Merge pull request #11783 from codesome/gauge-histogram

tsdb: Add gauge histogram support
This commit is contained in:
Ganesh Vernekar 2023-01-10 19:06:08 +05:30 committed by GitHub
commit 57bcbf1888
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13 changed files with 884 additions and 122 deletions

View file

@ -27,6 +27,8 @@ import (
// used to represent a histogram with integer counts and thus serves as a more
// generalized representation.
type FloatHistogram struct {
// Counter reset information.
CounterResetHint CounterResetHint
// Currently valid schema numbers are -4 <= n <= 8. They are all for
// base-2 bucket schemas, where 1 is a bucket boundary in each case, and
// then each power of two is divided into 2^n logarithmic buckets. Or

View file

@ -19,6 +19,17 @@ import (
"strings"
)
// CounterResetHint contains the known information about a counter reset,
// or alternatively that we are dealing with a gauge histogram, where counter resets do not apply.
type CounterResetHint byte
const (
UnknownCounterReset CounterResetHint = iota // UnknownCounterReset means we cannot say if this histogram signals a counter reset or not.
CounterReset // CounterReset means there was definitely a counter reset starting from this histogram.
NotCounterReset // NotCounterReset means there was definitely no counter reset with this histogram.
GaugeType // GaugeType means this is a gauge histogram, where counter resets do not happen.
)
// Histogram encodes a sparse, high-resolution histogram. See the design
// document for full details:
// https://docs.google.com/document/d/1cLNv3aufPZb3fNfaJgdaRBZsInZKKIHo9E6HinJVbpM/edit#
@ -35,6 +46,8 @@ import (
//
// Which bucket indices are actually used is determined by the spans.
type Histogram struct {
// Counter reset information.
CounterResetHint CounterResetHint
// Currently valid schema numbers are -4 <= n <= 8. They are all for
// base-2 bucket schemas, where 1 is a bucket boundary in each case, and
// then each power of two is divided into 2^n logarithmic buckets. Or
@ -295,6 +308,7 @@ func (h *Histogram) ToFloat() *FloatHistogram {
}
return &FloatHistogram{
CounterResetHint: h.CounterResetHint,
Schema: h.Schema,
ZeroThreshold: h.ZeroThreshold,
ZeroCount: float64(h.ZeroCount),

View file

@ -3158,10 +3158,12 @@ func TestSparseHistogramRate(t *testing.T) {
Schema: 1,
ZeroThreshold: 0.001,
ZeroCount: 1. / 15.,
Count: 4. / 15.,
Count: 8. / 15.,
Sum: 1.226666666666667,
PositiveSpans: []histogram.Span{{Offset: 0, Length: 2}, {Offset: 1, Length: 2}},
PositiveBuckets: []float64{1. / 15., 1. / 15., 1. / 15., 1. / 15.},
NegativeSpans: []histogram.Span{{Offset: 0, Length: 2}, {Offset: 1, Length: 2}},
NegativeBuckets: []float64{1. / 15., 1. / 15., 1. / 15., 1. / 15.},
}
require.Equal(t, expectedHistogram, actualHistogram)
}
@ -3199,10 +3201,12 @@ func TestSparseFloatHistogramRate(t *testing.T) {
Schema: 1,
ZeroThreshold: 0.001,
ZeroCount: 1. / 15.,
Count: 4. / 15.,
Count: 8. / 15.,
Sum: 1.226666666666667,
PositiveSpans: []histogram.Span{{Offset: 0, Length: 2}, {Offset: 1, Length: 2}},
PositiveBuckets: []float64{1. / 15., 1. / 15., 1. / 15., 1. / 15.},
NegativeSpans: []histogram.Span{{Offset: 0, Length: 2}, {Offset: 1, Length: 2}},
NegativeBuckets: []float64{1. / 15., 1. / 15., 1. / 15., 1. / 15.},
}
require.Equal(t, expectedHistogram, actualHistogram)
}

