ceremonyclient/pebble/table_cache_test.go

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2024-01-03 07:31:42 +00:00
// Copyright 2013 The LevelDB-Go and Pebble Authors. All rights reserved. Use
// of this source code is governed by a BSD-style license that can be found in
// the LICENSE file.
package pebble
import (
"bufio"
"bytes"
"context"
"fmt"
"io"
"os"
"path"
"strconv"
"strings"
"sync"
"testing"
"time"
"github.com/cockroachdb/errors"
"github.com/cockroachdb/pebble/internal/base"
"github.com/cockroachdb/pebble/internal/keyspan"
"github.com/cockroachdb/pebble/internal/manifest"
"github.com/cockroachdb/pebble/internal/testkeys"
"github.com/cockroachdb/pebble/objstorage"
"github.com/cockroachdb/pebble/objstorage/objstorageprovider"
"github.com/cockroachdb/pebble/sstable"
"github.com/cockroachdb/pebble/vfs"
"github.com/stretchr/testify/require"
"golang.org/x/exp/rand"
)
type tableCacheTestFile struct {
vfs.File
fs *tableCacheTestFS
name string
}
func (f *tableCacheTestFile) Close() error {
f.fs.mu.Lock()
if f.fs.closeCounts != nil {
f.fs.closeCounts[f.name]++
}
f.fs.mu.Unlock()
return f.File.Close()
}
type tableCacheTestFS struct {
vfs.FS
mu sync.Mutex
openCounts map[string]int
closeCounts map[string]int
openErrorEnabled bool
}
func (fs *tableCacheTestFS) Open(name string, opts ...vfs.OpenOption) (vfs.File, error) {
fs.mu.Lock()
if fs.openErrorEnabled {
fs.mu.Unlock()
return nil, errors.New("injected error")
}
if fs.openCounts != nil {
fs.openCounts[name]++
}
fs.mu.Unlock()
f, err := fs.FS.Open(name, opts...)
if len(opts) < 1 || opts[0] != vfs.RandomReadsOption {
return nil, errors.Errorf("sstable file %s not opened with random reads option", name)
}
if err != nil {
return nil, err
}
return &tableCacheTestFile{f, fs, name}, nil
}
func (fs *tableCacheTestFS) validate(
t *testing.T, c *tableCacheContainer, f func(i, gotO, gotC int) error,
) {
if err := fs.validateOpenTables(f); err != nil {
t.Error(err)
return
}
c.close()
if err := fs.validateNoneStillOpen(); err != nil {
t.Error(err)
return
}
}
func (fs *tableCacheTestFS) setOpenError(enabled bool) {
fs.mu.Lock()
defer fs.mu.Unlock()
fs.openErrorEnabled = enabled
}
// validateOpenTables validates that no tables in the cache are open twice, and
// the number still open is no greater than tableCacheTestCacheSize.
func (fs *tableCacheTestFS) validateOpenTables(f func(i, gotO, gotC int) error) error {
// try backs off to let any clean-up goroutines do their work.
return try(100*time.Microsecond, 20*time.Second, func() error {
fs.mu.Lock()
defer fs.mu.Unlock()
numStillOpen := 0
for i := 0; i < tableCacheTestNumTables; i++ {
filename := base.MakeFilepath(fs, "", fileTypeTable, base.FileNum(uint64(i)).DiskFileNum())
gotO, gotC := fs.openCounts[filename], fs.closeCounts[filename]
if gotO > gotC {
numStillOpen++
}
if gotC != gotO && gotC != gotO-1 {
return errors.Errorf("i=%d: table closed too many or too few times: opened %d times, closed %d times",
i, gotO, gotC)
}
if f != nil {
if err := f(i, gotO, gotC); err != nil {
return err
}
}
}
if numStillOpen > tableCacheTestCacheSize {
return errors.Errorf("numStillOpen is %d, want <= %d", numStillOpen, tableCacheTestCacheSize)
}
return nil
})
}
// validateNoneStillOpen validates that no tables in the cache are open.
func (fs *tableCacheTestFS) validateNoneStillOpen() error {
// try backs off to let any clean-up goroutines do their work.
return try(100*time.Microsecond, 20*time.Second, func() error {
fs.mu.Lock()
defer fs.mu.Unlock()
for i := 0; i < tableCacheTestNumTables; i++ {
filename := base.MakeFilepath(fs, "", fileTypeTable, base.FileNum(uint64(i)).DiskFileNum())
gotO, gotC := fs.openCounts[filename], fs.closeCounts[filename]
if gotO != gotC {
return errors.Errorf("i=%d: opened %d times, closed %d times", i, gotO, gotC)
}
}
return nil
})
}
const (
tableCacheTestNumTables = 300
tableCacheTestCacheSize = 100
)
// newTableCacheTest returns a shareable table cache to be used for tests.
