() {
c := Events{
&CounterEvent{
metricName: "foo_bar",
value: 1,
},
}
events <- c
close(events)
}()
config := `
mappings:
- match: .*_bar
match_type: regex
name: "${1}"
`
testMapper := &mapper.MetricMapper{}
err := testMapper.InitFromYAMLString(config, 0)
if err != nil {
t.Fatalf("Config load error: %s %s", config, err)
}
errorCounter := errorEventStats.WithLabelValues("empty_metric_name")
prev := getTelemetryCounterValue(errorCounter)
ex := NewExporter(testMapper)
ex.Listen(events)
updated := getTelemetryCounterValue(errorCounter)
if updated-prev != 1 {
t.Fatal("Empty metric name error event not counted")
}
}
// TestInvalidUtf8InDatadogTagValue validates robustness of exporter listener
// against datadog tags with invalid tag values.
// It sends the same tags first with a valid value, then with an invalid one.
// The exporter should not panic, but drop the invalid event
func TestInvalidUtf8InDatadogTagValue(t *testing.T) {
defer func() {
if e := recover(); e != nil {
err := e.(error)
t.Fatalf("Exporter listener should not panic on bad utf8: %q", err.Error())
}
}()
events := make(chan Events)
ueh := &unbufferedEventHandler{c: events}
go func() {
for _, l := range []statsDPacketHandler{&StatsDUDPListener{}, &mockStatsDTCPListener{}} {
l.SetEventHandler(ueh)
l.handlePacket([]byte("bar:200|c|#tag:value\nbar:200|c|#tag:\xc3\x28invalid"))
}
close(events)
}()
testMapper := mapper.MetricMapper{}
testMapper.InitCache(0)
ex := NewExporter(&testMapper)
ex.Listen(events)
}
// In the case of someone starting the statsd exporter with no mapping file specified
// which is valid, we want to make sure that the default quantile metrics are generated
// as well as the sum/count metrics
func TestSummaryWithQuantilesEmptyMapping(t *testing.T) {
// Start exporter with a synchronous channel
events := make(chan Events)
go func() {
testMapper := mapper.MetricMapper{}
testMapper.InitCache(0)
ex := NewExporter(&testMapper)
ex.Listen(events)
}()
name := "default_foo"
c := Events{
&TimerEvent{
metricName: name,
value: 300,
},
}
events <- c
events <- Events{}
close(events)
metrics, err := prometheus.DefaultGatherer.Gather()
if err != nil {
t.Fatal("Gather should not fail: ", err)
}
var metricFamily *dto.MetricFamily
for _, m := range metrics {
if *m.Name == name {
metricFamily = m
break
}
}
if metricFamily == nil {
t.Fatal("Metric could not be found")
}
quantiles := metricFamily.Metric[0].Summary.Quantile
if len(quantiles) == 0 {
t.Fatal("Summary has no quantiles available")
}
}
func TestHistogramUnits(t *testing.T) {
// Start exporter with a synchronous channel
events := make(chan Events)
go func() {
testMapper := mapper.MetricMapper{}
testMapper.InitCache(0)
ex := NewExporter(&testMapper)
ex.mapper.Defaults.TimerType = mapper.TimerTypeHistogram
ex.Listen(events)
}()
// Synchronously send a statsd event to wait for handleEvent execution.
// Then close events channel to stop a listener.
name := "foo"
c := Events{
&TimerEvent{
metricName: name,
value: 300,
},
}
events <- c
events <- Events{}
close(events)
// Check histogram value
metrics, err := prometheus.DefaultGatherer.Gather()
if err != nil {
t.Fatalf("Cannot gather from DefaultGatherer: %v", err)
}
value := getFloat64(metrics, name, prometheus.Labels{})
if value == nil {
t.Fatal("Histogram value should not be nil")
}
if *value == 300 {
t.Fatalf("Histogram observations not scaled into Seconds")
} else if *value != .300 {
t.Fatalf("Received unexpected value for histogram observation %f != .300", *value)
}
}
func TestCounterIncrement(t *testing.T) {
// Start exporter with a synchronous channel
events := make(chan Events)
go func() {
testMapper := mapper.MetricMapper{}
testMapper.InitCache(0)
ex := NewExporter(&testMapper)
ex.Listen(events)
}()
// Synchronously send a statsd event to wait for handleEvent execution.
// Then close events channel to stop a listener.
name := "foo_counter"
labels := map[string]string{
"foo": "bar",
}
c := Events{
&CounterEvent{
metricName: name,
value: 1,
labels: labels,
},
&CounterEvent{
metricName: name,
value: 1,
labels: labels,
},
}
events <- c
// Push empty event so that we block until the first event is consumed.
events <- Events{}
close(events)
// Check histogram value
metrics, err := prometheus.DefaultGatherer.Gather()
if err != nil {
t.Fatalf("Cannot gather from DefaultGatherer: %v", err)
}
value := getFloat64(metrics, name, labels)
if value == nil {
t.Fatal("Counter value should not be nil")
}
if *value != 2 {
t.Fatalf("Counter wasn't incremented properly")
}
}
type statsDPacketHandler interface {
handlePacket(packet []byte)
SetEventHandler(eh eventHandler)
}
type mockStatsDTCPListener struct {
StatsDTCPListener
}
func (ml *mockStatsDTCPListener) handlePacket(packet []byte) {
// Forcing IPv4 because the TravisCI build environment does not have IPv6
// addresses.
