prometheus/tsdb/chunks/head_chunks_test.go
Ganesh Vernekar 48fae12b89
Fix unsequential m-map files (#7414)
* Fix unsequential m-map files

Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>

* Fix review comments

Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in>
2020-06-18 19:24:58 +05:30

374 lines
12 KiB
Go

// Copyright 2020 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 chunks
import (
"encoding/binary"
"io/ioutil"
"math/rand"
"os"
"testing"
"github.com/prometheus/prometheus/tsdb/chunkenc"
"github.com/prometheus/prometheus/util/testutil"
)
func TestHeadReadWriter_WriteChunk_Chunk_IterateChunks(t *testing.T) {
hrw, close := testHeadReadWriter(t)
defer func() {
testutil.Ok(t, hrw.Close())
close()
}()
expectedBytes := []byte{}
nextChunkOffset := uint64(HeadChunkFileHeaderSize)
chkCRC32 := newCRC32()
type expectedDataType struct {
seriesRef, chunkRef uint64
mint, maxt int64
numSamples uint16
chunk chunkenc.Chunk
}
expectedData := []expectedDataType{}
var buf [MaxHeadChunkMetaSize]byte
totalChunks := 0
var firstFileName string
for hrw.curFileSequence < 3 || hrw.chkWriter.Buffered() == 0 {
addChunks := func(numChunks int) {
for i := 0; i < numChunks; i++ {
seriesRef, chkRef, mint, maxt, chunk := createChunk(t, totalChunks, hrw)
totalChunks++
expectedData = append(expectedData, expectedDataType{
seriesRef: seriesRef,
mint: mint,
maxt: maxt,
chunkRef: chkRef,
chunk: chunk,
numSamples: uint16(chunk.NumSamples()),
})
if hrw.curFileSequence != 1 {
// We are checking for bytes written only for the first file.
continue
}
// Calculating expected bytes written on disk for first file.
firstFileName = hrw.curFile.Name()
testutil.Equals(t, chunkRef(1, nextChunkOffset), chkRef)
bytesWritten := 0
chkCRC32.Reset()
binary.BigEndian.PutUint64(buf[bytesWritten:], seriesRef)
bytesWritten += SeriesRefSize
binary.BigEndian.PutUint64(buf[bytesWritten:], uint64(mint))
bytesWritten += MintMaxtSize
binary.BigEndian.PutUint64(buf[bytesWritten:], uint64(maxt))
bytesWritten += MintMaxtSize
buf[bytesWritten] = byte(chunk.Encoding())
bytesWritten += ChunkEncodingSize
n := binary.PutUvarint(buf[bytesWritten:], uint64(len(chunk.Bytes())))
bytesWritten += n
expectedBytes = append(expectedBytes, buf[:bytesWritten]...)
_, err := chkCRC32.Write(buf[:bytesWritten])
testutil.Ok(t, err)
expectedBytes = append(expectedBytes, chunk.Bytes()...)
_, err = chkCRC32.Write(chunk.Bytes())
testutil.Ok(t, err)
expectedBytes = append(expectedBytes, chkCRC32.Sum(nil)...)
// += seriesRef, mint, maxt, encoding, chunk data len, chunk data, CRC.
nextChunkOffset += SeriesRefSize + 2*MintMaxtSize + ChunkEncodingSize + uint64(n) + uint64(len(chunk.Bytes())) + CRCSize
}
}
addChunks(100)
hrw.CutNewFile()
addChunks(10) // For chunks in in-memory buffer.
}
// Checking on-disk bytes for the first file.
testutil.Assert(t, len(hrw.mmappedChunkFiles) == 3 && len(hrw.closers) == 3, "expected 3 mmapped files, got %d", len(hrw.mmappedChunkFiles))
actualBytes, err := ioutil.ReadFile(firstFileName)
testutil.Ok(t, err)
// Check header of the segment file.
testutil.Equals(t, MagicHeadChunks, int(binary.BigEndian.Uint32(actualBytes[0:MagicChunksSize])))
testutil.Equals(t, chunksFormatV1, int(actualBytes[MagicChunksSize]))
// Remaining chunk data.
fileEnd := HeadChunkFileHeaderSize + len(expectedBytes)
testutil.Equals(t, expectedBytes, actualBytes[HeadChunkFileHeaderSize:fileEnd])
// Test for the next chunk header to be all 0s. That marks the end of the file.
for _, b := range actualBytes[fileEnd : fileEnd+MaxHeadChunkMetaSize] {
testutil.Equals(t, byte(0), b)
}
// Testing reading of chunks.
for _, exp := range expectedData {
actChunk, err := hrw.Chunk(exp.chunkRef)
