Update tikv client version and add one PC support

2022-06-26 22:43:37 +08:00
parent a5bd0b3a16 dc59ccd110
commit 46e0b629e5
677 changed files with 41666 additions and 18455 deletions
--- a/weed/filer/abstract_sql/abstract_sql_store.go
+++ b/weed/filer/abstract_sql/abstract_sql_store.go
@@ -156,7 +156,7 @@ func (store *AbstractSqlStore) InsertEntry(ctx context.Context, entry *filer.Ent
 		return fmt.Errorf("encode %s: %s", entry.FullPath, err)
 	}

-	if len(entry.Chunks) > 50 {
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
 		meta = util.MaybeGzipData(meta)
 	}

--- a/weed/filer/abstract_sql/abstract_sql_store_kv.go
+++ b/weed/filer/abstract_sql/abstract_sql_store_kv.go
@@ -18,7 +18,7 @@ func (store *AbstractSqlStore) KvPut(ctx context.Context, key []byte, value []by
 		return fmt.Errorf("findDB: %v", err)
 	}

-	dirStr, dirHash, name := genDirAndName(key)
+	dirStr, dirHash, name := GenDirAndName(key)

 	res, err := db.ExecContext(ctx, store.GetSqlInsert(DEFAULT_TABLE), dirHash, name, dirStr, value)
 	if err == nil {
@@ -53,7 +53,7 @@ func (store *AbstractSqlStore) KvGet(ctx context.Context, key []byte) (value []b
 		return nil, fmt.Errorf("findDB: %v", err)
 	}

-	dirStr, dirHash, name := genDirAndName(key)
+	dirStr, dirHash, name := GenDirAndName(key)
 	row := db.QueryRowContext(ctx, store.GetSqlFind(DEFAULT_TABLE), dirHash, name, dirStr)

 	err = row.Scan(&value)
@@ -76,7 +76,7 @@ func (store *AbstractSqlStore) KvDelete(ctx context.Context, key []byte) (err er
 		return fmt.Errorf("findDB: %v", err)
 	}

-	dirStr, dirHash, name := genDirAndName(key)
+	dirStr, dirHash, name := GenDirAndName(key)

 	res, err := db.ExecContext(ctx, store.GetSqlDelete(DEFAULT_TABLE), dirHash, name, dirStr)
 	if err != nil {
@@ -92,7 +92,7 @@ func (store *AbstractSqlStore) KvDelete(ctx context.Context, key []byte) (err er

 }

-func genDirAndName(key []byte) (dirStr string, dirHash int64, name string) {
+func GenDirAndName(key []byte) (dirStr string, dirHash int64, name string) {
 	for len(key) < 8 {
 		key = append(key, 0)
 	}
--- a/weed/filer/arangodb/arangodb_store.go
+++ b/weed/filer/arangodb/arangodb_store.go
@@ -0,0 +1,347 @@
+package arangodb
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/arangodb/go-driver"
+	"github.com/arangodb/go-driver/http"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+func init() {
+	filer.Stores = append(filer.Stores, &ArangodbStore{})
+}
+
+var (
+	BUCKET_PREFIX      = "/buckets"
+	DEFAULT_COLLECTION = "seaweed_no_bucket"
+	KVMETA_COLLECTION  = "seaweed_kvmeta"
+)
+
+type ArangodbStore struct {
+	connect      driver.Connection
+	client       driver.Client
+	database     driver.Database
+	kvCollection driver.Collection
+
+	buckets map[string]driver.Collection
+	mu      sync.RWMutex
+
+	databaseName string
+}
+
+type Model struct {
+	Key       string `json:"_key"`
+	Directory string `json:"directory,omitempty"`
+	Name      string `json:"name,omitempty"`
+	Ttl       string `json:"ttl,omitempty"`
+
+	//arangodb does not support binary blobs
+	//we encode byte slice into uint64 slice
+	//see helpers.go
+	Meta []uint64 `json:"meta"`
+}
+
+func (store *ArangodbStore) GetName() string {
+	return "arangodb"
+}
+
+func (store *ArangodbStore) Initialize(configuration util.Configuration, prefix string) (err error) {
+	store.buckets = make(map[string]driver.Collection, 3)
+	store.databaseName = configuration.GetString(prefix + "db_name")
+	return store.connection(configuration.GetStringSlice(prefix+"servers"),
+		configuration.GetString(prefix+"username"),
+		configuration.GetString(prefix+"password"),
+		configuration.GetBool(prefix+"insecure_skip_verify"),
+	)
+}
+
+func (store *ArangodbStore) connection(uris []string, user string, pass string, insecure bool) (err error) {
+	ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
+
+	store.connect, err = http.NewConnection(http.ConnectionConfig{
+		Endpoints: uris,
+		TLSConfig: &tls.Config{
+			InsecureSkipVerify: insecure,
+		},
+	})
+	if err != nil {
+		return err
+	}
+	store.client, err = driver.NewClient(driver.ClientConfig{
+		Connection:     store.connect,
+		Authentication: driver.BasicAuthentication(user, pass),
+	})
+	if err != nil {
+		return err
+	}
+	ok, err := store.client.DatabaseExists(ctx, store.databaseName)
+	if err != nil {
+		return err
+	}
+	if ok {
+		store.database, err = store.client.Database(ctx, store.databaseName)
+	} else {
+		store.database, err = store.client.CreateDatabase(ctx, store.databaseName, &driver.CreateDatabaseOptions{})
+	}
+	if err != nil {
+		return err
+	}
+	if store.kvCollection, err = store.ensureCollection(ctx, KVMETA_COLLECTION); err != nil {
+		return err
+	}
+	return err
+}
+
+type key int
+
+const (
+	transactionKey key = 0
+)
+
+func (store *ArangodbStore) BeginTransaction(ctx context.Context) (context.Context, error) {
+	keys := make([]string, 0, len(store.buckets)+1)
+	for k := range store.buckets {
+		keys = append(keys, k)
+	}
+	keys = append(keys, store.kvCollection.Name())
+	txn, err := store.database.BeginTransaction(ctx, driver.TransactionCollections{
+		Exclusive: keys,
+	}, &driver.BeginTransactionOptions{})
+	if err != nil {
+		return nil, err
+	}
+
+	return context.WithValue(ctx, transactionKey, txn), nil
+}
+
+func (store *ArangodbStore) CommitTransaction(ctx context.Context) error {
+	val := ctx.Value(transactionKey)
+	cast, ok := val.(driver.TransactionID)
+	if !ok {
+		return fmt.Errorf("txn cast fail %s:", val)
+	}
+	err := store.database.CommitTransaction(ctx, cast, &driver.CommitTransactionOptions{})
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (store *ArangodbStore) RollbackTransaction(ctx context.Context) error {
+	val := ctx.Value(transactionKey)
+	cast, ok := val.(driver.TransactionID)
+	if !ok {
+		return fmt.Errorf("txn cast fail %s:", val)
+	}
+	err := store.database.AbortTransaction(ctx, cast, &driver.AbortTransactionOptions{})
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (store *ArangodbStore) InsertEntry(ctx context.Context, entry *filer.Entry) (err error) {
+	dir, name := entry.FullPath.DirAndName()
+	meta, err := entry.EncodeAttributesAndChunks()
+	if err != nil {
+		return fmt.Errorf("encode %s: %s", entry.FullPath, err)
+	}
+
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
+		meta = util.MaybeGzipData(meta)
+	}
+	model := &Model{
+		Key:       hashString(string(entry.FullPath)),
+		Directory: dir,
+		Name:      name,
+		Meta:      bytesToArray(meta),
+	}
+	if entry.TtlSec > 0 {
+		model.Ttl = time.Now().Add(time.Second * time.Duration(entry.TtlSec)).Format(time.RFC3339)
+	} else {
+		model.Ttl = ""
+	}
+
+	targetCollection, err := store.extractBucketCollection(ctx, entry.FullPath)
+	if err != nil {
+		return err
+	}
+	_, err = targetCollection.CreateDocument(ctx, model)
+	if driver.IsConflict(err) {
+		return store.UpdateEntry(ctx, entry)
+	}
+
+	if err != nil {
+		return fmt.Errorf("InsertEntry %s: %v", entry.FullPath, err)
+	}
+
+	return nil
+
+}
+
+func (store *ArangodbStore) UpdateEntry(ctx context.Context, entry *filer.Entry) (err error) {
+	dir, name := entry.FullPath.DirAndName()
+	meta, err := entry.EncodeAttributesAndChunks()
+	if err != nil {
+		return fmt.Errorf("encode %s: %s", entry.FullPath, err)
+	}
+
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
+		meta = util.MaybeGzipData(meta)
+	}
+	model := &Model{
+		Key:       hashString(string(entry.FullPath)),
+		Directory: dir,
+		Name:      name,
+		Meta:      bytesToArray(meta),
+	}
+	if entry.TtlSec > 0 {
+		model.Ttl = time.Now().Add(time.Duration(entry.TtlSec) * time.Second).Format(time.RFC3339)
+	} else {
+		model.Ttl = "none"
+	}
+	targetCollection, err := store.extractBucketCollection(ctx, entry.FullPath)
+	if err != nil {
+		return err
+	}
+	_, err = targetCollection.UpdateDocument(ctx, model.Key, model)
+	if err != nil {
+		return fmt.Errorf("UpdateEntry %s: %v", entry.FullPath, err)
+	}
+
+	return nil
+}
+
+func (store *ArangodbStore) FindEntry(ctx context.Context, fullpath util.FullPath) (entry *filer.Entry, err error) {
+	var data Model
+	targetCollection, err := store.extractBucketCollection(ctx, fullpath)
+	if err != nil {
+		return nil, err
+	}
+	_, err = targetCollection.ReadDocument(ctx, hashString(string(fullpath)), &data)
+	if err != nil {
+		if driver.IsNotFound(err) {
+			return nil, filer_pb.ErrNotFound
+		}
+		glog.Errorf("find %s: %v", fullpath, err)
+		return nil, filer_pb.ErrNotFound
+	}
+	if len(data.Meta) == 0 {
+		return nil, filer_pb.ErrNotFound
+	}
+	entry = &filer.Entry{
+		FullPath: fullpath,
+	}
+	err = entry.DecodeAttributesAndChunks(util.MaybeDecompressData(arrayToBytes(data.Meta)))
+	if err != nil {
+		return entry, fmt.Errorf("decode %s : %v", entry.FullPath, err)
+	}
+
+	return entry, nil
+}
+
+func (store *ArangodbStore) DeleteEntry(ctx context.Context, fullpath util.FullPath) (err error) {
+	targetCollection, err := store.extractBucketCollection(ctx, fullpath)
+	if err != nil {
+		return err
+	}
+	_, err = targetCollection.RemoveDocument(ctx, hashString(string(fullpath)))
+	if err != nil && !driver.IsNotFound(err) {
+		glog.Errorf("find %s: %v", fullpath, err)
+		return fmt.Errorf("delete %s : %v", fullpath, err)
+	}
+	return nil
+}
+
+// this runs in log time
+func (store *ArangodbStore) DeleteFolderChildren(ctx context.Context, fullpath util.FullPath) (err error) {
+	var query string
+	targetCollection, err := store.extractBucketCollection(ctx, fullpath)
+	if err != nil {
+		return err
+	}
+	query = query + fmt.Sprintf(`
+	for d in %s
+	filter starts_with(d.directory, "%s/")  || d.directory == "%s"
+	remove d._key in %s`,
+		targetCollection.Name(),
+		strings.Join(strings.Split(string(fullpath), "/"), ","),
+		string(fullpath),
+		targetCollection.Name(),
+	)
+	cur, err := store.database.Query(ctx, query, nil)
+	if err != nil {
+		return fmt.Errorf("delete %s : %v", fullpath, err)
+	}
+	defer cur.Close()
+	return nil
+}
+
+func (store *ArangodbStore) ListDirectoryEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, eachEntryFunc filer.ListEachEntryFunc) (lastFileName string, err error) {
+	return store.ListDirectoryPrefixedEntries(ctx, dirPath, startFileName, includeStartFile, limit, "", eachEntryFunc)
+}
+
+func (store *ArangodbStore) ListDirectoryPrefixedEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, prefix string, eachEntryFunc filer.ListEachEntryFunc) (lastFileName string, err error) {
+	targetCollection, err := store.extractBucketCollection(ctx, dirPath+"/")
+	if err != nil {
+		return lastFileName, err
+	}
+	query := "for d in " + targetCollection.Name()
+	if includeStartFile {
+		query = query + " filter d.name >= \"" + startFileName + "\" "
+	} else {
+		query = query + " filter d.name > \"" + startFileName + "\" "
+	}
+	if prefix != "" {
+		query = query + fmt.Sprintf(`&& starts_with(d.name, "%s")`, prefix)
+	}
+	query = query + `
+filter d.directory == @dir
+sort d.name asc
+`
+	if limit > 0 {
+		query = query + "limit " + strconv.Itoa(int(limit))
+	}
+	query = query + "\n return d"
+	cur, err := store.database.Query(ctx, query, map[string]interface{}{"dir": dirPath})
+	if err != nil {
+		return lastFileName, fmt.Errorf("failed to list directory entries: find error: %w", err)
+	}
+	defer cur.Close()
+	for cur.HasMore() {
+		var data Model
+		_, err = cur.ReadDocument(ctx, &data)
+		if err != nil {
+			break
+		}
+		entry := &filer.Entry{
+			FullPath: util.NewFullPath(data.Directory, data.Name),
+		}
+		lastFileName = data.Name
+		converted := arrayToBytes(data.Meta)
+		if decodeErr := entry.DecodeAttributesAndChunks(util.MaybeDecompressData(converted)); decodeErr != nil {
+			err = decodeErr
+			glog.V(0).Infof("list %s : %v", entry.FullPath, err)
+			break
+		}
+
+		if !eachEntryFunc(entry) {
+			break
+		}
+
+	}
+	return lastFileName, err
+}
+
+func (store *ArangodbStore) Shutdown() {
+}
--- a/weed/filer/arangodb/arangodb_store_bucket.go
+++ b/weed/filer/arangodb/arangodb_store_bucket.go
@@ -0,0 +1,40 @@
+package arangodb
+
+import (
+	"context"
+	"github.com/arangodb/go-driver"
+	"time"
+
+	"github.com/chrislusf/seaweedfs/weed/filer"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+)
+
+var _ filer.BucketAware = (*ArangodbStore)(nil)
+
+func (store *ArangodbStore) OnBucketCreation(bucket string) {
+	timeout, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	// create the collection && add to cache
+	_, err := store.ensureBucket(timeout, bucket)
+	if err != nil {
+		glog.Errorf("bucket create %s: %v", bucket, err)
+	}
+}
+func (store *ArangodbStore) OnBucketDeletion(bucket string) {
+	timeout, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	collection, err := store.ensureBucket(timeout, bucket)
+	if err != nil {
+		glog.Errorf("bucket delete %s: %v", bucket, err)
+		return
+	}
+	err = collection.Remove(timeout)
+	if err != nil && !driver.IsNotFound(err) {
+		glog.Errorf("bucket delete %s: %v", bucket, err)
+		return
+	}
+}
+func (store *ArangodbStore) CanDropWholeBucket() bool {
+	return true
+}
--- a/weed/filer/arangodb/arangodb_store_kv.go
+++ b/weed/filer/arangodb/arangodb_store_kv.go
@@ -0,0 +1,54 @@
+package arangodb
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/arangodb/go-driver"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+)
+
+func (store *ArangodbStore) KvPut(ctx context.Context, key []byte, value []byte) (err error) {
+	model := &Model{
+		Key:       hashString(".kvstore." + string(key)),
+		Directory: ".kvstore." + string(key),
+		Meta:      bytesToArray(value),
+	}
+
+	exists, err := store.kvCollection.DocumentExists(ctx, model.Key)
+	if err != nil {
+		return fmt.Errorf("kv put: %v", err)
+	}
+	if exists {
+		_, err = store.kvCollection.UpdateDocument(ctx, model.Key, model)
+	} else {
+		_, err = store.kvCollection.CreateDocument(ctx, model)
+	}
+	if err != nil {
+		return fmt.Errorf("kv put: %v", err)
+	}
+
+	return nil
+}
+func (store *ArangodbStore) KvGet(ctx context.Context, key []byte) (value []byte, err error) {
+	var model Model
+	_, err = store.kvCollection.ReadDocument(ctx, hashString(".kvstore."+string(key)), &model)
+	if driver.IsNotFound(err) {
+		return nil, filer.ErrKvNotFound
+	}
+	if err != nil {
+		glog.Errorf("kv get: %s %v", string(key), err)
+		return nil, filer.ErrKvNotFound
+	}
+	return arrayToBytes(model.Meta), nil
+}
+
+func (store *ArangodbStore) KvDelete(ctx context.Context, key []byte) (err error) {
+	_, err = store.kvCollection.RemoveDocument(ctx, hashString(".kvstore."+string(key)))
+	if err != nil {
+		glog.Errorf("kv del: %v", err)
+		return filer.ErrKvNotFound
+	}
+	return nil
+}
--- a/weed/filer/arangodb/helpers.go
+++ b/weed/filer/arangodb/helpers.go
@@ -0,0 +1,136 @@
+package arangodb
+
+import (
+	"context"
+	"crypto/md5"
+	"encoding/binary"
+	"encoding/hex"
+	"io"
+	"strings"
+
+	"github.com/arangodb/go-driver"
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+//convert a string into arango-key safe hex bytes hash
+func hashString(dir string) string {
+	h := md5.New()
+	io.WriteString(h, dir)
+	b := h.Sum(nil)
+	return hex.EncodeToString(b)
+}
+
+// convert slice of bytes into slice of uint64
+// the first uint64 indicates the length in bytes
+func bytesToArray(bs []byte) []uint64 {
+	out := make([]uint64, 0, 2+len(bs)/8)
+	out = append(out, uint64(len(bs)))
+	for len(bs)%8 != 0 {
+		bs = append(bs, 0)
+	}
+	for i := 0; i < len(bs); i = i + 8 {
+		out = append(out, binary.BigEndian.Uint64(bs[i:]))
+	}
+	return out
+}
+
+// convert from slice of uint64 back to bytes
+// if input length is 0 or 1, will return nil
+func arrayToBytes(xs []uint64) []byte {
+	if len(xs) < 2 {
+		return nil
+	}
+	first := xs[0]
+	out := make([]byte, len(xs)*8) // i think this can actually be len(xs)*8-8, but i dont think an extra 8 bytes hurts...
+	for i := 1; i < len(xs); i = i + 1 {
+		binary.BigEndian.PutUint64(out[((i-1)*8):], xs[i])
+	}
+	return out[:first]
+}
+
+// gets the collection the bucket points to from filepath
+func (store *ArangodbStore) extractBucketCollection(ctx context.Context, fullpath util.FullPath) (c driver.Collection, err error) {
+	bucket, _ := extractBucket(fullpath)
+	if bucket == "" {
+		bucket = DEFAULT_COLLECTION
+	}
+	c, err = store.ensureBucket(ctx, bucket)
+	if err != nil {
+		return nil, err
+	}
+	return c, err
+}
+
+// called by extractBucketCollection
+func extractBucket(fullpath util.FullPath) (string, string) {
+	if !strings.HasPrefix(string(fullpath), BUCKET_PREFIX+"/") {
+		return "", string(fullpath)
+	}
+	if strings.Count(string(fullpath), "/") < 3 {
+		return "", string(fullpath)
+	}
+	bucketAndObjectKey := string(fullpath)[len(BUCKET_PREFIX+"/"):]
+	t := strings.Index(bucketAndObjectKey, "/")
+	bucket := bucketAndObjectKey
+	shortPath := "/"
+	if t > 0 {
+		bucket = bucketAndObjectKey[:t]
+		shortPath = string(util.FullPath(bucketAndObjectKey[t:]))
+	}
+	return bucket, shortPath
+}
+
+// get bucket collection from cache. if not exist, creates the buckets collection and grab it
+func (store *ArangodbStore) ensureBucket(ctx context.Context, bucket string) (bc driver.Collection, err error) {
+	var ok bool
+	store.mu.RLock()
+	bc, ok = store.buckets[bucket]
+	store.mu.RUnlock()
+	if ok {
+		return bc, nil
+	}
+	store.mu.Lock()
+	defer store.mu.Unlock()
+	store.buckets[bucket], err = store.ensureCollection(ctx, bucket)
+	if err != nil {
+		return nil, err
+	}
+	return store.buckets[bucket], nil
+}
+
+// creates collection if not exist, ensures indices if not exist
+func (store *ArangodbStore) ensureCollection(ctx context.Context, name string) (c driver.Collection, err error) {
+	ok, err := store.database.CollectionExists(ctx, name)
+	if err != nil {
+		return
+	}
+	if ok {
+		c, err = store.database.Collection(ctx, name)
+	} else {
+		c, err = store.database.CreateCollection(ctx, name, &driver.CreateCollectionOptions{})
+	}
+	if err != nil {
+		return
+	}
+	// ensure indices
+	if _, _, err = c.EnsurePersistentIndex(ctx, []string{"directory", "name"},
+		&driver.EnsurePersistentIndexOptions{
+			Name: "directory_name_multi", Unique: true,
+		}); err != nil {
+		return
+	}
+	if _, _, err = c.EnsurePersistentIndex(ctx, []string{"directory"},
+		&driver.EnsurePersistentIndexOptions{Name: "IDX_directory"}); err != nil {
+		return
+	}
+	if _, _, err = c.EnsureTTLIndex(ctx, "ttl", 1,
+		&driver.EnsureTTLIndexOptions{Name: "IDX_TTL"}); err != nil {
+		return
+	}
+	if _, _, err = c.EnsurePersistentIndex(ctx, []string{"name"}, &driver.EnsurePersistentIndexOptions{
+		Name: "IDX_name",
+	}); err != nil {
+		return
+	}
+	return c, nil
+}
--- a/weed/filer/arangodb/readme.md
+++ b/weed/filer/arangodb/readme.md
@@ -0,0 +1,52 @@
+##arangodb
+
+database: https://github.com/arangodb/arangodb
+go driver: https://github.com/arangodb/go-driver
+
+options:
+
+```
+[arangodb]
+enabled=true
+db_name="seaweedfs"
+servers=["http://localhost:8529"]
+#basic auth
+user="root"
+pass="test"
+
+# tls settings
+insecure_skip_verify=true
+```
+
+i test using this dev database:
+`docker run -p 8529:8529 -e ARANGO_ROOT_PASSWORD=test arangodb/arangodb:3.9.0`
+
+
+## features i don't personally need but are missing
+ [ ] provide tls cert to arango
+ [ ] authentication that is not basic auth
+ [ ] synchronise endpoint interval config
+ [ ] automatic creation of custom index
+ [ ] configure default arangodb collection sharding rules
+ [ ] configure default arangodb collection replication rules
+
+
+## complexity
+
+ok, so if https://www.arangodb.com/docs/stable/indexing-index-basics.html#persistent-index is correct
+
+O(1)
+- InsertEntry
+- UpdateEntry
+- FindEntry
+- DeleteEntry
+- KvPut
+- KvGet
+- KvDelete
+
+O(log(BUCKET_SIZE))
+- DeleteFolderChildren
+
+O(log(DIRECTORY_SIZE))
+- ListDirectoryEntries
+- ListDirectoryPrefixedEntries
--- a/weed/filer/cassandra/cassandra_store.go
+++ b/weed/filer/cassandra/cassandra_store.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"github.com/gocql/gocql"
+	"time"

