[extension/filestorage] Change bbolt DB settings for improved performance

CHANGELOG.md

@@ -7,6 +7,7 @@
 - `cmd/mdatagen`: Add resource attributes definition to metadata.yaml and move `pdata.Metrics` creation to the
   generated code (#5270) 
 - Add `make crosslink` target to ensure replace statements are included in `go.mod` for all transitive dependencies within repository (#8822)
+- `filestorageextension`: Change bbolt DB settings for better performance (#9004)
 
 ### 🛑 Breaking changes 🛑
 

extension/storage/filestorage/client.go

@@ -33,8 +33,10 @@ type fileStorageClient struct {
 
 func newClient(filePath string, timeout time.Duration) (*fileStorageClient, error) {
 	options := &bbolt.Options{
-		Timeout: timeout,
-		NoSync:  true,
+		Timeout:        timeout,
+		NoSync:         true,
+		NoFreelistSync: true,
+		FreelistType:   bbolt.FreelistMapType,
 	}
 	db, err := bbolt.Open(filePath, 0600, options)
 	if err != nil {

extension/storage/filestorage/client_test.go

@@ -300,6 +300,76 @@ func BenchmarkClientDelete(b *testing.B) {
 	}
 }
 
+// check the performance impact of the max lifetime DB size
+// bbolt doesn't compact the freelist automatically, so there's a cost even if the data is deleted
+func BenchmarkClientSetLargeDB(b *testing.B) {
+	entrySizeInBytes := 1024 * 1024
+	entryCount := 2000
+	entry := make([]byte, entrySizeInBytes)
+	var testKey string
+
+	tempDir := newTempDir(b)
+	dbFile := filepath.Join(tempDir, "my_db")
+
+	client, err := newClient(dbFile, time.Second)
+	require.NoError(b, err)
+
+	ctx := context.Background()
+
+	for n := 0; n < entryCount; n++ {
+		testKey = fmt.Sprintf("testKey-%d", n)
+		client.Set(ctx, testKey, entry)
+	}
+
+	for n := 0; n < entryCount; n++ {
+		testKey = fmt.Sprintf("testKey-%d", n)
+		client.Delete(ctx, testKey)
+	}
+
+	testKey = "testKey"
+	testValue := []byte("testValue")
+	b.ResetTimer()
+	for n := 0; n < b.N; n++ {
+		client.Set(ctx, testKey, testValue)
+	}
+}
+
+// check the cost of opening an existing DB with data
+// this can change depending on freelist type and whether it's synced to disk
+func BenchmarkClientInitLargeDB(b *testing.B) {
+	entrySizeInBytes := 1024 * 1024
+	entry := make([]byte, entrySizeInBytes)
+	entryCount := 2000
+	var testKey string
+
+	tempDir := newTempDir(b)
+	dbFile := filepath.Join(tempDir, "my_db")
+
+	client, err := newClient(dbFile, time.Second)
+	require.NoError(b, err)
+
+	ctx := context.Background()
+
+	for n := 0; n < entryCount; n++ {
+		testKey = fmt.Sprintf("testKey-%d", n)
+		client.Set(ctx, testKey, entry)
+	}
+
+	err = client.Close(ctx)
+	require.NoError(b, err)
+
+	var tempClient *fileStorageClient
+	b.ResetTimer()
+	for n := 0; n < b.N; n++ {
+		tempClient, err = newClient(dbFile, time.Second)
+		require.NoError(b, err)
+		b.StopTimer()
+		err = tempClient.Close(ctx)
+		require.NoError(b, err)
+		b.StartTimer()
+	}
+}
+
 func newTempDir(tb testing.TB) string {
 	tempDir, err := ioutil.TempDir("", "")
 	require.NoError(tb, err)

extension/storage/filestorage/extension_test.go

@@ -270,46 +270,37 @@ func TestCompaction(t *testing.T) {
 	path := filepath.Join(tempDir, file.Name())
 	stats, err := os.Stat(path)
 	require.NoError(t, err)
-	newStats := stats
 
 	var key string
 	i := 0
 
-	// add data until database file changes size (we are checking compacted size)
-	for newStats.Size() <= stats.Size() {
-		key = fmt.Sprintf("key_%d", i)
-		err = client.Set(ctx, key, []byte(key))
-		require.NoError(t, err)
+	// magic numbers giving enough data to force bbolt to allocate a new page
+	// see https://github.com/open-telemetry/opentelemetry-collector-contrib/pull/9004 for some discussion
+	numEntries := 50
+	entrySize := 512
+	entry := make([]byte, entrySize)
 
-		// compact before checking size
-		c, fok := client.(*fileStorageClient)
-		require.True(t, fok)
-		client, err = c.Compact(ctx, tempDir, cfg.Timeout, 1)
-		require.NoError(t, err)
-
-		// check size after compaction
-		newStats, err = os.Stat(path)
+	// add the data to the db
+	for i = 0; i < numEntries; i++ {
+		key = fmt.Sprintf("key_%d", i)
+		err = client.Set(ctx, key, entry)
 		require.NoError(t, err)
-		i++
 	}
 
-	stats = newStats
-
-	// compact again just in case
+	// compact the db
 	c, ok := client.(*fileStorageClient)
 	require.True(t, ok)
 	client, err = c.Compact(ctx, tempDir, cfg.Timeout, 1)
 	require.NoError(t, err)
 
 	// check size after compaction
-	newStats, err = os.Stat(path)
+	newStats, err := os.Stat(path)
 	require.NoError(t, err)
-	require.Equal(t, stats.Size(), newStats.Size())
+	require.Less(t, stats.Size(), newStats.Size())
 
 	// remove data from database
-	for i = i - 1; i >= 0; i-- {
+	for i = 0; i < numEntries; i++ {
 		key = fmt.Sprintf("key_%d", i)
-		// Set the data
 		err = client.Delete(ctx, key)
 		require.NoError(t, err)
 	}
@@ -321,6 +312,7 @@ func TestCompaction(t *testing.T) {
 	require.NoError(t, err)
 
 	// check size
+	stats = newStats
 	newStats, err = os.Stat(path)
 	require.NoError(t, err)
 	require.Less(t, newStats.Size(), stats.Size())