// It is the caller's responsibility to unref the table cache.
func newTableCacheTest(size int64, tableCacheSize int, numShards int) *TableCache {
cache := NewCache(size)
defer cache.Unref()
return NewTableCache(cache, numShards, tableCacheSize)
}
func newTableCacheContainerTest(
tc *TableCache, dirname string,
) (*tableCacheContainer, *tableCacheTestFS, error) {
xxx := bytes.Repeat([]byte("x"), tableCacheTestNumTables)
fs := &tableCacheTestFS{
FS: vfs.NewMem(),
}
objProvider, err := objstorageprovider.Open(objstorageprovider.DefaultSettings(fs, dirname))
if err != nil {
return nil, nil, err
}
defer objProvider.Close()
for i := 0; i < tableCacheTestNumTables; i++ {
w, _, err := objProvider.Create(context.Background(), fileTypeTable, base.FileNum(uint64(i)).DiskFileNum(), objstorage.CreateOptions{})
if err != nil {
return nil, nil, errors.Wrap(err, "fs.Create")
}
tw := sstable.NewWriter(w, sstable.WriterOptions{TableFormat: sstable.TableFormatPebblev2})
ik := base.ParseInternalKey(fmt.Sprintf("k.SET.%d", i))
if err := tw.Add(ik, xxx[:i]); err != nil {
return nil, nil, errors.Wrap(err, "tw.Set")
}
if err := tw.RangeKeySet([]byte("k"), []byte("l"), nil, xxx[:i]); err != nil {
return nil, nil, errors.Wrap(err, "tw.Set")
}
if err := tw.Close(); err != nil {
return nil, nil, errors.Wrap(err, "tw.Close")
}
}
fs.mu.Lock()
fs.openCounts = map[string]int{}
fs.closeCounts = map[string]int{}
fs.mu.Unlock()
opts := &Options{}
opts.EnsureDefaults()
if tc == nil {
opts.Cache = NewCache(8 << 20) // 8 MB
defer opts.Cache.Unref()
} else {
opts.Cache = tc.cache
}
c := newTableCacheContainer(tc, opts.Cache.NewID(), objProvider, opts, tableCacheTestCacheSize,
&sstable.CategoryStatsCollector{})
return c, fs, nil
}
// Test basic reference counting for the table cache.
func TestTableCacheRefs(t *testing.T) {
tc := newTableCacheTest(8<<20, 10, 2)
v := tc.refs.Load()
if v != 1 {
require.Equal(t, 1, v)
}
tc.Ref()
v = tc.refs.Load()
if v != 2 {
require.Equal(t, 2, v)
}
tc.Unref()
v = tc.refs.Load()
if v != 1 {
require.Equal(t, 1, v)
}
tc.Unref()
v = tc.refs.Load()
if v != 0 {
require.Equal(t, 0, v)
}
defer func() {
if r := recover(); r != nil {
if fmt.Sprint(r) != "pebble: inconsistent reference count: -1" {
t.Fatalf("unexpected panic message")
}
} else if r == nil {
t.Fatalf("expected panic")
}
}()
tc.Unref()
}
// Basic test to determine if reads through the table cache are wired correctly.
func TestVirtualReadsWiring(t *testing.T) {
var d *DB
var err error
d, err = Open("",
&Options{
FS: vfs.NewMem(),
FormatMajorVersion: internalFormatNewest,
Comparer: testkeys.Comparer,
// Compactions which conflict with virtual sstable creation can be
// picked by Pebble. We disable that.
DisableAutomaticCompactions: true,
})
require.NoError(t, err)
defer d.Close()
b := newBatch(d)
// Some combination of sets, range deletes, and range key sets/unsets, so
// all of the table cache iterator functions are utilized.
require.NoError(t, b.Set([]byte{'a'}, []byte{'a'}, nil))
require.NoError(t, b.Set([]byte{'d'}, []byte{'d'}, nil))
require.NoError(t, b.DeleteRange([]byte{'c'}, []byte{'e'}, nil))
require.NoError(t, b.Set([]byte{'f'}, []byte{'f'}, nil))
require.NoError(t, b.RangeKeySet([]byte{'f'}, []byte{'k'}, nil, []byte{'c'}, nil))
require.NoError(t, b.RangeKeyUnset([]byte{'j'}, []byte{'k'}, nil, nil))
require.NoError(t, b.Set([]byte{'z'}, []byte{'z'}, nil))
require.NoError(t, d.Apply(b, nil))
require.NoError(t, d.Flush())
require.NoError(t, d.Compact([]byte{'a'}, []byte{'b'}, false))
require.Equal(t, 1, int(d.Metrics().Levels[6].NumFiles))
d.mu.Lock()
// Virtualize the single sstable in the lsm.
currVersion := d.mu.versions.currentVersion()
l6 := currVersion.Levels[6]
l6FileIter := l6.Iter()
parentFile := l6FileIter.First()
f1 := FileNum(d.mu.versions.nextFileNum)
f2 := f1 + 1
d.mu.versions.nextFileNum += 2
v1 := &manifest.FileMetadata{
FileBacking: parentFile.FileBacking,
FileNum: f1,
CreationTime: time.Now().Unix(),
Size: parentFile.Size / 2,
SmallestSeqNum: parentFile.SmallestSeqNum,
LargestSeqNum: parentFile.LargestSeqNum,
Smallest: base.MakeInternalKey([]byte{'a'}, parentFile.Smallest.SeqNum(), InternalKeyKindSet),
Largest: base.MakeInternalKey([]byte{'a'}, parentFile.Smallest.SeqNum(), InternalKeyKindSet),
HasPointKeys: true,
Virtual: true,
}
v1.Stats.NumEntries = 1
v2 := &manifest.FileMetadata{
FileBacking: parentFile.FileBacking,
FileNum: f2,
CreationTime: time.Now().Unix(),
Size: parentFile.Size / 2,
SmallestSeqNum: parentFile.SmallestSeqNum,
LargestSeqNum: parentFile.LargestSeqNum,
Smallest: base.MakeInternalKey([]byte{'d'}, parentFile.Smallest.SeqNum()+1, InternalKeyKindSet),
Largest: base.MakeInternalKey([]byte{'z'}, parentFile.Largest.SeqNum(), InternalKeyKindSet),
HasPointKeys: true,
Virtual: true,
}
v2.Stats.NumEntries = 6
v1.LargestPointKey = v1.Largest
v1.SmallestPointKey = v1.Smallest
v2.LargestPointKey = v2.Largest
v2.SmallestPointKey = v2.Smallest
v1.ValidateVirtual(parentFile)
d.checkVirtualBounds(v1)
v2.ValidateVirtual(parentFile)
d.checkVirtualBounds(v2)
// Write the version edit.