View file

@ -174,6 +174,7 @@ func newFloatHistogramIterator(b []byte) *floatHistogramIterator {
// The first 3 bytes contain chunk headers.
// We skip that for actual samples.
_, _ = it.br.readBits(24)
it.counterResetHeader = CounterResetHeader(b[2] & 0b11000000)
return it
}
@ -196,6 +197,14 @@ type FloatHistogramAppender struct {
pBuckets, nBuckets []xorValue
}
func (a *FloatHistogramAppender) GetCounterResetHeader() CounterResetHeader {
return CounterResetHeader(a.b.bytes()[2] & 0b11000000)
}
func (a *FloatHistogramAppender) NumSamples() int {
return int(binary.BigEndian.Uint16(a.b.bytes()))
}
// Append implements Appender. This implementation panics because normal float
// samples must never be appended to a histogram chunk.
func (a *FloatHistogramAppender) Append(int64, float64) {
@ -211,19 +220,14 @@ func (a *FloatHistogramAppender) AppendHistogram(int64, *histogram.Histogram) {
// Appendable returns whether the chunk can be appended to, and if so
// whether any recoding needs to happen using the provided interjections
// (in case of any new buckets, positive or negative range, respectively).
// If the sample is a gauge histogram, AppendableGauge must be used instead.
//
// The chunk is not appendable in the following cases:
//
// • The schema has changed.
//
// • The threshold for the zero bucket has changed.
//
// • Any buckets have disappeared.
//
// • There was a counter reset in the count of observations or in any bucket,
// including the zero bucket.
//
// • The last sample in the chunk was stale while the current sample is not stale.
// - The schema has changed.
// - The threshold for the zero bucket has changed.
// - Any buckets have disappeared.
// - There was a counter reset in the count of observations or in any bucket, including the zero bucket.
// - The last sample in the chunk was stale while the current sample is not stale.
//
// The method returns an additional boolean set to true if it is not appendable
// because of a counter reset. If the given sample is stale, it is always ok to
@ -232,6 +236,9 @@ func (a *FloatHistogramAppender) Appendable(h *histogram.FloatHistogram) (
positiveInterjections, negativeInterjections []Interjection,
okToAppend, counterReset bool,
) {
if a.NumSamples() > 0 && a.GetCounterResetHeader() == GaugeType {
return
}
if value.IsStaleNaN(h.Sum) {
// This is a stale sample whose buckets and spans don't matter.
okToAppend = true
@ -260,12 +267,12 @@ func (a *FloatHistogramAppender) Appendable(h *histogram.FloatHistogram) (
}
var ok bool
positiveInterjections, ok = compareSpans(a.pSpans, h.PositiveSpans)
positiveInterjections, ok = forwardCompareSpans(a.pSpans, h.PositiveSpans)
if !ok {
counterReset = true
return
}
negativeInterjections, ok = compareSpans(a.nSpans, h.NegativeSpans)
negativeInterjections, ok = forwardCompareSpans(a.nSpans, h.NegativeSpans)
if !ok {
counterReset = true
return
@ -281,6 +288,49 @@ func (a *FloatHistogramAppender) Appendable(h *histogram.FloatHistogram) (
return
}
// AppendableGauge returns whether the chunk can be appended to, and if so
// whether:
// 1. Any recoding needs to happen to the chunk using the provided interjections
// (in case of any new buckets, positive or negative range, respectively).
// 2. Any recoding needs to happen for the histogram being appended, using the backward interjections
// (in case of any missing buckets, positive or negative range, respectively).
//
// This method must be only used for gauge histograms.
//
// The chunk is not appendable in the following cases:
// - The schema has changed.
// - The threshold for the zero bucket has changed.
// - The last sample in the chunk was stale while the current sample is not stale.
func (a *FloatHistogramAppender) AppendableGauge(h *histogram.FloatHistogram) (
positiveInterjections, negativeInterjections []Interjection,
backwardPositiveInterjections, backwardNegativeInterjections []Interjection,
positiveSpans, negativeSpans []histogram.Span,
okToAppend bool,
) {
if a.NumSamples() > 0 && a.GetCounterResetHeader() != GaugeType {
return
}
if value.IsStaleNaN(h.Sum) {
// This is a stale sample whose buckets and spans don't matter.
okToAppend = true
return
}
if value.IsStaleNaN(a.sum.value) {
// If the last sample was stale, then we can only accept stale
// samples in this chunk.
return
}
if h.Schema != a.schema || h.ZeroThreshold != a.zThreshold {
return
}
positiveInterjections, backwardPositiveInterjections, positiveSpans = bidirectionalCompareSpans(a.pSpans, h.PositiveSpans)
negativeInterjections, backwardNegativeInterjections, negativeSpans = bidirectionalCompareSpans(a.nSpans, h.NegativeSpans)
okToAppend = true
return
}
// counterResetInAnyFloatBucket returns true if there was a counter reset for any
// bucket. This should be called only when the bucket layout is the same or new
// buckets were added. It does not handle the case of buckets missing.
@ -502,11 +552,29 @@ func (a *FloatHistogramAppender) Recode(
return hc, app
}
// RecodeHistogramm converts the current histogram (in-place) to accommodate an expansion of the set of
// (positive and/or negative) buckets used.
func (a *FloatHistogramAppender) RecodeHistogramm(
fh *histogram.FloatHistogram,
pBackwardInter, nBackwardInter []Interjection,
) {
if len(pBackwardInter) > 0 {
numPositiveBuckets := countSpans(fh.PositiveSpans)
fh.PositiveBuckets = interject(fh.PositiveBuckets, make([]float64, numPositiveBuckets), pBackwardInter, false)
}
if len(nBackwardInter) > 0 {
numNegativeBuckets := countSpans(fh.NegativeSpans)
fh.NegativeBuckets = interject(fh.NegativeBuckets, make([]float64, numNegativeBuckets), nBackwardInter, false)
}
}
type floatHistogramIterator struct {
br bstreamReader
numTotal uint16
numRead uint16
counterResetHeader CounterResetHeader
// Layout:
schema int32
zThreshold float64
@ -559,7 +627,12 @@ func (it *floatHistogramIterator) AtFloatHistogram() (int64, *histogram.FloatHis
return it.t, &histogram.FloatHistogram{Sum: it.sum.value}
}
it.atFloatHistogramCalled = true
crHint := histogram.UnknownCounterReset
if it.counterResetHeader == GaugeType {
crHint = histogram.GaugeType
}
return it.t, &histogram.FloatHistogram{
CounterResetHint: crHint,
Count: it.cnt.value,
ZeroCount: it.zCnt.value,
Sum: it.sum.value,
@ -587,6 +660,8 @@ func (it *floatHistogramIterator) Reset(b []byte) {
it.numTotal = binary.BigEndian.Uint16(b)
it.numRead = 0
it.counterResetHeader = CounterResetHeader(b[2] & 0b11000000)
it.t, it.tDelta = 0, 0
it.cnt, it.zCnt, it.sum = xorValue{}, xorValue{}, xorValue{}

