prometheus/storage/buffer_test.go
Filip Petkovski e2a9f8ac0f
Reuse float histogram objects
This commit reduces the memory needed to query native histogram objects
by reusing existing HPoint instances.

Signed-off-by: Filip Petkovski <filip.petkovsky@gmail.com>
2023-12-11 08:24:58 +01:00

335 lines
8.6 KiB
Go

// Copyright 2017 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 storage
import (
"math/rand"
"testing"
"github.com/stretchr/testify/require"
"github.com/prometheus/prometheus/model/histogram"
"github.com/prometheus/prometheus/tsdb/chunkenc"
"github.com/prometheus/prometheus/tsdb/tsdbutil"
)
func TestSampleRing(t *testing.T) {
cases := []struct {
input []int64
delta int64
size int
}{
{
input: []int64{1, 2, 3, 4, 5, 6, 7, 8, 9, 10},
delta: 2,
size: 1,
},
{
input: []int64{1, 2, 3, 4, 5, 6, 7, 8, 9, 10},
delta: 2,
size: 2,
},
{
input: []int64{1, 2, 3, 4, 5, 6, 7, 8, 9, 10},
delta: 7,
size: 3,
},
{
input: []int64{1, 2, 3, 4, 5, 16, 17, 18, 19, 20},
delta: 7,
size: 1,
},
{
input: []int64{1, 2, 3, 4, 6},
delta: 4,
size: 4,
},
}
for _, c := range cases {
r := newSampleRing(c.delta, c.size, chunkenc.ValFloat)
input := []fSample{}
for _, t := range c.input {
input = append(input, fSample{
t: t,
f: float64(rand.Intn(100)),
})
}
for i, s := range input {
r.add(s)
buffered := r.samples()
for _, sold := range input[:i] {
found := false
for _, bs := range buffered {
if bs.T() == sold.t && bs.F() == sold.f {
found = true
break
}
}
if found {
require.GreaterOrEqual(t, sold.t, s.t-c.delta, "%d: unexpected sample %d in buffer; buffer %v", i, sold.t, buffered)
} else {
require.Less(t, sold.t, s.t-c.delta, "%d: expected sample %d to be in buffer but was not; buffer %v", i, sold.t, buffered)
}
}
}
}
}
func TestSampleRingMixed(t *testing.T) {
h1 := tsdbutil.GenerateTestHistogram(1)
h2 := tsdbutil.GenerateTestHistogram(2)
// With ValNone as the preferred type, nothing should be initialized.
r := newSampleRing(10, 2, chunkenc.ValNone)
require.Zero(t, len(r.fBuf))
require.Zero(t, len(r.hBuf))
require.Zero(t, len(r.fhBuf))
require.Zero(t, len(r.iBuf))
// But then mixed adds should work as expected.
r.addF(fSample{t: 1, f: 3.14})
r.addH(hSample{t: 2, h: h1})
it := r.iterator()
require.Equal(t, chunkenc.ValFloat, it.Next())
ts, f := it.At()
require.Equal(t, int64(1), ts)
require.Equal(t, 3.14, f)
require.Equal(t, chunkenc.ValHistogram, it.Next())
var h *histogram.Histogram
ts, h = it.AtHistogram()
require.Equal(t, int64(2), ts)
require.Equal(t, h1, h)
require.Equal(t, chunkenc.ValNone, it.Next())
r.reset()
it = r.iterator()
require.Equal(t, chunkenc.ValNone, it.Next())
r.addF(fSample{t: 3, f: 4.2})
r.addH(hSample{t: 4, h: h2})
it = r.iterator()
require.Equal(t, chunkenc.ValFloat, it.Next())
ts, f = it.At()
require.Equal(t, int64(3), ts)
require.Equal(t, 4.2, f)
require.Equal(t, chunkenc.ValHistogram, it.Next())
ts, h = it.AtHistogram()
require.Equal(t, int64(4), ts)
require.Equal(t, h2, h)
require.Equal(t, chunkenc.ValNone, it.Next())
}
func TestBufferedSeriesIterator(t *testing.T) {
var it *BufferedSeriesIterator
bufferEq := func(exp []fSample) {
var b []fSample
bit := it.Buffer()
for bit.Next() == chunkenc.ValFloat {
t, f := bit.At()
b = append(b, fSample{t: t, f: f})
}
require.Equal(t, exp, b, "buffer mismatch")
}
sampleEq := func(ets int64, ev float64) {
ts, v := it.At()
require.Equal(t, ets, ts, "timestamp mismatch")
require.Equal(t, ev, v, "value mismatch")
}
prevSampleEq := func(ets int64, ev float64, eok bool) {
s, ok := it.PeekBack(1)
require.Equal(t, eok, ok, "exist mismatch")
require.Equal(t, ets, s.T(), "timestamp mismatch")
require.Equal(t, ev, s.F(), "value mismatch")
}
it = NewBufferIterator(NewListSeriesIterator(samples{
fSample{t: 1, f: 2},
fSample{t: 2, f: 3},
fSample{t: 3, f: 4},
fSample{t: 4, f: 5},
fSample{t: 5, f: 6},
fSample{t: 99, f: 8},
fSample{t: 100, f: 9},
fSample{t: 101, f: 10},
}), 2)
require.Equal(t, chunkenc.ValFloat, it.Seek(-123), "seek failed")
sampleEq(1, 2)
prevSampleEq(0, 0, false)
bufferEq(nil)
require.Equal(t, chunkenc.ValFloat, it.Next(), "next failed")
sampleEq(2, 3)