 	"github.com/chrislusf/seaweedfs/weed/filer"
 	"github.com/chrislusf/seaweedfs/weed/glog"
@@ -33,6 +34,7 @@ func (store *CassandraStore) Initialize(configuration util.Configuration, prefix
 		configuration.GetString(prefix+"password"),
 		configuration.GetStringSlice(prefix+"superLargeDirectories"),
 		configuration.GetString(prefix+"localDC"),
+		configuration.GetInt(prefix+"connection_timeout_millisecond"),
 	)
 }

@@ -41,12 +43,14 @@ func (store *CassandraStore) isSuperLargeDirectory(dir string) (dirHash string,
 	return
 }

-func (store *CassandraStore) initialize(keyspace string, hosts []string, username string, password string, superLargeDirectories []string, localDC string) (err error) {
+func (store *CassandraStore) initialize(keyspace string, hosts []string, username string, password string, superLargeDirectories []string, localDC string, timeout int) (err error) {
 	store.cluster = gocql.NewCluster(hosts...)
 	if username != "" && password != "" {
 		store.cluster.Authenticator = gocql.PasswordAuthenticator{Username: username, Password: password}
 	}
 	store.cluster.Keyspace = keyspace
+	store.cluster.Timeout = time.Duration(timeout) * time.Millisecond
+	glog.V(0).Infof("timeout = %d", timeout)
 	fallback := gocql.RoundRobinHostPolicy()
 	if localDC != "" {
 		fallback = gocql.DCAwareRoundRobinPolicy(localDC)
@@ -96,7 +100,7 @@ func (store *CassandraStore) InsertEntry(ctx context.Context, entry *filer.Entry
 		return fmt.Errorf("encode %s: %s", entry.FullPath, err)
 	}

-	if len(entry.Chunks) > 50 {
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
 		meta = util.MaybeGzipData(meta)
 	}

--- a/weed/filer/configuration.go
+++ b/weed/filer/configuration.go
@@ -12,7 +12,7 @@ var (
 	Stores []FilerStore
 )

-func (f *Filer) LoadConfiguration(config *util.ViperProxy) {
+func (f *Filer) LoadConfiguration(config *util.ViperProxy) (isFresh bool) {

 	validateOneEnabledStore(config)

@@ -24,7 +24,7 @@ func (f *Filer) LoadConfiguration(config *util.ViperProxy) {
 			if err := store.Initialize(config, store.GetName()+"."); err != nil {
 				glog.Fatalf("failed to initialize store for %s: %+v", store.GetName(), err)
 			}
-			f.SetStore(store)
+			isFresh = f.SetStore(store)
 			glog.V(0).Infof("configured filer store to %s", store.GetName())
 			hasDefaultStoreConfigured = true
 			break
@@ -77,6 +77,7 @@ func (f *Filer) LoadConfiguration(config *util.ViperProxy) {
 		glog.V(0).Infof("configure filer %s for %s", store.GetName(), location)
 	}

+	return
 }

 func validateOneEnabledStore(config *util.ViperProxy) {
--- a/weed/filer/elastic/v7/doc.go
+++ b/weed/filer/elastic/v7/doc.go
@@ -0,0 +1,9 @@
+/*
+
+Package elastic is for elastic filer store.
+
+The referenced "github.com/olivere/elastic/v7" library is too big when compiled.
+So this is only compiled in "make full_install".
+
+*/
+package elastic
--- a/weed/filer/elastic/v7/elastic_store.go
+++ b/weed/filer/elastic/v7/elastic_store.go
@@ -1,3 +1,6 @@
+//go:build elastic
+// +build elastic
+
 package elastic

 import (
--- a/weed/filer/elastic/v7/elastic_store_kv.go
+++ b/weed/filer/elastic/v7/elastic_store_kv.go
@@ -1,3 +1,6 @@
+//go:build elastic
+// +build elastic
+
 package elastic

 import (
--- a/weed/filer/entry.go
+++ b/weed/filer/entry.go
@@ -15,15 +15,14 @@ type Attr struct {
 	Uid           uint32      // owner uid
 	Gid           uint32      // group gid
 	Mime          string      // mime type
-	Replication   string      // replication
-	Collection    string      // collection name
 	TtlSec        int32       // ttl in seconds
-	DiskType      string
 	UserName      string
 	GroupNames    []string
 	SymlinkTarget string
 	Md5           []byte
 	FileSize      uint64
+	Rdev          uint32
+	Inode         uint64
 }

 func (attr Attr) IsDirectory() bool {
@@ -43,6 +42,7 @@ type Entry struct {
 	HardLinkCounter int32
 	Content         []byte
 	Remote          *filer_pb.RemoteEntry
+	Quota           int64
 }

 func (entry *Entry) Size() uint64 {
@@ -70,6 +70,7 @@ func (entry *Entry) ShallowClone() *Entry {
 	newEntry.HardLinkCounter = entry.HardLinkCounter
 	newEntry.Content = entry.Content
 	newEntry.Remote = entry.Remote
+	newEntry.Quota = entry.Quota

 	return newEntry
 }
@@ -96,6 +97,7 @@ func (entry *Entry) ToExistingProtoEntry(message *filer_pb.Entry) {
 	message.HardLinkCounter = entry.HardLinkCounter
 	message.Content = entry.Content
 	message.RemoteEntry = entry.Remote
+	message.Quota = entry.Quota
 }

 func FromPbEntryToExistingEntry(message *filer_pb.Entry, fsEntry *Entry) {
@@ -106,6 +108,7 @@ func FromPbEntryToExistingEntry(message *filer_pb.Entry, fsEntry *Entry) {
 	fsEntry.HardLinkCounter = message.HardLinkCounter
 	fsEntry.Content = message.Content
 	fsEntry.Remote = message.RemoteEntry
+	fsEntry.Quota = message.Quota
 }

 func (entry *Entry) ToProtoFullEntry() *filer_pb.FullEntry {
--- a/weed/filer/entry_codec.go
+++ b/weed/filer/entry_codec.go
@@ -39,15 +39,14 @@ func EntryAttributeToPb(entry *Entry) *filer_pb.FuseAttributes {
 		Uid:           entry.Uid,
 		Gid:           entry.Gid,
 		Mime:          entry.Mime,
-		Collection:    entry.Attr.Collection,
-		Replication:   entry.Attr.Replication,
 		TtlSec:        entry.Attr.TtlSec,
-		DiskType:      entry.Attr.DiskType,
 		UserName:      entry.Attr.UserName,
 		GroupName:     entry.Attr.GroupNames,
 		SymlinkTarget: entry.Attr.SymlinkTarget,
 		Md5:           entry.Attr.Md5,
 		FileSize:      entry.Attr.FileSize,
+		Rdev:          entry.Attr.Rdev,
+		Inode:         entry.Attr.Inode,
 	}
 }

@@ -65,15 +64,14 @@ func PbToEntryAttribute(attr *filer_pb.FuseAttributes) Attr {
 	t.Uid = attr.Uid
 	t.Gid = attr.Gid
 	t.Mime = attr.Mime
-	t.Collection = attr.Collection
-	t.Replication = attr.Replication
 	t.TtlSec = attr.TtlSec
-	t.DiskType = attr.DiskType
 	t.UserName = attr.UserName
 	t.GroupNames = attr.GroupName
 	t.SymlinkTarget = attr.SymlinkTarget
 	t.Md5 = attr.Md5
 	t.FileSize = attr.FileSize
+	t.Rdev = attr.Rdev
+	t.Inode = attr.Inode

 	return t
 }
@@ -118,6 +116,9 @@ func EqualEntry(a, b *Entry) bool {
 	if !proto.Equal(a.Remote, b.Remote) {
 		return false
 	}
+	if a.Quota != b.Quota {
+		return false
+	}
 	return true
 }

--- a/weed/filer/etcd/etcd_store.go
+++ b/weed/filer/etcd/etcd_store.go
@@ -7,7 +7,7 @@ import (
 	"strings"
 	"time"

-	"go.etcd.io/etcd/clientv3"
+	"go.etcd.io/etcd/client/v3"

 	"github.com/chrislusf/seaweedfs/weed/filer"
 	"github.com/chrislusf/seaweedfs/weed/glog"
@@ -82,7 +82,7 @@ func (store *EtcdStore) InsertEntry(ctx context.Context, entry *filer.Entry) (er
 		return fmt.Errorf("encoding %s %+v: %v", entry.FullPath, entry.Attr, err)
 	}

-	if len(entry.Chunks) > 50 {
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
 		meta = weed_util.MaybeGzipData(meta)
 	}

@@ -152,7 +152,7 @@ func (store *EtcdStore) ListDirectoryEntries(ctx context.Context, dirPath weed_u
 	}

 	resp, err := store.client.Get(ctx, string(lastFileStart),
-		clientv3.WithPrefix(), clientv3.WithSort(clientv3.SortByKey, clientv3.SortDescend))
+		clientv3.WithFromKey(), clientv3.WithLimit(limit+1))
 	if err != nil {
 		return lastFileName, fmt.Errorf("list %s : %v", dirPath, err)
 	}
--- a/weed/filer/etcd/etcd_store_test.go
+++ b/weed/filer/etcd/etcd_store_test.go
@@ -0,0 +1,16 @@
+package etcd
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/filer/store_test"
+	"testing"
+)
+
+func TestStore(t *testing.T) {
+	// run "make test_etcd" under docker folder.
+	// to set up local env
+	if false {
+		store := &EtcdStore{}
+		store.initialize("localhost:2379", "3s")
+		store_test.TestFilerStore(t, store)
+	}
+}
--- a/weed/filer/filechunk_manifest.go
+++ b/weed/filer/filechunk_manifest.go
@@ -3,11 +3,15 @@ package filer
 import (
 	"bytes"
 	"fmt"
-	"github.com/chrislusf/seaweedfs/weed/wdclient"
 	"io"
 	"math"
+	"net/url"
+	"strings"
+	"sync"
 	"time"

+	"github.com/chrislusf/seaweedfs/weed/wdclient"
+
 	"github.com/golang/protobuf/proto"

 	"github.com/chrislusf/seaweedfs/weed/glog"
@@ -19,6 +23,12 @@ const (
 	ManifestBatch = 10000
 )

+var bytesBufferPool = sync.Pool{
+	New: func() interface{} {
+		return new(bytes.Buffer)
+	},
+}
+
 func HasChunkManifest(chunks []*filer_pb.FileChunk) bool {
 	for _, chunk := range chunks {
 		if chunk.IsChunkManifest {
@@ -54,17 +64,17 @@ func ResolveChunkManifest(lookupFileIdFn wdclient.LookupFileIdFunctionType, chun

 		resolvedChunks, err := ResolveOneChunkManifest(lookupFileIdFn, chunk)
 		if err != nil {
-			return chunks, nil, err
+			return dataChunks, nil, err
 		}

 		manifestChunks = append(manifestChunks, chunk)
 		// recursive
-		dchunks, mchunks, subErr := ResolveChunkManifest(lookupFileIdFn, resolvedChunks, startOffset, stopOffset)
+		subDataChunks, subManifestChunks, subErr := ResolveChunkManifest(lookupFileIdFn, resolvedChunks, startOffset, stopOffset)
 		if subErr != nil {
-			return chunks, nil, subErr
+			return dataChunks, nil, subErr
 		}
-		dataChunks = append(dataChunks, dchunks...)
-		manifestChunks = append(manifestChunks, mchunks...)
+		dataChunks = append(dataChunks, subDataChunks...)
+		manifestChunks = append(manifestChunks, subManifestChunks...)
 	}
 	return
 }
@@ -75,12 +85,15 @@ func ResolveOneChunkManifest(lookupFileIdFn wdclient.LookupFileIdFunctionType, c
 	}

 	// IsChunkManifest
-	data, err := fetchChunk(lookupFileIdFn, chunk.GetFileIdString(), chunk.CipherKey, chunk.IsCompressed)
+	bytesBuffer := bytesBufferPool.Get().(*bytes.Buffer)
+	bytesBuffer.Reset()
+	defer bytesBufferPool.Put(bytesBuffer)
+	err := fetchWholeChunk(bytesBuffer, lookupFileIdFn, chunk.GetFileIdString(), chunk.CipherKey, chunk.IsCompressed)
 	if err != nil {
 		return nil, fmt.Errorf("fail to read manifest %s: %v", chunk.GetFileIdString(), err)
 	}
 	m := &filer_pb.FileChunkManifest{}
-	if err := proto.Unmarshal(data, m); err != nil {
+	if err := proto.Unmarshal(bytesBuffer.Bytes(), m); err != nil {
 		return nil, fmt.Errorf("fail to unmarshal manifest %s: %v", chunk.GetFileIdString(), err)
 	}

@@ -90,26 +103,43 @@ func ResolveOneChunkManifest(lookupFileIdFn wdclient.LookupFileIdFunctionType, c
 }

 // TODO fetch from cache for weed mount?
-func fetchChunk(lookupFileIdFn wdclient.LookupFileIdFunctionType, fileId string, cipherKey []byte, isGzipped bool) ([]byte, error) {
+func fetchWholeChunk(bytesBuffer *bytes.Buffer, lookupFileIdFn wdclient.LookupFileIdFunctionType, fileId string, cipherKey []byte, isGzipped bool) error {
 	urlStrings, err := lookupFileIdFn(fileId)
 	if err != nil {
 		glog.Errorf("operation LookupFileId %s failed, err: %v", fileId, err)
-		return nil, err
+		return err
 	}
-	return retriedFetchChunkData(urlStrings, cipherKey, isGzipped, true, 0, 0)
+	err = retriedStreamFetchChunkData(bytesBuffer, urlStrings, cipherKey, isGzipped, true, 0, 0)
+	if err != nil {
+		return err
+	}
+	return nil
 }

-func retriedFetchChunkData(urlStrings []string, cipherKey []byte, isGzipped bool, isFullChunk bool, offset int64, size int) ([]byte, error) {
+func fetchChunkRange(buffer []byte, lookupFileIdFn wdclient.LookupFileIdFunctionType, fileId string, cipherKey []byte, isGzipped bool, offset int64) (int, error) {
+	urlStrings, err := lookupFileIdFn(fileId)
+	if err != nil {
+		glog.Errorf("operation LookupFileId %s failed, err: %v", fileId, err)
+		return 0, err
+	}
+	return retriedFetchChunkData(buffer, urlStrings, cipherKey, isGzipped, false, offset)
+}
+
+func retriedFetchChunkData(buffer []byte, urlStrings []string, cipherKey []byte, isGzipped bool, isFullChunk bool, offset int64) (n int, err error) {

-	var err error
 	var shouldRetry bool
-	receivedData := make([]byte, 0, size)

 	for waitTime := time.Second; waitTime < util.RetryWaitTime; waitTime += waitTime / 2 {
 		for _, urlString := range urlStrings {
-			receivedData = receivedData[:0]
-			shouldRetry, err = util.ReadUrlAsStream(urlString+"?readDeleted=true", cipherKey, isGzipped, isFullChunk, offset, size, func(data []byte) {
-				receivedData = append(receivedData, data...)
+			n = 0
+			if strings.Contains(urlString, "%") {
+				urlString = url.PathEscape(urlString)
+			}
+			shouldRetry, err = util.ReadUrlAsStream(urlString+"?readDeleted=true", cipherKey, isGzipped, isFullChunk, offset, len(buffer), func(data []byte) {
+				if n < len(buffer) {
+					x := copy(buffer[n:], data)
+					n += x
+				}
 			})
 			if !shouldRetry {
 				break
@@ -128,7 +158,7 @@ func retriedFetchChunkData(urlStrings []string, cipherKey []byte, isGzipped bool
 		}
 	}

-	return receivedData, err
+	return n, err

 }

--- a/weed/filer/filechunks.go
+++ b/weed/filer/filechunks.go
@@ -3,11 +3,12 @@ package filer
 import (
 	"bytes"
 	"fmt"
-	"github.com/chrislusf/seaweedfs/weed/wdclient"
 	"math"
-	"sort"
 	"sync"

+	"github.com/chrislusf/seaweedfs/weed/wdclient"
+	"golang.org/x/exp/slices"
+
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 	"github.com/chrislusf/seaweedfs/weed/util"
 )
@@ -23,7 +24,16 @@ func TotalSize(chunks []*filer_pb.FileChunk) (size uint64) {
 }

 func FileSize(entry *filer_pb.Entry) (size uint64) {
-	return maxUint64(TotalSize(entry.Chunks), entry.Attributes.FileSize)
+	if entry == nil || entry.Attributes == nil {
+		return 0
+	}
+	fileSize := entry.Attributes.FileSize
+	if entry.RemoteEntry != nil {
+		if entry.RemoteEntry.RemoteMtime > entry.Attributes.Mtime {
+			fileSize = maxUint64(fileSize, uint64(entry.RemoteEntry.RemoteSize))
+		}
+	}
+	return maxUint64(TotalSize(entry.Chunks), fileSize)
 }

 func ETag(entry *filer_pb.Entry) (etag string) {
@@ -101,6 +111,21 @@ func DoMinusChunks(as, bs []*filer_pb.FileChunk) (delta []*filer_pb.FileChunk) {
 	return
 }

+func DoMinusChunksBySourceFileId(as, bs []*filer_pb.FileChunk) (delta []*filer_pb.FileChunk) {
+
+	fileIds := make(map[string]bool)
+	for _, interval := range bs {
+		fileIds[interval.GetFileIdString()] = true
+	}
+	for _, chunk := range as {
+		if _, found := fileIds[chunk.GetSourceFileId()]; !found {
+			delta = append(delta, chunk)
+		}
+	}
+
+	return
+}
+
 type ChunkView struct {
 	FileId      string
 	Offset      int64
@@ -224,19 +249,26 @@ func MergeIntoVisibles(visibles []VisibleInterval, chunk *filer_pb.FileChunk) (n
 func NonOverlappingVisibleIntervals(lookupFileIdFn wdclient.LookupFileIdFunctionType, chunks []*filer_pb.FileChunk, startOffset int64, stopOffset int64) (visibles []VisibleInterval, err error) {

 	chunks, _, err = ResolveChunkManifest(lookupFileIdFn, chunks, startOffset, stopOffset)
+	if err != nil {
+		return
+	}

-	sort.Slice(chunks, func(i, j int) bool {
-		if chunks[i].Mtime == chunks[j].Mtime {
-			filer_pb.EnsureFid(chunks[i])
-			filer_pb.EnsureFid(chunks[j])
-			if chunks[i].Fid == nil || chunks[j].Fid == nil {
+	visibles2 := readResolvedChunks(chunks)
+
+	if true {
+		return visibles2, err
+	}
+	slices.SortFunc(chunks, func(a, b *filer_pb.FileChunk) bool {
+		if a.Mtime == b.Mtime {
+			filer_pb.EnsureFid(a)
+			filer_pb.EnsureFid(b)
+			if a.Fid == nil || b.Fid == nil {
 				return true
 			}
-			return chunks[i].Fid.FileKey < chunks[j].Fid.FileKey
+			return a.Fid.FileKey < b.Fid.FileKey
 		}
-		return chunks[i].Mtime < chunks[j].Mtime // keep this to make tests run
+		return a.Mtime < b.Mtime
 	})
-
 	for _, chunk := range chunks {

 		// glog.V(0).Infof("merge [%d,%d)", chunk.Offset, chunk.Offset+int64(chunk.Size))
@@ -246,9 +278,26 @@ func NonOverlappingVisibleIntervals(lookupFileIdFn wdclient.LookupFileIdFunction

 	}

+	if len(visibles) != len(visibles2) {
+		fmt.Printf("different visibles size %d : %d\n", len(visibles), len(visibles2))
+	} else {
+		for i := 0; i < len(visibles); i++ {
+			checkDifference(visibles[i], visibles2[i])
+		}
+	}
+
 	return
 }

+func checkDifference(x, y VisibleInterval) {
+	if x.start != y.start ||
+		x.stop != y.stop ||
+		x.fileId != y.fileId ||
+		x.modifiedTime != y.modifiedTime {
+		fmt.Printf("different visible %+v : %+v\n", x, y)
+	}
+}
+
 // find non-overlapping visible intervals
 // visible interval map to one file chunk

--- a/weed/filer/filechunks2_test.go
+++ b/weed/filer/filechunks2_test.go
@@ -1,7 +1,7 @@
 package filer

 import (
-	"sort"
+	"golang.org/x/exp/slices"
 	"testing"