View file

@ -358,3 +358,171 @@ func TestFloatHistogramChunkAppendable(t *testing.T) {
require.True(t, cr)
}
}
func TestFloatHistogramChunkAppendableGauge(t *testing.T) {
c := Chunk(NewFloatHistogramChunk())
// Create fresh appender and add the first histogram.
app, err := c.Appender()
require.NoError(t, err)
require.Equal(t, 0, c.NumSamples())
ts := int64(1234567890)
h1 := &histogram.FloatHistogram{
Count: 5,
ZeroCount: 2,
Sum: 18.4,
ZeroThreshold: 1e-125,
Schema: 1,
PositiveSpans: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 2, Length: 1},
{Offset: 3, Length: 2},
{Offset: 3, Length: 1},
{Offset: 1, Length: 1},
},
PositiveBuckets: []float64{6, 3, 3, 2, 4, 5, 1},
}
app.AppendFloatHistogram(ts, h1.Copy())
require.Equal(t, 1, c.NumSamples())
c.(*FloatHistogramChunk).SetCounterResetHeader(GaugeType)
{ // Schema change.
h2 := h1.Copy()
h2.Schema++
hApp, _ := app.(*FloatHistogramAppender)
_, _, _, _, _, _, ok := hApp.AppendableGauge(h2)
require.False(t, ok)
}
{ // Zero threshold change.
h2 := h1.Copy()
h2.ZeroThreshold += 0.1
hApp, _ := app.(*FloatHistogramAppender)
_, _, _, _, _, _, ok := hApp.AppendableGauge(h2)
require.False(t, ok)
}
{ // New histogram that has more buckets.
h2 := h1.Copy()
h2.PositiveSpans = []histogram.Span{
{Offset: 0, Length: 3},
{Offset: 1, Length: 1},
{Offset: 1, Length: 4},
{Offset: 3, Length: 3},
}
h2.Count += 9
h2.ZeroCount++
h2.Sum = 30
h2.PositiveBuckets = []float64{7, 5, 1, 3, 1, 0, 2, 5, 5, 0, 1}
hApp, _ := app.(*FloatHistogramAppender)
pI, nI, pBackwardI, nBackwardI, _, _, ok := hApp.AppendableGauge(h2)
require.Greater(t, len(pI), 0)
require.Len(t, nI, 0)
require.Len(t, pBackwardI, 0)
require.Len(t, nBackwardI, 0)
require.True(t, ok)
}
{ // New histogram that has buckets missing.
h2 := h1.Copy()
h2.PositiveSpans = []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 2, Length: 1},
{Offset: 3, Length: 1},
{Offset: 4, Length: 1},
{Offset: 1, Length: 1},
}
h2.Count -= 4
h2.Sum--
h2.PositiveBuckets = []float64{6, 3, 3, 2, 5, 1}
hApp, _ := app.(*FloatHistogramAppender)
pI, nI, pBackwardI, nBackwardI, _, _, ok := hApp.AppendableGauge(h2)
require.Len(t, pI, 0)
require.Len(t, nI, 0)
require.Greater(t, len(pBackwardI), 0)
require.Len(t, nBackwardI, 0)
require.True(t, ok)
}
{ // New histogram that has a bucket missing and new buckets.
h2 := h1.Copy()
h2.PositiveSpans = []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 5, Length: 2},
{Offset: 3, Length: 1},
{Offset: 1, Length: 1},
}
h2.Sum = 21
h2.PositiveBuckets = []float64{6, 3, 2, 4, 5, 1}
hApp, _ := app.(*FloatHistogramAppender)
pI, nI, pBackwardI, nBackwardI, _, _, ok := hApp.AppendableGauge(h2)
require.Greater(t, len(pI), 0)
require.Greater(t, len(pBackwardI), 0)
require.Len(t, nI, 0)
require.Len(t, nBackwardI, 0)
require.True(t, ok)
}
{ // New histogram that has a counter reset while buckets are same.
h2 := h1.Copy()
h2.Sum = 23
h2.PositiveBuckets = []float64{6, 2, 3, 2, 4, 5, 1}
hApp, _ := app.(*FloatHistogramAppender)
pI, nI, pBackwardI, nBackwardI, _, _, ok := hApp.AppendableGauge(h2)
require.Len(t, pI, 0)
require.Len(t, nI, 0)
require.Len(t, pBackwardI, 0)
require.Len(t, nBackwardI, 0)
require.True(t, ok)
}
{ // New histogram that has a counter reset while new buckets were added.
h2 := h1.Copy()
h2.PositiveSpans = []histogram.Span{
{Offset: 0, Length: 3},
{Offset: 1, Length: 1},
{Offset: 1, Length: 4},
{Offset: 3, Length: 3},
}
h2.Sum = 29
h2.PositiveBuckets = []float64{7, 5, 1, 3, 1, 0, 2, 5, 5, 0, 0}
hApp, _ := app.(*FloatHistogramAppender)
pI, nI, pBackwardI, nBackwardI, _, _, ok := hApp.AppendableGauge(h2)
require.Greater(t, len(pI), 0)
require.Len(t, nI, 0)
require.Len(t, pBackwardI, 0)
require.Len(t, nBackwardI, 0)
require.True(t, ok)
}
{
// New histogram that has a counter reset while new buckets were
// added before the first bucket and reset on first bucket.
h2 := h1.Copy()
h2.PositiveSpans = []histogram.Span{
{Offset: -3, Length: 2},
{Offset: 1, Length: 2},
{Offset: 2, Length: 1},
{Offset: 3, Length: 2},
{Offset: 3, Length: 1},
{Offset: 1, Length: 1},
}
h2.Sum = 26
h2.PositiveBuckets = []float64{1, 2, 5, 3, 3, 2, 4, 5, 1}
hApp, _ := app.(*FloatHistogramAppender)
pI, nI, pBackwardI, nBackwardI, _, _, ok := hApp.AppendableGauge(h2)
require.Greater(t, len(pI), 0)
require.Len(t, nI, 0)
require.Len(t, pBackwardI, 0)
require.Len(t, nBackwardI, 0)
require.True(t, ok)
}
}

View file

@ -286,12 +286,12 @@ func (a *HistogramAppender) Appendable(h *histogram.Histogram) (
}
var ok bool
positiveInterjections, ok = compareSpans(a.pSpans, h.PositiveSpans)
positiveInterjections, ok = forwardCompareSpans(a.pSpans, h.PositiveSpans)
if !ok {
counterReset = true
return
}
negativeInterjections, ok = compareSpans(a.nSpans, h.NegativeSpans)
negativeInterjections, ok = forwardCompareSpans(a.nSpans, h.NegativeSpans)
if !ok {
counterReset = true
return