fileMetrics := func(ve *versionEdit) map[int]*LevelMetrics {
metrics := newFileMetrics(ve.NewFiles)
for de, f := range ve.DeletedFiles {
lm := metrics[de.Level]
if lm == nil {
lm = &LevelMetrics{}
metrics[de.Level] = lm
}
metrics[de.Level].NumFiles--
metrics[de.Level].Size -= int64(f.Size)
}
return metrics
}
applyVE := func(ve *versionEdit) error {
d.mu.versions.logLock()
jobID := d.mu.nextJobID
d.mu.nextJobID++
err := d.mu.versions.logAndApply(jobID, ve, fileMetrics(ve), false, func() []compactionInfo {
return d.getInProgressCompactionInfoLocked(nil)
})
d.updateReadStateLocked(nil)
return err
}
ve := manifest.VersionEdit{}
d1 := manifest.DeletedFileEntry{Level: 6, FileNum: parentFile.FileNum}
n1 := manifest.NewFileEntry{Level: 6, Meta: v1}
n2 := manifest.NewFileEntry{Level: 6, Meta: v2}
ve.DeletedFiles = make(map[manifest.DeletedFileEntry]*manifest.FileMetadata)
ve.DeletedFiles[d1] = parentFile
ve.NewFiles = append(ve.NewFiles, n1)
ve.NewFiles = append(ve.NewFiles, n2)
ve.CreatedBackingTables = append(ve.CreatedBackingTables, parentFile.FileBacking)
require.NoError(t, applyVE(&ve))
currVersion = d.mu.versions.currentVersion()
l6 = currVersion.Levels[6]
l6FileIter = l6.Iter()
for f := l6FileIter.First(); f != nil; f = l6FileIter.Next() {
require.Equal(t, true, f.Virtual)
}
d.mu.Unlock()
// Confirm that there were only 2 virtual sstables in L6.
require.Equal(t, 2, int(d.Metrics().Levels[6].NumFiles))
// These reads will go through the table cache.
iter, _ := d.NewIter(nil)
expected := []byte{'a', 'f', 'z'}
for i, x := 0, iter.First(); x; i, x = i+1, iter.Next() {
require.Equal(t, []byte{expected[i]}, iter.Value())
}
iter.Close()
}
// The table cache shouldn't be usable after all the dbs close.
func TestSharedTableCacheUseAfterAllFree(t *testing.T) {
tc := newTableCacheTest(8<<20, 10, 1)
db1, err := Open("test",
&Options{
FS: vfs.NewMem(),
Cache: tc.cache,
TableCache: tc,
})
require.NoError(t, err)
// Release our reference, now that the db has a reference.
tc.Unref()
db2, err := Open("test",
&Options{
FS: vfs.NewMem(),
Cache: tc.cache,
TableCache: tc,
})
require.NoError(t, err)
require.NoError(t, db1.Close())
require.NoError(t, db2.Close())
v := tc.refs.Load()
if v != 0 {
t.Fatalf("expected reference count %d, got %d", 0, v)
}
defer func() {
// The cache ref gets incremented before the panic, so we should
// decrement it to prevent the finalizer from detecting a leak.
tc.cache.Unref()
if r := recover(); r != nil {
if fmt.Sprint(r) != "pebble: inconsistent reference count: 1" {
t.Fatalf("unexpected panic message")
}
} else if r == nil {
t.Fatalf("expected panic")
}
}()
db3, _ := Open("test",
&Options{
FS: vfs.NewMem(),
Cache: tc.cache,
TableCache: tc,
})
_ = db3
}
// Test whether a shared table cache is usable by a db, after
// one of the db's releases its reference.
func TestSharedTableCacheUseAfterOneFree(t *testing.T) {
tc := newTableCacheTest(8<<20, 10, 1)
db1, err := Open("test",
&Options{
FS: vfs.NewMem(),
Cache: tc.cache,
TableCache: tc,
})
require.NoError(t, err)
// Release our reference, now that the db has a reference.
tc.Unref()
db2, err := Open("test",
&Options{
FS: vfs.NewMem(),
Cache: tc.cache,
TableCache: tc,
})
require.NoError(t, err)
defer func() {
require.NoError(t, db2.Close())
}()
// Make db1 release a reference to the cache. It should
// still be usable by db2.
require.NoError(t, db1.Close())
v := tc.refs.Load()
if v != 1 {
t.Fatalf("expected reference count %d, got %d", 1, v)
}
// Check if db2 is still usable.