lc, err := net.ListenTCP("tcp4", nil)
if err != nil {
panic(fmt.Sprintf("mockStatsDTCPListener: listen failed: %v", err))
}
defer lc.Close()
go func() {
cc, err := net.DialTCP("tcp", nil, lc.Addr().(*net.TCPAddr))
if err != nil {
panic(fmt.Sprintf("mockStatsDTCPListener: dial failed: %v", err))
}
defer cc.Close()
n, err := cc.Write(packet)
if err != nil || n != len(packet) {
panic(fmt.Sprintf("mockStatsDTCPListener: write failed: %v,%d", err, n))
}
}()
sc, err := lc.AcceptTCP()
if err != nil {
panic(fmt.Sprintf("mockStatsDTCPListener: accept failed: %v", err))
}
ml.handleConn(sc)
}
func TestEscapeMetricName(t *testing.T) {
scenarios := map[string]string{
"clean": "clean",
"0starts_with_digit": "_0starts_with_digit",
"with_underscore": "with_underscore",
"with.dot": "with_dot",
"with😱emoji": "with_emoji",
"with.*.multiple": "with___multiple",
"test.web-server.foo.bar": "test_web_server_foo_bar",
"": "",
}
for in, want := range scenarios {
if got := escapeMetricName(in); want != got {
t.Errorf("expected `%s` to be escaped to `%s`, got `%s`", in, want, got)
}
}
}
// TestTtlExpiration validates expiration of time series.
// foobar metric without mapping should expire with default ttl of 1s
// bazqux metric should expire with ttl of 2s
func TestTtlExpiration(t *testing.T) {
// Mock a time.NewTicker
tickerCh := make(chan time.Time)
clock.ClockInstance = &clock.Clock{
TickerCh: tickerCh,
}
config := `
defaults:
ttl: 1s
mappings:
- match: bazqux.*
name: bazqux
ttl: 2s
`
// Create mapper from config and start an Exporter with a synchronous channel
testMapper := &mapper.MetricMapper{}
err := testMapper.InitFromYAMLString(config, 0)
if err != nil {
t.Fatalf("Config load error: %s %s", config, err)
}
events := make(chan Events)
defer close(events)
go func() {
ex := NewExporter(testMapper)
ex.Listen(events)
}()
ev := Events{
// event with default ttl = 1s
&GaugeEvent{
metricName: "foobar",
value: 200,
},
// event with ttl = 2s from a mapping
&TimerEvent{
metricName: "bazqux.main",
value: 42000,
},
}
var metrics []*dto.MetricFamily
var foobarValue *float64
var bazquxValue *float64
// Step 1. Send events with statsd metrics.
// Send empty Events to wait for events are handled.
// saveLabelValues will use fake instant as a lastRegisteredAt time.
clock.ClockInstance.Instant = time.Unix(0, 0)
events <- ev
events <- Events{}
// Check values
metrics, err = prometheus.DefaultGatherer.Gather()
if err != nil {
t.Fatal("Gather should not fail")
}
foobarValue = getFloat64(metrics, "foobar", prometheus.Labels{})
bazquxValue = getFloat64(metrics, "bazqux", prometheus.Labels{})
if foobarValue == nil || bazquxValue == nil {
t.Fatalf("Gauge `foobar` and Summary `bazqux` should be gathered")
}
if *foobarValue != 200 {
t.Fatalf("Gauge `foobar` observation %f is not expected. Should be 200", *foobarValue)
}
if *bazquxValue != 42 {
t.Fatalf("Summary `bazqux` observation %f is not expected. Should be 42", *bazquxValue)
}
// Step 2. Increase Instant to emulate metrics expiration after 1s
clock.ClockInstance.Instant = time.Unix(1, 10)
clock.ClockInstance.TickerCh <- time.Unix(0, 0)
events <- Events{}
// Check values
metrics, err = prometheus.DefaultGatherer.Gather()
if err != nil {
t.Fatal("Gather should not fail")
}
foobarValue = getFloat64(metrics, "foobar", prometheus.Labels{})
bazquxValue = getFloat64(metrics, "bazqux", prometheus.Labels{})
if foobarValue != nil {
t.Fatalf("Gauge `foobar` should be expired")
}
if bazquxValue == nil {
t.Fatalf("Summary `bazqux` should be gathered")
}
if *bazquxValue != 42 {
t.Fatalf("Summary `bazqux` observation %f is not expected. Should be 42", *bazquxValue)
}
// Step 3. Increase Instant to emulate metrics expiration after 2s
clock.ClockInstance.Instant = time.Unix(2, 200)
clock.ClockInstance.TickerCh <- time.Unix(0, 0)
events <- Events{}
// Check values
metrics, err = prometheus.DefaultGatherer.Gather()
if err != nil {
t.Fatal("Gather should not fail")
}
foobarValue = getFloat64(metrics, "foobar", prometheus.Labels{})
bazquxValue = getFloat64(metrics, "bazqux", prometheus.Labels{})
if bazquxValue != nil {
t.Fatalf("Summary `bazqux` should be expired")
}
if foobarValue != nil {
t.Fatalf("Gauge `foobar` should not be gathered after expiration")
}
}
func TestHashLabelNames(t *testing.T) {
r := newRegistry(nil)
// Validate value hash changes and name has doesn't when just the value changes.