 	"github.com/chrislusf/seaweedfs/weed/glog"
@@ -34,11 +34,11 @@ func TestCompactFileChunksRealCase(t *testing.T) {
 }

 func printChunks(name string, chunks []*filer_pb.FileChunk) {
-	sort.Slice(chunks, func(i, j int) bool {
-		if chunks[i].Offset == chunks[j].Offset {
-			return chunks[i].Mtime < chunks[j].Mtime
+	slices.SortFunc(chunks, func(a, b *filer_pb.FileChunk) bool {
+		if a.Offset == b.Offset {
+			return a.Mtime < b.Mtime
 		}
-		return chunks[i].Offset < chunks[j].Offset
+		return a.Offset < b.Offset
 	})
 	for _, chunk := range chunks {
 		glog.V(0).Infof("%s chunk %s [%10d,%10d)", name, chunk.GetFileIdString(), chunk.Offset, chunk.Offset+int64(chunk.Size))
--- a/weed/filer/filechunks_read.go
+++ b/weed/filer/filechunks_read.go
@@ -0,0 +1,116 @@
+package filer
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"golang.org/x/exp/slices"
+)
+
+func readResolvedChunks(chunks []*filer_pb.FileChunk) (visibles []VisibleInterval) {
+
+	var points []*Point
+	for _, chunk := range chunks {
+		points = append(points, &Point{
+			x:       chunk.Offset,
+			ts:      chunk.Mtime,
+			chunk:   chunk,
+			isStart: true,
+		})
+		points = append(points, &Point{
+			x:       chunk.Offset + int64(chunk.Size),
+			ts:      chunk.Mtime,
+			chunk:   chunk,
+			isStart: false,
+		})
+	}
+	slices.SortFunc(points, func(a, b *Point) bool {
+		if a.x != b.x {
+			return a.x < b.x
+		}
+		if a.ts != b.ts {
+			return a.ts < b.ts
+		}
+		return !a.isStart
+	})
+
+	var prevX int64
+	var queue []*Point
+	for _, point := range points {
+		if point.isStart {
+			if len(queue) > 0 {
+				lastIndex := len(queue) - 1
+				lastPoint := queue[lastIndex]
+				if point.x != prevX && lastPoint.ts < point.ts {
+					visibles = addToVisibles(visibles, prevX, lastPoint, point)
+					prevX = point.x
+				}
+			}
+			// insert into queue
+			for i := len(queue); i >= 0; i-- {
+				if i == 0 || queue[i-1].ts <= point.ts {
+					if i == len(queue) {
+						prevX = point.x
+					}
+					queue = addToQueue(queue, i, point)
+					break
+				}
+			}
+		} else {
+			lastIndex := len(queue) - 1
+			index := lastIndex
+			var startPoint *Point
+			for ; index >= 0; index-- {
+				startPoint = queue[index]
+				if startPoint.ts == point.ts {
+					queue = removeFromQueue(queue, index)
+					break
+				}
+			}
+			if index == lastIndex && startPoint != nil {
+				visibles = addToVisibles(visibles, prevX, startPoint, point)
+				prevX = point.x
+			}
+		}
+	}
+
+	return
+}
+
+func removeFromQueue(queue []*Point, index int) []*Point {
+	for i := index; i < len(queue)-1; i++ {
+		queue[i] = queue[i+1]
+	}
+	queue = queue[:len(queue)-1]
+	return queue
+}
+
+func addToQueue(queue []*Point, index int, point *Point) []*Point {
+	queue = append(queue, point)
+	for i := len(queue) - 1; i > index; i-- {
+		queue[i], queue[i-1] = queue[i-1], queue[i]
+	}
+	return queue
+}
+
+func addToVisibles(visibles []VisibleInterval, prevX int64, startPoint *Point, point *Point) []VisibleInterval {
+	if prevX < point.x {
+		chunk := startPoint.chunk
+		visibles = append(visibles, VisibleInterval{
+			start:        prevX,
+			stop:         point.x,
+			fileId:       chunk.GetFileIdString(),
+			modifiedTime: chunk.Mtime,
+			chunkOffset:  prevX - chunk.Offset,
+			chunkSize:    chunk.Size,
+			cipherKey:    chunk.CipherKey,
+			isGzipped:    chunk.IsCompressed,
+		})
+	}
+	return visibles
+}
+
+type Point struct {
+	x       int64
+	ts      int64
+	chunk   *filer_pb.FileChunk
+	isStart bool
+}
--- a/weed/filer/filechunks_read_test.go
+++ b/weed/filer/filechunks_read_test.go
@@ -0,0 +1,210 @@
+package filer
+
+import (
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"math/rand"
+	"testing"
+)
+
+func TestReadResolvedChunks(t *testing.T) {
+
+	chunks := []*filer_pb.FileChunk{
+		{
+			FileId: "a",
+			Offset: 0,
+			Size:   100,
+			Mtime:  1,
+		},
+		{
+			FileId: "b",
+			Offset: 50,
+			Size:   100,
+			Mtime:  2,
+		},
+		{
+			FileId: "c",
+			Offset: 200,
+			Size:   50,
+			Mtime:  3,
+		},
+		{
+			FileId: "d",
+			Offset: 250,
+			Size:   50,
+			Mtime:  4,
+		},
+		{
+			FileId: "e",
+			Offset: 175,
+			Size:   100,
+			Mtime:  5,
+		},
+	}
+
+	visibles := readResolvedChunks(chunks)
+
+	for _, visible := range visibles {
+		fmt.Printf("[%d,%d) %s %d\n", visible.start, visible.stop, visible.fileId, visible.modifiedTime)
+	}
+
+}
+
+func TestRandomizedReadResolvedChunks(t *testing.T) {
+
+	var limit int64 = 1024 * 1024
+	array := make([]int64, limit)
+	var chunks []*filer_pb.FileChunk
+	for ts := int64(0); ts < 1024; ts++ {
+		x := rand.Int63n(limit)
+		y := rand.Int63n(limit)
+		size := x - y
+		if size < 0 {
+			size = -size
+		}
+		if size > 1024 {
+			size = 1024
+		}
+		start := x
+		if start > y {
+			start = y
+		}
+		chunks = append(chunks, randomWrite(array, start, size, ts))
+	}
+
+	visibles := readResolvedChunks(chunks)
+
+	for _, visible := range visibles {
+		for i := visible.start; i < visible.stop; i++ {
+			if array[i] != visible.modifiedTime {
+				t.Errorf("position %d expected ts %d actual ts %d", i, array[i], visible.modifiedTime)
+			}
+		}
+	}
+
+	// fmt.Printf("visibles %d", len(visibles))
+
+}
+
+func randomWrite(array []int64, start int64, size int64, ts int64) *filer_pb.FileChunk {
+	for i := start; i < start+size; i++ {
+		array[i] = ts
+	}
+	// fmt.Printf("write [%d,%d) %d\n", start, start+size, ts)
+	return &filer_pb.FileChunk{
+		FileId: "",
+		Offset: start,
+		Size:   uint64(size),
+		Mtime:  ts,
+	}
+}
+
+func TestSequentialReadResolvedChunks(t *testing.T) {
+
+	var chunkSize int64 = 1024 * 1024 * 2
+	var chunks []*filer_pb.FileChunk
+	for ts := int64(0); ts < 13; ts++ {
+		chunks = append(chunks, &filer_pb.FileChunk{
+			FileId: "",
+			Offset: chunkSize * ts,
+			Size:   uint64(chunkSize),
+			Mtime:  1,
+		})
+	}
+
+	visibles := readResolvedChunks(chunks)
+
+	fmt.Printf("visibles %d", len(visibles))
+
+}
+
+func TestActualReadResolvedChunks(t *testing.T) {
+
+	chunks := []*filer_pb.FileChunk{
+		{
+			FileId: "5,e7b96fef48",
+			Offset: 0,
+			Size:   2097152,
+			Mtime:  1634447487595823000,
+		},
+		{
+			FileId: "5,e5562640b9",
+			Offset: 2097152,
+			Size:   2097152,
+			Mtime:  1634447487595826000,
+		},
+		{
+			FileId: "5,df033e0fe4",
+			Offset: 4194304,
+			Size:   2097152,
+			Mtime:  1634447487595827000,
+		},
+		{
+			FileId: "7,eb08148a9b",
+			Offset: 6291456,
+			Size:   2097152,
+			Mtime:  1634447487595827000,
+		},
+		{
+			FileId: "7,e0f92d1604",
+			Offset: 8388608,
+			Size:   2097152,
+			Mtime:  1634447487595828000,
+		},
+		{
+			FileId: "7,e33cb63262",
+			Offset: 10485760,
+			Size:   2097152,
+			Mtime:  1634447487595828000,
+		},
+		{
+			FileId: "5,ea98e40e93",
+			Offset: 12582912,
+			Size:   2097152,
+			Mtime:  1634447487595829000,
+		},
+		{
+			FileId: "5,e165661172",
+			Offset: 14680064,
+			Size:   2097152,
+			Mtime:  1634447487595829000,
+		},
+		{
+			FileId: "3,e692097486",
+			Offset: 16777216,
+			Size:   2097152,
+			Mtime:  1634447487595830000,
+		},
+		{
+			FileId: "3,e28e2e3cbd",
+			Offset: 18874368,
+			Size:   2097152,
+			Mtime:  1634447487595830000,
+		},
+		{
+			FileId: "3,e443974d4e",
+			Offset: 20971520,
+			Size:   2097152,
+			Mtime:  1634447487595830000,
+		},
+		{
+			FileId: "2,e815bed597",
+			Offset: 23068672,
+			Size:   2097152,
+			Mtime:  1634447487595831000,
+		},
+		{
+			FileId: "5,e94715199e",
+			Offset: 25165824,
+			Size:   1974736,
+			Mtime:  1634447487595832000,
+		},
+	}
+
+	visibles := readResolvedChunks(chunks)
+
+	for _, visible := range visibles {
+		fmt.Printf("[%d,%d) %s %d\n", visible.start, visible.stop, visible.fileId, visible.modifiedTime)
+	}
+
+}
--- a/weed/filer/filer.go
+++ b/weed/filer/filer.go
@@ -3,7 +3,11 @@ package filer
 import (
 	"context"
 	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/cluster"
+	"github.com/chrislusf/seaweedfs/weed/pb"
+	"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
 	"os"
+	"sort"
 	"strings"
 	"time"

@@ -33,8 +37,6 @@ type Filer struct {
 	fileIdDeletionQueue *util.UnboundedQueue
 	GrpcDialOption      grpc.DialOption
 	DirBucketsPath      string
-	FsyncBuckets        []string
-	buckets             *FilerBuckets
 	Cipher              bool
 	LocalMetaLogBuffer  *log_buffer.LogBuffer
 	metaLogCollection   string
@@ -43,16 +45,18 @@ type Filer struct {
 	Signature           int32
 	FilerConf           *FilerConf
 	RemoteStorage       *FilerRemoteStorage
+	UniqueFileId        uint32
 }

-func NewFiler(masters []string, grpcDialOption grpc.DialOption,
-	filerHost string, filerGrpcPort uint32, collection string, replication string, dataCenter string, notifyFn func()) *Filer {
+func NewFiler(masters map[string]pb.ServerAddress, grpcDialOption grpc.DialOption, filerHost pb.ServerAddress,
+	filerGroup string, collection string, replication string, dataCenter string, notifyFn func()) *Filer {
 	f := &Filer{
-		MasterClient:        wdclient.NewMasterClient(grpcDialOption, "filer", filerHost, filerGrpcPort, dataCenter, masters),
+		MasterClient:        wdclient.NewMasterClient(grpcDialOption, filerGroup, cluster.FilerType, filerHost, dataCenter, masters),
 		fileIdDeletionQueue: util.NewUnboundedQueue(),
 		GrpcDialOption:      grpcDialOption,
 		FilerConf:           NewFilerConf(),
 		RemoteStorage:       NewFilerRemoteStorage(),
+		UniqueFileId:        uint32(util.RandomInt32()),
 	}
 	f.LocalMetaLogBuffer = log_buffer.NewLogBuffer("local", LogFlushInterval, f.logFlushFunc, notifyFn)
 	f.metaLogCollection = collection
@@ -63,32 +67,69 @@ func NewFiler(masters []string, grpcDialOption grpc.DialOption,
 	return f
 }

-func (f *Filer) AggregateFromPeers(self string, filers []string) {
-
-	// set peers
-	found := false
-	for _, peer := range filers {
-		if peer == self {
-			found = true
-		}
+func (f *Filer) MaybeBootstrapFromPeers(self pb.ServerAddress, existingNodes []*master_pb.ClusterNodeUpdate, snapshotTime time.Time) (err error) {
+	if len(existingNodes) == 0 {
+		return
 	}
-	if !found {
-		filers = append(filers, self)
+	sort.Slice(existingNodes, func(i, j int) bool {
+		return existingNodes[i].CreatedAtNs < existingNodes[j].CreatedAtNs
+	})
+	earliestNode := existingNodes[0]
+	if earliestNode.Address == string(self) {
+		return
 	}

-	f.MetaAggregator = NewMetaAggregator(filers, f.GrpcDialOption)
-	f.MetaAggregator.StartLoopSubscribe(f, self)
+	glog.V(0).Infof("bootstrap from %v", earliestNode.Address)
+	err = pb.FollowMetadata(pb.ServerAddress(earliestNode.Address), f.GrpcDialOption, "bootstrap", int32(f.UniqueFileId), "/", nil,
+		0, snapshotTime.UnixNano(), f.Signature, func(resp *filer_pb.SubscribeMetadataResponse) error {
+			return Replay(f.Store, resp)
+		}, pb.FatalOnError)
+	return
+}
+
+func (f *Filer) AggregateFromPeers(self pb.ServerAddress, existingNodes []*master_pb.ClusterNodeUpdate, startFrom time.Time) {
+
+	f.MetaAggregator = NewMetaAggregator(f, self, f.GrpcDialOption)
+	f.MasterClient.OnPeerUpdate = f.MetaAggregator.OnPeerUpdate
+
+	for _, peerUpdate := range existingNodes {
+		f.MetaAggregator.OnPeerUpdate(peerUpdate, startFrom)
+	}

 }

-func (f *Filer) SetStore(store FilerStore) {
+func (f *Filer) ListExistingPeerUpdates() (existingNodes []*master_pb.ClusterNodeUpdate) {
+
+	if grpcErr := pb.WithMasterClient(false, f.MasterClient.GetMaster(), f.GrpcDialOption, func(client master_pb.SeaweedClient) error {
+		resp, err := client.ListClusterNodes(context.Background(), &master_pb.ListClusterNodesRequest{
+			ClientType: cluster.FilerType,
+			FilerGroup: f.MasterClient.FilerGroup,
+		})
+
+		glog.V(0).Infof("the cluster has %d filers\n", len(resp.ClusterNodes))
+		for _, node := range resp.ClusterNodes {
+			existingNodes = append(existingNodes, &master_pb.ClusterNodeUpdate{
+				NodeType:    cluster.FilerType,
+				Address:     node.Address,
+				IsLeader:    node.IsLeader,
+				IsAdd:       true,
+				CreatedAtNs: node.CreatedAtNs,
+			})
+		}
+		return err
+	}); grpcErr != nil {
+		glog.V(0).Infof("connect to %s: %v", f.MasterClient.GetMaster(), grpcErr)
+	}
+	return
+}
+
+func (f *Filer) SetStore(store FilerStore) (isFresh bool) {
 	f.Store = NewFilerStoreWrapper(store)

-	f.setOrLoadFilerStoreSignature(store)
-
+	return f.setOrLoadFilerStoreSignature(store)
 }

-func (f *Filer) setOrLoadFilerStoreSignature(store FilerStore) {
+func (f *Filer) setOrLoadFilerStoreSignature(store FilerStore) (isFresh bool) {
 	storeIdBytes, err := store.KvGet(context.Background(), []byte(FilerStoreId))
 	if err == ErrKvNotFound || err == nil && len(storeIdBytes) == 0 {
 		f.Signature = util.RandomInt32()
@@ -98,23 +139,25 @@ func (f *Filer) setOrLoadFilerStoreSignature(store FilerStore) {
 			glog.Fatalf("set %s=%d : %v", FilerStoreId, f.Signature, err)
 		}
 		glog.V(0).Infof("create %s to %d", FilerStoreId, f.Signature)
+		return true
 	} else if err == nil && len(storeIdBytes) == 4 {
 		f.Signature = int32(util.BytesToUint32(storeIdBytes))
 		glog.V(0).Infof("existing %s = %d", FilerStoreId, f.Signature)
 	} else {
 		glog.Fatalf("read %v=%v : %v", FilerStoreId, string(storeIdBytes), err)
 	}
+	return false
 }

 func (f *Filer) GetStore() (store FilerStore) {
 	return f.Store
 }

-func (fs *Filer) GetMaster() string {
+func (fs *Filer) GetMaster() pb.ServerAddress {
 	return fs.MasterClient.GetMaster()
 }

-func (fs *Filer) KeepConnectedToMaster() {
+func (fs *Filer) KeepMasterClientConnected() {
 	fs.MasterClient.KeepConnectedToMaster()
 }

@@ -130,7 +173,7 @@ func (f *Filer) RollbackTransaction(ctx context.Context) error {
 	return f.Store.RollbackTransaction(ctx)
 }

-func (f *Filer) CreateEntry(ctx context.Context, entry *Entry, o_excl bool, isFromOtherCluster bool, signatures []int32) error {
+func (f *Filer) CreateEntry(ctx context.Context, entry *Entry, o_excl bool, isFromOtherCluster bool, signatures []int32, skipCreateParentDir bool) error {

 	if string(entry.FullPath) == "/" {
 		return nil
@@ -148,9 +191,11 @@ func (f *Filer) CreateEntry(ctx context.Context, entry *Entry, o_excl bool, isFr

 	if oldEntry == nil {

-		dirParts := strings.Split(string(entry.FullPath), "/")
-		if err := f.ensureParentDirecotryEntry(ctx, entry, dirParts, len(dirParts)-1, isFromOtherCluster); err != nil {
-			return err
+		if !skipCreateParentDir {
+			dirParts := strings.Split(string(entry.FullPath), "/")
+			if err := f.ensureParentDirecotryEntry(ctx, entry, dirParts, len(dirParts)-1, isFromOtherCluster); err != nil {
+				return err
+			}
 		}

 		glog.V(4).Infof("InsertEntry %s: new entry: %v", entry.FullPath, entry.Name())
@@ -170,7 +215,6 @@ func (f *Filer) CreateEntry(ctx context.Context, entry *Entry, o_excl bool, isFr
 		}
 	}

-	f.maybeAddBucket(entry)
 	f.NotifyUpdateEvent(ctx, oldEntry, entry, true, isFromOtherCluster, signatures)

 	f.deleteChunksIfNotNew(oldEntry, entry)
@@ -207,15 +251,13 @@ func (f *Filer) ensureParentDirecotryEntry(ctx context.Context, entry *Entry, di
 		dirEntry = &Entry{
 			FullPath: util.FullPath(dirPath),
 			Attr: Attr{
-				Mtime:       now,
-				Crtime:      now,
-				Mode:        os.ModeDir | entry.Mode | 0111,
-				Uid:         entry.Uid,
-				Gid:         entry.Gid,
-				Collection:  entry.Collection,
-				Replication: entry.Replication,
-				UserName:    entry.UserName,
-				GroupNames:  entry.GroupNames,
+				Mtime:      now,
+				Crtime:     now,
+				Mode:       os.ModeDir | entry.Mode | 0111,
+				Uid:        entry.Uid,
+				Gid:        entry.Gid,
+				UserName:   entry.UserName,
+				GroupNames: entry.GroupNames,
 			},
 		}

@@ -227,7 +269,6 @@ func (f *Filer) ensureParentDirecotryEntry(ctx context.Context, entry *Entry, di
 				return fmt.Errorf("mkdir %s: %v", dirPath, mkdirErr)
 			}
 		} else {
-			f.maybeAddBucket(dirEntry)
 			f.NotifyUpdateEvent(ctx, nil, dirEntry, false, isFromOtherCluster, nil)
 		}

@@ -285,14 +326,19 @@ func (f *Filer) FindEntry(ctx context.Context, p util.FullPath) (entry *Entry, e

 func (f *Filer) doListDirectoryEntries(ctx context.Context, p util.FullPath, startFileName string, inclusive bool, limit int64, prefix string, eachEntryFunc ListEachEntryFunc) (expiredCount int64, lastFileName string, err error) {
 	lastFileName, err = f.Store.ListDirectoryPrefixedEntries(ctx, p, startFileName, inclusive, limit, prefix, func(entry *Entry) bool {
-		if entry.TtlSec > 0 {
-			if entry.Crtime.Add(time.Duration(entry.TtlSec) * time.Second).Before(time.Now()) {
-				f.Store.DeleteOneEntry(ctx, entry)
-				expiredCount++
-				return true
+		select {
+		case <-ctx.Done():
+			return false
+		default:
+			if entry.TtlSec > 0 {
+				if entry.Crtime.Add(time.Duration(entry.TtlSec) * time.Second).Before(time.Now()) {
+					f.Store.DeleteOneEntry(ctx, entry)
+					expiredCount++
+					return true
+				}
 			}
+			return eachEntryFunc(entry)
 		}
-		return eachEntryFunc(entry)
 	})
 	if err != nil {
 		return expiredCount, lastFileName, err
--- a/weed/filer/filer_buckets.go
+++ b/weed/filer/filer_buckets.go
@@ -1,76 +1,9 @@
 package filer

 import (
-	"context"
-	"math"
 	"strings"
-	"sync"
-
-	"github.com/chrislusf/seaweedfs/weed/glog"
-	"github.com/chrislusf/seaweedfs/weed/util"
 )

-type BucketName string
-type BucketOption struct {
-	Name        BucketName
-	Replication string
-	fsync       bool
-}
-type FilerBuckets struct {
-	dirBucketsPath string
-	buckets        map[BucketName]*BucketOption
-	sync.RWMutex
-}
-
-func (f *Filer) LoadBuckets() {
-
-	f.buckets = &FilerBuckets{
-		buckets: make(map[BucketName]*BucketOption),
-	}
-
-	limit := int64(math.MaxInt32)
-
-	entries, _, err := f.ListDirectoryEntries(context.Background(), util.FullPath(f.DirBucketsPath), "", false, limit, "", "", "")
-
-	if err != nil {
-		glog.V(1).Infof("no buckets found: %v", err)
-		return
-	}
-
-	shouldFsyncMap := make(map[string]bool)
-	for _, bucket := range f.FsyncBuckets {
-		shouldFsyncMap[bucket] = true
-	}
-
-	glog.V(1).Infof("buckets found: %d", len(entries))
-
-	f.buckets.Lock()
-	for _, entry := range entries {
-		_, shouldFsnyc := shouldFsyncMap[entry.Name()]
-		f.buckets.buckets[BucketName(entry.Name())] = &BucketOption{
-			Name:        BucketName(entry.Name()),
-			Replication: entry.Replication,
-			fsync:       shouldFsnyc,
-		}
-	}
-	f.buckets.Unlock()
-
-}
-
-func (f *Filer) ReadBucketOption(buketName string) (replication string, fsync bool) {
-
-	f.buckets.RLock()
-	defer f.buckets.RUnlock()
-
-	option, found := f.buckets.buckets[BucketName(buketName)]
-
-	if !found {
-		return "", false
-	}
-	return option.Replication, option.fsync
-
-}
-
 func (f *Filer) isBucket(entry *Entry) bool {
 	if !entry.IsDirectory() {
 		return false
@@ -83,43 +16,6 @@ func (f *Filer) isBucket(entry *Entry) bool {
 		return false
 	}

-	f.buckets.RLock()
-	defer f.buckets.RUnlock()
-
-	_, found := f.buckets.buckets[BucketName(dirName)]
-
-	return found
-
-}
-
-func (f *Filer) maybeAddBucket(entry *Entry) {
-	if !entry.IsDirectory() {
-		return
-	}
-	parent, dirName := entry.FullPath.DirAndName()
-	if parent != f.DirBucketsPath {
-		return
-	}
-	f.addBucket(dirName, &BucketOption{
-		Name:        BucketName(dirName),
-		Replication: entry.Replication,
-	})
-}
-
-func (f *Filer) addBucket(buketName string, bucketOption *BucketOption) {
-
-	f.buckets.Lock()
-	defer f.buckets.Unlock()
-
-	f.buckets.buckets[BucketName(buketName)] = bucketOption
-
-}
-
-func (f *Filer) deleteBucket(buketName string) {
-
-	f.buckets.Lock()
-	defer f.buckets.Unlock()
-
-	delete(f.buckets.buckets, BucketName(buketName))
+	return true

 }
--- a/weed/filer/filer_conf.go
+++ b/weed/filer/filer_conf.go
@@ -3,6 +3,10 @@ package filer
 import (
 	"bytes"
 	"context"
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/pb"
+	"github.com/chrislusf/seaweedfs/weed/wdclient"
+	"google.golang.org/grpc"
 	"io"

 	"github.com/chrislusf/seaweedfs/weed/glog"
@@ -26,6 +30,29 @@ type FilerConf struct {
 	rules ptrie.Trie
 }