start := []byte("a")
end := []byte("d")
require.NoError(t, db2.Set(start, nil, nil))
require.NoError(t, db2.Flush())
require.NoError(t, db2.DeleteRange(start, end, nil))
require.NoError(t, db2.Compact(start, end, false))
}
// A basic test which makes sure that a shared table cache is usable
// by more than one database at once.
func TestSharedTableCacheUsable(t *testing.T) {
tc := newTableCacheTest(8<<20, 10, 1)
db1, err := Open("test",
&Options{
FS: vfs.NewMem(),
Cache: tc.cache,
TableCache: tc,
})
require.NoError(t, err)
// Release our reference, now that the db has a reference.
tc.Unref()
defer func() {
require.NoError(t, db1.Close())
}()
db2, err := Open("test",
&Options{
FS: vfs.NewMem(),
Cache: tc.cache,
TableCache: tc,
})
require.NoError(t, err)
defer func() {
require.NoError(t, db2.Close())
}()
start := []byte("a")
end := []byte("z")
require.NoError(t, db1.Set(start, nil, nil))
require.NoError(t, db1.Flush())
require.NoError(t, db1.DeleteRange(start, end, nil))
require.NoError(t, db1.Compact(start, end, false))
start = []byte("x")
end = []byte("y")
require.NoError(t, db2.Set(start, nil, nil))
require.NoError(t, db2.Flush())
require.NoError(t, db2.Set(start, []byte{'a'}, nil))
require.NoError(t, db2.Flush())
require.NoError(t, db2.DeleteRange(start, end, nil))
require.NoError(t, db2.Compact(start, end, false))
}
func TestSharedTableConcurrent(t *testing.T) {
tc := newTableCacheTest(8<<20, 10, 1)
db1, err := Open("test",
&Options{
FS: vfs.NewMem(),
Cache: tc.cache,
TableCache: tc,
})
require.NoError(t, err)
// Release our reference, now that the db has a reference.
tc.Unref()
defer func() {
require.NoError(t, db1.Close())
}()
db2, err := Open("test",
&Options{
FS: vfs.NewMem(),
Cache: tc.cache,
TableCache: tc,
})
require.NoError(t, err)
defer func() {
require.NoError(t, db2.Close())
}()
var wg sync.WaitGroup
wg.Add(2)
// Now that both dbs have a reference to the table cache,
// we'll run go routines which will use the DBs concurrently.
concFunc := func(db *DB) {
for i := 0; i < 1000; i++ {
start := []byte("a")
end := []byte("z")
require.NoError(t, db.Set(start, nil, nil))
require.NoError(t, db.Flush())
require.NoError(t, db.DeleteRange(start, end, nil))
require.NoError(t, db.Compact(start, end, false))
}
wg.Done()
}
go concFunc(db1)
go concFunc(db2)
wg.Wait()
}
func testTableCacheRandomAccess(t *testing.T, concurrent bool) {
const N = 2000
c, fs, err := newTableCacheContainerTest(nil, "")
require.NoError(t, err)
rngMu := sync.Mutex{}
rng := rand.New(rand.NewSource(1))
errc := make(chan error, N)
for i := 0; i < N; i++ {
go func(i int) {
rngMu.Lock()
fileNum, sleepTime := rng.Intn(tableCacheTestNumTables), rng.Intn(1000)
rngMu.Unlock()
m := &fileMetadata{FileNum: FileNum(fileNum)}
m.InitPhysicalBacking()
m.Ref()
defer m.Unref()
iter, _, err := c.newIters(context.Background(), m, nil, internalIterOpts{})
if err != nil {
errc <- errors.Errorf("i=%d, fileNum=%d: find: %v", i, fileNum, err)
return
}
key, value := iter.SeekGE([]byte("k"), base.SeekGEFlagsNone)
if concurrent {
time.Sleep(time.Duration(sleepTime) * time.Microsecond)
}
if key == nil {
errc <- errors.Errorf("i=%d, fileNum=%d: valid.0: got false, want true", i, fileNum)
return
}
v, _, err := value.Value(nil)
if err != nil {
errc <- errors.Errorf("i=%d, fileNum=%d: err extracting value: %v", err)
}
if got := len(v); got != fileNum {
errc <- errors.Errorf("i=%d, fileNum=%d: value: got %d bytes, want %d", i, fileNum, got, fileNum)
return
}
if key, _ := iter.Next(); key != nil {
errc <- errors.Errorf("i=%d, fileNum=%d: next.1: got true, want false", i, fileNum)
return
}
if err := iter.Close(); err != nil {
errc <- errors.Wrapf(err, "close error i=%d, fileNum=%dv", i, fileNum)
return
}
errc <- nil
}(i)
if !concurrent {
require.NoError(t, <-errc)
}
}
if concurrent {
for i := 0; i < N; i++ {
require.NoError(t, <-errc)
}
}
fs.validate(t, c, nil)
}
func TestTableCacheRandomAccessSequential(t *testing.T) { testTableCacheRandomAccess(t, false) }