hash1, _ := r.hashLabels(map[string]string{
"label": "value1",
})
hash2, _ := r.hashLabels(map[string]string{
"label": "value2",
})
if hash1.names != hash2.names {
t.Fatal("Hash of label names should match, but doesn't")
}
if hash1.values == hash2.values {
t.Fatal("Hash of label names shouldn't match, but do")
}
// Validate value and name hashes change when the name changes.
hash1, _ = r.hashLabels(map[string]string{
"label1": "value",
})
hash2, _ = r.hashLabels(map[string]string{
"label2": "value",
})
if hash1.names == hash2.names {
t.Fatal("Hash of label names shouldn't match, but do")
}
if hash1.values == hash2.values {
t.Fatal("Hash of label names shouldn't match, but do")
}
}
// getFloat64 search for metric by name in array of MetricFamily and then search a value by labels.
// Method returns a value or nil if metric is not found.
func getFloat64(metrics []*dto.MetricFamily, name string, labels prometheus.Labels) *float64 {
var metricFamily *dto.MetricFamily
for _, m := range metrics {
if *m.Name == name {
metricFamily = m
break
}
}
if metricFamily == nil {
return nil
}
var metric *dto.Metric
labelStr := fmt.Sprintf("%v", labels)
for _, m := range metricFamily.Metric {
l := labelPairsAsLabels(m.GetLabel())
ls := fmt.Sprintf("%v", l)
if labelStr == ls {
metric = m
break
}
}
if metric == nil {
return nil
}
var value float64
if metric.Gauge != nil {
value = metric.Gauge.GetValue()
return &value
}
if metric.Counter != nil {
value = metric.Counter.GetValue()
return &value
}
if metric.Histogram != nil {
value = metric.Histogram.GetSampleSum()
return &value
}
if metric.Summary != nil {
value = metric.Summary.GetSampleSum()
return &value
}
if metric.Untyped != nil {
value = metric.Untyped.GetValue()
return &value
}
panic(fmt.Errorf("collected a non-gauge/counter/histogram/summary/untyped metric: %s", metric))
}
func labelPairsAsLabels(pairs []*dto.LabelPair) (labels prometheus.Labels) {
labels = prometheus.Labels{}
for _, pair := range pairs {
if pair.Name == nil {
continue
}
value := ""
if pair.Value != nil {
value = *pair.Value
}
labels[*pair.Name] = value
}
return
}
func getTelemetryCounterValue(counter prometheus.Counter) float64 {
var metric dto.Metric
err := counter.Write(&metric)
if err != nil {
return 0.0
}
return metric.Counter.GetValue()
}
func BenchmarkEscapeMetricName(b *testing.B) {
scenarios := []string{
"clean",
"0starts_with_digit",
"with_underscore",
"with.dot",
"with😱emoji",
"with.*.multiple",
"test.web-server.foo.bar",
"",
}
for _, s := range scenarios {
b.Run(s, func(b *testing.B) {
for n := 0; n < b.N; n++ {
escapeMetricName(s)
}
})
}
}
func BenchmarkParseDogStatsDTagsToLabels(b *testing.B) {
scenarios := map[string]string{
"1 tag w/hash": "#test:tag",
"1 tag w/o hash": "test:tag",
"2 tags, mixed hashes": "tag1:test,#tag2:test",
"3 long tags": "tag1:reallylongtagthisisreallylong,tag2:anotherreallylongtag,tag3:thisisyetanotherextraordinarilylongtag",
"a-z tags": "a:0,b:1,c:2,d:3,e:4,f:5,g:6,h:7,i:8,j:9,k:0,l:1,m:2,n:3,o:4,p:5,q:6,r:7,s:8,t:9,u:0,v:1,w:2,x:3,y:4,z:5",
}
for name, tags := range scenarios {
b.Run(name, func(b *testing.B) {
for n := 0; n < b.N; n++ {
parseDogStatsDTagsToLabels(tags)
}
})
}
}
func BenchmarkHashNameAndLabels(b *testing.B) {
scenarios := []struct {
name string
metric string
labels map[string]string
}{
{
name: "no labels",
labels: map[string]string{},
}, {
name: "one label",
labels: map[string]string{
"label": "value",
},
}, {
name: "many labels",
labels: map[string]string{
"label0": "value",
"label1": "value",
"label2": "value",
"label3": "value",
"label4": "value",
"label5": "value",
"label6": "value",
"label7": "value",
"label8": "value",
"label9": "value",
},
},
}
r := newRegistry(nil)
for _, s := range scenarios {
b.Run(s.name, func(b *testing.B) {
for n := 0; n < b.N; n++ {
r.hashLabels(s.labels)
}
})
}
}