prometheus/tsdb/wlog/checkpoint_test.go
Justin Lei 32d87282ad
Add Zstandard compression option for wlog (#11666)
Snappy remains as the default compression but there is now a flag to switch 
the compression algorithm.

Signed-off-by: Justin Lei <justin.lei@grafana.com>
2023-07-11 14:57:57 +02:00

337 lines
11 KiB
Go

// Copyright 2018 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 wlog
import (
"fmt"
"os"
"path/filepath"
"sort"
"strings"
"testing"
"github.com/go-kit/log"
"github.com/pkg/errors"
"github.com/stretchr/testify/require"
"github.com/prometheus/prometheus/model/histogram"
"github.com/prometheus/prometheus/model/labels"
"github.com/prometheus/prometheus/tsdb/chunks"
"github.com/prometheus/prometheus/tsdb/record"
)
func TestLastCheckpoint(t *testing.T) {
dir := t.TempDir()
_, _, err := LastCheckpoint(dir)
require.Equal(t, record.ErrNotFound, err)
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.0000"), 0o777))
s, k, err := LastCheckpoint(dir)
require.NoError(t, err)
require.Equal(t, filepath.Join(dir, "checkpoint.0000"), s)
require.Equal(t, 0, k)
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.xyz"), 0o777))
s, k, err = LastCheckpoint(dir)
require.NoError(t, err)
require.Equal(t, filepath.Join(dir, "checkpoint.0000"), s)
require.Equal(t, 0, k)
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.1"), 0o777))
s, k, err = LastCheckpoint(dir)
require.NoError(t, err)
require.Equal(t, filepath.Join(dir, "checkpoint.1"), s)
require.Equal(t, 1, k)
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.1000"), 0o777))
s, k, err = LastCheckpoint(dir)
require.NoError(t, err)
require.Equal(t, filepath.Join(dir, "checkpoint.1000"), s)
require.Equal(t, 1000, k)
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.99999999"), 0o777))
s, k, err = LastCheckpoint(dir)
require.NoError(t, err)
require.Equal(t, filepath.Join(dir, "checkpoint.99999999"), s)
require.Equal(t, 99999999, k)
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.100000000"), 0o777))
s, k, err = LastCheckpoint(dir)
require.NoError(t, err)
require.Equal(t, filepath.Join(dir, "checkpoint.100000000"), s)
require.Equal(t, 100000000, k)
}
func TestDeleteCheckpoints(t *testing.T) {
dir := t.TempDir()
require.NoError(t, DeleteCheckpoints(dir, 0))
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.00"), 0o777))
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.01"), 0o777))
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.02"), 0o777))
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.03"), 0o777))
require.NoError(t, DeleteCheckpoints(dir, 2))
files, err := os.ReadDir(dir)
require.NoError(t, err)
fns := []string{}
for _, f := range files {
fns = append(fns, f.Name())
}
require.Equal(t, []string{"checkpoint.02", "checkpoint.03"}, fns)
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.99999999"), 0o777))
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.100000000"), 0o777))
require.NoError(t, os.MkdirAll(filepath.Join(dir, "checkpoint.100000001"), 0o777))
require.NoError(t, DeleteCheckpoints(dir, 100000000))
files, err = os.ReadDir(dir)
require.NoError(t, err)
fns = []string{}
for _, f := range files {
fns = append(fns, f.Name())
}
require.Equal(t, []string{"checkpoint.100000000", "checkpoint.100000001"}, fns)
}
func TestCheckpoint(t *testing.T) {
makeHistogram := func(i int) *histogram.Histogram {
return &histogram.Histogram{
Count: 5 + uint64(i*4),
ZeroCount: 2 + uint64(i),
ZeroThreshold: 0.001,
Sum: 18.4 * float64(i+1),
Schema: 1,
PositiveSpans: []histogram.Span{
{Offset: 0, Length: 2},
{Offset: 1, Length: 2},
},
PositiveBuckets: []int64{int64(i + 1), 1, -1, 0},
}
}
for _, compress := range []CompressionType{CompressionNone, CompressionSnappy, CompressionZstd} {
t.Run(fmt.Sprintf("compress=%s", compress), func(t *testing.T) {
dir := t.TempDir()
var enc record.Encoder
// Create a dummy segment to bump the initial number.