testutil.Ok(t, err)
testutil.Equals(t, exp.chunk.Bytes(), actChunk.Bytes())
}
// Testing IterateAllChunks method.
dir := hrw.dir.Name()
testutil.Ok(t, hrw.Close())
hrw, err = NewChunkDiskMapper(dir, chunkenc.NewPool())
testutil.Ok(t, err)
idx := 0
err = hrw.IterateAllChunks(func(seriesRef, chunkRef uint64, mint, maxt int64, numSamples uint16) error {
t.Helper()
expData := expectedData[idx]
testutil.Equals(t, expData.seriesRef, seriesRef)
testutil.Equals(t, expData.chunkRef, chunkRef)
testutil.Equals(t, expData.maxt, maxt)
testutil.Equals(t, expData.maxt, maxt)
testutil.Equals(t, expData.numSamples, numSamples)
actChunk, err := hrw.Chunk(expData.chunkRef)
testutil.Ok(t, err)
testutil.Equals(t, expData.chunk.Bytes(), actChunk.Bytes())
idx++
return nil
})
testutil.Ok(t, err)
testutil.Equals(t, len(expectedData), idx)
}
// TestHeadReadWriter_Truncate tests
// * If truncation is happening properly based on the time passed.
// * The active file is not deleted even if the passed time makes it eligible to be deleted.
// * Empty current file does not lead to creation of another file after truncation.
// * Non-empty current file leads to creation of another file after truncation.
func TestHeadReadWriter_Truncate(t *testing.T) {
hrw, close := testHeadReadWriter(t)
defer func() {
testutil.Ok(t, hrw.Close())
close()
}()
timeRange := 0
fileTimeStep := 100
totalFiles := 7
startIndexAfter1stTruncation, startIndexAfter2ndTruncation := 3, 6
filesDeletedAfter1stTruncation, filesDeletedAfter2ndTruncation := 2, 5
var timeToTruncate, timeToTruncateAfterRestart int64
addChunk := func() int {
mint := timeRange + 1 // Just after the the new file cut.
maxt := timeRange + fileTimeStep - 1 // Just before the next file.
// Write a chunks to set maxt for the segment.
_, err := hrw.WriteChunk(1, int64(mint), int64(maxt), randomChunk(t))
testutil.Ok(t, err)
timeRange += fileTimeStep
return mint
}
cutFile := func(i int) {
testutil.Ok(t, hrw.CutNewFile())
mint := addChunk()
if i == startIndexAfter1stTruncation {
timeToTruncate = int64(mint)
} else if i == startIndexAfter2ndTruncation {
timeToTruncateAfterRestart = int64(mint)
}
}
// Cut segments.
for i := 1; i <= totalFiles; i++ {
cutFile(i)
}
// Verifying the files.
verifyFiles := func(remainingFiles, startIndex int) {
t.Helper()
files, err := ioutil.ReadDir(hrw.dir.Name())
testutil.Ok(t, err)
testutil.Equals(t, remainingFiles, len(files), "files on disk")
testutil.Equals(t, remainingFiles, len(hrw.mmappedChunkFiles), "hrw.mmappedChunkFiles")
testutil.Equals(t, remainingFiles, len(hrw.closers), "closers")
for i := 1; i <= totalFiles; i++ {
_, ok := hrw.mmappedChunkFiles[i]
if i < startIndex {
testutil.Equals(t, false, ok)
} else {
testutil.Equals(t, true, ok)
}
}
}
// Verify the number of segments.
verifyFiles(totalFiles, 1)
// Truncating files.
testutil.Ok(t, hrw.Truncate(timeToTruncate))
totalFiles++ // Truncation creates a new file as the last file is not empty.
verifyFiles(totalFiles-filesDeletedAfter1stTruncation, startIndexAfter1stTruncation)
addChunk() // Add a chunk so that new file is not truncated.
dir := hrw.dir.Name()
testutil.Ok(t, hrw.Close())
// Restarted.
var err error
hrw, err = NewChunkDiskMapper(dir, chunkenc.NewPool())
testutil.Ok(t, err)
testutil.Assert(t, !hrw.fileMaxtSet, "")
testutil.Ok(t, hrw.IterateAllChunks(func(_, _ uint64, _, _ int64, _ uint16) error { return nil }))
testutil.Assert(t, hrw.fileMaxtSet, "")
// Truncating files after restart. As the last file was empty, this creates no new files.
testutil.Ok(t, hrw.Truncate(timeToTruncateAfterRestart))
verifyFiles(totalFiles-filesDeletedAfter2ndTruncation, startIndexAfter2ndTruncation)