func TestTableCacheRandomAccessConcurrent(t *testing.T) { testTableCacheRandomAccess(t, true) }
func testTableCacheFrequentlyUsedInternal(t *testing.T, rangeIter bool) {
const (
N = 1000
pinned0 = 7
pinned1 = 11
)
c, fs, err := newTableCacheContainerTest(nil, "")
require.NoError(t, err)
for i := 0; i < N; i++ {
for _, j := range [...]int{pinned0, i % tableCacheTestNumTables, pinned1} {
var iter io.Closer
var err error
m := &fileMetadata{FileNum: FileNum(j)}
m.InitPhysicalBacking()
m.Ref()
if rangeIter {
iter, err = c.newRangeKeyIter(m, keyspan.SpanIterOptions{})
} else {
iter, _, err = c.newIters(context.Background(), m, nil, internalIterOpts{})
}
if err != nil {
t.Fatalf("i=%d, j=%d: find: %v", i, j, err)
}
if err := iter.Close(); err != nil {
t.Fatalf("i=%d, j=%d: close: %v", i, j, err)
}
}
}
fs.validate(t, c, func(i, gotO, gotC int) error {
if i == pinned0 || i == pinned1 {
if gotO != 1 || gotC != 0 {
return errors.Errorf("i=%d: pinned table: got %d, %d, want %d, %d", i, gotO, gotC, 1, 0)
}
}
return nil
})
}
func TestTableCacheFrequentlyUsed(t *testing.T) {
for i, iterType := range []string{"point", "range"} {
t.Run(fmt.Sprintf("iter=%s", iterType), func(t *testing.T) {
testTableCacheFrequentlyUsedInternal(t, i == 1)
})
}
}
func TestSharedTableCacheFrequentlyUsed(t *testing.T) {
const (
N = 1000
pinned0 = 7
pinned1 = 11
)
tc := newTableCacheTest(8<<20, 2*tableCacheTestCacheSize, 16)
c1, fs1, err := newTableCacheContainerTest(tc, "")
require.NoError(t, err)
c2, fs2, err := newTableCacheContainerTest(tc, "")
require.NoError(t, err)
tc.Unref()
for i := 0; i < N; i++ {
for _, j := range [...]int{pinned0, i % tableCacheTestNumTables, pinned1} {
m := &fileMetadata{FileNum: FileNum(j)}
m.InitPhysicalBacking()
m.Ref()
iter1, _, err := c1.newIters(context.Background(), m, nil, internalIterOpts{})
if err != nil {
t.Fatalf("i=%d, j=%d: find: %v", i, j, err)
}
iter2, _, err := c2.newIters(context.Background(), m, nil, internalIterOpts{})
if err != nil {
t.Fatalf("i=%d, j=%d: find: %v", i, j, err)
}
if err := iter1.Close(); err != nil {
t.Fatalf("i=%d, j=%d: close: %v", i, j, err)
}
if err := iter2.Close(); err != nil {
t.Fatalf("i=%d, j=%d: close: %v", i, j, err)
}
}
}
fs1.validate(t, c1, func(i, gotO, gotC int) error {
if i == pinned0 || i == pinned1 {
if gotO != 1 || gotC != 0 {
return errors.Errorf("i=%d: pinned table: got %d, %d, want %d, %d", i, gotO, gotC, 1, 0)
}
}
return nil
})
fs2.validate(t, c2, func(i, gotO, gotC int) error {
if i == pinned0 || i == pinned1 {
if gotO != 1 || gotC != 0 {
return errors.Errorf("i=%d: pinned table: got %d, %d, want %d, %d", i, gotO, gotC, 1, 0)
}
}
return nil
})
}
func testTableCacheEvictionsInternal(t *testing.T, rangeIter bool) {
const (
N = 1000
lo, hi = 10, 20
)
c, fs, err := newTableCacheContainerTest(nil, "")
require.NoError(t, err)
rng := rand.New(rand.NewSource(2))
for i := 0; i < N; i++ {
j := rng.Intn(tableCacheTestNumTables)
var iter io.Closer
var err error
m := &fileMetadata{FileNum: FileNum(j)}
m.InitPhysicalBacking()
m.Ref()
if rangeIter {
iter, err = c.newRangeKeyIter(m, keyspan.SpanIterOptions{})
} else {
iter, _, err = c.newIters(context.Background(), m, nil, internalIterOpts{})
}
if err != nil {
t.Fatalf("i=%d, j=%d: find: %v", i, j, err)
}
if err := iter.Close(); err != nil {
t.Fatalf("i=%d, j=%d: close: %v", i, j, err)
}
c.evict(base.FileNum(lo + rng.Uint64n(hi-lo)).DiskFileNum())
}
sumEvicted, nEvicted := 0, 0
sumSafe, nSafe := 0, 0
fs.validate(t, c, func(i, gotO, gotC int) error {
if lo <= i && i < hi {
sumEvicted += gotO
nEvicted++
} else {
sumSafe += gotO
nSafe++
}
return nil
})
fEvicted := float64(sumEvicted) / float64(nEvicted)
fSafe := float64(sumSafe) / float64(nSafe)
// The magic 1.25 number isn't derived from formal modeling. It's just a guess. For
// (lo, hi, tableCacheTestCacheSize, tableCacheTestNumTables) = (10, 20, 100, 300),
// the ratio seems to converge on roughly 1.5 for large N, compared to 1.0 if we do
// not evict any cache entries.