View file

@ -165,21 +165,23 @@ func (b *bucketIterator) Next() (int, bool) {
if b.span >= len(b.spans) {
return 0, false
}
try:
if b.bucket < int(b.spans[b.span].Length-1) { // Try to move within same span.
if b.bucket < int(b.spans[b.span].Length)-1 { // Try to move within same span.
b.bucket++
b.idx++
return b.idx, true
} else if b.span < len(b.spans)-1 { // Try to move from one span to the next.
}
for b.span < len(b.spans)-1 { // Try to move from one span to the next.
b.span++
b.idx += int(b.spans[b.span].Offset + 1)
b.bucket = 0
if b.spans[b.span].Length == 0 {
// Pathological case that should never happen. We can't use this span, let's try again.
goto try
b.idx--
continue
}
return b.idx, true
}
// We're out of options.
return 0, false
}
@ -191,7 +193,7 @@ type Interjection struct {
num int
}
// compareSpans returns the interjections to convert a slice of deltas to a new
// forwardCompareSpans returns the interjections to convert a slice of deltas to a new
// slice representing an expanded set of buckets, or false if incompatible
// (e.g. if buckets were removed).
//
@ -226,11 +228,11 @@ type Interjection struct {
// match a new span layout that adds buckets, we simply need to generate a list
// of interjections.
//
// Note: Within compareSpans we don't have to worry about the changes to the
// Note: Within forwardCompareSpans we don't have to worry about the changes to the
// spans themselves, thanks to the iterators we get to work with the more useful
// bucket indices (which of course directly correspond to the buckets we have to
// adjust).
func compareSpans(a, b []histogram.Span) ([]Interjection, bool) {
func forwardCompareSpans(a, b []histogram.Span) (forward []Interjection, ok bool) {
ai := newBucketIterator(a)
bi := newBucketIterator(b)
@ -278,6 +280,102 @@ loop:
return interjections, true
}
// bidirectionalCompareSpans does everything that forwardCompareSpans does and
// also returns interjections in the other direction (i.e. buckets missing in b that are missing in a).
func bidirectionalCompareSpans(a, b []histogram.Span) (forward, backward []Interjection, mergedSpans []histogram.Span) {
ai := newBucketIterator(a)
bi := newBucketIterator(b)
var interjections, bInterjections []Interjection
var lastBucket int
addBucket := func(b int) {
offset := b - lastBucket - 1
if offset == 0 && len(mergedSpans) > 0 {
mergedSpans[len(mergedSpans)-1].Length++
} else {
if len(mergedSpans) == 0 {
offset++
}
mergedSpans = append(mergedSpans, histogram.Span{
Offset: int32(offset),
Length: 1,
})
}
lastBucket = b
}
// When inter.num becomes > 0, this becomes a valid interjection that
// should be yielded when we finish a streak of new buckets.
var inter, bInter Interjection
av, aOK := ai.Next()
bv, bOK := bi.Next()
loop:
for {
switch {
case aOK && bOK:
switch {
case av == bv: // Both have an identical value. move on!
// Finish WIP interjection and reset.
if inter.num > 0 {
interjections = append(interjections, inter)
inter.num = 0
}
if bInter.num > 0 {
bInterjections = append(bInterjections, bInter)
bInter.num = 0
}
addBucket(av)
av, aOK = ai.Next()
bv, bOK = bi.Next()
inter.pos++
bInter.pos++
case av < bv: // b misses a value that is in a.
bInter.num++
// Collect the forward interjection before advancing the
// position of 'a'.
if inter.num > 0 {
interjections = append(interjections, inter)
inter.num = 0
}
addBucket(av)
inter.pos++
av, aOK = ai.Next()
case av > bv: // a misses a value that is in b. Forward b and recompare.
inter.num++
// Collect the backward interjection before advancing the
// position of 'b'.
if bInter.num > 0 {
bInterjections = append(bInterjections, bInter)
bInter.num = 0
}
addBucket(bv)
bInter.pos++
bv, bOK = bi.Next()
}
case aOK && !bOK: // b misses a value that is in a.
bInter.num++
addBucket(av)
av, aOK = ai.Next()
case !aOK && bOK: // a misses a value that is in b. Forward b and recompare.
inter.num++
addBucket(bv)
bv, bOK = bi.Next()
default: // Both iterators ran out. We're done.
if inter.num > 0 {
interjections = append(interjections, inter)
}
if bInter.num > 0 {
bInterjections = append(bInterjections, bInter)
}
break loop
}
}
return interjections, bInterjections, mergedSpans
}
// interject merges 'in' with the provided interjections and writes them into
// 'out', which must already have the appropriate length.
func interject[BV bucketValue](in, out []BV, interjections []Interjection, deltas bool) []BV {

