// Copyright 2022 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 tsdb
import (
"math"
"testing"
"github.com/prometheus/prometheus/model/histogram"
"github.com/prometheus/prometheus/storage"
"github.com/prometheus/prometheus/tsdb/chunkenc"
"github.com/prometheus/prometheus/tsdb/tsdbutil"
"github.com/stretchr/testify/require"
)
const testMaxSize int = 32
// Formulas chosen to make testing easy.
func valEven(pos int) int { return pos*2 + 2 } // s[0]=2, s[1]=4, s[2]=6, ..., s[31]=64 - Predictable pre-existing values
func valOdd(pos int) int { return pos*2 + 1 } // s[0]=1, s[1]=3, s[2]=5, ..., s[31]=63 - New values will interject at chosen position because they sort before the pre-existing vals.
func samplify(v int) sample { return sample{int64(v), float64(v), nil, nil} }
func makeEvenSampleSlice(n int) []sample {
s := make([]sample, n)
for i := 0; i < n; i++ {
s[i] = samplify(valEven(i))
}
return s
}
// TestOOOInsert tests the following cases:
// - Number of pre-existing samples anywhere from 0 to testMaxSize-1.
// - Insert new sample before first pre-existing samples, after the last, and anywhere in between.
// - With a chunk initial capacity of testMaxSize/8 and testMaxSize, which lets us test non-full and full chunks, and chunks that need to expand themselves.
// Note: In all samples used, t always equals v in numeric value. when we talk about 'value' we just refer to a value that will be used for both sample.t and sample.v.
func TestOOOInsert(t *testing.T) {
for numPreExisting := 0; numPreExisting <= testMaxSize; numPreExisting++ {
// For example, if we have numPreExisting 2, then:
// chunk.samples indexes filled 0 1
// chunk.samples with these values 2 4 // valEven
// we want to test inserting at index 0 1 2 // insertPos=0..numPreExisting
// we can do this by using values 1, 3 5 // valOdd(insertPos)
for insertPos := 0; insertPos <= numPreExisting; insertPos++ {
chunk := NewOOOChunk()
chunk.samples = makeEvenSampleSlice(numPreExisting)
newSample := samplify(valOdd(insertPos))
chunk.Insert(newSample.t, newSample.f, nil, nil)
var expSamples []sample
// Our expected new samples slice, will be first the original samples.
for i := 0; i < insertPos; i++ {
expSamples = append(expSamples, samplify(valEven(i)))
}
// Then the new sample.
expSamples = append(expSamples, newSample)
// Followed by any original samples that were pushed back by the new one.
for i := insertPos; i < numPreExisting; i++ {
expSamples = append(expSamples, samplify(valEven(i)))
}
require.Equal(t, expSamples, chunk.samples, "numPreExisting %d, insertPos %d", numPreExisting, insertPos)
}
}
}
// TestOOOInsertDuplicate tests the correct behavior when inserting a sample that is a duplicate of any
// pre-existing samples, with between 1 and testMaxSize pre-existing samples and
// with a chunk initial capacity of testMaxSize/8 and testMaxSize, which lets us test non-full and full chunks, and chunks that need to expand themselves.
func TestOOOInsertDuplicate(t *testing.T) {
for num := 1; num <= testMaxSize; num++ {
for dupPos := 0; dupPos < num; dupPos++ {
chunk := NewOOOChunk()
chunk.samples = makeEvenSampleSlice(num)
dupSample := chunk.samples[dupPos]
dupSample.f = 0.123
ok := chunk.Insert(dupSample.t, dupSample.f, nil, nil)
expSamples := makeEvenSampleSlice(num) // We expect no change.
require.False(t, ok)
require.Equal(t, expSamples, chunk.samples, "num %d, dupPos %d", num, dupPos)
}
}
}
type chunkVerify struct {
encoding chunkenc.Encoding
minTime int64
maxTime int64
}
func TestOOOChunks_ToEncodedChunks(t *testing.T) {
h1 := tsdbutil.GenerateTestHistogram(1)
// Make h2 appendable but with more buckets, to trigger recoding.