if ratio := fEvicted / fSafe; ratio < 1.25 {
t.Errorf("evicted tables were opened %.3f times on average, safe tables %.3f, ratio %.3f < 1.250",
fEvicted, fSafe, ratio)
}
}
func TestTableCacheEvictions(t *testing.T) {
for i, iterType := range []string{"point", "range"} {
t.Run(fmt.Sprintf("iter=%s", iterType), func(t *testing.T) {
testTableCacheEvictionsInternal(t, i == 1)
})
}
}
func TestSharedTableCacheEvictions(t *testing.T) {
const (
N = 1000
lo, hi = 10, 20
)
tc := newTableCacheTest(8<<20, 2*tableCacheTestCacheSize, 16)
c1, fs1, err := newTableCacheContainerTest(tc, "")
require.NoError(t, err)
c2, fs2, err := newTableCacheContainerTest(tc, "")
require.NoError(t, err)
tc.Unref()
rng := rand.New(rand.NewSource(2))
for i := 0; i < N; i++ {
j := rng.Intn(tableCacheTestNumTables)
m := &fileMetadata{FileNum: FileNum(j)}
m.InitPhysicalBacking()
m.Ref()
iter1, _, err := c1.newIters(context.Background(), m, nil, internalIterOpts{})
if err != nil {
t.Fatalf("i=%d, j=%d: find: %v", i, j, err)
}
iter2, _, err := c2.newIters(context.Background(), m, nil, internalIterOpts{})
if err != nil {
t.Fatalf("i=%d, j=%d: find: %v", i, j, err)
}
if err := iter1.Close(); err != nil {
t.Fatalf("i=%d, j=%d: close: %v", i, j, err)
}
if err := iter2.Close(); err != nil {
t.Fatalf("i=%d, j=%d: close: %v", i, j, err)
}
c1.evict(base.FileNum(lo + rng.Uint64n(hi-lo)).DiskFileNum())
c2.evict(base.FileNum(lo + rng.Uint64n(hi-lo)).DiskFileNum())
}
check := func(fs *tableCacheTestFS, c *tableCacheContainer) (float64, float64, float64) {
sumEvicted, nEvicted := 0, 0
sumSafe, nSafe := 0, 0
fs.validate(t, c, func(i, gotO, gotC int) error {
if lo <= i && i < hi {
sumEvicted += gotO
nEvicted++
} else {
sumSafe += gotO
nSafe++
}
return nil
})
fEvicted := float64(sumEvicted) / float64(nEvicted)
fSafe := float64(sumSafe) / float64(nSafe)
return fEvicted, fSafe, fEvicted / fSafe
}
// The magic 1.25 number isn't derived from formal modeling. It's just a guess. For
// (lo, hi, tableCacheTestCacheSize, tableCacheTestNumTables) = (10, 20, 100, 300),
// the ratio seems to converge on roughly 1.5 for large N, compared to 1.0 if we do
// not evict any cache entries.
if fEvicted, fSafe, ratio := check(fs1, c1); ratio < 1.25 {
t.Errorf(
"evicted tables were opened %.3f times on average, safe tables %.3f, ratio %.3f < 1.250",
fEvicted, fSafe, ratio,
)
}
if fEvicted, fSafe, ratio := check(fs2, c2); ratio < 1.25 {
t.Errorf(
"evicted tables were opened %.3f times on average, safe tables %.3f, ratio %.3f < 1.250",
fEvicted, fSafe, ratio,
)
}
}
func TestTableCacheIterLeak(t *testing.T) {
c, _, err := newTableCacheContainerTest(nil, "")
require.NoError(t, err)
m := &fileMetadata{FileNum: 0}
m.InitPhysicalBacking()
m.Ref()
defer m.Unref()
iter, _, err := c.newIters(context.Background(), m, nil, internalIterOpts{})
require.NoError(t, err)
if err := c.close(); err == nil {
t.Fatalf("expected failure, but found success")
} else if !strings.HasPrefix(err.Error(), "leaked iterators:") {
t.Fatalf("expected leaked iterators, but found %+v", err)
} else {
t.Log(err.Error())
}
require.NoError(t, iter.Close())
}
func TestSharedTableCacheIterLeak(t *testing.T) {
tc := newTableCacheTest(8<<20, 2*tableCacheTestCacheSize, 16)
c1, _, err := newTableCacheContainerTest(tc, "")
require.NoError(t, err)
c2, _, err := newTableCacheContainerTest(tc, "")
require.NoError(t, err)
c3, _, err := newTableCacheContainerTest(tc, "")
require.NoError(t, err)
tc.Unref()
m := &fileMetadata{FileNum: 0}
m.InitPhysicalBacking()
m.Ref()
defer m.Unref()
iter, _, err := c1.newIters(context.Background(), m, nil, internalIterOpts{})
require.NoError(t, err)
if err := c1.close(); err == nil {
t.Fatalf("expected failure, but found success")
} else if !strings.HasPrefix(err.Error(), "leaked iterators:") {
t.Fatalf("expected leaked iterators, but found %+v", err)
} else {
t.Log(err.Error())
}
// Closing c2 shouldn't error out since c2 isn't leaking any iterators.
require.NoError(t, c2.close())
// Closing c3 should error out since c3 holds the last reference to
// the TableCache, and when the TableCache closes, it will detect
// that there was a leaked iterator.