View file

@ -111,12 +111,11 @@ func TestBucketIterator(t *testing.T) {
}
}
func TestInterjection(t *testing.T) {
func TestCompareSpansAndInterject(t *testing.T) {
scenarios := []struct {
description string
spansA, spansB []histogram.Span
valid bool
interjections []Interjection
interjections, backwardInterjections []Interjection
bucketsIn, bucketsOut []int64
}{
{
@ -127,7 +126,6 @@ func TestInterjection(t *testing.T) {
spansB: []histogram.Span{
{Offset: -11, Length: 4},
},
valid: true,
interjections: []Interjection{
{
pos: 0,
@ -145,7 +143,6 @@ func TestInterjection(t *testing.T) {
spansB: []histogram.Span{
{Offset: -10, Length: 4},
},
valid: true,
interjections: []Interjection{
{
pos: 3,
@ -163,7 +160,6 @@ func TestInterjection(t *testing.T) {
spansB: []histogram.Span{
{Offset: -12, Length: 5},
},
valid: true,
interjections: []Interjection{
{
pos: 0,
@ -181,7 +177,6 @@ func TestInterjection(t *testing.T) {
spansB: []histogram.Span{
{Offset: -10, Length: 5},
},
valid: true,
interjections: []Interjection{
{
pos: 3,
@ -199,7 +194,6 @@ func TestInterjection(t *testing.T) {
spansB: []histogram.Span{
{Offset: -12, Length: 7},
},
valid: true,
interjections: []Interjection{
{
pos: 0,
@ -221,7 +215,9 @@ func TestInterjection(t *testing.T) {
spansB: []histogram.Span{
{Offset: -9, Length: 3},
},
valid: false,
backwardInterjections: []Interjection{
{pos: 0, num: 1},
},
},
{
description: "single removal of bucket in the middle",
@ -232,7 +228,9 @@ func TestInterjection(t *testing.T) {
{Offset: -10, Length: 2},
{Offset: 1, Length: 1},
},
valid: false,
backwardInterjections: []Interjection{
{pos: 2, num: 1},
},
},
{
description: "single removal of bucket at the end",
@ -242,7 +240,9 @@ func TestInterjection(t *testing.T) {
spansB: []histogram.Span{
{Offset: -10, Length: 3},
},
valid: false,
backwardInterjections: []Interjection{
{pos: 3, num: 1},
},
},
{
description: "as described in doc comment",
@ -259,7 +259,6 @@ func TestInterjection(t *testing.T) {
{Offset: 1, Length: 4},
{Offset: 3, Length: 3},
},
valid: true,
interjections: []Interjection{
{
pos: 2,
@ -277,12 +276,67 @@ func TestInterjection(t *testing.T) {
bucketsIn: []int64{6, -3, 0, -1, 2, 1, -4},
bucketsOut: []int64{6, -3, -3, 3, -3, 0, 2, 2, 1, -5, 1},
},
{
description: "both forward and backward interjections, complex case",
spansA: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 2, Length: 1},
{Offset: 3, Length: 2},
{Offset: 3, Length: 1},
{Offset: 1, Length: 1},
},
spansB: []histogram.Span{
{Offset: 1, Length: 2},
{Offset: 1, Length: 1},
{Offset: 1, Length: 2},
{Offset: 1, Length: 1},
{Offset: 4, Length: 1},
},
interjections: []Interjection{
{
pos: 2,
num: 1,
},
{
pos: 3,
num: 2,
},
{
pos: 6,
num: 1,
},
},
backwardInterjections: []Interjection{
{
pos: 0,
num: 1,
},
{
pos: 5,
num: 1,
},
{
pos: 6,
num: 1,
},
{
pos: 7,
num: 1,
},
},
},
}
for _, s := range scenarios {
t.Run(s.description, func(t *testing.T) {
interjections, valid := compareSpans(s.spansA, s.spansB)
if !s.valid {
if len(s.backwardInterjections) > 0 {
interjections, bInterjections, _ := bidirectionalCompareSpans(s.spansA, s.spansB)
require.Equal(t, s.interjections, interjections)
require.Equal(t, s.backwardInterjections, bInterjections)
}
interjections, valid := forwardCompareSpans(s.spansA, s.spansB)
if len(s.backwardInterjections) > 0 {
require.False(t, valid, "compareScan unexpectedly returned true")
return
}
@ -292,6 +346,24 @@ func TestInterjection(t *testing.T) {
gotBuckets := make([]int64, len(s.bucketsOut))
interject(s.bucketsIn, gotBuckets, interjections, true)
require.Equal(t, s.bucketsOut, gotBuckets)
floatBucketsIn := make([]float64, len(s.bucketsIn))
last := s.bucketsIn[0]
floatBucketsIn[0] = float64(last)
for i := 1; i < len(floatBucketsIn); i++ {
last += s.bucketsIn[i]
floatBucketsIn[i] = float64(last)
}
floatBucketsOut := make([]float64, len(s.bucketsOut))
last = s.bucketsOut[0]
floatBucketsOut[0] = float64(last)
for i := 1; i < len(floatBucketsOut); i++ {
last += s.bucketsOut[i]
floatBucketsOut[i] = float64(last)
}
gotFloatBuckets := make([]float64, len(floatBucketsOut))
interject(floatBucketsIn, gotFloatBuckets, interjections, false)
require.Equal(t, floatBucketsOut, gotFloatBuckets)
})
}
}
@ -369,3 +441,135 @@ func TestWriteReadHistogramChunkLayout(t *testing.T) {
require.Equal(t, want.negativeSpans, gotNegativeSpans)
}
}
func TestSpansFromBidirectionalCompareSpans(t *testing.T) {
cases := []struct {
s1, s2, exp []histogram.Span
}{
{ // All empty.
s1: []histogram.Span{},
s2: []histogram.Span{},
},
{ // Same spans.
s1: []histogram.Span{},
s2: []histogram.Span{},
},
{
// Has the cases of
// 1. |----| (partial overlap)
// |----|
//
// 2. |-----| (no gap but no overlap as well)
// |---|
//
// 3. |----| (complete overlap)
// |----|
s1: []histogram.Span{
{Offset: 0, Length: 3},
{Offset: 3, Length: 3},
{Offset: 5, Length: 3},
},
s2: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 2, Length: 2},
{Offset: 2, Length: 3},
{Offset: 3, Length: 3},
},
exp: []histogram.Span{
{Offset: 0, Length: 3},
{Offset: 1, Length: 7},
{Offset: 3, Length: 3},
},
},
{
// s1 is superset of s2.
s1: []histogram.Span{
{Offset: 0, Length: 3},
{Offset: 3, Length: 5},
{Offset: 3, Length: 3},
},
s2: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 5, Length: 3},
{Offset: 4, Length: 3},
},
exp: []histogram.Span{
{Offset: 0, Length: 3},
{Offset: 3, Length: 5},
{Offset: 3, Length: 3},
},
},
{
// No overlaps but one span is side by side.
s1: []histogram.Span{
{Offset: 0, Length: 3},
{Offset: 3, Length: 3},
{Offset: 5, Length: 3},
},
s2: []histogram.Span{
{Offset: 3, Length: 3},
{Offset: 4, Length: 2},
},
exp: []histogram.Span{
{Offset: 0, Length: 9},
{Offset: 1, Length: 2},
{Offset: 2, Length: 3},
},
},
{
// No buckets in one of them.
s1: []histogram.Span{
{Offset: 0, Length: 3},
{Offset: 3, Length: 3},
{Offset: 5, Length: 3},
},
s2: []histogram.Span{},
exp: []histogram.Span{
{Offset: 0, Length: 3},
{Offset: 3, Length: 3},
{Offset: 5, Length: 3},
},
},
{ // Zero length spans.
s1: []histogram.Span{
{Offset: -5, Length: 0},
{Offset: 2, Length: 0},
{Offset: 3, Length: 3},
{Offset: 1, Length: 0},
{Offset: 2, Length: 3},
{Offset: 2, Length: 0},
{Offset: 2, Length: 0},
{Offset: 1, Length: 3},
{Offset: 4, Length: 0},
{Offset: 5, Length: 0},
},
s2: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 2, Length: 2},
{Offset: 1, Length: 0},
{Offset: 1, Length: 3},
{Offset: 3, Length: 3},
},
exp: []histogram.Span{
{Offset: 0, Length: 3},
{Offset: 1, Length: 7},
{Offset: 3, Length: 3},
},
},
}
for _, c := range cases {
s1c := make([]histogram.Span, len(c.s1))
s2c := make([]histogram.Span, len(c.s2))
copy(s1c, c.s1)
copy(s2c, c.s2)
_, _, act := bidirectionalCompareSpans(c.s1, c.s2)
require.Equal(t, c.exp, act)
// Check that s1 and s2 are not modified.
require.Equal(t, s1c, c.s1)
require.Equal(t, s2c, c.s2)
_, _, act = bidirectionalCompareSpans(c.s2, c.s1)
require.Equal(t, c.exp, act)
}
}

