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// Copyright 2015 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 prometheus
import (
"math"
"math/rand"
"reflect"
"runtime"
"sort"
"sync"
"testing"
"testing/quick"
dto "github.com/prometheus/client_model/go"
)
func benchmarkHistogramObserve(w int, b *testing.B) {
b.StopTimer()
wg := new(sync.WaitGroup)
wg.Add(w)
g := new(sync.WaitGroup)
g.Add(1)
s := NewHistogram(HistogramOpts{})
for i := 0; i < w; i++ {
go func() {
g.Wait()
for i := 0; i < b.N; i++ {
s.Observe(float64(i))
}
wg.Done()
}()
}
b.StartTimer()
g.Done()
wg.Wait()
}
func BenchmarkHistogramObserve1(b *testing.B) {
benchmarkHistogramObserve(1, b)
}
func BenchmarkHistogramObserve2(b *testing.B) {
benchmarkHistogramObserve(2, b)
}
func BenchmarkHistogramObserve4(b *testing.B) {
benchmarkHistogramObserve(4, b)
}
func BenchmarkHistogramObserve8(b *testing.B) {
benchmarkHistogramObserve(8, b)
}
func benchmarkHistogramWrite(w int, b *testing.B) {
b.StopTimer()
wg := new(sync.WaitGroup)
wg.Add(w)
g := new(sync.WaitGroup)
g.Add(1)
s := NewHistogram(HistogramOpts{})
for i := 0; i < 1000000; i++ {
s.Observe(float64(i))
}
for j := 0; j < w; j++ {
outs := make([]dto.Metric, b.N)
go func(o []dto.Metric) {
g.Wait()
for i := 0; i < b.N; i++ {
s.Write(&o[i])
}
wg.Done()
}(outs)
}
b.StartTimer()
g.Done()
wg.Wait()
}
func BenchmarkHistogramWrite1(b *testing.B) {
benchmarkHistogramWrite(1, b)
}
func BenchmarkHistogramWrite2(b *testing.B) {
benchmarkHistogramWrite(2, b)
}
func BenchmarkHistogramWrite4(b *testing.B) {
benchmarkHistogramWrite(4, b)
}
func BenchmarkHistogramWrite8(b *testing.B) {
benchmarkHistogramWrite(8, b)
}
func TestHistogramNonMonotonicBuckets(t *testing.T) {
testCases := map[string][]float64{
"not strictly monotonic": {1, 2, 2, 3},
"not monotonic at all": {1, 2, 4, 3, 5},
"have +Inf in the middle": {1, 2, math.Inf(+1), 3},
}
for name, buckets := range testCases {
func() {
defer func() {
if r := recover(); r == nil {
t.Errorf("Buckets %v are %s but NewHistogram did not panic.", buckets, name)
}
}()
_ = NewHistogram(HistogramOpts{
Name: "test_histogram",
Help: "helpless",
Buckets: buckets,
})
}()
}
}
// Intentionally adding +Inf here to test if that case is handled correctly.
// Also, getCumulativeCounts depends on it.
var testBuckets = []float64{-2, -1, -0.5, 0, 0.5, 1, 2, math.Inf(+1)}
func TestHistogramConcurrency(t *testing.T) {
if testing.Short() {
t.Skip("Skipping test in short mode.")
}
rand.Seed(42)
it := func(n uint32) bool {
mutations := int(n%1e4 + 1e4)
concLevel := int(n%5 + 1)
total := mutations * concLevel
var start, end sync.WaitGroup
start.Add(1)
end.Add(concLevel)
sum := NewHistogram(HistogramOpts{
Name: "test_histogram",
Help: "helpless",
Buckets: testBuckets,
})
allVars := make([]float64, total)
var sampleSum float64
for i := 0; i < concLevel; i++ {
vals := make([]float64, mutations)
for j := 0; j < mutations; j++ {
v := rand.NormFloat64()
vals[j] = v
allVars[i*mutations+j] = v
sampleSum += v
}
go func(vals []float64) {
start.Wait()
for _, v := range vals {
sum.Observe(v)
}
end.Done()
}(vals)
}
sort.Float64s(allVars)
start.Done()
end.Wait()
m := &dto.Metric{}
sum.Write(m)
if got, want := int(*m.Histogram.SampleCount), total; got != want {
t.Errorf("got sample count %d, want %d", got, want)
}
if got, want := *m.Histogram.SampleSum, sampleSum; math.Abs((got-want)/want) > 0.001 {
t.Errorf("got sample sum %f, want %f", got, want)
}
wantCounts := getCumulativeCounts(allVars)
if got, want := len(m.Histogram.Bucket), len(testBuckets)-1; got != want {
t.Errorf("got %d buckets in protobuf, want %d", got, want)
}
for i, wantBound := range testBuckets {
if i == len(testBuckets)-1 {
break // No +Inf bucket in protobuf.