if err := c3.close(); err == nil {
t.Fatalf("expected failure, but found success")
} else if !strings.HasPrefix(err.Error(), "leaked iterators:") {
t.Fatalf("expected leaked iterators, but found %+v", err)
} else {
t.Log(err.Error())
}
require.NoError(t, iter.Close())
}
func TestTableCacheRetryAfterFailure(t *testing.T) {
// Test a retry can succeed after a failure, i.e., errors are not cached.
c, fs, err := newTableCacheContainerTest(nil, "")
require.NoError(t, err)
fs.setOpenError(true /* enabled */)
m := &fileMetadata{FileNum: 0}
m.InitPhysicalBacking()
m.Ref()
defer m.Unref()
if _, _, err = c.newIters(context.Background(), m, nil, internalIterOpts{}); err == nil {
t.Fatalf("expected failure, but found success")
}
require.Equal(t, "pebble: backing file 000000 error: injected error", err.Error())
fs.setOpenError(false /* enabled */)
var iter internalIterator
iter, _, err = c.newIters(context.Background(), m, nil, internalIterOpts{})
require.NoError(t, err)
require.NoError(t, iter.Close())
fs.validate(t, c, nil)
}
// memFile is a file-like struct that buffers all data written to it in memory.
// Implements the objstorage.Writable interface.
type memFile struct {
buf bytes.Buffer
}
var _ objstorage.Writable = (*memFile)(nil)
// Finish is part of the objstorage.Writable interface.
func (*memFile) Finish() error {
return nil
}
// Abort is part of the objstorage.Writable interface.
func (*memFile) Abort() {}
// Write is part of the objstorage.Writable interface.
func (f *memFile) Write(p []byte) error {
_, err := f.buf.Write(p)
return err
}
func TestTableCacheErrorBadMagicNumber(t *testing.T) {
var file memFile
tw := sstable.NewWriter(&file, sstable.WriterOptions{TableFormat: sstable.TableFormatPebblev2})
tw.Set([]byte("a"), nil)
require.NoError(t, tw.Close())
buf := file.buf.Bytes()
// Bad magic number.
buf[len(buf)-1] = 0
fs := &tableCacheTestFS{
FS: vfs.NewMem(),
}
const testFileNum = 3
objProvider, err := objstorageprovider.Open(objstorageprovider.DefaultSettings(fs, ""))
require.NoError(t, err)
w, _, err := objProvider.Create(context.Background(), fileTypeTable,
base.FileNum(testFileNum).DiskFileNum(), objstorage.CreateOptions{})
w.Write(buf)
require.NoError(t, w.Finish())
opts := &Options{}
opts.EnsureDefaults()
opts.Cache = NewCache(8 << 20) // 8 MB
defer opts.Cache.Unref()
c := newTableCacheContainer(nil, opts.Cache.NewID(), objProvider, opts, tableCacheTestCacheSize,
&sstable.CategoryStatsCollector{})
require.NoError(t, err)
defer c.close()
m := &fileMetadata{FileNum: testFileNum}
m.InitPhysicalBacking()
m.Ref()
defer m.Unref()
if _, _, err = c.newIters(context.Background(), m, nil, internalIterOpts{}); err == nil {
t.Fatalf("expected failure, but found success")
}
require.Equal(t,
"pebble: backing file 000003 error: pebble/table: invalid table (bad magic number: 0xf09faab3f09faa00)",
err.Error())
}
func TestTableCacheEvictClose(t *testing.T) {
errs := make(chan error, 10)
db, err := Open("test",
&Options{
FS: vfs.NewMem(),
EventListener: &EventListener{
TableDeleted: func(info TableDeleteInfo) {
errs <- info.Err
},
},
})
require.NoError(t, err)
start := []byte("a")
end := []byte("z")
require.NoError(t, db.Set(start, nil, nil))
require.NoError(t, db.Flush())
require.NoError(t, db.DeleteRange(start, end, nil))
require.NoError(t, db.Compact(start, end, false))
require.NoError(t, db.Close())
close(errs)
for err := range errs {
require.NoError(t, err)
}
}
func TestTableCacheClockPro(t *testing.T) {
// Test data was generated from the python code. See also
// internal/cache/clockpro_test.go:TestCache.
f, err := os.Open("internal/cache/testdata/cache")
require.NoError(t, err)
mem := vfs.NewMem()
objProvider, err := objstorageprovider.Open(objstorageprovider.DefaultSettings(mem, ""))
require.NoError(t, err)
defer objProvider.Close()
makeTable := func(dfn base.DiskFileNum) {
require.NoError(t, err)
f, _, err := objProvider.Create(context.Background(), fileTypeTable, dfn, objstorage.CreateOptions{})
require.NoError(t, err)
w := sstable.NewWriter(f, sstable.WriterOptions{})
require.NoError(t, w.Set([]byte("a"), nil))
require.NoError(t, w.Close())
}
opts := &Options{
Cache: NewCache(8 << 20), // 8 MB
}
opts.EnsureDefaults()
defer opts.Cache.Unref()
cache := &tableCacheShard{}
// NB: The table cache size of 200 is required for the expected test values.
cache.init(200)
dbOpts := &tableCacheOpts{}
dbOpts.loggerAndTracer = &base.LoggerWithNoopTracer{Logger: opts.Logger}
dbOpts.cacheID = 0
dbOpts.objProvider = objProvider
dbOpts.opts = opts.MakeReaderOptions()
scanner := bufio.NewScanner(f)
tables := make(map[int]bool)
line := 1
for scanner.Scan() {
fields := bytes.Fields(scanner.Bytes())
key, err := strconv.Atoi(string(fields[0]))
require.NoError(t, err)
// Ensure that underlying sstables exist on disk, creating each table the
// first time it is seen.