prevSampleEq(1, 2, true)
bufferEq([]fSample{{t: 1, f: 2}})
require.Equal(t, chunkenc.ValFloat, it.Next(), "next failed")
require.Equal(t, chunkenc.ValFloat, it.Next(), "next failed")
require.Equal(t, chunkenc.ValFloat, it.Next(), "next failed")
sampleEq(5, 6)
prevSampleEq(4, 5, true)
bufferEq([]fSample{{t: 2, f: 3}, {t: 3, f: 4}, {t: 4, f: 5}})
require.Equal(t, chunkenc.ValFloat, it.Seek(5), "seek failed")
sampleEq(5, 6)
prevSampleEq(4, 5, true)
bufferEq([]fSample{{t: 2, f: 3}, {t: 3, f: 4}, {t: 4, f: 5}})
require.Equal(t, chunkenc.ValFloat, it.Seek(101), "seek failed")
sampleEq(101, 10)
prevSampleEq(100, 9, true)
bufferEq([]fSample{{t: 99, f: 8}, {t: 100, f: 9}})
require.Equal(t, chunkenc.ValNone, it.Next(), "next succeeded unexpectedly")
require.Equal(t, chunkenc.ValNone, it.Seek(1024), "seek succeeded unexpectedly")
}
// At() should not be called once Next() returns false.
func TestBufferedSeriesIteratorNoBadAt(t *testing.T) {
done := false
m := &mockSeriesIterator{
seek: func(int64) chunkenc.ValueType { return chunkenc.ValNone },
at: func() (int64, float64) {
require.False(t, done, "unexpectedly done")
done = true
return 0, 0
},
next: func() chunkenc.ValueType {
if done {
return chunkenc.ValNone
}
return chunkenc.ValFloat
},
err: func() error { return nil },
}
it := NewBufferIterator(m, 60)
it.Next()
it.Next()
}
func TestBufferedSeriesIteratorMixedHistograms(t *testing.T) {
histograms := tsdbutil.GenerateTestHistograms(2)
it := NewBufferIterator(NewListSeriesIterator(samples{
fhSample{t: 1, fh: histograms[0].ToFloat(nil)},
hSample{t: 2, h: histograms[1]},
}), 2)
require.Equal(t, chunkenc.ValNone, it.Seek(3))
require.NoError(t, it.Err())
buf := it.Buffer()
require.Equal(t, chunkenc.ValFloatHistogram, buf.Next())
_, fh := buf.AtFloatHistogram(nil)
require.Equal(t, histograms[0].ToFloat(nil), fh)
require.Equal(t, chunkenc.ValHistogram, buf.Next())
_, fh = buf.AtFloatHistogram(nil)
require.Equal(t, histograms[1].ToFloat(nil), fh)
}
func BenchmarkBufferedSeriesIterator(b *testing.B) {
// Simulate a 5 minute rate.
it := NewBufferIterator(newFakeSeriesIterator(int64(b.N), 30), 5*60)
b.SetBytes(16)
b.ReportAllocs()
b.ResetTimer()
for it.Next() != chunkenc.ValNone {
// Scan everything.
}
require.NoError(b, it.Err())
}
type mockSeriesIterator struct {
seek func(int64) chunkenc.ValueType
at func() (int64, float64)
next func() chunkenc.ValueType
err func() error
}
func (m *mockSeriesIterator) Seek(t int64) chunkenc.ValueType { return m.seek(t) }
func (m *mockSeriesIterator) At() (int64, float64) { return m.at() }
func (m *mockSeriesIterator) Next() chunkenc.ValueType { return m.next() }
func (m *mockSeriesIterator) Err() error { return m.err() }
func (m *mockSeriesIterator) AtHistogram() (int64, *histogram.Histogram) {
return 0, nil // Not really mocked.
}
func (m *mockSeriesIterator) AtFloatHistogram() (int64, *histogram.FloatHistogram) {
return 0, nil // Not really mocked.
}
func (m *mockSeriesIterator) AtT() int64 {
return 0 // Not really mocked.
}
type fakeSeriesIterator struct {
nsamples int64
step int64
idx int64
}
func newFakeSeriesIterator(nsamples, step int64) *fakeSeriesIterator {
return &fakeSeriesIterator{nsamples: nsamples, step: step, idx: -1}
}
func (it *fakeSeriesIterator) At() (int64, float64) {
return it.idx * it.step, 123 // Value doesn't matter.
}
func (it *fakeSeriesIterator) AtHistogram() (int64, *histogram.Histogram) {
return it.idx * it.step, &histogram.Histogram{} // Value doesn't matter.
}
func (it *fakeSeriesIterator) AtFloatHistogram() (int64, *histogram.FloatHistogram) {
return it.idx * it.step, &histogram.FloatHistogram{} // Value doesn't matter.
}
func (it *fakeSeriesIterator) AtT() int64 {
return it.idx * it.step
}
func (it *fakeSeriesIterator) Next() chunkenc.ValueType {
it.idx++
if it.idx >= it.nsamples {
return chunkenc.ValNone
}
return chunkenc.ValFloat
}
func (it *fakeSeriesIterator) Seek(t int64) chunkenc.ValueType {
it.idx = t / it.step
if it.idx >= it.nsamples {
return chunkenc.ValNone
}
return chunkenc.ValFloat
}
func (it *fakeSeriesIterator) Err() error { return nil }