seg, err := CreateSegment(dir, 100)
require.NoError(t, err)
require.NoError(t, seg.Close())
// Manually create checkpoint for 99 and earlier.
w, err := New(nil, nil, filepath.Join(dir, "checkpoint.0099"), compress)
require.NoError(t, err)
// Add some data we expect to be around later.
err = w.Log(enc.Series([]record.RefSeries{
{Ref: 0, Labels: labels.FromStrings("a", "b", "c", "0")},
{Ref: 1, Labels: labels.FromStrings("a", "b", "c", "1")},
}, nil))
require.NoError(t, err)
// Log an unknown record, that might have come from a future Prometheus version.
require.NoError(t, w.Log([]byte{255}))
require.NoError(t, w.Close())
// Start a WAL and write records to it as usual.
w, err = NewSize(nil, nil, dir, 64*1024, compress)
require.NoError(t, err)
samplesInWAL, histogramsInWAL := 0, 0
var last int64
for i := 0; ; i++ {
_, n, err := Segments(w.Dir())
require.NoError(t, err)
if n >= 106 {
break
}
// Write some series initially.
if i == 0 {
b := enc.Series([]record.RefSeries{
{Ref: 2, Labels: labels.FromStrings("a", "b", "c", "2")},
{Ref: 3, Labels: labels.FromStrings("a", "b", "c", "3")},
{Ref: 4, Labels: labels.FromStrings("a", "b", "c", "4")},
{Ref: 5, Labels: labels.FromStrings("a", "b", "c", "5")},
}, nil)
require.NoError(t, w.Log(b))
b = enc.Metadata([]record.RefMetadata{
{Ref: 2, Unit: "unit", Help: "help"},
{Ref: 3, Unit: "unit", Help: "help"},
{Ref: 4, Unit: "unit", Help: "help"},
{Ref: 5, Unit: "unit", Help: "help"},
}, nil)
require.NoError(t, w.Log(b))
}
// Write samples until the WAL has enough segments.
// Make them have drifting timestamps within a record to see that they
// get filtered properly.
b := enc.Samples([]record.RefSample{
{Ref: 0, T: last, V: float64(i)},
{Ref: 1, T: last + 10000, V: float64(i)},
{Ref: 2, T: last + 20000, V: float64(i)},
{Ref: 3, T: last + 30000, V: float64(i)},
}, nil)
require.NoError(t, w.Log(b))
samplesInWAL += 4
h := makeHistogram(i)
b = enc.HistogramSamples([]record.RefHistogramSample{
{Ref: 0, T: last, H: h},
{Ref: 1, T: last + 10000, H: h},
{Ref: 2, T: last + 20000, H: h},
{Ref: 3, T: last + 30000, H: h},
}, nil)
require.NoError(t, w.Log(b))
histogramsInWAL += 4
b = enc.Exemplars([]record.RefExemplar{
{Ref: 1, T: last, V: float64(i), Labels: labels.FromStrings("traceID", fmt.Sprintf("trace-%d", i))},
}, nil)
require.NoError(t, w.Log(b))
// Write changing metadata for each series. In the end, only the latest
// version should end up in the checkpoint.
b = enc.Metadata([]record.RefMetadata{
{Ref: 0, Unit: fmt.Sprintf("%d", last), Help: fmt.Sprintf("%d", last)},
{Ref: 1, Unit: fmt.Sprintf("%d", last), Help: fmt.Sprintf("%d", last)},
{Ref: 2, Unit: fmt.Sprintf("%d", last), Help: fmt.Sprintf("%d", last)},
{Ref: 3, Unit: fmt.Sprintf("%d", last), Help: fmt.Sprintf("%d", last)},
}, nil)
require.NoError(t, w.Log(b))
last += 100
}
require.NoError(t, w.Close())
_, err = Checkpoint(log.NewNopLogger(), w, 100, 106, func(x chunks.HeadSeriesRef) bool {
return x%2 == 0
}, last/2)
require.NoError(t, err)
require.NoError(t, w.Truncate(107))
require.NoError(t, DeleteCheckpoints(w.Dir(), 106))
// Only the new checkpoint should be left.