+func ReadFilerConf(filerGrpcAddress pb.ServerAddress, grpcDialOption grpc.DialOption, masterClient *wdclient.MasterClient) (*FilerConf, error) {
+	var buf bytes.Buffer
+	if err := pb.WithGrpcFilerClient(false, filerGrpcAddress, grpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
+		if masterClient != nil {
+			return ReadEntry(masterClient, client, DirectoryEtcSeaweedFS, FilerConfName, &buf)
+		} else {
+			content, err := ReadInsideFiler(client, DirectoryEtcSeaweedFS, FilerConfName)
+			buf = *bytes.NewBuffer(content)
+			return err
+		}
+	}); err != nil && err != filer_pb.ErrNotFound {
+		return nil, fmt.Errorf("read %s/%s: %v", DirectoryEtcSeaweedFS, FilerConfName, err)
+	}
+
+	fc := NewFilerConf()
+	if buf.Len() > 0 {
+		if err := fc.LoadFromBytes(buf.Bytes()); err != nil {
+			return nil, fmt.Errorf("parse %s/%s: %v", DirectoryEtcSeaweedFS, FilerConfName, err)
+		}
+	}
+	return fc, nil
+}
+
 func NewFilerConf() (fc *FilerConf) {
 	fc = &FilerConf{
 		rules: ptrie.New(),
@@ -48,12 +75,12 @@ func (fc *FilerConf) loadFromFiler(filer *Filer) (err error) {
 		return fc.LoadFromBytes(entry.Content)
 	}

-	return fc.loadFromChunks(filer, entry.Content, entry.Chunks)
+	return fc.loadFromChunks(filer, entry.Content, entry.Chunks, entry.Size())
 }

-func (fc *FilerConf) loadFromChunks(filer *Filer, content []byte, chunks []*filer_pb.FileChunk) (err error) {
+func (fc *FilerConf) loadFromChunks(filer *Filer, content []byte, chunks []*filer_pb.FileChunk, size uint64) (err error) {
 	if len(content) == 0 {
-		content, err = filer.readEntry(chunks)
+		content, err = filer.readEntry(chunks, size)
 		if err != nil {
 			glog.Errorf("read filer conf content: %v", err)
 			return
@@ -115,21 +142,32 @@ func (fc *FilerConf) MatchStorageRule(path string) (pathConf *filer_pb.FilerConf
 	return pathConf
 }

+func (fc *FilerConf) GetCollectionTtls(collection string) (ttls map[string]string) {
+	ttls = make(map[string]string)
+	fc.rules.Walk(func(key []byte, value interface{}) bool {
+		t := value.(*filer_pb.FilerConf_PathConf)
+		if t.Collection == collection {
+			ttls[t.LocationPrefix] = t.GetTtl()
+		}
+		return true
+	})
+	return ttls
+}
+
 // merge if values in b is not empty, merge them into a
 func mergePathConf(a, b *filer_pb.FilerConf_PathConf) {
 	a.Collection = util.Nvl(b.Collection, a.Collection)
 	a.Replication = util.Nvl(b.Replication, a.Replication)
 	a.Ttl = util.Nvl(b.Ttl, a.Ttl)
-	if b.DiskType != "" {
-		a.DiskType = b.DiskType
-	}
+	a.DiskType = util.Nvl(b.DiskType, a.DiskType)
 	a.Fsync = b.Fsync || a.Fsync
 	if b.VolumeGrowthCount > 0 {
 		a.VolumeGrowthCount = b.VolumeGrowthCount
 	}
-	if b.ReadOnly {
-		a.ReadOnly = b.ReadOnly
-	}
+	a.ReadOnly = b.ReadOnly || a.ReadOnly
+	a.DataCenter = util.Nvl(b.DataCenter, a.DataCenter)
+	a.Rack = util.Nvl(b.Rack, a.Rack)
+	a.DataNode = util.Nvl(b.DataNode, a.DataNode)
 }

 func (fc *FilerConf) ToProto() *filer_pb.FilerConf {
--- a/weed/filer/filer_delete_entry.go
+++ b/weed/filer/filer_delete_entry.go
@@ -9,12 +9,13 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/util"
 )

-type HardLinkId []byte
-
 const (
 	MsgFailDelNonEmptyFolder = "fail to delete non-empty folder"
 )

+type OnChunksFunc func([]*filer_pb.FileChunk) error
+type OnHardLinkIdsFunc func([]HardLinkId) error
+
 func (f *Filer) DeleteEntryMetaAndData(ctx context.Context, p util.FullPath, isRecursive, ignoreRecursiveError, shouldDeleteChunks, isFromOtherCluster bool, signatures []int32) (err error) {
 	if p == "/" {
 		return nil
@@ -24,23 +25,30 @@ func (f *Filer) DeleteEntryMetaAndData(ctx context.Context, p util.FullPath, isR
 	if findErr != nil {
 		return findErr
 	}
-
 	isDeleteCollection := f.isBucket(entry)
-
-	var chunks []*filer_pb.FileChunk
-	var hardLinkIds []HardLinkId
-	chunks = append(chunks, entry.Chunks...)
 	if entry.IsDirectory() {
 		// delete the folder children, not including the folder itself
-		var dirChunks []*filer_pb.FileChunk
-		var dirHardLinkIds []HardLinkId
-		dirChunks, dirHardLinkIds, err = f.doBatchDeleteFolderMetaAndData(ctx, entry, isRecursive, ignoreRecursiveError, shouldDeleteChunks && !isDeleteCollection, isDeleteCollection, isFromOtherCluster, signatures)
+		err = f.doBatchDeleteFolderMetaAndData(ctx, entry, isRecursive, ignoreRecursiveError, shouldDeleteChunks && !isDeleteCollection, isDeleteCollection, isFromOtherCluster, signatures, func(chunks []*filer_pb.FileChunk) error {
+			if shouldDeleteChunks && !isDeleteCollection {
+				f.DirectDeleteChunks(chunks)
+			}
+			return nil
+		}, func(hardLinkIds []HardLinkId) error {
+			// A case not handled:
+			// what if the chunk is in a different collection?
+			if shouldDeleteChunks {
+				f.maybeDeleteHardLinks(hardLinkIds)
+			}
+			return nil
+		})
 		if err != nil {
 			glog.V(0).Infof("delete directory %s: %v", p, err)
 			return fmt.Errorf("delete directory %s: %v", p, err)
 		}
-		chunks = append(chunks, dirChunks...)
-		hardLinkIds = append(hardLinkIds, dirHardLinkIds...)
+	}
+
+	if shouldDeleteChunks && !isDeleteCollection {
+		f.DirectDeleteChunks(entry.Chunks)
 	}

 	// delete the file or folder
@@ -49,25 +57,15 @@ func (f *Filer) DeleteEntryMetaAndData(ctx context.Context, p util.FullPath, isR
 		return fmt.Errorf("delete file %s: %v", p, err)
 	}

-	if shouldDeleteChunks && !isDeleteCollection {
-		f.DirectDeleteChunks(chunks)
-	}
-	// A case not handled:
-	// what if the chunk is in a different collection?
-	if shouldDeleteChunks {
-		f.maybeDeleteHardLinks(hardLinkIds)
-	}
-
 	if isDeleteCollection {
 		collectionName := entry.Name()
 		f.doDeleteCollection(collectionName)
-		f.deleteBucket(collectionName)
 	}

 	return nil
 }

-func (f *Filer) doBatchDeleteFolderMetaAndData(ctx context.Context, entry *Entry, isRecursive, ignoreRecursiveError, shouldDeleteChunks, isDeletingBucket, isFromOtherCluster bool, signatures []int32) (chunks []*filer_pb.FileChunk, hardlinkIds []HardLinkId, err error) {
+func (f *Filer) doBatchDeleteFolderMetaAndData(ctx context.Context, entry *Entry, isRecursive, ignoreRecursiveError, shouldDeleteChunks, isDeletingBucket, isFromOtherCluster bool, signatures []int32, onChunksFn OnChunksFunc, onHardLinkIdsFn OnHardLinkIdsFunc) (err error) {

 	lastFileName := ""
 	includeLastFile := false
@@ -76,34 +74,30 @@ func (f *Filer) doBatchDeleteFolderMetaAndData(ctx context.Context, entry *Entry
 			entries, _, err := f.ListDirectoryEntries(ctx, entry.FullPath, lastFileName, includeLastFile, PaginationSize, "", "", "")
 			if err != nil {
 				glog.Errorf("list folder %s: %v", entry.FullPath, err)
-				return nil, nil, fmt.Errorf("list folder %s: %v", entry.FullPath, err)
+				return fmt.Errorf("list folder %s: %v", entry.FullPath, err)
 			}
 			if lastFileName == "" && !isRecursive && len(entries) > 0 {
 				// only for first iteration in the loop
-				glog.Errorf("deleting a folder %s has children: %+v ...", entry.FullPath, entries[0].Name())
-				return nil, nil, fmt.Errorf("%s: %s", MsgFailDelNonEmptyFolder, entry.FullPath)
+				glog.V(0).Infof("deleting a folder %s has children: %+v ...", entry.FullPath, entries[0].Name())
+				return fmt.Errorf("%s: %s", MsgFailDelNonEmptyFolder, entry.FullPath)
 			}

 			for _, sub := range entries {
 				lastFileName = sub.Name()
-				var dirChunks []*filer_pb.FileChunk
-				var dirHardLinkIds []HardLinkId
 				if sub.IsDirectory() {
 					subIsDeletingBucket := f.isBucket(sub)
-					dirChunks, dirHardLinkIds, err = f.doBatchDeleteFolderMetaAndData(ctx, sub, isRecursive, ignoreRecursiveError, shouldDeleteChunks, subIsDeletingBucket, false, nil)
-					chunks = append(chunks, dirChunks...)
-					hardlinkIds = append(hardlinkIds, dirHardLinkIds...)
+					err = f.doBatchDeleteFolderMetaAndData(ctx, sub, isRecursive, ignoreRecursiveError, shouldDeleteChunks, subIsDeletingBucket, false, nil, onChunksFn, onHardLinkIdsFn)
 				} else {
 					f.NotifyUpdateEvent(ctx, sub, nil, shouldDeleteChunks, isFromOtherCluster, nil)
 					if len(sub.HardLinkId) != 0 {
 						// hard link chunk data are deleted separately
-						hardlinkIds = append(hardlinkIds, sub.HardLinkId)
+						err = onHardLinkIdsFn([]HardLinkId{sub.HardLinkId})
 					} else {
-						chunks = append(chunks, sub.Chunks...)
+						err = onChunksFn(sub.Chunks)
 					}
 				}
 				if err != nil && !ignoreRecursiveError {
-					return nil, nil, err
+					return err
 				}
 			}

@@ -113,22 +107,26 @@ func (f *Filer) doBatchDeleteFolderMetaAndData(ctx context.Context, entry *Entry
 		}
 	}

-	glog.V(3).Infof("deleting directory %v delete %d chunks: %v", entry.FullPath, len(chunks), shouldDeleteChunks)
+	glog.V(3).Infof("deleting directory %v delete chunks: %v", entry.FullPath, shouldDeleteChunks)

 	if storeDeletionErr := f.Store.DeleteFolderChildren(ctx, entry.FullPath); storeDeletionErr != nil {
-		return nil, nil, fmt.Errorf("filer store delete: %v", storeDeletionErr)
+		return fmt.Errorf("filer store delete: %v", storeDeletionErr)
 	}

 	f.NotifyUpdateEvent(ctx, entry, nil, shouldDeleteChunks, isFromOtherCluster, signatures)

-	return chunks, hardlinkIds, nil
+	return nil
 }

 func (f *Filer) doDeleteEntryMetaAndData(ctx context.Context, entry *Entry, shouldDeleteChunks bool, isFromOtherCluster bool, signatures []int32) (err error) {

 	glog.V(3).Infof("deleting entry %v, delete chunks: %v", entry.FullPath, shouldDeleteChunks)

-	if storeDeletionErr := f.Store.DeleteOneEntry(ctx, entry); storeDeletionErr != nil {
+	if !entry.IsDirectory() && !shouldDeleteChunks {
+		if storeDeletionErr := f.Store.DeleteOneEntrySkipHardlink(ctx, entry.FullPath); storeDeletionErr != nil {
+			return fmt.Errorf("filer store delete skip hardlink: %v", storeDeletionErr)
+		}
+	} else if storeDeletionErr := f.Store.DeleteOneEntry(ctx, entry); storeDeletionErr != nil {
 		return fmt.Errorf("filer store delete: %v", storeDeletionErr)
 	}
 	if !entry.IsDirectory() {
@@ -140,7 +138,7 @@ func (f *Filer) doDeleteEntryMetaAndData(ctx context.Context, entry *Entry, shou

 func (f *Filer) doDeleteCollection(collectionName string) (err error) {

-	return f.MasterClient.WithClient(func(client master_pb.SeaweedClient) error {
+	return f.MasterClient.WithClient(false, func(client master_pb.SeaweedClient) error {
 		_, err := client.CollectionDelete(context.Background(), &master_pb.CollectionDeleteRequest{
 			Name: collectionName,
 		})
--- a/weed/filer/filer_deletion.go
+++ b/weed/filer/filer_deletion.go
@@ -1,6 +1,7 @@
 package filer

 import (
+	"math"
 	"strings"
 	"time"

@@ -129,6 +130,12 @@ func (f *Filer) DeleteChunks(chunks []*filer_pb.FileChunk) {
 	}
 }

+func (f *Filer) DeleteChunksNotRecursive(chunks []*filer_pb.FileChunk) {
+	for _, chunk := range chunks {
+		f.fileIdDeletionQueue.EnQueue(chunk.GetFileIdString())
+	}
+}
+
 func (f *Filer) deleteChunksIfNotNew(oldEntry, newEntry *Entry) {

 	if oldEntry == nil {
@@ -136,18 +143,41 @@ func (f *Filer) deleteChunksIfNotNew(oldEntry, newEntry *Entry) {
 	}
 	if newEntry == nil {
 		f.DeleteChunks(oldEntry.Chunks)
+		return
 	}

 	var toDelete []*filer_pb.FileChunk
 	newChunkIds := make(map[string]bool)
-	for _, newChunk := range newEntry.Chunks {
+	newDataChunks, newManifestChunks, err := ResolveChunkManifest(f.MasterClient.GetLookupFileIdFunction(),
+		newEntry.Chunks, 0, math.MaxInt64)
+	if err != nil {
+		glog.Errorf("Failed to resolve new entry chunks when delete old entry chunks. new: %s, old: %s",
+			newEntry.Chunks, oldEntry.Chunks)
+		return
+	}
+	for _, newChunk := range newDataChunks {
+		newChunkIds[newChunk.GetFileIdString()] = true
+	}
+	for _, newChunk := range newManifestChunks {
 		newChunkIds[newChunk.GetFileIdString()] = true
 	}

-	for _, oldChunk := range oldEntry.Chunks {
+	oldDataChunks, oldManifestChunks, err := ResolveChunkManifest(f.MasterClient.GetLookupFileIdFunction(),
+		oldEntry.Chunks, 0, math.MaxInt64)
+	if err != nil {
+		glog.Errorf("Failed to resolve old entry chunks when delete old entry chunks. new: %s, old: %s",
+			newEntry.Chunks, oldEntry.Chunks)
+		return
+	}
+	for _, oldChunk := range oldDataChunks {
 		if _, found := newChunkIds[oldChunk.GetFileIdString()]; !found {
 			toDelete = append(toDelete, oldChunk)
 		}
 	}
-	f.DeleteChunks(toDelete)
+	for _, oldChunk := range oldManifestChunks {
+		if _, found := newChunkIds[oldChunk.GetFileIdString()]; !found {
+			toDelete = append(toDelete, oldChunk)
+		}
+	}
+	f.DeleteChunksNotRecursive(toDelete)
 }
--- a/weed/filer/filer_hardlink.go
+++ b/weed/filer/filer_hardlink.go
@@ -0,0 +1,16 @@
+package filer
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+const (
+	HARD_LINK_MARKER = '\x01'
+)
+
+type HardLinkId []byte // 16 bytes + 1 marker byte
+
+func NewHardLinkId() HardLinkId {
+	bytes := append(util.RandomBytes(16), HARD_LINK_MARKER)
+	return bytes
+}
--- a/weed/filer/filer_notify.go
+++ b/weed/filer/filer_notify.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"math"
 	"strings"
 	"time"

@@ -92,14 +93,14 @@ func (f *Filer) logFlushFunc(startTime, stopTime time.Time, buf []byte) {

 	startTime, stopTime = startTime.UTC(), stopTime.UTC()

-	targetFile := fmt.Sprintf("%s/%04d-%02d-%02d/%02d-%02d.segment", SystemLogDir,
-		startTime.Year(), startTime.Month(), startTime.Day(), startTime.Hour(), startTime.Minute(),
+	targetFile := fmt.Sprintf("%s/%04d-%02d-%02d/%02d-%02d.%08x", SystemLogDir,
+		startTime.Year(), startTime.Month(), startTime.Day(), startTime.Hour(), startTime.Minute(), f.UniqueFileId,
 		// startTime.Second(), startTime.Nanosecond(),
 	)

 	for {
 		if err := f.appendToFile(targetFile, buf); err != nil {
-			glog.V(1).Infof("log write failed %s: %v", targetFile, err)
+			glog.V(0).Infof("metadata log write failed %s: %v", targetFile, err)
 			time.Sleep(737 * time.Millisecond)
 		} else {
 			break
@@ -107,49 +108,67 @@ func (f *Filer) logFlushFunc(startTime, stopTime time.Time, buf []byte) {
 	}
 }

-func (f *Filer) ReadPersistedLogBuffer(startTime time.Time, eachLogEntryFn func(logEntry *filer_pb.LogEntry) error) (lastTsNs int64, err error) {
+func (f *Filer) ReadPersistedLogBuffer(startTime time.Time, stopTsNs int64, eachLogEntryFn func(logEntry *filer_pb.LogEntry) error) (lastTsNs int64, isDone bool, err error) {

 	startTime = startTime.UTC()
 	startDate := fmt.Sprintf("%04d-%02d-%02d", startTime.Year(), startTime.Month(), startTime.Day())
-	startHourMinute := fmt.Sprintf("%02d-%02d.segment", startTime.Hour(), startTime.Minute())
+	startHourMinute := fmt.Sprintf("%02d-%02d", startTime.Hour(), startTime.Minute())
+	var stopDate, stopHourMinute string
+	if stopTsNs != 0 {
+		stopTime := time.Unix(0, stopTsNs+24*60*60*int64(time.Nanosecond)).UTC()
+		stopDate = fmt.Sprintf("%04d-%02d-%02d", stopTime.Year(), stopTime.Month(), stopTime.Day())
+		stopHourMinute = fmt.Sprintf("%02d-%02d", stopTime.Hour(), stopTime.Minute())
+	}

 	sizeBuf := make([]byte, 4)
 	startTsNs := startTime.UnixNano()

-	dayEntries, _, listDayErr := f.ListDirectoryEntries(context.Background(), SystemLogDir, startDate, true, 366, "", "", "")
+	dayEntries, _, listDayErr := f.ListDirectoryEntries(context.Background(), SystemLogDir, startDate, true, math.MaxInt32, "", "", "")
 	if listDayErr != nil {
-		return lastTsNs, fmt.Errorf("fail to list log by day: %v", listDayErr)
+		return lastTsNs, isDone, fmt.Errorf("fail to list log by day: %v", listDayErr)
 	}
 	for _, dayEntry := range dayEntries {
+		if stopDate != "" {
+			if strings.Compare(dayEntry.Name(), stopDate) > 0 {
+				break
+			}
+		}
 		// println("checking day", dayEntry.FullPath)
-		hourMinuteEntries, _, listHourMinuteErr := f.ListDirectoryEntries(context.Background(), util.NewFullPath(SystemLogDir, dayEntry.Name()), "", false, 24*60, "", "", "")
+		hourMinuteEntries, _, listHourMinuteErr := f.ListDirectoryEntries(context.Background(), util.NewFullPath(SystemLogDir, dayEntry.Name()), "", false, math.MaxInt32, "", "", "")
 		if listHourMinuteErr != nil {
-			return lastTsNs, fmt.Errorf("fail to list log %s by day: %v", dayEntry.Name(), listHourMinuteErr)
+			return lastTsNs, isDone, fmt.Errorf("fail to list log %s by day: %v", dayEntry.Name(), listHourMinuteErr)
 		}
 		for _, hourMinuteEntry := range hourMinuteEntries {
 			// println("checking hh-mm", hourMinuteEntry.FullPath)
 			if dayEntry.Name() == startDate {
-				if strings.Compare(hourMinuteEntry.Name(), startHourMinute) < 0 {
+				hourMinute := util.FileNameBase(hourMinuteEntry.Name())
+				if strings.Compare(hourMinute, startHourMinute) < 0 {
 					continue
 				}
 			}
+			if dayEntry.Name() == stopDate {
+				hourMinute := util.FileNameBase(hourMinuteEntry.Name())
+				if strings.Compare(hourMinute, stopHourMinute) > 0 {
+					break
+				}
+			}
 			// println("processing", hourMinuteEntry.FullPath)
 			chunkedFileReader := NewChunkStreamReaderFromFiler(f.MasterClient, hourMinuteEntry.Chunks)
-			if lastTsNs, err = ReadEachLogEntry(chunkedFileReader, sizeBuf, startTsNs, eachLogEntryFn); err != nil {
+			if lastTsNs, err = ReadEachLogEntry(chunkedFileReader, sizeBuf, startTsNs, stopTsNs, eachLogEntryFn); err != nil {
 				chunkedFileReader.Close()
 				if err == io.EOF {
 					continue
 				}
-				return lastTsNs, fmt.Errorf("reading %s: %v", hourMinuteEntry.FullPath, err)
+				return lastTsNs, isDone, fmt.Errorf("reading %s: %v", hourMinuteEntry.FullPath, err)
 			}
 			chunkedFileReader.Close()
 		}
 	}

-	return lastTsNs, nil
+	return lastTsNs, isDone, nil
 }

-func ReadEachLogEntry(r io.Reader, sizeBuf []byte, ns int64, eachLogEntryFn func(logEntry *filer_pb.LogEntry) error) (lastTsNs int64, err error) {
+func ReadEachLogEntry(r io.Reader, sizeBuf []byte, startTsNs, stopTsNs int64, eachLogEntryFn func(logEntry *filer_pb.LogEntry) error) (lastTsNs int64, err error) {
 	for {
 		n, err := r.Read(sizeBuf)
 		if err != nil {
@@ -172,9 +191,12 @@ func ReadEachLogEntry(r io.Reader, sizeBuf []byte, ns int64, eachLogEntryFn func
 		if err = proto.Unmarshal(entryData, logEntry); err != nil {
 			return lastTsNs, err
 		}
-		if logEntry.TsNs <= ns {
+		if logEntry.TsNs <= startTsNs {
 			continue
 		}
+		if stopTsNs != 0 && logEntry.TsNs > stopTsNs {
+			return lastTsNs, err
+		}
 		// println("each log: ", logEntry.TsNs)
 		if err := eachLogEntryFn(logEntry); err != nil {
 			return lastTsNs, err
--- a/weed/filer/filer_notify_append.go
+++ b/weed/filer/filer_notify_append.go
@@ -33,6 +33,8 @@ func (f *Filer) appendToFile(targetFile string, data []byte) error {
 				Gid:    OS_GID,
 			},
 		}
+	} else if err != nil {
+		return fmt.Errorf("find %s: %v", fullpath, err)
 	} else {
 		offset = int64(TotalSize(entry.Chunks))
 	}
@@ -41,7 +43,7 @@ func (f *Filer) appendToFile(targetFile string, data []byte) error {
 	entry.Chunks = append(entry.Chunks, uploadResult.ToPbFileChunk(assignResult.Fid, offset))