// First chunk after restart creates a new file.
addChunk()
totalFiles++
// Truncating till current time should not delete the current active file.
testutil.Ok(t, hrw.Truncate(int64(timeRange+fileTimeStep)))
verifyFiles(2, totalFiles) // One file is the active file and one was newly created.
}
// TestHeadReadWriter_Truncate_NoUnsequentialFiles tests
// that truncation leaves no unsequential files on disk, mainly under the following case
// * There is an empty file in between the sequence while the truncation
// deletes files only upto a sequence before that (i.e. stops deleting
// after it has found a file that is not deletable).
// This tests https://github.com/prometheus/prometheus/issues/7412 where
// the truncation used to check all the files for deletion and end up
// deleting empty files in between and breaking the sequence.
func TestHeadReadWriter_Truncate_NoUnsequentialFiles(t *testing.T) {
hrw, close := testHeadReadWriter(t)
defer func() {
testutil.Ok(t, hrw.Close())
close()
}()
timeRange := 0
addChunk := func() {
step := 100
mint, maxt := timeRange+1, timeRange+step-1
_, err := hrw.WriteChunk(1, int64(mint), int64(maxt), randomChunk(t))
testutil.Ok(t, err)
timeRange += step
}
emptyFile := func() {
testutil.Ok(t, hrw.CutNewFile())
}
nonEmptyFile := func() {
emptyFile()
addChunk()
}
addChunk() // 1. Created with the first chunk.
nonEmptyFile() // 2.
nonEmptyFile() // 3.
emptyFile() // 4.
nonEmptyFile() // 5.
emptyFile() // 6.
// Verifying the files.
verifyFiles := func(remainingFiles []int) {
t.Helper()
files, err := ioutil.ReadDir(hrw.dir.Name())
testutil.Ok(t, err)
testutil.Equals(t, len(remainingFiles), len(files), "files on disk")
testutil.Equals(t, len(remainingFiles), len(hrw.mmappedChunkFiles), "hrw.mmappedChunkFiles")
testutil.Equals(t, len(remainingFiles), len(hrw.closers), "closers")
for _, i := range remainingFiles {
_, ok := hrw.mmappedChunkFiles[i]
testutil.Equals(t, true, ok)
}
}
verifyFiles([]int{1, 2, 3, 4, 5, 6})
// Truncating files till 2. It should not delete anything after 3 (inclusive)
// though files 4 and 6 are empty.
file2Maxt := hrw.mmappedChunkFiles[2].maxt
testutil.Ok(t, hrw.Truncate(file2Maxt+1))
// As 6 was empty, it should not create another file.
verifyFiles([]int{3, 4, 5, 6})
addChunk()
// Truncate creates another file as 6 is not empty now.
testutil.Ok(t, hrw.Truncate(file2Maxt+1))
verifyFiles([]int{3, 4, 5, 6, 7})
dir := hrw.dir.Name()
testutil.Ok(t, hrw.Close())
// Restarting checks for unsequential files.
var err error
hrw, err = NewChunkDiskMapper(dir, chunkenc.NewPool())
testutil.Ok(t, err)
verifyFiles([]int{3, 4, 5, 6, 7})
}
func testHeadReadWriter(t *testing.T) (hrw *ChunkDiskMapper, close func()) {
tmpdir, err := ioutil.TempDir("", "data")
testutil.Ok(t, err)
hrw, err = NewChunkDiskMapper(tmpdir, chunkenc.NewPool())
testutil.Ok(t, err)
testutil.Assert(t, !hrw.fileMaxtSet, "")
testutil.Ok(t, hrw.IterateAllChunks(func(_, _ uint64, _, _ int64, _ uint16) error { return nil }))
testutil.Assert(t, hrw.fileMaxtSet, "")
return hrw, func() {
testutil.Ok(t, os.RemoveAll(tmpdir))
}
}
func randomChunk(t *testing.T) chunkenc.Chunk {
chunk := chunkenc.NewXORChunk()
len := rand.Int() % 120
app, err := chunk.Appender()
testutil.Ok(t, err)
for i := 0; i < len; i++ {
app.Append(rand.Int63(), rand.Float64())
}
return chunk
}
func createChunk(t *testing.T, idx int, hrw *ChunkDiskMapper) (seriesRef uint64, chunkRef uint64, mint, maxt int64, chunk chunkenc.Chunk) {
var err error
seriesRef = uint64(rand.Int63())
mint = int64((idx)*1000 + 1)
maxt = int64((idx + 1) * 1000)
chunk = randomChunk(t)
chunkRef, err = hrw.WriteChunk(seriesRef, mint, maxt, chunk)
testutil.Ok(t, err)
return
}