h2 := h1.Copy()
h2.PositiveSpans = append(h2.PositiveSpans, histogram.Span{Offset: 1, Length: 1})
h2.PositiveBuckets = append(h2.PositiveBuckets, 12)
testCases := map[string]struct {
samples []sample
expectedCounterResets []histogram.CounterResetHint
expectedChunks []chunkVerify
}{
"empty": {
samples: []sample{},
},
"has floats": {
samples: []sample{
{t: 1000, f: 43.0},
{t: 1100, f: 42.0},
},
expectedCounterResets: []histogram.CounterResetHint{histogram.UnknownCounterReset, histogram.UnknownCounterReset},
expectedChunks: []chunkVerify{
{encoding: chunkenc.EncXOR, minTime: 1000, maxTime: 1100},
},
},
"mix of floats and histograms": {
samples: []sample{
{t: 1000, f: 43.0},
{t: 1100, h: h1},
{t: 1200, f: 42.0},
},
expectedCounterResets: []histogram.CounterResetHint{histogram.UnknownCounterReset, histogram.UnknownCounterReset, histogram.UnknownCounterReset},
expectedChunks: []chunkVerify{
{encoding: chunkenc.EncXOR, minTime: 1000, maxTime: 1000},
{encoding: chunkenc.EncHistogram, minTime: 1100, maxTime: 1100},
{encoding: chunkenc.EncXOR, minTime: 1200, maxTime: 1200},
},
},
"has a counter reset": {
samples: []sample{
{t: 1000, h: h2},
{t: 1100, h: h1},
},
expectedCounterResets: []histogram.CounterResetHint{histogram.UnknownCounterReset, histogram.CounterReset},
expectedChunks: []chunkVerify{
{encoding: chunkenc.EncHistogram, minTime: 1000, maxTime: 1000},
{encoding: chunkenc.EncHistogram, minTime: 1100, maxTime: 1100},
},
},
"has a recoded histogram": { // Regression test for wrong minT, maxT in histogram recoding.
samples: []sample{
{t: 0, h: h1},
{t: 1, h: h2},
},
expectedCounterResets: []histogram.CounterResetHint{histogram.UnknownCounterReset, histogram.NotCounterReset},
expectedChunks: []chunkVerify{
{encoding: chunkenc.EncHistogram, minTime: 0, maxTime: 1},
},
},
}
for name, tc := range testCases {
t.Run(name, func(t *testing.T) {
// Sanity check.
require.Equal(t, len(tc.samples), len(tc.expectedCounterResets), "number of samples and counter resets")
oooChunk := OOOChunk{}
for _, s := range tc.samples {
switch s.Type() {
case chunkenc.ValFloat:
oooChunk.Insert(s.t, s.f, nil, nil)
case chunkenc.ValHistogram:
oooChunk.Insert(s.t, 0, s.h.Copy(), nil)
case chunkenc.ValFloatHistogram:
oooChunk.Insert(s.t, 0, nil, s.fh.Copy())
default:
t.Fatalf("unexpected sample type %d", s.Type())
}
}
chunks, err := oooChunk.ToEncodedChunks(math.MinInt64, math.MaxInt64)
require.NoError(t, err)
require.Equal(t, len(tc.expectedChunks), len(chunks), "number of chunks")
sampleIndex := 0
for i, c := range chunks {
require.Equal(t, tc.expectedChunks[i].encoding, c.chunk.Encoding(), "chunk %d encoding", i)
require.Equal(t, tc.expectedChunks[i].minTime, c.minTime, "chunk %d minTime", i)
require.Equal(t, tc.expectedChunks[i].maxTime, c.maxTime, "chunk %d maxTime", i)
samples, err := storage.ExpandSamples(c.chunk.Iterator(nil), newSample)
require.GreaterOrEqual(t, len(tc.samples)-sampleIndex, len(samples), "too many samples in chunk %d expected less than %d", i, len(tc.samples)-sampleIndex)
require.NoError(t, err)
if len(samples) == 0 {
// Ignore empty chunks.
continue
}
switch c.chunk.Encoding() {
case chunkenc.EncXOR:
for j, s := range samples {
require.Equal(t, chunkenc.ValFloat, s.Type())
// XOR chunks don't have counter reset hints, so we shouldn't expect anything else than UnknownCounterReset.
require.Equal(t, histogram.UnknownCounterReset, tc.expectedCounterResets[sampleIndex+j], "sample reset hint %d", sampleIndex+j)
require.Equal(t, tc.samples[sampleIndex+j].f, s.F(), "sample %d", sampleIndex+j)
}
case chunkenc.EncHistogram:
for j, s := range samples {
require.Equal(t, chunkenc.ValHistogram, s.Type())
require.Equal(t, tc.expectedCounterResets[sampleIndex+j], s.H().CounterResetHint, "sample reset hint %d", sampleIndex+j)
compareTo := tc.samples[sampleIndex+j].h.Copy()
compareTo.CounterResetHint = tc.expectedCounterResets[sampleIndex+j]
require.Equal(t, compareTo, s.H().Compact(0), "sample %d", sampleIndex+j)
}
case chunkenc.EncFloatHistogram:
for j, s := range samples {
require.Equal(t, chunkenc.ValFloatHistogram, s.Type())
require.Equal(t, tc.expectedCounterResets[sampleIndex+j], s.FH().CounterResetHint, "sample reset hint %d", sampleIndex+j)
compareTo := tc.samples[sampleIndex+j].fh.Copy()
compareTo.CounterResetHint = tc.expectedCounterResets[sampleIndex+j]
require.Equal(t, compareTo, s.FH().Compact(0), "sample %d", sampleIndex+j)
}
}
sampleIndex += len(samples)
}
require.Equal(t, len(tc.samples), sampleIndex, "number of samples")
})
}
}