 	// update the entry
-	err = f.CreateEntry(context.Background(), entry, false, false, nil)
+	err = f.CreateEntry(context.Background(), entry, false, false, nil, false)

 	return err
 }
@@ -66,7 +68,16 @@ func (f *Filer) assignAndUpload(targetFile string, data []byte) (*operation.Assi

 	// upload data
 	targetUrl := "http://" + assignResult.Url + "/" + assignResult.Fid
-	uploadResult, err := operation.UploadData(targetUrl, "", f.Cipher, data, false, "", nil, assignResult.Auth)
+	uploadOption := &operation.UploadOption{
+		UploadUrl:         targetUrl,
+		Filename:          "",
+		Cipher:            f.Cipher,
+		IsInputCompressed: false,
+		MimeType:          "",
+		PairMap:           nil,
+		Jwt:               assignResult.Auth,
+	}
+	uploadResult, err := operation.UploadData(data, uploadOption)
 	if err != nil {
 		return nil, nil, fmt.Errorf("upload data %s: %v", targetUrl, err)
 	}
--- a/weed/filer/filer_on_meta_event.go
+++ b/weed/filer/filer_on_meta_event.go
@@ -2,8 +2,6 @@ package filer

 import (
 	"bytes"
-	"math"
-
 	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 	"github.com/chrislusf/seaweedfs/weed/util"
@@ -24,12 +22,12 @@ func (f *Filer) onBucketEvents(event *filer_pb.SubscribeMetadataResponse) {
 		}
 	}
 	if f.DirBucketsPath == event.Directory {
-		if message.OldEntry == nil && message.NewEntry != nil {
+		if filer_pb.IsCreate(event) {
 			if message.NewEntry.IsDirectory {
 				f.Store.OnBucketCreation(message.NewEntry.Name)
 			}
 		}
-		if message.OldEntry != nil && message.NewEntry == nil {
+		if filer_pb.IsDelete(event) {
 			if message.OldEntry.IsDirectory {
 				f.Store.OnBucketDeletion(message.OldEntry.Name)
 			}
@@ -55,9 +53,9 @@ func (f *Filer) maybeReloadFilerConfiguration(event *filer_pb.SubscribeMetadataR
 	}
 }

-func (f *Filer) readEntry(chunks []*filer_pb.FileChunk) ([]byte, error) {
+func (f *Filer) readEntry(chunks []*filer_pb.FileChunk, size uint64) ([]byte, error) {
 	var buf bytes.Buffer
-	err := StreamContent(f.MasterClient, &buf, chunks, 0, math.MaxInt64)
+	err := StreamContent(f.MasterClient, &buf, chunks, 0, int64(size))
 	if err != nil {
 		return nil, err
 	}
@@ -66,7 +64,7 @@ func (f *Filer) readEntry(chunks []*filer_pb.FileChunk) ([]byte, error) {

 func (f *Filer) reloadFilerConfiguration(entry *filer_pb.Entry) {
 	fc := NewFilerConf()
-	err := fc.loadFromChunks(f, entry.Content, entry.Chunks)
+	err := fc.loadFromChunks(f, entry.Content, entry.Chunks, FileSize(entry))
 	if err != nil {
 		glog.Errorf("read filer conf chunks: %v", err)
 		return
--- a/weed/filer/filer_search.go
+++ b/weed/filer/filer_search.go
@@ -23,15 +23,15 @@ func splitPattern(pattern string) (prefix string, restPattern string) {
 // For now, prefix and namePattern are mutually exclusive
 func (f *Filer) ListDirectoryEntries(ctx context.Context, p util.FullPath, startFileName string, inclusive bool, limit int64, prefix string, namePattern string, namePatternExclude string) (entries []*Entry, hasMore bool, err error) {

+	if limit > math.MaxInt32-1 {
+		limit = math.MaxInt32 - 1
+	}
+
 	_, err = f.StreamListDirectoryEntries(ctx, p, startFileName, inclusive, limit+1, prefix, namePattern, namePatternExclude, func(entry *Entry) bool {
 		entries = append(entries, entry)
 		return true
 	})

-	if limit == math.MaxInt64 {
-		limit = math.MaxInt64 - 1
-	}
-
 	hasMore = int64(len(entries)) >= limit+1
 	if hasMore {
 		entries = entries[:limit]
--- a/weed/filer/filerstore.go
+++ b/weed/filer/filerstore.go
@@ -4,8 +4,11 @@ import (
 	"context"
 	"errors"
 	"github.com/chrislusf/seaweedfs/weed/util"
+	"io"
 )

+const CountEntryChunksForGzip = 50
+
 var (
 	ErrUnsupportedListDirectoryPrefixed      = errors.New("unsupported directory prefix listing")
 	ErrUnsupportedSuperLargeDirectoryListing = errors.New("unsupported super large directory listing")
@@ -45,3 +48,7 @@ type BucketAware interface {
 	OnBucketDeletion(bucket string)
 	CanDropWholeBucket() bool
 }
+
+type Debuggable interface {
+	Debug(writer io.Writer)
+}
--- a/weed/filer/filerstore_hardlink.go
+++ b/weed/filer/filerstore_hardlink.go
@@ -9,16 +9,20 @@ import (
 )

 func (fsw *FilerStoreWrapper) handleUpdateToHardLinks(ctx context.Context, entry *Entry) error {
-	if len(entry.HardLinkId) == 0 {
+
+	if entry.IsDirectory() {
 		return nil
 	}
-	// handle hard links
-	if err := fsw.setHardLink(ctx, entry); err != nil {
-		return fmt.Errorf("setHardLink %d: %v", entry.HardLinkId, err)
+
+	if len(entry.HardLinkId) > 0 {
+		// handle hard links
+		if err := fsw.setHardLink(ctx, entry); err != nil {
+			return fmt.Errorf("setHardLink %d: %v", entry.HardLinkId, err)
+		}
 	}

 	// check what is existing entry
-	glog.V(4).Infof("handleUpdateToHardLinks FindEntry %s", entry.FullPath)
+	// glog.V(4).Infof("handleUpdateToHardLinks FindEntry %s", entry.FullPath)
 	actualStore := fsw.getActualStore(entry.FullPath)
 	existingEntry, err := actualStore.FindEntry(ctx, entry.FullPath)
 	if err != nil && err != filer_pb.ErrNotFound {
@@ -46,6 +50,8 @@ func (fsw *FilerStoreWrapper) setHardLink(ctx context.Context, entry *Entry) err
 		return encodeErr
 	}

+	glog.V(4).Infof("setHardLink %v nlink:%d", entry.FullPath, entry.HardLinkCounter)
+
 	return fsw.KvPut(ctx, key, newBlob)
 }

@@ -55,7 +61,6 @@ func (fsw *FilerStoreWrapper) maybeReadHardLink(ctx context.Context, entry *Entr
 	}
 	key := entry.HardLinkId

-	glog.V(4).Infof("maybeReadHardLink KvGet %v", key)
 	value, err := fsw.KvGet(ctx, key)
 	if err != nil {
 		glog.Errorf("read %s hardlink %d: %v", entry.FullPath, entry.HardLinkId, err)
@@ -67,6 +72,8 @@ func (fsw *FilerStoreWrapper) maybeReadHardLink(ctx context.Context, entry *Entr
 		return err
 	}

+	glog.V(4).Infof("maybeReadHardLink %v nlink:%d", entry.FullPath, entry.HardLinkCounter)
+
 	return nil
 }

--- a/weed/filer/filerstore_translate_path.go
+++ b/weed/filer/filerstore_translate_path.go
@@ -3,20 +3,21 @@ package filer
 import (
 	"context"
 	"github.com/chrislusf/seaweedfs/weed/util"
+	"math"
 	"strings"
 )

 var (
-	_ = FilerStore(&FilerStorePathTranlator{})
+	_ = FilerStore(&FilerStorePathTranslator{})
 )

-type FilerStorePathTranlator struct {
+type FilerStorePathTranslator struct {
 	actualStore FilerStore
 	storeRoot   string
 }

-func NewFilerStorePathTranlator(storeRoot string, store FilerStore) *FilerStorePathTranlator {
-	if innerStore, ok := store.(*FilerStorePathTranlator); ok {
+func NewFilerStorePathTranslator(storeRoot string, store FilerStore) *FilerStorePathTranslator {
+	if innerStore, ok := store.(*FilerStorePathTranslator); ok {
 		return innerStore
 	}

@@ -24,13 +25,13 @@ func NewFilerStorePathTranlator(storeRoot string, store FilerStore) *FilerStoreP
 		storeRoot += "/"
 	}

-	return &FilerStorePathTranlator{
+	return &FilerStorePathTranslator{
 		actualStore: store,
 		storeRoot:   storeRoot,
 	}
 }

-func (t *FilerStorePathTranlator) translatePath(fp util.FullPath) (newPath util.FullPath) {
+func (t *FilerStorePathTranslator) translatePath(fp util.FullPath) (newPath util.FullPath) {
 	newPath = fp
 	if t.storeRoot == "/" {
 		return
@@ -41,7 +42,7 @@ func (t *FilerStorePathTranlator) translatePath(fp util.FullPath) (newPath util.
 	}
 	return
 }
-func (t *FilerStorePathTranlator) changeEntryPath(entry *Entry) (previousPath util.FullPath) {
+func (t *FilerStorePathTranslator) changeEntryPath(entry *Entry) (previousPath util.FullPath) {
 	previousPath = entry.FullPath
 	if t.storeRoot == "/" {
 		return
@@ -49,33 +50,33 @@ func (t *FilerStorePathTranlator) changeEntryPath(entry *Entry) (previousPath ut
 	entry.FullPath = t.translatePath(previousPath)
 	return
 }
-func (t *FilerStorePathTranlator) recoverEntryPath(entry *Entry, previousPath util.FullPath) {
+func (t *FilerStorePathTranslator) recoverEntryPath(entry *Entry, previousPath util.FullPath) {
 	entry.FullPath = previousPath
 }

-func (t *FilerStorePathTranlator) GetName() string {
+func (t *FilerStorePathTranslator) GetName() string {
 	return t.actualStore.GetName()
 }

-func (t *FilerStorePathTranlator) Initialize(configuration util.Configuration, prefix string) error {
+func (t *FilerStorePathTranslator) Initialize(configuration util.Configuration, prefix string) error {
 	return t.actualStore.Initialize(configuration, prefix)
 }

-func (t *FilerStorePathTranlator) InsertEntry(ctx context.Context, entry *Entry) error {
+func (t *FilerStorePathTranslator) InsertEntry(ctx context.Context, entry *Entry) error {
 	previousPath := t.changeEntryPath(entry)
 	defer t.recoverEntryPath(entry, previousPath)

 	return t.actualStore.InsertEntry(ctx, entry)
 }

-func (t *FilerStorePathTranlator) UpdateEntry(ctx context.Context, entry *Entry) error {
+func (t *FilerStorePathTranslator) UpdateEntry(ctx context.Context, entry *Entry) error {
 	previousPath := t.changeEntryPath(entry)
 	defer t.recoverEntryPath(entry, previousPath)

 	return t.actualStore.UpdateEntry(ctx, entry)
 }

-func (t *FilerStorePathTranlator) FindEntry(ctx context.Context, fp util.FullPath) (entry *Entry, err error) {
+func (t *FilerStorePathTranslator) FindEntry(ctx context.Context, fp util.FullPath) (entry *Entry, err error) {
 	if t.storeRoot == "/" {
 		return t.actualStore.FindEntry(ctx, fp)
 	}
@@ -87,12 +88,12 @@ func (t *FilerStorePathTranlator) FindEntry(ctx context.Context, fp util.FullPat
 	return
 }

-func (t *FilerStorePathTranlator) DeleteEntry(ctx context.Context, fp util.FullPath) (err error) {
+func (t *FilerStorePathTranslator) DeleteEntry(ctx context.Context, fp util.FullPath) (err error) {
 	newFullPath := t.translatePath(fp)
 	return t.actualStore.DeleteEntry(ctx, newFullPath)
 }

-func (t *FilerStorePathTranlator) DeleteOneEntry(ctx context.Context, existingEntry *Entry) (err error) {
+func (t *FilerStorePathTranslator) DeleteOneEntry(ctx context.Context, existingEntry *Entry) (err error) {

 	previousPath := t.changeEntryPath(existingEntry)
 	defer t.recoverEntryPath(existingEntry, previousPath)
@@ -100,13 +101,13 @@ func (t *FilerStorePathTranlator) DeleteOneEntry(ctx context.Context, existingEn
 	return t.actualStore.DeleteEntry(ctx, existingEntry.FullPath)
 }

-func (t *FilerStorePathTranlator) DeleteFolderChildren(ctx context.Context, fp util.FullPath) (err error) {
+func (t *FilerStorePathTranslator) DeleteFolderChildren(ctx context.Context, fp util.FullPath) (err error) {
 	newFullPath := t.translatePath(fp)

 	return t.actualStore.DeleteFolderChildren(ctx, newFullPath)
 }

-func (t *FilerStorePathTranlator) ListDirectoryEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, eachEntryFunc ListEachEntryFunc) (string, error) {
+func (t *FilerStorePathTranslator) ListDirectoryEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, eachEntryFunc ListEachEntryFunc) (string, error) {

 	newFullPath := t.translatePath(dirPath)

@@ -116,38 +117,42 @@ func (t *FilerStorePathTranlator) ListDirectoryEntries(ctx context.Context, dirP
 	})
 }

-func (t *FilerStorePathTranlator) ListDirectoryPrefixedEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, prefix string, eachEntryFunc ListEachEntryFunc) (string, error) {
+func (t *FilerStorePathTranslator) ListDirectoryPrefixedEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, prefix string, eachEntryFunc ListEachEntryFunc) (string, error) {

 	newFullPath := t.translatePath(dirPath)

+	if limit > math.MaxInt32-1 {
+		limit = math.MaxInt32 - 1
+	}
+
 	return t.actualStore.ListDirectoryPrefixedEntries(ctx, newFullPath, startFileName, includeStartFile, limit, prefix, func(entry *Entry) bool {
 		entry.FullPath = dirPath[:len(t.storeRoot)-1] + entry.FullPath
 		return eachEntryFunc(entry)
 	})
 }

-func (t *FilerStorePathTranlator) BeginTransaction(ctx context.Context) (context.Context, error) {
+func (t *FilerStorePathTranslator) BeginTransaction(ctx context.Context) (context.Context, error) {
 	return t.actualStore.BeginTransaction(ctx)
 }

-func (t *FilerStorePathTranlator) CommitTransaction(ctx context.Context) error {
+func (t *FilerStorePathTranslator) CommitTransaction(ctx context.Context) error {
 	return t.actualStore.CommitTransaction(ctx)
 }

-func (t *FilerStorePathTranlator) RollbackTransaction(ctx context.Context) error {
+func (t *FilerStorePathTranslator) RollbackTransaction(ctx context.Context) error {
 	return t.actualStore.RollbackTransaction(ctx)
 }

-func (t *FilerStorePathTranlator) Shutdown() {
+func (t *FilerStorePathTranslator) Shutdown() {
 	t.actualStore.Shutdown()
 }

-func (t *FilerStorePathTranlator) KvPut(ctx context.Context, key []byte, value []byte) (err error) {
+func (t *FilerStorePathTranslator) KvPut(ctx context.Context, key []byte, value []byte) (err error) {
 	return t.actualStore.KvPut(ctx, key, value)
 }
-func (t *FilerStorePathTranlator) KvGet(ctx context.Context, key []byte) (value []byte, err error) {
+func (t *FilerStorePathTranslator) KvGet(ctx context.Context, key []byte) (value []byte, err error) {
 	return t.actualStore.KvGet(ctx, key)
 }
-func (t *FilerStorePathTranlator) KvDelete(ctx context.Context, key []byte) (err error) {
+func (t *FilerStorePathTranslator) KvDelete(ctx context.Context, key []byte) (err error) {
 	return t.actualStore.KvDelete(ctx, key)
 }
--- a/weed/filer/filerstore_wrapper.go
+++ b/weed/filer/filerstore_wrapper.go
@@ -4,6 +4,8 @@ import (
 	"context"
 	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/viant/ptrie"
+	"io"
+	"math"
 	"strings"
 	"time"

@@ -14,12 +16,14 @@ import (

 var (
 	_ = VirtualFilerStore(&FilerStoreWrapper{})
+	_ = Debuggable(&FilerStoreWrapper{})
 )

 type VirtualFilerStore interface {
 	FilerStore
 	DeleteHardLink(ctx context.Context, hardLinkId HardLinkId) error
 	DeleteOneEntry(ctx context.Context, entry *Entry) error
+	DeleteOneEntrySkipHardlink(ctx context.Context, fullpath util.FullPath) error
 	AddPathSpecificStore(path string, storeId string, store FilerStore)
 	OnBucketCreation(bucket string)
 	OnBucketDeletion(bucket string)
@@ -72,7 +76,7 @@ func (fsw *FilerStoreWrapper) OnBucketDeletion(bucket string) {
 }

 func (fsw *FilerStoreWrapper) AddPathSpecificStore(path string, storeId string, store FilerStore) {
-	fsw.storeIdToStore[storeId] = NewFilerStorePathTranlator(path, store)
+	fsw.storeIdToStore[storeId] = NewFilerStorePathTranslator(path, store)
 	err := fsw.pathToStore.Put([]byte(path), storeId)
 	if err != nil {
 		glog.Fatalf("put path specific store: %v", err)
@@ -124,7 +128,7 @@ func (fsw *FilerStoreWrapper) InsertEntry(ctx context.Context, entry *Entry) err
 		return err
 	}

-	glog.V(4).Infof("InsertEntry %s", entry.FullPath)
+	// glog.V(4).Infof("InsertEntry %s", entry.FullPath)
 	return actualStore.InsertEntry(ctx, entry)
 }

@@ -145,7 +149,7 @@ func (fsw *FilerStoreWrapper) UpdateEntry(ctx context.Context, entry *Entry) err
 		return err
 	}

-	glog.V(4).Infof("UpdateEntry %s", entry.FullPath)
+	// glog.V(4).Infof("UpdateEntry %s", entry.FullPath)
 	return actualStore.UpdateEntry(ctx, entry)
 }

@@ -189,7 +193,7 @@ func (fsw *FilerStoreWrapper) DeleteEntry(ctx context.Context, fp util.FullPath)
 		}
 	}

-	glog.V(4).Infof("DeleteEntry %s", fp)
+	// glog.V(4).Infof("DeleteEntry %s", fp)
 	return actualStore.DeleteEntry(ctx, fp)
 }

@@ -209,10 +213,22 @@ func (fsw *FilerStoreWrapper) DeleteOneEntry(ctx context.Context, existingEntry
 		}
 	}

-	glog.V(4).Infof("DeleteOneEntry %s", existingEntry.FullPath)
+	// glog.V(4).Infof("DeleteOneEntry %s", existingEntry.FullPath)
 	return actualStore.DeleteEntry(ctx, existingEntry.FullPath)
 }

+func (fsw *FilerStoreWrapper) DeleteOneEntrySkipHardlink(ctx context.Context, fullpath util.FullPath) (err error) {
+	actualStore := fsw.getActualStore(fullpath)
+	stats.FilerStoreCounter.WithLabelValues(actualStore.GetName(), "delete").Inc()
+	start := time.Now()
+	defer func() {
+		stats.FilerStoreHistogram.WithLabelValues(actualStore.GetName(), "delete").Observe(time.Since(start).Seconds())
+	}()
+
+	glog.V(4).Infof("DeleteOneEntrySkipHardlink %s", fullpath)
+	return actualStore.DeleteEntry(ctx, fullpath)
+}
+
 func (fsw *FilerStoreWrapper) DeleteFolderChildren(ctx context.Context, fp util.FullPath) (err error) {
 	actualStore := fsw.getActualStore(fp + "/")
 	stats.FilerStoreCounter.WithLabelValues(actualStore.GetName(), "deleteFolderChildren").Inc()
@@ -221,7 +237,7 @@ func (fsw *FilerStoreWrapper) DeleteFolderChildren(ctx context.Context, fp util.
 		stats.FilerStoreHistogram.WithLabelValues(actualStore.GetName(), "deleteFolderChildren").Observe(time.Since(start).Seconds())
 	}()

-	glog.V(4).Infof("DeleteFolderChildren %s", fp)
+	// glog.V(4).Infof("DeleteFolderChildren %s", fp)
 	return actualStore.DeleteFolderChildren(ctx, fp)
 }

@@ -233,7 +249,7 @@ func (fsw *FilerStoreWrapper) ListDirectoryEntries(ctx context.Context, dirPath
 		stats.FilerStoreHistogram.WithLabelValues(actualStore.GetName(), "list").Observe(time.Since(start).Seconds())
 	}()