if !tables[key] {
makeTable(base.FileNum(uint64(key)).DiskFileNum())
tables[key] = true
}
oldHits := cache.hits.Load()
m := &fileMetadata{FileNum: FileNum(key)}
m.InitPhysicalBacking()
m.Ref()
v := cache.findNode(m, dbOpts)
cache.unrefValue(v)
hit := cache.hits.Load() != oldHits
wantHit := fields[1][0] == 'h'
if hit != wantHit {
t.Errorf("%d: cache hit mismatch: got %v, want %v\n", line, hit, wantHit)
}
line++
m.Unref()
}
}
func BenchmarkNewItersAlloc(b *testing.B) {
opts := &Options{
FS: vfs.NewMem(),
FormatMajorVersion: internalFormatNewest,
}
d, err := Open("", opts)
require.NoError(b, err)
defer func() { require.NoError(b, d.Close()) }()
require.NoError(b, d.Set([]byte{'a'}, []byte{'a'}, nil))
require.NoError(b, d.Flush())
require.NoError(b, d.Compact([]byte{'a'}, []byte{'z'}, false))
d.mu.Lock()
currVersion := d.mu.versions.currentVersion()
it := currVersion.Levels[6].Iter()
m := it.First()
require.NotNil(b, m)
d.mu.Unlock()
// Open once so that the Reader is cached.
iter, _, err := d.newIters(context.Background(), m, nil, internalIterOpts{})
require.NoError(b, iter.Close())
require.NoError(b, err)
for i := 0; i < b.N; i++ {
b.StartTimer()
iter, _, err := d.newIters(context.Background(), m, nil, internalIterOpts{})
b.StopTimer()
require.NoError(b, err)
require.NoError(b, iter.Close())
}
}
// TestTableCacheNoSuchFileError verifies that when the table cache hits a "no
// such file" error, it generates a useful fatal message.
func TestTableCacheNoSuchFileError(t *testing.T) {
const dirname = "test"
mem := vfs.NewMem()
logger := &catchFatalLogger{}
d, err := Open(dirname, &Options{
FS: mem,
Logger: logger,
})
require.NoError(t, err)
defer func() { _ = d.Close() }()
require.NoError(t, d.Set([]byte("a"), []byte("val_a"), nil))
require.NoError(t, d.Set([]byte("b"), []byte("val_b"), nil))
require.NoError(t, d.Flush())
ls, err := mem.List(dirname)
require.NoError(t, err)
// Find the sst file.
var sst string
for _, file := range ls {
if strings.HasSuffix(file, ".sst") {
if sst != "" {
t.Fatalf("multiple SSTs found: %s, %s", sst, file)
}
sst = file
}
}
if sst == "" {
t.Fatalf("no SST found after flush")
}
require.NoError(t, mem.Remove(path.Join(dirname, sst)))
_, _, _ = d.Get([]byte("a"))
require.NotZero(t, len(logger.fatalMsgs), "no fatal message emitted")
require.Equal(t, 1, len(logger.fatalMsgs), "expected one fatal message; got: %v", logger.fatalMsgs)
require.Contains(t, logger.fatalMsgs[0], "directory contains 6 files, 0 unknown, 0 tables, 2 logs, 1 manifests")
}
func BenchmarkTableCacheHotPath(b *testing.B) {
mem := vfs.NewMem()
objProvider, err := objstorageprovider.Open(objstorageprovider.DefaultSettings(mem, ""))
require.NoError(b, err)
defer objProvider.Close()
makeTable := func(dfn base.DiskFileNum) {
require.NoError(b, err)
f, _, err := objProvider.Create(context.Background(), fileTypeTable, dfn, objstorage.CreateOptions{})
require.NoError(b, err)
w := sstable.NewWriter(f, sstable.WriterOptions{})
require.NoError(b, w.Set([]byte("a"), nil))
require.NoError(b, w.Close())
}
opts := &Options{
Cache: NewCache(8 << 20), // 8 MB
}
opts.EnsureDefaults()
defer opts.Cache.Unref()
cache := &tableCacheShard{}
cache.init(2)
dbOpts := &tableCacheOpts{}
dbOpts.loggerAndTracer = &base.LoggerWithNoopTracer{Logger: opts.Logger}
dbOpts.cacheID = 0
dbOpts.objProvider = objProvider
dbOpts.opts = opts.MakeReaderOptions()
makeTable(1)
m := &fileMetadata{FileNum: 1}
m.InitPhysicalBacking()
m.Ref()
b.ResetTimer()
for i := 0; i < b.N; i++ {
v := cache.findNode(m, dbOpts)
cache.unrefValue(v)
}
}
type catchFatalLogger struct {
fatalMsgs []string
}
var _ Logger = (*catchFatalLogger)(nil)
func (tl *catchFatalLogger) Infof(format string, args ...interface{}) {}
func (tl *catchFatalLogger) Errorf(format string, args ...interface{}) {}
func (tl *catchFatalLogger) Fatalf(format string, args ...interface{}) {
tl.fatalMsgs = append(tl.fatalMsgs, fmt.Sprintf(format, args...))
}