files, err := os.ReadDir(dir)
require.NoError(t, err)
require.Equal(t, 1, len(files))
require.Equal(t, "checkpoint.00000106", files[0].Name())
sr, err := NewSegmentsReader(filepath.Join(dir, "checkpoint.00000106"))
require.NoError(t, err)
defer sr.Close()
var dec record.Decoder
var series []record.RefSeries
var metadata []record.RefMetadata
r := NewReader(sr)
samplesInCheckpoint, histogramsInCheckpoint := 0, 0
for r.Next() {
rec := r.Record()
switch dec.Type(rec) {
case record.Series:
series, err = dec.Series(rec, series)
require.NoError(t, err)
case record.Samples:
samples, err := dec.Samples(rec, nil)
require.NoError(t, err)
for _, s := range samples {
require.GreaterOrEqual(t, s.T, last/2, "sample with wrong timestamp")
}
samplesInCheckpoint += len(samples)
case record.HistogramSamples:
histograms, err := dec.HistogramSamples(rec, nil)
require.NoError(t, err)
for _, h := range histograms {
require.GreaterOrEqual(t, h.T, last/2, "histogram with wrong timestamp")
}
histogramsInCheckpoint += len(histograms)
case record.Exemplars:
exemplars, err := dec.Exemplars(rec, nil)
require.NoError(t, err)
for _, e := range exemplars {
require.GreaterOrEqual(t, e.T, last/2, "exemplar with wrong timestamp")
}
case record.Metadata:
metadata, err = dec.Metadata(rec, metadata)
require.NoError(t, err)
}
}
require.NoError(t, r.Err())
// Making sure we replayed some samples. We expect >50% samples to be still present.
require.Greater(t, float64(samplesInCheckpoint)/float64(samplesInWAL), 0.5)
require.Less(t, float64(samplesInCheckpoint)/float64(samplesInWAL), 0.8)
require.Greater(t, float64(histogramsInCheckpoint)/float64(histogramsInWAL), 0.5)
require.Less(t, float64(histogramsInCheckpoint)/float64(histogramsInWAL), 0.8)
expectedRefSeries := []record.RefSeries{
{Ref: 0, Labels: labels.FromStrings("a", "b", "c", "0")},
{Ref: 2, Labels: labels.FromStrings("a", "b", "c", "2")},
{Ref: 4, Labels: labels.FromStrings("a", "b", "c", "4")},
}
require.Equal(t, expectedRefSeries, series)
expectedRefMetadata := []record.RefMetadata{
{Ref: 0, Unit: fmt.Sprintf("%d", last-100), Help: fmt.Sprintf("%d", last-100)},
{Ref: 2, Unit: fmt.Sprintf("%d", last-100), Help: fmt.Sprintf("%d", last-100)},
{Ref: 4, Unit: "unit", Help: "help"},
}
sort.Slice(metadata, func(i, j int) bool { return metadata[i].Ref < metadata[j].Ref })
require.Equal(t, expectedRefMetadata, metadata)
})
}
}
func TestCheckpointNoTmpFolderAfterError(t *testing.T) {
// Create a new wlog with invalid data.
dir := t.TempDir()
w, err := NewSize(nil, nil, dir, 64*1024, CompressionNone)
require.NoError(t, err)
var enc record.Encoder
require.NoError(t, w.Log(enc.Series([]record.RefSeries{
{Ref: 0, Labels: labels.FromStrings("a", "b", "c", "2")},
}, nil)))
require.NoError(t, w.Close())
// Corrupt data.
f, err := os.OpenFile(filepath.Join(w.Dir(), "00000000"), os.O_WRONLY, 0o666)
require.NoError(t, err)
_, err = f.WriteAt([]byte{42}, 1)
require.NoError(t, err)
require.NoError(t, f.Close())
// Run the checkpoint and since the wlog contains corrupt data this should return an error.
_, err = Checkpoint(log.NewNopLogger(), w, 0, 1, nil, 0)
require.Error(t, err)
// Walk the wlog dir to make sure there are no tmp folder left behind after the error.
err = filepath.Walk(w.Dir(), func(path string, info os.FileInfo, err error) error {
if err != nil {
return errors.Wrapf(err, "access err %q: %v", path, err)
}
if info.IsDir() && strings.HasSuffix(info.Name(), ".tmp") {
return fmt.Errorf("wlog dir contains temporary folder:%s", info.Name())
}
return nil
})
require.NoError(t, err)
}