View file

@ -17,6 +17,7 @@ import (
"fmt"
"io"
"math"
"math/rand"
"path/filepath"
"sync"
"time"
@ -2026,7 +2027,7 @@ func (h *Head) updateWALReplayStatusRead(current int) {
func GenerateTestHistograms(n int) (r []*histogram.Histogram) {
for i := 0; i < n; i++ {
r = append(r, &histogram.Histogram{
Count: 5 + uint64(i*4),
Count: 10 + uint64(i*8),
ZeroCount: 2 + uint64(i),
ZeroThreshold: 0.001,
Sum: 18.4 * float64(i+1),
@ -2036,6 +2037,11 @@ func GenerateTestHistograms(n int) (r []*histogram.Histogram) {
{Offset: 1, Length: 2},
},
PositiveBuckets: []int64{int64(i + 1), 1, -1, 0},
NegativeSpans: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 1, Length: 2},
},
NegativeBuckets: []int64{int64(i + 1), 1, -1, 0},
})
}
@ -2045,7 +2051,7 @@ func GenerateTestHistograms(n int) (r []*histogram.Histogram) {
func GenerateTestFloatHistograms(n int) (r []*histogram.FloatHistogram) {
for i := 0; i < n; i++ {
r = append(r, &histogram.FloatHistogram{
Count: 5 + float64(i*4),
Count: 10 + float64(i*8),
ZeroCount: 2 + float64(i),
ZeroThreshold: 0.001,
Sum: 18.4 * float64(i+1),
@ -2055,6 +2061,37 @@ func GenerateTestFloatHistograms(n int) (r []*histogram.FloatHistogram) {
{Offset: 1, Length: 2},
},
PositiveBuckets: []float64{float64(i + 1), float64(i + 2), float64(i + 1), float64(i + 1)},
NegativeSpans: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 1, Length: 2},
},
NegativeBuckets: []float64{float64(i + 1), float64(i + 2), float64(i + 1), float64(i + 1)},
})
}
return r
}
func GenerateTestGaugeHistograms(n int) (r []*histogram.FloatHistogram) {
for x := 0; x < n; x++ {
i := rand.Intn(n)
r = append(r, &histogram.FloatHistogram{
CounterResetHint: histogram.GaugeType,
Count: 10 + float64(i*8),
ZeroCount: 2 + float64(i),
ZeroThreshold: 0.001,
Sum: 18.4 * float64(i+1),
Schema: 1,
PositiveSpans: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 1, Length: 2},
},
PositiveBuckets: []float64{float64(i + 1), float64(i + 2), float64(i + 1), float64(i + 1)},
NegativeSpans: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 1, Length: 2},
},
NegativeBuckets: []float64{float64(i + 1), float64(i + 2), float64(i + 1), float64(i + 1)},
})
}

View file

@ -1138,9 +1138,10 @@ func (s *memSeries) append(t int64, v float64, appendID uint64, chunkDiskMapper
// appendHistogram adds the histogram.
// It is unsafe to call this concurrently with s.iterator(...) without holding the series lock.
// TODO(codesome): Support gauge histograms here.
func (s *memSeries) appendHistogram(t int64, h *histogram.Histogram, appendID uint64, chunkDiskMapper *chunks.ChunkDiskMapper, chunkRange int64) (sampleInOrder, chunkCreated bool) {
// Head controls the execution of recoding, so that we own the proper
// chunk reference afterwards. We check for Appendable before
// chunk reference afterwards. We check for Appendable from appender before
// appendPreprocessor because in case it ends up creating a new chunk,
// we need to know if there was also a counter reset or not to set the
// meta properly.
@ -1209,24 +1210,37 @@ func (s *memSeries) appendHistogram(t int64, h *histogram.Histogram, appendID ui
// It is unsafe to call this concurrently with s.iterator(...) without holding the series lock.
func (s *memSeries) appendFloatHistogram(t int64, fh *histogram.FloatHistogram, appendID uint64, chunkDiskMapper *chunks.ChunkDiskMapper, chunkRange int64) (sampleInOrder, chunkCreated bool) {
// Head controls the execution of recoding, so that we own the proper
// chunk reference afterwards. We check for Appendable before
// chunk reference afterwards. We check for Appendable from appender before
// appendPreprocessor because in case it ends up creating a new chunk,
// we need to know if there was also a counter reset or not to set the
// meta properly.
app, _ := s.app.(*chunkenc.FloatHistogramAppender)
var (
positiveInterjections, negativeInterjections []chunkenc.Interjection
pBackwardInter, nBackwardInter []chunkenc.Interjection
pMergedSpans, nMergedSpans []histogram.Span
okToAppend, counterReset bool
)
c, sampleInOrder, chunkCreated := s.appendPreprocessor(t, chunkenc.EncFloatHistogram, chunkDiskMapper, chunkRange)
if !sampleInOrder {
return sampleInOrder, chunkCreated
}
gauge := fh.CounterResetHint == histogram.GaugeType
if app != nil {
if gauge {
positiveInterjections, negativeInterjections, pBackwardInter, nBackwardInter,
pMergedSpans, nMergedSpans, okToAppend = app.AppendableGauge(fh)
} else {
positiveInterjections, negativeInterjections, okToAppend, counterReset = app.Appendable(fh)
}
}
if !chunkCreated {
if len(pBackwardInter)+len(nBackwardInter) > 0 {
fh.PositiveSpans = pMergedSpans
fh.NegativeSpans = nMergedSpans
app.RecodeHistogramm(fh, pBackwardInter, nBackwardInter)
}
// We have 3 cases here
// - !okToAppend -> We need to cut a new chunk.
// - okToAppend but we have interjections → Existing chunk needs
@ -1251,7 +1265,9 @@ func (s *memSeries) appendFloatHistogram(t int64, fh *histogram.FloatHistogram,
if chunkCreated {
hc := s.headChunk.chunk.(*chunkenc.FloatHistogramChunk)
header := chunkenc.UnknownCounterReset
if counterReset {
if gauge {
header = chunkenc.GaugeType
} else if counterReset {
header = chunkenc.CounterReset
} else if okToAppend {
header = chunkenc.NotCounterReset