-	glog.V(4).Infof("ListDirectoryEntries %s from %s limit %d", dirPath, startFileName, limit)
+	// glog.V(4).Infof("ListDirectoryEntries %s from %s limit %d", dirPath, startFileName, limit)
 	return actualStore.ListDirectoryEntries(ctx, dirPath, startFileName, includeStartFile, limit, func(entry *Entry) bool {
 		fsw.maybeReadHardLink(ctx, entry)
 		filer_pb.AfterEntryDeserialization(entry.Chunks)
@@ -248,14 +264,18 @@ func (fsw *FilerStoreWrapper) ListDirectoryPrefixedEntries(ctx context.Context,
 	defer func() {
 		stats.FilerStoreHistogram.WithLabelValues(actualStore.GetName(), "prefixList").Observe(time.Since(start).Seconds())
 	}()
-	glog.V(4).Infof("ListDirectoryPrefixedEntries %s from %s prefix %s limit %d", dirPath, startFileName, prefix, limit)
-	lastFileName, err = actualStore.ListDirectoryPrefixedEntries(ctx, dirPath, startFileName, includeStartFile, limit, prefix, eachEntryFunc)
+	if limit > math.MaxInt32-1 {
+		limit = math.MaxInt32 - 1
+	}
+	// glog.V(4).Infof("ListDirectoryPrefixedEntries %s from %s prefix %s limit %d", dirPath, startFileName, prefix, limit)
+	adjustedEntryFunc := func(entry *Entry) bool {
+		fsw.maybeReadHardLink(ctx, entry)
+		filer_pb.AfterEntryDeserialization(entry.Chunks)
+		return eachEntryFunc(entry)
+	}
+	lastFileName, err = actualStore.ListDirectoryPrefixedEntries(ctx, dirPath, startFileName, includeStartFile, limit, prefix, adjustedEntryFunc)
 	if err == ErrUnsupportedListDirectoryPrefixed {
-		lastFileName, err = fsw.prefixFilterEntries(ctx, dirPath, startFileName, includeStartFile, limit, prefix, func(entry *Entry) bool {
-			fsw.maybeReadHardLink(ctx, entry)
-			filer_pb.AfterEntryDeserialization(entry.Chunks)
-			return eachEntryFunc(entry)
-		})
+		lastFileName, err = fsw.prefixFilterEntries(ctx, dirPath, startFileName, includeStartFile, limit, prefix, adjustedEntryFunc)
 	}
 	return lastFileName, err
 }
@@ -278,8 +298,10 @@ func (fsw *FilerStoreWrapper) prefixFilterEntries(ctx context.Context, dirPath u

 	count := int64(0)
 	for count < limit && len(notPrefixed) > 0 {
+		var isLastItemHasPrefix bool
 		for _, entry := range notPrefixed {
 			if strings.HasPrefix(entry.Name(), prefix) {
+				isLastItemHasPrefix = true
 				count++
 				if !eachEntryFunc(entry) {
 					return
@@ -287,17 +309,21 @@ func (fsw *FilerStoreWrapper) prefixFilterEntries(ctx context.Context, dirPath u
 				if count >= limit {
 					break
 				}
+			} else {
+				isLastItemHasPrefix = false
 			}
 		}
-		if count < limit {
+		if count < limit && isLastItemHasPrefix && len(notPrefixed) == int(limit) {
 			notPrefixed = notPrefixed[:0]
-			_, err = actualStore.ListDirectoryEntries(ctx, dirPath, lastFileName, false, limit, func(entry *Entry) bool {
+			lastFileName, err = actualStore.ListDirectoryEntries(ctx, dirPath, lastFileName, false, limit, func(entry *Entry) bool {
 				notPrefixed = append(notPrefixed, entry)
 				return true
 			})
 			if err != nil {
 				return
 			}
+		} else {
+			break
 		}
 	}
 	return
@@ -328,3 +354,9 @@ func (fsw *FilerStoreWrapper) KvGet(ctx context.Context, key []byte) (value []by
 func (fsw *FilerStoreWrapper) KvDelete(ctx context.Context, key []byte) (err error) {
 	return fsw.getDefaultStore().KvDelete(ctx, key)
 }
+
+func (fsw *FilerStoreWrapper) Debug(writer io.Writer) {
+	if debuggable, ok := fsw.getDefaultStore().(Debuggable); ok {
+		debuggable.Debug(writer)
+	}
+}
--- a/weed/filer/hbase/hbase_store.go
+++ b/weed/filer/hbase/hbase_store.go
@@ -75,7 +75,7 @@ func (store *HbaseStore) InsertEntry(ctx context.Context, entry *filer.Entry) er
 	if err != nil {
 		return fmt.Errorf("encoding %s %+v: %v", entry.FullPath, entry.Attr, err)
 	}
-	if len(entry.Chunks) > 50 {
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
 		value = util.MaybeGzipData(value)
 	}

--- a/weed/filer/leveldb/leveldb_store.go
+++ b/weed/filer/leveldb/leveldb_store.go
@@ -6,8 +6,10 @@ import (
 	"fmt"
 	"github.com/syndtr/goleveldb/leveldb"
 	leveldb_errors "github.com/syndtr/goleveldb/leveldb/errors"
+	"github.com/syndtr/goleveldb/leveldb/filter"
 	"github.com/syndtr/goleveldb/leveldb/opt"
 	leveldb_util "github.com/syndtr/goleveldb/leveldb/util"
+	"io"
 	"os"

 	"github.com/chrislusf/seaweedfs/weed/filer"
@@ -20,6 +22,10 @@ const (
 	DIR_FILE_SEPARATOR = byte(0x00)
 )

+var (
+	_ = filer.Debuggable(&LevelDBStore{})
+)
+
 func init() {
 	filer.Stores = append(filer.Stores, &LevelDBStore{})
 }
@@ -45,9 +51,9 @@ func (store *LevelDBStore) initialize(dir string) (err error) {
 	}

 	opts := &opt.Options{
-		BlockCacheCapacity:            32 * 1024 * 1024, // default value is 8MiB
-		WriteBuffer:                   16 * 1024 * 1024, // default value is 4MiB
-		CompactionTableSizeMultiplier: 10,
+		BlockCacheCapacity: 32 * 1024 * 1024,         // default value is 8MiB
+		WriteBuffer:        16 * 1024 * 1024,         // default value is 4MiB
+		Filter:             filter.NewBloomFilter(8), // false positive rate 0.02
 	}

 	if store.db, err = leveldb.OpenFile(dir, opts); err != nil {
@@ -80,7 +86,7 @@ func (store *LevelDBStore) InsertEntry(ctx context.Context, entry *filer.Entry)
 		return fmt.Errorf("encoding %s %+v: %v", entry.FullPath, entry.Attr, err)
 	}

-	if len(entry.Chunks) > 50 {
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
 		value = weed_util.MaybeGzipData(value)
 	}

@@ -241,3 +247,13 @@ func getNameFromKey(key []byte) string {
 func (store *LevelDBStore) Shutdown() {
 	store.db.Close()
 }
+
+func (store *LevelDBStore) Debug(writer io.Writer) {
+	iter := store.db.NewIterator(&leveldb_util.Range{}, nil)
+	for iter.Next() {
+		key := iter.Key()
+		fullName := bytes.Replace(key, []byte{DIR_FILE_SEPARATOR}, []byte{' '}, 1)
+		fmt.Fprintf(writer, "%v\n", string(fullName))
+	}
+	iter.Release()
+}
--- a/weed/filer/leveldb/leveldb_store_test.go
+++ b/weed/filer/leveldb/leveldb_store_test.go
@@ -3,7 +3,6 @@ package leveldb
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"testing"
 	"time"
@@ -13,9 +12,8 @@ import (
 )

 func TestCreateAndFind(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
-	dir, _ := ioutil.TempDir("", "seaweedfs_filer_test")
-	defer os.RemoveAll(dir)
+	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	dir := t.TempDir()
 	store := &LevelDBStore{}
 	store.initialize(dir)
 	testFiler.SetStore(store)
@@ -33,7 +31,7 @@ func TestCreateAndFind(t *testing.T) {
 		},
 	}

-	if err := testFiler.CreateEntry(ctx, entry1, false, false, nil); err != nil {
+	if err := testFiler.CreateEntry(ctx, entry1, false, false, nil, false); err != nil {
 		t.Errorf("create entry %v: %v", entry1.FullPath, err)
 		return
 	}
@@ -67,9 +65,8 @@ func TestCreateAndFind(t *testing.T) {
 }

 func TestEmptyRoot(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
-	dir, _ := ioutil.TempDir("", "seaweedfs_filer_test2")
-	defer os.RemoveAll(dir)
+	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	dir := t.TempDir()
 	store := &LevelDBStore{}
 	store.initialize(dir)
 	testFiler.SetStore(store)
@@ -90,9 +87,8 @@ func TestEmptyRoot(t *testing.T) {
 }

 func BenchmarkInsertEntry(b *testing.B) {
-	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
-	dir, _ := ioutil.TempDir("", "seaweedfs_filer_bench")
-	defer os.RemoveAll(dir)
+	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	dir := b.TempDir()
 	store := &LevelDBStore{}
 	store.initialize(dir)
 	testFiler.SetStore(store)
--- a/weed/filer/leveldb2/leveldb2_store.go
+++ b/weed/filer/leveldb2/leveldb2_store.go
@@ -46,10 +46,9 @@ func (store *LevelDB2Store) initialize(dir string, dbCount int) (err error) {
 	}

 	opts := &opt.Options{
-		BlockCacheCapacity:            32 * 1024 * 1024, // default value is 8MiB
-		WriteBuffer:                   16 * 1024 * 1024, // default value is 4MiB
-		CompactionTableSizeMultiplier: 4,
-		Filter:                        filter.NewBloomFilter(8), // false positive rate 0.02
+		BlockCacheCapacity: 32 * 1024 * 1024,         // default value is 8MiB
+		WriteBuffer:        16 * 1024 * 1024,         // default value is 4MiB
+		Filter:             filter.NewBloomFilter(8), // false positive rate 0.02
 	}

 	for d := 0; d < dbCount; d++ {
@@ -89,7 +88,7 @@ func (store *LevelDB2Store) InsertEntry(ctx context.Context, entry *filer.Entry)
 		return fmt.Errorf("encoding %s %+v: %v", entry.FullPath, entry.Attr, err)
 	}

-	if len(entry.Chunks) > 50 {
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
 		value = weed_util.MaybeGzipData(value)
 	}

--- a/weed/filer/leveldb2/leveldb2_store_test.go
+++ b/weed/filer/leveldb2/leveldb2_store_test.go
@@ -2,8 +2,6 @@ package leveldb

 import (
 	"context"
-	"io/ioutil"
-	"os"
 	"testing"

 	"github.com/chrislusf/seaweedfs/weed/filer"
@@ -11,9 +9,8 @@ import (
 )

 func TestCreateAndFind(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
-	dir, _ := ioutil.TempDir("", "seaweedfs_filer_test")
-	defer os.RemoveAll(dir)
+	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	dir := t.TempDir()
 	store := &LevelDB2Store{}
 	store.initialize(dir, 2)
 	testFiler.SetStore(store)
@@ -31,7 +28,7 @@ func TestCreateAndFind(t *testing.T) {
 		},
 	}

-	if err := testFiler.CreateEntry(ctx, entry1, false, false, nil); err != nil {
+	if err := testFiler.CreateEntry(ctx, entry1, false, false, nil, false); err != nil {
 		t.Errorf("create entry %v: %v", entry1.FullPath, err)
 		return
 	}
@@ -65,9 +62,8 @@ func TestCreateAndFind(t *testing.T) {
 }

 func TestEmptyRoot(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
-	dir, _ := ioutil.TempDir("", "seaweedfs_filer_test2")
-	defer os.RemoveAll(dir)
+	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	dir := t.TempDir()
 	store := &LevelDB2Store{}
 	store.initialize(dir, 2)
 	testFiler.SetStore(store)
--- a/weed/filer/leveldb3/leveldb3_store.go
+++ b/weed/filer/leveldb3/leveldb3_store.go
@@ -66,17 +66,15 @@ func (store *LevelDB3Store) initialize(dir string) (err error) {
 func (store *LevelDB3Store) loadDB(name string) (*leveldb.DB, error) {
 	bloom := filter.NewBloomFilter(8) // false positive rate 0.02
 	opts := &opt.Options{
-		BlockCacheCapacity:            32 * 1024 * 1024, // default value is 8MiB
-		WriteBuffer:                   16 * 1024 * 1024, // default value is 4MiB
-		CompactionTableSizeMultiplier: 4,
-		Filter:                        bloom,
+		BlockCacheCapacity: 32 * 1024 * 1024, // default value is 8MiB
+		WriteBuffer:        16 * 1024 * 1024, // default value is 4MiB
+		Filter:             bloom,
 	}
 	if name != DEFAULT {
 		opts = &opt.Options{
-			BlockCacheCapacity:            4 * 1024 * 1024, // default value is 8MiB
-			WriteBuffer:                   2 * 1024 * 1024, // default value is 4MiB
-			CompactionTableSizeMultiplier: 4,
-			Filter:                        bloom,
+			BlockCacheCapacity: 16 * 1024 * 1024, // default value is 8MiB
+			WriteBuffer:        8 * 1024 * 1024,  // default value is 4MiB
+			Filter:             bloom,
 		}
 	}

@@ -179,7 +177,7 @@ func (store *LevelDB3Store) InsertEntry(ctx context.Context, entry *filer.Entry)
 		return fmt.Errorf("encoding %s %+v: %v", entry.FullPath, entry.Attr, err)
 	}

-	if len(entry.Chunks) > 50 {
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
 		value = weed_util.MaybeGzipData(value)
 	}

--- a/weed/filer/leveldb3/leveldb3_store_test.go
+++ b/weed/filer/leveldb3/leveldb3_store_test.go
@@ -2,8 +2,6 @@ package leveldb

 import (
 	"context"
-	"io/ioutil"
-	"os"
 	"testing"

 	"github.com/chrislusf/seaweedfs/weed/filer"
@@ -11,9 +9,8 @@ import (
 )

 func TestCreateAndFind(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
-	dir, _ := ioutil.TempDir("", "seaweedfs_filer_test")
-	defer os.RemoveAll(dir)
+	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	dir := t.TempDir()
 	store := &LevelDB3Store{}
 	store.initialize(dir)
 	testFiler.SetStore(store)
@@ -31,7 +28,7 @@ func TestCreateAndFind(t *testing.T) {
 		},
 	}

-	if err := testFiler.CreateEntry(ctx, entry1, false, false, nil); err != nil {
+	if err := testFiler.CreateEntry(ctx, entry1, false, false, nil, false); err != nil {
 		t.Errorf("create entry %v: %v", entry1.FullPath, err)
 		return
 	}
@@ -65,9 +62,8 @@ func TestCreateAndFind(t *testing.T) {
 }

 func TestEmptyRoot(t *testing.T) {
-	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
-	dir, _ := ioutil.TempDir("", "seaweedfs_filer_test2")
-	defer os.RemoveAll(dir)
+	testFiler := filer.NewFiler(nil, nil, "", "", "", "", "", nil)
+	dir := t.TempDir()
 	store := &LevelDB3Store{}
 	store.initialize(dir)
 	testFiler.SetStore(store)
--- a/weed/filer/meta_aggregator.go
+++ b/weed/filer/meta_aggregator.go
@@ -3,6 +3,8 @@ package filer
 import (
 	"context"
 	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/cluster"
+	"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
 	"github.com/chrislusf/seaweedfs/weed/util"
 	"io"
 	"sync"
@@ -18,9 +20,13 @@ import (
 )

 type MetaAggregator struct {
-	filers         []string
-	grpcDialOption grpc.DialOption
-	MetaLogBuffer  *log_buffer.LogBuffer
+	filer           *Filer
+	self            pb.ServerAddress
+	isLeader        bool
+	grpcDialOption  grpc.DialOption
+	MetaLogBuffer   *log_buffer.LogBuffer
+	peerStatues     map[pb.ServerAddress]int
+	peerStatuesLock sync.Mutex
 	// notifying clients
 	ListenersLock sync.Mutex
 	ListenersCond *sync.Cond
@@ -28,10 +34,12 @@ type MetaAggregator struct {

 // MetaAggregator only aggregates data "on the fly". The logs are not re-persisted to disk.
 // The old data comes from what each LocalMetadata persisted on disk.
-func NewMetaAggregator(filers []string, grpcDialOption grpc.DialOption) *MetaAggregator {
+func NewMetaAggregator(filer *Filer, self pb.ServerAddress, grpcDialOption grpc.DialOption) *MetaAggregator {
 	t := &MetaAggregator{
-		filers:         filers,
+		filer:          filer,
+		self:           self,
 		grpcDialOption: grpcDialOption,
+		peerStatues:    make(map[pb.ServerAddress]int),
 	}
 	t.ListenersCond = sync.NewCond(&t.ListenersLock)
 	t.MetaLogBuffer = log_buffer.NewLogBuffer("aggr", LogFlushInterval, nil, func() {
@@ -40,13 +48,66 @@ func NewMetaAggregator(filers []string, grpcDialOption grpc.DialOption) *MetaAgg
 	return t
 }

-func (ma *MetaAggregator) StartLoopSubscribe(f *Filer, self string) {
-	for _, filer := range ma.filers {
-		go ma.subscribeToOneFiler(f, self, filer)
+func (ma *MetaAggregator) OnPeerUpdate(update *master_pb.ClusterNodeUpdate, startFrom time.Time) {
+	if update.NodeType != cluster.FilerType {
+		return
+	}
+
+	address := pb.ServerAddress(update.Address)
+	if update.IsAdd {
+		// every filer should subscribe to a new filer
+		if ma.setActive(address, true) {
+			go ma.loopSubscribeToOnefiler(ma.filer, ma.self, address, startFrom)
+		}
+	} else {
+		ma.setActive(address, false)
 	}
 }

-func (ma *MetaAggregator) subscribeToOneFiler(f *Filer, self string, peer string) {
+func (ma *MetaAggregator) setActive(address pb.ServerAddress, isActive bool) (notDuplicated bool) {
+	ma.peerStatuesLock.Lock()
+	defer ma.peerStatuesLock.Unlock()
+	if isActive {
+		if _, found := ma.peerStatues[address]; found {
+			ma.peerStatues[address] += 1
+		} else {
+			ma.peerStatues[address] = 1
+			notDuplicated = true
+		}
+	} else {
+		if _, found := ma.peerStatues[address]; found {
+			delete(ma.peerStatues, address)
+		}
+	}
+	return
+}
+func (ma *MetaAggregator) isActive(address pb.ServerAddress) (isActive bool) {
+	ma.peerStatuesLock.Lock()
+	defer ma.peerStatuesLock.Unlock()
+	var count int
+	count, isActive = ma.peerStatues[address]
+	return count > 0 && isActive
+}
+
+func (ma *MetaAggregator) loopSubscribeToOnefiler(f *Filer, self pb.ServerAddress, peer pb.ServerAddress, startFrom time.Time) {
+	lastTsNs := startFrom.UnixNano()
+	for {
+		glog.V(0).Infof("loopSubscribeToOnefiler read %s start from %v %d", peer, time.Unix(0, lastTsNs), lastTsNs)
+		nextLastTsNs, err := ma.doSubscribeToOneFiler(f, self, peer, lastTsNs)
+		if !ma.isActive(peer) {
+			glog.V(0).Infof("stop subscribing remote %s meta change", peer)
+			return
+		}
+		if err != nil {
+			glog.V(0).Infof("subscribing remote %s meta change: %v", peer, err)
+		} else if lastTsNs < nextLastTsNs {
+			lastTsNs = nextLastTsNs
+		}
+		time.Sleep(1733 * time.Millisecond)
+	}
+}
+
+func (ma *MetaAggregator) doSubscribeToOneFiler(f *Filer, self pb.ServerAddress, peer pb.ServerAddress, startFrom int64) (int64, error) {

 	/*
 		Each filer reads the "filer.store.id", which is the store's signature when filer starts.
@@ -60,20 +121,26 @@ func (ma *MetaAggregator) subscribeToOneFiler(f *Filer, self string, peer string

 	var maybeReplicateMetadataChange func(*filer_pb.SubscribeMetadataResponse)
 	lastPersistTime := time.Now()
-	lastTsNs := time.Now().Add(-LogFlushInterval).UnixNano()
+	lastTsNs := startFrom

 	peerSignature, err := ma.readFilerStoreSignature(peer)
-	for err != nil {
-		glog.V(0).Infof("connecting to peer filer %s: %v", peer, err)
-		time.Sleep(1357 * time.Millisecond)
-		peerSignature, err = ma.readFilerStoreSignature(peer)
+	if err != nil {
+		return lastTsNs, fmt.Errorf("connecting to peer filer %s: %v", peer, err)
 	}

 	// when filer store is not shared by multiple filers
 	if peerSignature != f.Signature {
-		lastTsNs = 0
 		if prevTsNs, err := ma.readOffset(f, peer, peerSignature); err == nil {
 			lastTsNs = prevTsNs
+			defer func(prevTsNs int64) {
+				if lastTsNs != prevTsNs && lastTsNs != lastPersistTime.UnixNano() {
+					if err := ma.updateOffset(f, peer, peerSignature, lastTsNs); err == nil {
+						glog.V(0).Infof("last sync time with %s at %v (%d)", peer, time.Unix(0, lastTsNs), lastTsNs)
+					} else {
+						glog.Errorf("failed to save last sync time with %s at %v (%d)", peer, time.Unix(0, lastTsNs), lastTsNs)
+					}
+				}
+			}(prevTsNs)
 		}

 		glog.V(0).Infof("follow peer: %v, last %v (%d)", peer, time.Unix(0, lastTsNs), lastTsNs)
@@ -110,54 +177,50 @@ func (ma *MetaAggregator) subscribeToOneFiler(f *Filer, self string, peer string
 		}
 		dir := event.Directory
 		// println("received meta change", dir, "size", len(data))
-		ma.MetaLogBuffer.AddToBuffer([]byte(dir), data, 0)
+		ma.MetaLogBuffer.AddToBuffer([]byte(dir), data, event.TsNs)
 		if maybeReplicateMetadataChange != nil {
 			maybeReplicateMetadataChange(event)
 		}
 		return nil
 	}

-	for {
-		glog.V(4).Infof("subscribing remote %s meta change: %v", peer, time.Unix(0, lastTsNs))
-		err := pb.WithFilerClient(peer, ma.grpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
-			ctx, cancel := context.WithCancel(context.Background())
-			defer cancel()
-			stream, err := client.SubscribeLocalMetadata(ctx, &filer_pb.SubscribeMetadataRequest{
-				ClientName: "filer:" + self,
-				PathPrefix: "/",
-				SinceNs:    lastTsNs,
-			})
-			if err != nil {
-				return fmt.Errorf("subscribe: %v", err)
-			}
-
-			for {
-				resp, listenErr := stream.Recv()
-				if listenErr == io.EOF {
-					return nil
-				}
-				if listenErr != nil {
-					return listenErr
-				}
-
-				if err := processEventFn(resp); err != nil {
-					return fmt.Errorf("process %v: %v", resp, err)
-				}
-				lastTsNs = resp.TsNs
-
-				f.onMetadataChangeEvent(resp)
-
-			}
+	glog.V(4).Infof("subscribing remote %s meta change: %v", peer, time.Unix(0, lastTsNs))
+	err = pb.WithFilerClient(true, peer, ma.grpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+		stream, err := client.SubscribeLocalMetadata(ctx, &filer_pb.SubscribeMetadataRequest{
+			ClientName: "filer:" + string(self),
+			PathPrefix: "/",
+			SinceNs:    lastTsNs,
+			ClientId:   int32(ma.filer.UniqueFileId),
 		})
 		if err != nil {
-			glog.V(0).Infof("subscribing remote %s meta change: %v", peer, err)
-			time.Sleep(1733 * time.Millisecond)
+			return fmt.Errorf("subscribe: %v", err)
 		}
-	}
+
+		for {
+			resp, listenErr := stream.Recv()
+			if listenErr == io.EOF {
+				return nil
+			}
+			if listenErr != nil {
+				return listenErr
+			}
+
+			if err := processEventFn(resp); err != nil {
+				return fmt.Errorf("process %v: %v", resp, err)
+			}
+			lastTsNs = resp.TsNs
+
+			f.onMetadataChangeEvent(resp)
+
+		}
+	})
+	return lastTsNs, err
 }

-func (ma *MetaAggregator) readFilerStoreSignature(peer string) (sig int32, err error) {
-	err = pb.WithFilerClient(peer, ma.grpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
+func (ma *MetaAggregator) readFilerStoreSignature(peer pb.ServerAddress) (sig int32, err error) {
+	err = pb.WithFilerClient(false, peer, ma.grpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
 		resp, err := client.GetFilerConfiguration(context.Background(), &filer_pb.GetFilerConfigurationRequest{})
 		if err != nil {
 			return err
@@ -172,18 +235,13 @@ const (
 	MetaOffsetPrefix = "Meta"
 )

-func (ma *MetaAggregator) readOffset(f *Filer, peer string, peerSignature int32) (lastTsNs int64, err error) {
+func (ma *MetaAggregator) readOffset(f *Filer, peer pb.ServerAddress, peerSignature int32) (lastTsNs int64, err error) {

 	key := []byte(MetaOffsetPrefix + "xxxx")
 	util.Uint32toBytes(key[len(MetaOffsetPrefix):], uint32(peerSignature))

 	value, err := f.Store.KvGet(context.Background(), key)