}
if gotBound := *m.Histogram.Bucket[i].UpperBound; gotBound != wantBound {
t.Errorf("got bound %f, want %f", gotBound, wantBound)
}
if gotCount, wantCount := *m.Histogram.Bucket[i].CumulativeCount, wantCounts[i]; gotCount != wantCount {
t.Errorf("got count %d, want %d", gotCount, wantCount)
}
}
return true
}
if err := quick.Check(it, nil); err != nil {
t.Error(err)
}
}
func TestHistogramVecConcurrency(t *testing.T) {
if testing.Short() {
t.Skip("Skipping test in short mode.")
}
rand.Seed(42)
objectives := make([]float64, 0, len(DefObjectives))
for qu := range DefObjectives {
objectives = append(objectives, qu)
}
sort.Float64s(objectives)
it := func(n uint32) bool {
mutations := int(n%1e4 + 1e4)
concLevel := int(n%7 + 1)
vecLength := int(n%3 + 1)
var start, end sync.WaitGroup
start.Add(1)
end.Add(concLevel)
his := NewHistogramVec(
HistogramOpts{
Name: "test_histogram",
Help: "helpless",
Buckets: []float64{-2, -1, -0.5, 0, 0.5, 1, 2, math.Inf(+1)},
},
[]string{"label"},
)
allVars := make([][]float64, vecLength)
sampleSums := make([]float64, vecLength)
for i := 0; i < concLevel; i++ {
vals := make([]float64, mutations)
picks := make([]int, mutations)
for j := 0; j < mutations; j++ {
v := rand.NormFloat64()
vals[j] = v
pick := rand.Intn(vecLength)
picks[j] = pick
allVars[pick] = append(allVars[pick], v)
sampleSums[pick] += v
}
go func(vals []float64) {
start.Wait()
for i, v := range vals {
his.WithLabelValues(string('A' + picks[i])).Observe(v)
}
end.Done()
}(vals)
}
for _, vars := range allVars {
sort.Float64s(vars)
}
start.Done()
end.Wait()
for i := 0; i < vecLength; i++ {
m := &dto.Metric{}
s := his.WithLabelValues(string('A' + i))
s.(Histogram).Write(m)
if got, want := len(m.Histogram.Bucket), len(testBuckets)-1; got != want {
t.Errorf("got %d buckets in protobuf, want %d", got, want)
}
if got, want := int(*m.Histogram.SampleCount), len(allVars[i]); got != want {
t.Errorf("got sample count %d, want %d", got, want)
}
if got, want := *m.Histogram.SampleSum, sampleSums[i]; math.Abs((got-want)/want) > 0.001 {
t.Errorf("got sample sum %f, want %f", got, want)
}
wantCounts := getCumulativeCounts(allVars[i])
for j, wantBound := range testBuckets {
if j == len(testBuckets)-1 {
break // No +Inf bucket in protobuf.
}
if gotBound := *m.Histogram.Bucket[j].UpperBound; gotBound != wantBound {
t.Errorf("got bound %f, want %f", gotBound, wantBound)
}
if gotCount, wantCount := *m.Histogram.Bucket[j].CumulativeCount, wantCounts[j]; gotCount != wantCount {
t.Errorf("got count %d, want %d", gotCount, wantCount)
}
}
}
return true
}
if err := quick.Check(it, nil); err != nil {
t.Error(err)
}
}
func getCumulativeCounts(vars []float64) []uint64 {
counts := make([]uint64, len(testBuckets))
for _, v := range vars {
for i := len(testBuckets) - 1; i >= 0; i-- {
if v > testBuckets[i] {
break
}
counts[i]++
}
}
return counts
}
func TestBuckets(t *testing.T) {
got := LinearBuckets(-15, 5, 6)
want := []float64{-15, -10, -5, 0, 5, 10}
if !reflect.DeepEqual(got, want) {
t.Errorf("linear buckets: got %v, want %v", got, want)
}
got = ExponentialBuckets(100, 1.2, 3)
want = []float64{100, 120, 144}
if !reflect.DeepEqual(got, want) {
t.Errorf("exponential buckets: got %v, want %v", got, want)
}
}
func TestHistogramAtomicObserve(t *testing.T) {
var (
quit = make(chan struct{})
his = NewHistogram(HistogramOpts{
Buckets: []float64{0.5, 10, 20},
})
)
defer func() { close(quit) }()
observe := func() {
for {
select {
case <-quit:
return
default:
his.Observe(1)
}
}
}
go observe()
go observe()
go observe()
for i := 0; i < 100; i++ {
m := &dto.Metric{}
if err := his.Write(m); err != nil {
t.Fatal("unexpected error writing histogram:", err)
}
h := m.GetHistogram()
if h.GetSampleCount() != uint64(h.GetSampleSum()) ||
h.GetSampleCount() != h.GetBucket()[1].GetCumulativeCount() ||
h.GetSampleCount() != h.GetBucket()[2].GetCumulativeCount() {
t.Fatalf(
"inconsistent counts in histogram: count=%d sum=%f buckets=[%d, %d]",
h.GetSampleCount(), h.GetSampleSum(),
h.GetBucket()[1].GetCumulativeCount(), h.GetBucket()[2].GetCumulativeCount(),
)
}
runtime.Gosched()
}
}