View file

@ -110,7 +110,9 @@ func populateTestWAL(t testing.TB, w *wlog.WL, recs []interface{}) {
func readTestWAL(t testing.TB, dir string) (recs []interface{}) {
sr, err := wlog.NewSegmentsReader(dir)
require.NoError(t, err)
defer sr.Close()
defer func() {
require.NoError(t, sr.Close())
}()
var dec record.Decoder
r := wlog.NewReader(sr)
@ -127,6 +129,14 @@ func readTestWAL(t testing.TB, dir string) (recs []interface{}) {
samples, err := dec.Samples(rec, nil)
require.NoError(t, err)
recs = append(recs, samples)
case record.HistogramSamples:
samples, err := dec.HistogramSamples(rec, nil)
require.NoError(t, err)
recs = append(recs, samples)
case record.FloatHistogramSamples:
samples, err := dec.FloatHistogramSamples(rec, nil)
require.NoError(t, err)
recs = append(recs, samples)
case record.Tombstones:
tstones, err := dec.Tombstones(rec, nil)
require.NoError(t, err)
@ -2824,6 +2834,7 @@ func TestAppendHistogram(t *testing.T) {
ingestTs := int64(0)
app := head.Appender(context.Background())
// Integer histograms.
type timedHistogram struct {
t int64
h *histogram.Histogram
@ -2844,6 +2855,7 @@ func TestAppendHistogram(t *testing.T) {
t int64
h *histogram.FloatHistogram
}
// Float counter histograms.
expFloatHistograms := make([]timedFloatHistogram, 0, numHistograms)
for _, fh := range GenerateTestFloatHistograms(numHistograms) {
_, err := app.AppendHistogram(0, l, ingestTs, nil, fh)
@ -2855,6 +2867,18 @@ func TestAppendHistogram(t *testing.T) {
app = head.Appender(context.Background())
}
}
// Float gauge histograms.
for _, fh := range GenerateTestGaugeHistograms(numHistograms) {
_, err := app.AppendHistogram(0, l, ingestTs, nil, fh)
require.NoError(t, err)
expFloatHistograms = append(expFloatHistograms, timedFloatHistogram{ingestTs, fh})
ingestTs++
if ingestTs%50 == 0 {
require.NoError(t, app.Commit())
app = head.Appender(context.Background())
}
}
require.NoError(t, app.Commit())
q, err := NewBlockQuerier(head, head.MinTime(), head.MaxTime())
@ -2898,7 +2922,7 @@ func TestHistogramInWALAndMmapChunk(t *testing.T) {
// Series with only histograms.
s1 := labels.FromStrings("a", "b1")
k1 := s1.String()
numHistograms := 450
numHistograms := 300
exp := map[string][]tsdbutil.Sample{}
app := head.Appender(context.Background())
ts := int64(0)
@ -2916,8 +2940,15 @@ func TestHistogramInWALAndMmapChunk(t *testing.T) {
}
}
require.NoError(t, app.Commit())
for _, gauge := range []bool{true, false} {
app = head.Appender(context.Background())
for _, h := range GenerateTestFloatHistograms(numHistograms) {
var hists []*histogram.FloatHistogram
if gauge {
hists = GenerateTestGaugeHistograms(numHistograms)
} else {
hists = GenerateTestFloatHistograms(numHistograms)
}
for _, h := range hists {
h.Count = h.Count * 2
h.NegativeSpans = h.PositiveSpans
h.NegativeBuckets = h.PositiveBuckets
@ -2931,11 +2962,12 @@ func TestHistogramInWALAndMmapChunk(t *testing.T) {
}
}
require.NoError(t, app.Commit())
}
// There should be 7 mmap chunks in s1.
ms := head.series.getByHash(s1.Hash(), s1)
require.Len(t, ms.mmappedChunks, 7)
expMmapChunks := make([]*mmappedChunk, 0, 7)
require.Len(t, ms.mmappedChunks, 8)
expMmapChunks := make([]*mmappedChunk, 0, 8)
for _, mmap := range ms.mmappedChunks {
require.Greater(t, mmap.numSamples, uint16(0))
cpy := *mmap
@ -2972,8 +3004,15 @@ func TestHistogramInWALAndMmapChunk(t *testing.T) {
}
}
require.NoError(t, app.Commit())
for _, gauge := range []bool{true, false} {
app = head.Appender(context.Background())
for _, h := range GenerateTestFloatHistograms(100) {
var hists []*histogram.FloatHistogram
if gauge {
hists = GenerateTestGaugeHistograms(100)
} else {
hists = GenerateTestFloatHistograms(100)
}
for _, h := range hists {
ts++
h.Count = h.Count * 2
h.NegativeSpans = h.PositiveSpans
@ -2996,27 +3035,37 @@ func TestHistogramInWALAndMmapChunk(t *testing.T) {
}
}
require.NoError(t, app.Commit())
}
// Restart head.
require.NoError(t, head.Close())
startHead := func() {
w, err := wlog.NewSize(nil, nil, head.wal.Dir(), 32768, false)
require.NoError(t, err)
head, err = NewHead(nil, nil, w, nil, head.opts, nil)
require.NoError(t, err)
require.NoError(t, head.Init(0))
}
startHead()
// Checking contents of s1.
ms = head.series.getByHash(s1.Hash(), s1)
require.Equal(t, expMmapChunks, ms.mmappedChunks)
for _, mmap := range ms.mmappedChunks {
require.Greater(t, mmap.numSamples, uint16(0))
}
require.Equal(t, expHeadChunkSamples, ms.headChunk.chunk.NumSamples())
testQuery := func() {
q, err := NewBlockQuerier(head, head.MinTime(), head.MaxTime())
require.NoError(t, err)
act := query(t, q, labels.MustNewMatcher(labels.MatchRegexp, "a", "b.*"))
require.Equal(t, exp, act)
}
testQuery()
// Restart with no mmap chunks to test WAL replay.
require.NoError(t, head.Close())
require.NoError(t, os.RemoveAll(mmappedChunksDir(head.opts.ChunkDirRoot)))
startHead()
testQuery()
}
func TestChunkSnapshot(t *testing.T) {
@ -3522,7 +3571,7 @@ func TestHistogramCounterResetHeader(t *testing.T) {
if floatHisto {
_, err = app.AppendHistogram(0, l, ts, nil, h.ToFloat())
} else {
_, err = app.AppendHistogram(0, l, ts, h, nil)
_, err = app.AppendHistogram(0, l, ts, h.Copy(), nil)
}
require.NoError(t, err)
require.NoError(t, app.Commit())
@ -3553,10 +3602,6 @@ func TestHistogramCounterResetHeader(t *testing.T) {
}
h := GenerateTestHistograms(1)[0]
if len(h.NegativeBuckets) == 0 {
h.NegativeSpans = append([]histogram.Span{}, h.PositiveSpans...)
h.NegativeBuckets = append([]int64{}, h.PositiveBuckets...)
}
h.PositiveBuckets = []int64{100, 1, 1, 1}
h.NegativeBuckets = []int64{100, 1, 1, 1}
h.Count = 1000
@ -4517,3 +4562,78 @@ func TestHeadMinOOOTimeUpdate(t *testing.T) {
require.NoError(t, h.truncateOOO(0, 2))
require.Equal(t, 295*time.Minute.Milliseconds(), h.MinOOOTime())
}
func TestGaugeHistogramWALAndChunkHeader(t *testing.T) {
l := labels.FromStrings("a", "b")
head, _ := newTestHead(t, 1000, false, false)
t.Cleanup(func() {
require.NoError(t, head.Close())
})
require.NoError(t, head.Init(0))
ts := int64(0)
appendHistogram := func(h *histogram.FloatHistogram) {
ts++
app := head.Appender(context.Background())
_, err := app.AppendHistogram(0, l, ts, nil, h.Copy())
require.NoError(t, err)
require.NoError(t, app.Commit())
}
hists := GenerateTestGaugeHistograms(5)
hists[0].CounterResetHint = histogram.UnknownCounterReset
appendHistogram(hists[0])
appendHistogram(hists[1])
appendHistogram(hists[2])
hists[3].CounterResetHint = histogram.UnknownCounterReset
appendHistogram(hists[3])
appendHistogram(hists[3])
appendHistogram(hists[4])
checkHeaders := func() {
ms, _, err := head.getOrCreate(l.Hash(), l)
require.NoError(t, err)
require.Len(t, ms.mmappedChunks, 3)
expHeaders := []chunkenc.CounterResetHeader{
chunkenc.UnknownCounterReset,
chunkenc.GaugeType,
chunkenc.UnknownCounterReset,
chunkenc.GaugeType,
}
for i, mmapChunk := range ms.mmappedChunks {
chk, err := head.chunkDiskMapper.Chunk(mmapChunk.ref)
require.NoError(t, err)
require.Equal(t, expHeaders[i], chk.(*chunkenc.FloatHistogramChunk).GetCounterResetHeader())
}
require.Equal(t, expHeaders[len(expHeaders)-1], ms.headChunk.chunk.(*chunkenc.FloatHistogramChunk).GetCounterResetHeader())
}
checkHeaders()
recs := readTestWAL(t, head.wal.Dir())
require.Equal(t, []interface{}{
[]record.RefSeries{
{
Ref: 1,
Labels: labels.FromStrings("a", "b"),
},
},
[]record.RefFloatHistogramSample{{Ref: 1, T: 1, FH: hists[0]}},
[]record.RefFloatHistogramSample{{Ref: 1, T: 2, FH: hists[1]}},
[]record.RefFloatHistogramSample{{Ref: 1, T: 3, FH: hists[2]}},
[]record.RefFloatHistogramSample{{Ref: 1, T: 4, FH: hists[3]}},
[]record.RefFloatHistogramSample{{Ref: 1, T: 5, FH: hists[3]}},
[]record.RefFloatHistogramSample{{Ref: 1, T: 6, FH: hists[4]}},
}, recs)
// Restart Head without mmap chunks to expect the WAL replay to recognize gauge histograms.
require.NoError(t, head.Close())
require.NoError(t, os.RemoveAll(mmappedChunksDir(head.opts.ChunkDirRoot)))
w, err := wlog.NewSize(nil, nil, head.wal.Dir(), 32768, false)
require.NoError(t, err)
head, err = NewHead(nil, nil, w, nil, head.opts, nil)
require.NoError(t, err)
require.NoError(t, head.Init(0))
checkHeaders()
}