-	if err == ErrKvNotFound {
-		glog.Warningf("readOffset %s not found", peer)
-		return 0, nil
-	}
-
 	if err != nil {
 		return 0, fmt.Errorf("readOffset %s : %v", peer, err)
 	}
@@ -195,7 +253,7 @@ func (ma *MetaAggregator) readOffset(f *Filer, peer string, peerSignature int32)
 	return
 }

-func (ma *MetaAggregator) updateOffset(f *Filer, peer string, peerSignature int32, lastTsNs int64) (err error) {
+func (ma *MetaAggregator) updateOffset(f *Filer, peer pb.ServerAddress, peerSignature int32, lastTsNs int64) (err error) {

 	key := []byte(MetaOffsetPrefix + "xxxx")
 	util.Uint32toBytes(key[len(MetaOffsetPrefix):], uint32(peerSignature))
--- a/weed/filer/mongodb/mongodb_store.go
+++ b/weed/filer/mongodb/mongodb_store.go
@@ -107,7 +107,7 @@ func (store *MongodbStore) UpdateEntry(ctx context.Context, entry *filer.Entry)
 		return fmt.Errorf("encode %s: %s", entry.FullPath, err)
 	}

-	if len(entry.Chunks) > 50 {
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
 		meta = util.MaybeGzipData(meta)
 	}

@@ -159,7 +159,7 @@ func (store *MongodbStore) DeleteEntry(ctx context.Context, fullpath util.FullPa
 	dir, name := fullpath.DirAndName()

 	where := bson.M{"directory": dir, "name": name}
-	_, err := store.connect.Database(store.database).Collection(store.collectionName).DeleteOne(ctx, where)
+	_, err := store.connect.Database(store.database).Collection(store.collectionName).DeleteMany(ctx, where)
 	if err != nil {
 		return fmt.Errorf("delete %s : %v", fullpath, err)
 	}
@@ -193,11 +193,15 @@ func (store *MongodbStore) ListDirectoryEntries(ctx context.Context, dirPath uti
 	optLimit := int64(limit)
 	opts := &options.FindOptions{Limit: &optLimit, Sort: bson.M{"name": 1}}
 	cur, err := store.connect.Database(store.database).Collection(store.collectionName).Find(ctx, where, opts)
+	if err != nil {
+		return lastFileName, fmt.Errorf("failed to list directory entries: find error: %w", err)
+	}
+
 	for cur.Next(ctx) {
 		var data Model
-		err := cur.Decode(&data)
-		if err != nil && err != mongo.ErrNoDocuments {
-			return lastFileName, err
+		err = cur.Decode(&data)
+		if err != nil {
+			break
 		}

 		entry := &filer.Entry{
--- a/weed/filer/mysql2/mysql2_store.go
+++ b/weed/filer/mysql2/mysql2_store.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
+	"strings"
 	"time"

 	"github.com/chrislusf/seaweedfs/weed/filer"
@@ -82,7 +83,7 @@ func (store *MysqlStore2) initialize(createTable, upsertQuery string, enableUpse
 		return fmt.Errorf("connect to %s error:%v", sqlUrl, err)
 	}

-	if err = store.CreateTable(context.Background(), abstract_sql.DEFAULT_TABLE); err != nil {
+	if err = store.CreateTable(context.Background(), abstract_sql.DEFAULT_TABLE); err != nil && !strings.Contains(err.Error(), "table already exist") {
 		return fmt.Errorf("init table %s: %v", abstract_sql.DEFAULT_TABLE, err)
 	}

--- a/weed/filer/permission.go
+++ b/weed/filer/permission.go
@@ -1,22 +0,0 @@
-package filer
-
-func hasWritePermission(dir *Entry, entry *Entry) bool {
-
-	if dir == nil {
-		return false
-	}
-
-	if dir.Uid == entry.Uid && dir.Mode&0200 > 0 {
-		return true
-	}
-
-	if dir.Gid == entry.Gid && dir.Mode&0020 > 0 {
-		return true
-	}
-
-	if dir.Mode&0002 > 0 {
-		return true
-	}
-
-	return false
-}
--- a/weed/filer/read_remote.go
+++ b/weed/filer/read_remote.go
@@ -21,13 +21,13 @@ func MapFullPathToRemoteStorageLocation(localMountedDir util.FullPath, remoteMou
 	return remoteLocation
 }

-func MapRemoteStorageLocationPathToFullPath(localMountedDir util.FullPath, remoteMountedLocation *remote_pb.RemoteStorageLocation, remoteLocationPath string)(fp util.FullPath)  {
+func MapRemoteStorageLocationPathToFullPath(localMountedDir util.FullPath, remoteMountedLocation *remote_pb.RemoteStorageLocation, remoteLocationPath string) (fp util.FullPath) {
 	return localMountedDir.Child(remoteLocationPath[len(remoteMountedLocation.Path):])
 }

-func DownloadToLocal(filerClient filer_pb.FilerClient, remoteConf *remote_pb.RemoteConf, remoteLocation *remote_pb.RemoteStorageLocation, parent util.FullPath, entry *filer_pb.Entry) error {
-	return filerClient.WithFilerClient(func(client filer_pb.SeaweedFilerClient) error {
-		_, err := client.DownloadToLocal(context.Background(), &filer_pb.DownloadToLocalRequest{
+func CacheRemoteObjectToLocalCluster(filerClient filer_pb.FilerClient, remoteConf *remote_pb.RemoteConf, remoteLocation *remote_pb.RemoteStorageLocation, parent util.FullPath, entry *filer_pb.Entry) error {
+	return filerClient.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+		_, err := client.CacheRemoteObjectToLocalCluster(context.Background(), &filer_pb.CacheRemoteObjectToLocalClusterRequest{
 			Directory: string(parent),
 			Name:      entry.Name,
 		})
--- a/weed/filer/read_write.go
+++ b/weed/filer/read_write.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 	"github.com/chrislusf/seaweedfs/weed/wdclient"
-	"math"
 	"time"
 )

@@ -23,7 +22,7 @@ func ReadEntry(masterClient *wdclient.MasterClient, filerClient filer_pb.Seaweed
 		return err
 	}

-	return StreamContent(masterClient, byteBuffer, respLookupEntry.Entry.Chunks, 0, math.MaxInt64)
+	return StreamContent(masterClient, byteBuffer, respLookupEntry.Entry.Chunks, 0, int64(FileSize(respLookupEntry.Entry)))

 }

@@ -54,15 +53,14 @@ func SaveInsideFiler(client filer_pb.SeaweedFilerClient, dir, name string, conte
 				Name:        name,
 				IsDirectory: false,
 				Attributes: &filer_pb.FuseAttributes{
-					Mtime:       time.Now().Unix(),
-					Crtime:      time.Now().Unix(),
-					FileMode:    uint32(0644),
-					Collection:  "",
-					Replication: "",
-					FileSize:    uint64(len(content)),
+					Mtime:    time.Now().Unix(),
+					Crtime:   time.Now().Unix(),
+					FileMode: uint32(0644),
+					FileSize: uint64(len(content)),
 				},
 				Content: content,
 			},
+			SkipCheckParentDirectory: true,
 		})
 	} else if err == nil {
 		entry := resp.Entry
--- a/weed/filer/reader_at.go
+++ b/weed/filer/reader_at.go
@@ -12,20 +12,16 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/util"
 	"github.com/chrislusf/seaweedfs/weed/util/chunk_cache"
 	"github.com/chrislusf/seaweedfs/weed/wdclient"
-	"github.com/golang/groupcache/singleflight"
 )

 type ChunkReadAt struct {
-	masterClient *wdclient.MasterClient
-	chunkViews   []*ChunkView
-	lookupFileId wdclient.LookupFileIdFunctionType
-	readerLock   sync.Mutex
-	fileSize     int64
-
-	fetchGroup      singleflight.Group
-	chunkCache      chunk_cache.ChunkCache
-	lastChunkFileId string
-	lastChunkData   []byte
+	masterClient  *wdclient.MasterClient
+	chunkViews    []*ChunkView
+	readerLock    sync.Mutex
+	fileSize      int64
+	readerCache   *ReaderCache
+	readerPattern *ReaderPattern
+	lastChunkFid  string
 }

 var _ = io.ReaderAt(&ChunkReadAt{})
@@ -43,7 +39,7 @@ func LookupFn(filerClient filer_pb.FilerClient) wdclient.LookupFileIdFunctionTyp

 		if !found {
 			util.Retry("lookup volume "+vid, func() error {
-				err = filerClient.WithFilerClient(func(client filer_pb.SeaweedFilerClient) error {
+				err = filerClient.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
 					resp, err := client.LookupVolume(context.Background(), &filer_pb.LookupVolumeRequest{
 						VolumeIds: []string{vid},
 					})
@@ -88,21 +84,22 @@ func LookupFn(filerClient filer_pb.FilerClient) wdclient.LookupFileIdFunctionTyp
 func NewChunkReaderAtFromClient(lookupFn wdclient.LookupFileIdFunctionType, chunkViews []*ChunkView, chunkCache chunk_cache.ChunkCache, fileSize int64) *ChunkReadAt {

 	return &ChunkReadAt{
-		chunkViews:   chunkViews,
-		lookupFileId: lookupFn,
-		chunkCache:   chunkCache,
-		fileSize:     fileSize,
+		chunkViews:    chunkViews,
+		fileSize:      fileSize,
+		readerCache:   newReaderCache(32, chunkCache, lookupFn),
+		readerPattern: NewReaderPattern(),
 	}
 }

 func (c *ChunkReadAt) Close() error {
-	c.lastChunkData = nil
-	c.lastChunkFileId = ""
+	c.readerCache.destroy()
 	return nil
 }

 func (c *ChunkReadAt) ReadAt(p []byte, offset int64) (n int, err error) {

+	c.readerPattern.MonitorReadAt(offset, len(p))
+
 	c.readerLock.Lock()
 	defer c.readerLock.Unlock()

@@ -113,19 +110,17 @@ func (c *ChunkReadAt) ReadAt(p []byte, offset int64) (n int, err error) {
 func (c *ChunkReadAt) doReadAt(p []byte, offset int64) (n int, err error) {

 	startOffset, remaining := offset, int64(len(p))
-	var nextChunk *ChunkView
+	var nextChunks []*ChunkView
 	for i, chunk := range c.chunkViews {
 		if remaining <= 0 {
 			break
 		}
 		if i+1 < len(c.chunkViews) {
-			nextChunk = c.chunkViews[i+1]
-		} else {
-			nextChunk = nil
+			nextChunks = c.chunkViews[i+1:]
 		}
 		if startOffset < chunk.LogicOffset {
 			gap := int(chunk.LogicOffset - startOffset)
-			glog.V(4).Infof("zero [%d,%d)", startOffset, startOffset+int64(gap))
+			glog.V(4).Infof("zero [%d,%d)", startOffset, chunk.LogicOffset)
 			n += int(min(int64(gap), remaining))
 			startOffset, remaining = chunk.LogicOffset, remaining-int64(gap)
 			if remaining <= 0 {
@@ -138,16 +133,13 @@ func (c *ChunkReadAt) doReadAt(p []byte, offset int64) (n int, err error) {
 			continue
 		}
 		// glog.V(4).Infof("read [%d,%d), %d/%d chunk %s [%d,%d)", chunkStart, chunkStop, i, len(c.chunkViews), chunk.FileId, chunk.LogicOffset-chunk.Offset, chunk.LogicOffset-chunk.Offset+int64(chunk.Size))
-		var buffer []byte
 		bufferOffset := chunkStart - chunk.LogicOffset + chunk.Offset
-		bufferLength := chunkStop - chunkStart
-		buffer, err = c.readChunkSlice(chunk, nextChunk, uint64(bufferOffset), uint64(bufferLength))
+		copied, err := c.readChunkSliceAt(p[startOffset-offset:chunkStop-chunkStart+startOffset-offset], chunk, nextChunks, uint64(bufferOffset))
 		if err != nil {
 			glog.Errorf("fetching chunk %+v: %v\n", chunk, err)
-			return
+			return copied, err
 		}

-		copied := copy(p[startOffset-offset:chunkStop-chunkStart+startOffset-offset], buffer)
 		n += copied
 		startOffset, remaining = startOffset+int64(copied), remaining-int64(copied)
 	}
@@ -169,77 +161,25 @@ func (c *ChunkReadAt) doReadAt(p []byte, offset int64) (n int, err error) {

 }

-func (c *ChunkReadAt) readChunkSlice(chunkView *ChunkView, nextChunkViews *ChunkView, offset, length uint64) ([]byte, error) {
+func (c *ChunkReadAt) readChunkSliceAt(buffer []byte, chunkView *ChunkView, nextChunkViews []*ChunkView, offset uint64) (n int, err error) {

-	chunkSlice := c.chunkCache.GetChunkSlice(chunkView.FileId, offset, length)
-	if len(chunkSlice) > 0 {
-		return chunkSlice, nil
-	}
-	chunkData, err := c.readFromWholeChunkData(chunkView, nextChunkViews)
-	if err != nil {
-		return nil, err
-	}
-	wanted := min(int64(length), int64(len(chunkData))-int64(offset))
-	return chunkData[offset : int64(offset)+wanted], nil
-}
-
-func (c *ChunkReadAt) readFromWholeChunkData(chunkView *ChunkView, nextChunkViews ...*ChunkView) (chunkData []byte, err error) {
-
-	if c.lastChunkFileId == chunkView.FileId {
-		return c.lastChunkData, nil
+	if c.readerPattern.IsRandomMode() {
+		return fetchChunkRange(buffer, c.readerCache.lookupFileIdFn, chunkView.FileId, chunkView.CipherKey, chunkView.IsGzipped, int64(offset))
 	}

-	v, doErr := c.readOneWholeChunk(chunkView)
-
-	if doErr != nil {
-		return nil, doErr
-	}
-
-	chunkData = v.([]byte)
-
-	c.lastChunkData = chunkData
-	c.lastChunkFileId = chunkView.FileId
-
-	for _, nextChunkView := range nextChunkViews {
-		if c.chunkCache != nil && nextChunkView != nil {
-			go c.readOneWholeChunk(nextChunkView)
+	n, err = c.readerCache.ReadChunkAt(buffer, chunkView.FileId, chunkView.CipherKey, chunkView.IsGzipped, int64(offset), int(chunkView.ChunkSize), chunkView.LogicOffset == 0)
+	if c.lastChunkFid != chunkView.FileId {
+		if chunkView.Offset == 0 { // start of a new chunk
+			if c.lastChunkFid != "" {
+				c.readerCache.UnCache(c.lastChunkFid)
+				c.readerCache.MaybeCache(nextChunkViews)
+			} else {
+				if len(nextChunkViews) >= 1 {
+					c.readerCache.MaybeCache(nextChunkViews[:1]) // just read the next chunk if at the very beginning
+				}
+			}
 		}
 	}
-
+	c.lastChunkFid = chunkView.FileId
 	return
 }
-
-func (c *ChunkReadAt) readOneWholeChunk(chunkView *ChunkView) (interface{}, error) {
-
-	var err error
-
-	return c.fetchGroup.Do(chunkView.FileId, func() (interface{}, error) {
-
-		glog.V(4).Infof("readFromWholeChunkData %s offset %d [%d,%d) size at least %d", chunkView.FileId, chunkView.Offset, chunkView.LogicOffset, chunkView.LogicOffset+int64(chunkView.Size), chunkView.ChunkSize)
-
-		data := c.chunkCache.GetChunk(chunkView.FileId, chunkView.ChunkSize)
-		if data != nil {
-			glog.V(4).Infof("cache hit %s [%d,%d)", chunkView.FileId, chunkView.LogicOffset-chunkView.Offset, chunkView.LogicOffset-chunkView.Offset+int64(len(data)))
-		} else {
-			var err error
-			data, err = c.doFetchFullChunkData(chunkView)
-			if err != nil {
-				return data, err
-			}
-			c.chunkCache.SetChunk(chunkView.FileId, data)
-		}
-		return data, err
-	})
-}
-
-func (c *ChunkReadAt) doFetchFullChunkData(chunkView *ChunkView) ([]byte, error) {
-
-	glog.V(4).Infof("+ doFetchFullChunkData %s", chunkView.FileId)
-
-	data, err := fetchChunk(c.lookupFileId, chunkView.FileId, chunkView.CipherKey, chunkView.IsGzipped)
-
-	glog.V(4).Infof("- doFetchFullChunkData %s", chunkView.FileId)
-
-	return data, err
-
-}
--- a/weed/filer/reader_at_test.go
+++ b/weed/filer/reader_at_test.go
@@ -21,8 +21,12 @@ func (m *mockChunkCache) GetChunk(fileId string, minSize uint64) (data []byte) {
 	return data
 }

-func (m *mockChunkCache) GetChunkSlice(fileId string, offset, length uint64) []byte {
-	return nil
+func (m *mockChunkCache) ReadChunkAt(data []byte, fileId string, offset uint64) (n int, err error) {
+	x, _ := strconv.Atoi(fileId)
+	for i := 0; i < len(data); i++ {
+		data[i] = byte(x)
+	}
+	return len(data), nil
 }

 func (m *mockChunkCache) SetChunk(fileId string, data []byte) {
@@ -64,11 +68,11 @@ func TestReaderAt(t *testing.T) {
 	}

 	readerAt := &ChunkReadAt{
-		chunkViews:   ViewFromVisibleIntervals(visibles, 0, math.MaxInt64),
-		lookupFileId: nil,
-		readerLock:   sync.Mutex{},
-		fileSize:     10,
-		chunkCache:   &mockChunkCache{},
+		chunkViews:    ViewFromVisibleIntervals(visibles, 0, math.MaxInt64),
+		readerLock:    sync.Mutex{},
+		fileSize:      10,
+		readerCache:   newReaderCache(3, &mockChunkCache{}, nil),
+		readerPattern: NewReaderPattern(),
 	}

 	testReadAt(t, readerAt, 0, 10, 10, io.EOF)
@@ -80,7 +84,7 @@ func TestReaderAt(t *testing.T) {

 func testReadAt(t *testing.T, readerAt *ChunkReadAt, offset int64, size int, expected int, expectedErr error) {
 	data := make([]byte, size)
-	n, err := readerAt.ReadAt(data, offset)
+	n, err := readerAt.doReadAt(data, offset)

 	for _, d := range data {
 		fmt.Printf("%x", d)
@@ -114,11 +118,11 @@ func TestReaderAt0(t *testing.T) {
 	}

 	readerAt := &ChunkReadAt{
-		chunkViews:   ViewFromVisibleIntervals(visibles, 0, math.MaxInt64),
-		lookupFileId: nil,
-		readerLock:   sync.Mutex{},
-		fileSize:     10,
-		chunkCache:   &mockChunkCache{},
+		chunkViews:    ViewFromVisibleIntervals(visibles, 0, math.MaxInt64),
+		readerLock:    sync.Mutex{},
+		fileSize:      10,
+		readerCache:   newReaderCache(3, &mockChunkCache{}, nil),
+		readerPattern: NewReaderPattern(),
 	}

 	testReadAt(t, readerAt, 0, 10, 10, io.EOF)
@@ -142,11 +146,11 @@ func TestReaderAt1(t *testing.T) {
 	}

 	readerAt := &ChunkReadAt{
-		chunkViews:   ViewFromVisibleIntervals(visibles, 0, math.MaxInt64),
-		lookupFileId: nil,
-		readerLock:   sync.Mutex{},
-		fileSize:     20,
-		chunkCache:   &mockChunkCache{},
+		chunkViews:    ViewFromVisibleIntervals(visibles, 0, math.MaxInt64),
+		readerLock:    sync.Mutex{},
+		fileSize:      20,
+		readerCache:   newReaderCache(3, &mockChunkCache{}, nil),
+		readerPattern: NewReaderPattern(),
 	}