View file

@ -441,6 +441,8 @@ func (d *Decoder) HistogramSamples(rec []byte, histograms []RefHistogramSample)
H: &histogram.Histogram{},
}
rh.H.CounterResetHint = histogram.CounterResetHint(dec.Byte())
rh.H.Schema = int32(dec.Varint64())
rh.H.ZeroThreshold = math.Float64frombits(dec.Be64())
@ -517,6 +519,8 @@ func (d *Decoder) FloatHistogramSamples(rec []byte, histograms []RefFloatHistogr
FH: &histogram.FloatHistogram{},
}
rh.FH.CounterResetHint = histogram.CounterResetHint(dec.Byte())
rh.FH.Schema = int32(dec.Varint64())
rh.FH.ZeroThreshold = dec.Be64Float64()
@ -715,6 +719,8 @@ func (e *Encoder) HistogramSamples(histograms []RefHistogramSample, b []byte) []
buf.PutVarint64(int64(h.Ref) - int64(first.Ref))
buf.PutVarint64(h.T - first.T)
buf.PutByte(byte(h.H.CounterResetHint))
buf.PutVarint64(int64(h.H.Schema))
buf.PutBE64(math.Float64bits(h.H.ZeroThreshold))
@ -766,6 +772,8 @@ func (e *Encoder) FloatHistogramSamples(histograms []RefFloatHistogramSample, b
buf.PutVarint64(int64(h.Ref) - int64(first.Ref))
buf.PutVarint64(h.T - first.T)
buf.PutByte(byte(h.FH.CounterResetHint))
buf.PutVarint64(int64(h.FH.Schema))
buf.PutBEFloat64(h.FH.ZeroThreshold)

View file

@ -165,6 +165,22 @@ func TestRecord_EncodeDecode(t *testing.T) {
decFloatHistograms, err := dec.FloatHistogramSamples(enc.FloatHistogramSamples(floatHistograms, nil), nil)
require.NoError(t, err)
require.Equal(t, floatHistograms, decFloatHistograms)
// Gauge ingeger histograms.
for i := range histograms {
histograms[i].H.CounterResetHint = histogram.GaugeType
}
decHistograms, err = dec.HistogramSamples(enc.HistogramSamples(histograms, nil), nil)
require.NoError(t, err)
require.Equal(t, histograms, decHistograms)
// Gauge float histograms.
for i := range floatHistograms {
floatHistograms[i].FH.CounterResetHint = histogram.GaugeType
}
decFloatHistograms, err = dec.FloatHistogramSamples(enc.FloatHistogramSamples(floatHistograms, nil), nil)
require.NoError(t, err)
require.Equal(t, floatHistograms, decFloatHistograms)
}
// TestRecord_Corrupted ensures that corrupted records return the correct error.