 	testReadAt(t, readerAt, 0, 20, 20, io.EOF)
--- a/weed/filer/reader_cache.go
+++ b/weed/filer/reader_cache.go
@@ -0,0 +1,192 @@
+package filer
+
+import (
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/util/chunk_cache"
+	"github.com/chrislusf/seaweedfs/weed/util/mem"
+	"github.com/chrislusf/seaweedfs/weed/wdclient"
+	"sync"
+	"time"
+)
+
+type ReaderCache struct {
+	chunkCache     chunk_cache.ChunkCache
+	lookupFileIdFn wdclient.LookupFileIdFunctionType
+	sync.Mutex
+	downloaders map[string]*SingleChunkCacher
+	limit       int
+}
+
+type SingleChunkCacher struct {
+	sync.RWMutex
+	parent        *ReaderCache
+	chunkFileId   string
+	data          []byte
+	err           error
+	cipherKey     []byte
+	isGzipped     bool
+	chunkSize     int
+	shouldCache   bool
+	wg            sync.WaitGroup
+	completedTime time.Time
+}
+
+func newReaderCache(limit int, chunkCache chunk_cache.ChunkCache, lookupFileIdFn wdclient.LookupFileIdFunctionType) *ReaderCache {
+	return &ReaderCache{
+		limit:          limit,
+		chunkCache:     chunkCache,
+		lookupFileIdFn: lookupFileIdFn,
+		downloaders:    make(map[string]*SingleChunkCacher),
+	}
+}
+
+func (rc *ReaderCache) MaybeCache(chunkViews []*ChunkView) {
+	if rc.lookupFileIdFn == nil {
+		return
+	}
+
+	rc.Lock()
+	defer rc.Unlock()
+
+	for _, chunkView := range chunkViews {
+		if _, found := rc.downloaders[chunkView.FileId]; found {
+			continue
+		}
+
+		if len(rc.downloaders) >= rc.limit {
+			// if still no slots, return
+			return
+		}
+
+		// glog.V(4).Infof("prefetch %s offset %d", chunkView.FileId, chunkView.LogicOffset)
+		// cache this chunk if not yet
+		cacher := newSingleChunkCacher(rc, chunkView.FileId, chunkView.CipherKey, chunkView.IsGzipped, int(chunkView.ChunkSize), false)
+		cacher.wg.Add(1)
+		go cacher.startCaching()
+		cacher.wg.Wait()
+		rc.downloaders[chunkView.FileId] = cacher
+
+	}
+
+	return
+}
+
+func (rc *ReaderCache) ReadChunkAt(buffer []byte, fileId string, cipherKey []byte, isGzipped bool, offset int64, chunkSize int, shouldCache bool) (int, error) {
+	rc.Lock()
+	defer rc.Unlock()
+	if cacher, found := rc.downloaders[fileId]; found {
+		return cacher.readChunkAt(buffer, offset)
+	}
+	if shouldCache || rc.lookupFileIdFn == nil {
+		n, err := rc.chunkCache.ReadChunkAt(buffer, fileId, uint64(offset))
+		if n > 0 {
+			return n, err
+		}
+	}
+
+	if len(rc.downloaders) >= rc.limit {
+		oldestFid, oldestTime := "", time.Now()
+		for fid, downloader := range rc.downloaders {
+			if !downloader.completedTime.IsZero() {
+				if downloader.completedTime.Before(oldestTime) {
+					oldestFid, oldestTime = fid, downloader.completedTime
+				}
+			}
+		}
+		if oldestFid != "" {
+			oldDownloader := rc.downloaders[oldestFid]
+			delete(rc.downloaders, oldestFid)
+			oldDownloader.destroy()
+		}
+	}
+
+	// glog.V(4).Infof("cache1 %s", fileId)
+
+	cacher := newSingleChunkCacher(rc, fileId, cipherKey, isGzipped, chunkSize, shouldCache)
+	cacher.wg.Add(1)
+	go cacher.startCaching()
+	cacher.wg.Wait()
+	rc.downloaders[fileId] = cacher
+
+	return cacher.readChunkAt(buffer, offset)
+}
+
+func (rc *ReaderCache) UnCache(fileId string) {
+	rc.Lock()
+	defer rc.Unlock()
+	// glog.V(4).Infof("uncache %s", fileId)
+	if downloader, found := rc.downloaders[fileId]; found {
+		downloader.destroy()
+		delete(rc.downloaders, fileId)
+	}
+}
+
+func (rc *ReaderCache) destroy() {
+	rc.Lock()
+	defer rc.Unlock()
+
+	for _, downloader := range rc.downloaders {
+		downloader.destroy()
+	}
+
+}
+
+func newSingleChunkCacher(parent *ReaderCache, fileId string, cipherKey []byte, isGzipped bool, chunkSize int, shouldCache bool) *SingleChunkCacher {
+	t := &SingleChunkCacher{
+		parent:      parent,
+		chunkFileId: fileId,
+		cipherKey:   cipherKey,
+		isGzipped:   isGzipped,
+		chunkSize:   chunkSize,
+		shouldCache: shouldCache,
+	}
+	return t
+}
+
+func (s *SingleChunkCacher) startCaching() {
+	s.Lock()
+	defer s.Unlock()
+
+	s.wg.Done() // means this has been started
+
+	urlStrings, err := s.parent.lookupFileIdFn(s.chunkFileId)
+	if err != nil {
+		s.err = fmt.Errorf("operation LookupFileId %s failed, err: %v", s.chunkFileId, err)
+		return
+	}
+
+	s.data = mem.Allocate(s.chunkSize)
+
+	_, s.err = retriedFetchChunkData(s.data, urlStrings, s.cipherKey, s.isGzipped, true, 0)
+	if s.err != nil {
+		mem.Free(s.data)
+		s.data = nil
+		return
+	}
+
+	s.completedTime = time.Now()
+	if s.shouldCache {
+		s.parent.chunkCache.SetChunk(s.chunkFileId, s.data)
+	}
+
+	return
+}
+
+func (s *SingleChunkCacher) destroy() {
+	if s.data != nil {
+		mem.Free(s.data)
+		s.data = nil
+	}
+}
+
+func (s *SingleChunkCacher) readChunkAt(buf []byte, offset int64) (int, error) {
+	s.RLock()
+	defer s.RUnlock()
+
+	if s.err != nil {
+		return 0, s.err
+	}
+
+	return copy(buf, s.data[offset:]), nil
+
+}
--- a/weed/filer/reader_pattern.go
+++ b/weed/filer/reader_pattern.go
@@ -0,0 +1,38 @@
+package filer
+
+type ReaderPattern struct {
+	isStreaming    bool
+	lastReadOffset int64
+}
+
+// For streaming read: only cache the first chunk
+// For random read: only fetch the requested range, instead of the whole chunk
+
+func NewReaderPattern() *ReaderPattern {
+	return &ReaderPattern{
+		isStreaming:    true,
+		lastReadOffset: -1,
+	}
+}
+
+func (rp *ReaderPattern) MonitorReadAt(offset int64, size int) {
+	isStreaming := true
+	if rp.lastReadOffset > offset {
+		isStreaming = false
+	}
+	if rp.lastReadOffset == -1 {
+		if offset != 0 {
+			isStreaming = false
+		}
+	}
+	rp.lastReadOffset = offset
+	rp.isStreaming = isStreaming
+}
+
+func (rp *ReaderPattern) IsStreamingMode() bool {
+	return rp.isStreaming
+}
+
+func (rp *ReaderPattern) IsRandomMode() bool {
+	return !rp.isStreaming
+}
--- a/weed/filer/redis/universal_redis_store.go
+++ b/weed/filer/redis/universal_redis_store.go
@@ -3,7 +3,7 @@ package redis
 import (
 	"context"
 	"fmt"
-	"sort"
+	"golang.org/x/exp/slices"
 	"strings"
 	"time"

@@ -40,7 +40,7 @@ func (store *UniversalRedisStore) InsertEntry(ctx context.Context, entry *filer.
 		return fmt.Errorf("encoding %s %+v: %v", entry.FullPath, entry.Attr, err)
 	}

-	if len(entry.Chunks) > 50 {
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
 		value = util.MaybeGzipData(value)
 	}

@@ -120,6 +120,8 @@ func (store *UniversalRedisStore) DeleteFolderChildren(ctx context.Context, full
 		if err != nil {
 			return fmt.Errorf("delete %s in parent dir: %v", fullpath, err)
 		}
+		// not efficient, but need to remove if it is a directory
+		store.Client.Del(ctx, genDirectoryListKey(string(path)))
 	}

 	return nil
@@ -155,8 +157,8 @@ func (store *UniversalRedisStore) ListDirectoryEntries(ctx context.Context, dirP
 	}

 	// sort
-	sort.Slice(members, func(i, j int) bool {
-		return strings.Compare(members[i], members[j]) < 0
+	slices.SortFunc(members, func(a, b string) bool {
+		return strings.Compare(a, b) < 0
 	})

 	// limit
--- a/weed/filer/redis2/redis_sentinel_store.go
+++ b/weed/filer/redis2/redis_sentinel_store.go
@@ -0,0 +1,45 @@
+package redis2
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/go-redis/redis/v8"
+	"time"
+)
+
+func init() {
+	filer.Stores = append(filer.Stores, &Redis2SentinelStore{})
+}
+
+type Redis2SentinelStore struct {
+	UniversalRedis2Store
+}
+
+func (store *Redis2SentinelStore) GetName() string {
+	return "redis2_sentinel"
+}
+
+func (store *Redis2SentinelStore) Initialize(configuration util.Configuration, prefix string) (err error) {
+	return store.initialize(
+		configuration.GetStringSlice(prefix+"addresses"),
+		configuration.GetString(prefix+"masterName"),
+		configuration.GetString(prefix+"username"),
+		configuration.GetString(prefix+"password"),
+		configuration.GetInt(prefix+"database"),
+	)
+}
+
+func (store *Redis2SentinelStore) initialize(addresses []string, masterName string, username string, password string, database int) (err error) {
+	store.Client = redis.NewFailoverClient(&redis.FailoverOptions{
+		MasterName:      masterName,
+		SentinelAddrs:   addresses,
+		Username:        username,
+		Password:        password,
+		DB:              database,
+		MinRetryBackoff: time.Millisecond * 100,
+		MaxRetryBackoff: time.Minute * 1,
+		ReadTimeout:     time.Second * 30,
+		WriteTimeout:    time.Second * 5,
+	})
+	return
+}
--- a/weed/filer/redis2/universal_redis_store.go
+++ b/weed/filer/redis2/universal_redis_store.go
@@ -52,7 +52,7 @@ func (store *UniversalRedis2Store) InsertEntry(ctx context.Context, entry *filer
 		return fmt.Errorf("encoding %s %+v: %v", entry.FullPath, entry.Attr, err)
 	}

-	if len(entry.Chunks) > 50 {
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
 		value = util.MaybeGzipData(value)
 	}

@@ -133,7 +133,10 @@ func (store *UniversalRedis2Store) DeleteFolderChildren(ctx context.Context, ful
 		return nil
 	}

-	members, err := store.Client.ZRange(ctx, genDirectoryListKey(string(fullpath)), 0, -1).Result()
+	members, err := store.Client.ZRangeByLex(ctx, genDirectoryListKey(string(fullpath)), &redis.ZRangeBy{
+		Min: "-",
+		Max: "+",
+	}).Result()
 	if err != nil {
 		return fmt.Errorf("DeleteFolderChildren %s : %v", fullpath, err)
 	}
@@ -144,6 +147,8 @@ func (store *UniversalRedis2Store) DeleteFolderChildren(ctx context.Context, ful
 		if err != nil {
 			return fmt.Errorf("DeleteFolderChildren %s in parent dir: %v", fullpath, err)
 		}
+		// not efficient, but need to remove if it is a directory
+		store.Client.Del(ctx, genDirectoryListKey(string(path)))
 	}

 	return nil
@@ -156,14 +161,22 @@ func (store *UniversalRedis2Store) ListDirectoryPrefixedEntries(ctx context.Cont
 func (store *UniversalRedis2Store) ListDirectoryEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, eachEntryFunc filer.ListEachEntryFunc) (lastFileName string, err error) {

 	dirListKey := genDirectoryListKey(string(dirPath))
-	start := int64(0)
+
+	min := "-"
 	if startFileName != "" {
-		start, _ = store.Client.ZRank(ctx, dirListKey, startFileName).Result()
-		if !includeStartFile {
-			start++
+		if includeStartFile {
+			min = "[" + startFileName
+		} else {
+			min = "(" + startFileName
 		}
 	}
-	members, err := store.Client.ZRange(ctx, dirListKey, start, start+int64(limit)-1).Result()
+
+	members, err := store.Client.ZRangeByLex(ctx, dirListKey, &redis.ZRangeBy{
+		Min:    min,
+		Max:    "+",
+		Offset: 0,
+		Count:  limit,
+	}).Result()
 	if err != nil {
 		return lastFileName, fmt.Errorf("list %s : %v", dirPath, err)
 	}
--- a/weed/filer/redis3/ItemList.go
+++ b/weed/filer/redis3/ItemList.go
@@ -0,0 +1,507 @@
+package redis3
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/util/skiplist"
+	"github.com/go-redis/redis/v8"
+)
+
+type ItemList struct {
+	skipList  *skiplist.SkipList
+	batchSize int
+	client    redis.UniversalClient
+	prefix    string
+}
+
+func newItemList(client redis.UniversalClient, prefix string, store skiplist.ListStore, batchSize int) *ItemList {
+	return &ItemList{
+		skipList:  skiplist.New(store),
+		batchSize: batchSize,
+		client:    client,
+		prefix:    prefix,
+	}
+}
+
+/*
+Be reluctant to create new nodes. Try to fit into either previous node or next node.
+Prefer to add to previous node.
+
+There are multiple cases after finding the name for greater or equal node
+ 1. found and node.Key == name
+    The node contains a batch with leading key the same as the name
+    nothing to do
+ 2. no such node found or node.Key > name
+
+    if no such node found
+      prevNode = list.LargestNode
+
+	// case 2.1
+    if previousNode contains name
+      nothing to do
+
+    // prefer to add to previous node
+    if prevNode != nil {
+		// case 2.2
+		if prevNode has capacity
+			prevNode.add name, and save
+			return
+		// case 2.3
+		split prevNode by name
+    }
+
+	// case 2.4
+	// merge into next node. Avoid too many nodes if adding data in reverse order.
+	if nextNode is not nil and nextNode has capacity
+	  delete nextNode.Key
+      nextNode.Key = name
+      nextNode.batch.add name
+      insert nodeNode.Key
+	  return
+
+	// case 2.5
+    if prevNode is nil
+      insert new node with key = name, value = batch{name}
+      return
+
+*/
+
+func (nl *ItemList) canAddMember(node *skiplist.SkipListElementReference, name string) (alreadyContains bool, nodeSize int, err error) {
+	ctx := context.Background()
+	pipe := nl.client.TxPipeline()
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	countOperation := pipe.ZLexCount(ctx, key, "-", "+")
+	scoreOperationt := pipe.ZScore(ctx, key, name)
+	if _, err = pipe.Exec(ctx); err != nil && err != redis.Nil {
+		return false, 0, err
+	}
+	if err == redis.Nil {
+		err = nil
+	}
+	alreadyContains = scoreOperationt.Err() == nil
+	nodeSize = int(countOperation.Val())
+	return
+}
+
+func (nl *ItemList) WriteName(name string) error {
+
+	lookupKey := []byte(name)
+	prevNode, nextNode, found, err := nl.skipList.FindGreaterOrEqual(lookupKey)
+	if err != nil {
+		return err
+	}
+	// case 1: the name already exists as one leading key in the batch
+	if found && bytes.Compare(nextNode.Key, lookupKey) == 0 {
+		return nil
+	}
+
+	var prevNodeReference *skiplist.SkipListElementReference
+	if !found {
+		prevNodeReference = nl.skipList.GetLargestNodeReference()
+	}
+
+	if nextNode != nil && prevNode == nil {
+		prevNodeReference = nextNode.Prev
+	}
+
+	if prevNodeReference != nil {
+		alreadyContains, nodeSize, err := nl.canAddMember(prevNodeReference, name)
+		if err != nil {
+			return err
+		}
+		if alreadyContains {
+			// case 2.1
+			return nil
+		}
+
+		// case 2.2
+		if nodeSize < nl.batchSize {
+			return nl.NodeAddMember(prevNodeReference, name)
+		}
+
+		// case 2.3
+		x := nl.NodeInnerPosition(prevNodeReference, name)
+		y := nodeSize - x
+		addToX := x <= y
+		// add to a new node
+		if x == 0 || y == 0 {
+			if err := nl.ItemAdd(lookupKey, 0, name); err != nil {
+				return err
+			}
+			return nil
+		}
+		if addToX {
+			// collect names before name, add them to X
+			namesToX, err := nl.NodeRangeBeforeExclusive(prevNodeReference, name)
+			if err != nil {
+				return nil
+			}
+			// delete skiplist reference to old node
+			if _, err := nl.skipList.DeleteByKey(prevNodeReference.Key); err != nil {
+				return err
+			}
+			// add namesToY and name to a new X
+			namesToX = append(namesToX, name)
+			if err := nl.ItemAdd([]byte(namesToX[0]), 0, namesToX...); err != nil {
+				return nil
+			}
+			// remove names less than name from current Y
+			if err := nl.NodeDeleteBeforeExclusive(prevNodeReference, name); err != nil {
+				return nil
+			}
+
+			// point skip list to current Y
+			if err := nl.ItemAdd(lookupKey, prevNodeReference.ElementPointer); err != nil {
+				return nil
+			}
+			return nil
+		} else {
+			// collect names after name, add them to Y
+			namesToY, err := nl.NodeRangeAfterExclusive(prevNodeReference, name)
+			if err != nil {
+				return nil
+			}
+			// add namesToY and name to a new Y
+			namesToY = append(namesToY, name)
+			if err := nl.ItemAdd(lookupKey, 0, namesToY...); err != nil {
+				return nil
+			}
+			// remove names after name from current X
+			if err := nl.NodeDeleteAfterExclusive(prevNodeReference, name); err != nil {
+				return nil
+			}
+			return nil
+		}
+
+	}
+
+	// case 2.4
+	if nextNode != nil {
+		nodeSize := nl.NodeSize(nextNode.Reference())
+		if nodeSize < nl.batchSize {
+			if id, err := nl.skipList.DeleteByKey(nextNode.Key); err != nil {
+				return err
+			} else {
+				if err := nl.ItemAdd(lookupKey, id, name); err != nil {
+					return err
+				}
+			}
+			return nil
+		}
+	}
+
+	// case 2.5
+	// now prevNode is nil
+	return nl.ItemAdd(lookupKey, 0, name)
+}
+
+/*
+// case 1: exists in nextNode
+if nextNode != nil && nextNode.Key == name {
+	remove from nextNode, update nextNode
+	// TODO: merge with prevNode if possible?
+	return
+}
+if nextNode is nil
+	prevNode = list.Largestnode
+if prevNode == nil and nextNode.Prev != nil
+	prevNode = load(nextNode.Prev)
+
+// case 2: does not exist
+// case 2.1
+if prevNode == nil {
+	return
+}
+// case 2.2
+if prevNameBatch does not contain name {
+	return
+}
+
+// case 3
+delete from prevNameBatch
+if prevNameBatch + nextNode < capacityList
+	// case 3.1
+	merge
+else
+	// case 3.2
+	update prevNode
+
+
+*/
+func (nl *ItemList) DeleteName(name string) error {
+	lookupKey := []byte(name)
+	prevNode, nextNode, found, err := nl.skipList.FindGreaterOrEqual(lookupKey)
+	if err != nil {
+		return err
+	}
+
+	// case 1
+	if found && bytes.Compare(nextNode.Key, lookupKey) == 0 {
+		if _, err := nl.skipList.DeleteByKey(nextNode.Key); err != nil {
+			return err
+		}
+		if err := nl.NodeDeleteMember(nextNode.Reference(), name); err != nil {
+			return err
+		}
+		minName := nl.NodeMin(nextNode.Reference())
+		if minName == "" {
+			return nl.NodeDelete(nextNode.Reference())
+		}
+		return nl.ItemAdd([]byte(minName), nextNode.Id)
+	}
+
+	if !found {
+		prevNode, err = nl.skipList.GetLargestNode()
+		if err != nil {
+			return err
+		}
+	}
+
+	if nextNode != nil && prevNode == nil {
+		prevNode, err = nl.skipList.LoadElement(nextNode.Prev)
+		if err != nil {
+			return err
+		}
+	}
+
+	// case 2
+	if prevNode == nil {
+		// case 2.1
+		return nil
+	}
+	if !nl.NodeContainsItem(prevNode.Reference(), name) {
+		return nil
+	}
+
+	// case 3
+	if err := nl.NodeDeleteMember(prevNode.Reference(), name); err != nil {
+		return err
+	}
+	prevSize := nl.NodeSize(prevNode.Reference())
+	if prevSize == 0 {
+		if _, err := nl.skipList.DeleteByKey(prevNode.Key); err != nil {
+			return err
+		}
+		return nil
+	}
+	nextSize := nl.NodeSize(nextNode.Reference())
+	if nextSize > 0 && prevSize+nextSize < nl.batchSize {
+		// case 3.1 merge nextNode and prevNode
+		if _, err := nl.skipList.DeleteByKey(nextNode.Key); err != nil {
+			return err
+		}
+		nextNames, err := nl.NodeRangeBeforeExclusive(nextNode.Reference(), "")
+		if err != nil {
+			return err
+		}
+		if err := nl.NodeAddMember(prevNode.Reference(), nextNames...); err != nil {
+			return err
+		}
+		return nl.NodeDelete(nextNode.Reference())
+	} else {
+		// case 3.2 update prevNode
+		// no action to take
+		return nil
+	}
+
+	return nil
+}
+
+func (nl *ItemList) ListNames(startFrom string, visitNamesFn func(name string) bool) error {
+	lookupKey := []byte(startFrom)
+	prevNode, nextNode, found, err := nl.skipList.FindGreaterOrEqual(lookupKey)
+	if err != nil {
+		return err
+	}
+	if found && bytes.Compare(nextNode.Key, lookupKey) == 0 {
+		prevNode = nil
+	}
+	if !found {
+		prevNode, err = nl.skipList.GetLargestNode()
+		if err != nil {
+			return err
+		}
+	}
+
+	if prevNode != nil {
+		if !nl.NodeScanIncluseiveAfter(prevNode.Reference(), startFrom, visitNamesFn) {
+			return nil
+		}
+	}
+
+	for nextNode != nil {
+		if !nl.NodeScanIncluseiveAfter(nextNode.Reference(), startFrom, visitNamesFn) {
+			return nil
+		}
+		nextNode, err = nl.skipList.LoadElement(nextNode.Next[0])
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (nl *ItemList) RemoteAllListElement() error {
+
+	t := nl.skipList
+
+	nodeRef := t.StartLevels[0]
+	for nodeRef != nil {
+		node, err := t.LoadElement(nodeRef)
+		if err != nil {
+			return err
+		}
+		if node == nil {
+			return nil
+		}
+		if err := t.DeleteElement(node); err != nil {
+			return err
+		}
+		if err := nl.NodeDelete(node.Reference()); err != nil {
+			return err
+		}
+		nodeRef = node.Next[0]
+	}
+	return nil
+
+}
+
+func (nl *ItemList) NodeContainsItem(node *skiplist.SkipListElementReference, item string) bool {
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	_, err := nl.client.ZScore(context.Background(), key, item).Result()
+	if err == redis.Nil {
+		return false
+	}
+	if err == nil {
+		return true
+	}
+	return false
+}
+
+func (nl *ItemList) NodeSize(node *skiplist.SkipListElementReference) int {
+	if node == nil {
+		return 0
+	}
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	return int(nl.client.ZLexCount(context.Background(), key, "-", "+").Val())
+}
+
+func (nl *ItemList) NodeAddMember(node *skiplist.SkipListElementReference, names ...string) error {
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	var members []*redis.Z
+	for _, name := range names {
+		members = append(members, &redis.Z{
+			Score:  0,
+			Member: name,
+		})
+	}
+	return nl.client.ZAddNX(context.Background(), key, members...).Err()
+}
+func (nl *ItemList) NodeDeleteMember(node *skiplist.SkipListElementReference, name string) error {
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	return nl.client.ZRem(context.Background(), key, name).Err()
+}
+
+func (nl *ItemList) NodeDelete(node *skiplist.SkipListElementReference) error {
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	return nl.client.Del(context.Background(), key).Err()
+}
+
+func (nl *ItemList) NodeInnerPosition(node *skiplist.SkipListElementReference, name string) int {
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	return int(nl.client.ZLexCount(context.Background(), key, "-", "("+name).Val())
+}
+
+func (nl *ItemList) NodeMin(node *skiplist.SkipListElementReference) string {
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	slice := nl.client.ZRangeByLex(context.Background(), key, &redis.ZRangeBy{
+		Min:    "-",
+		Max:    "+",
+		Offset: 0,
+		Count:  1,
+	}).Val()
+	if len(slice) > 0 {
+		s := slice[0]
+		return s
+	}
+	return ""
+}
+
+func (nl *ItemList) NodeScanIncluseiveAfter(node *skiplist.SkipListElementReference, startFrom string, visitNamesFn func(name string) bool) bool {
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	if startFrom == "" {
+		startFrom = "-"
+	} else {
+		startFrom = "[" + startFrom
+	}
+	names := nl.client.ZRangeByLex(context.Background(), key, &redis.ZRangeBy{
+		Min: startFrom,
+		Max: "+",
+	}).Val()
+	for _, n := range names {
+		if !visitNamesFn(n) {
+			return false
+		}
+	}
+	return true
+}
+
+func (nl *ItemList) NodeRangeBeforeExclusive(node *skiplist.SkipListElementReference, stopAt string) ([]string, error) {
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	if stopAt == "" {
+		stopAt = "+"
+	} else {
+		stopAt = "(" + stopAt
+	}
+	return nl.client.ZRangeByLex(context.Background(), key, &redis.ZRangeBy{
+		Min: "-",
+		Max: stopAt,
+	}).Result()
+}
+func (nl *ItemList) NodeRangeAfterExclusive(node *skiplist.SkipListElementReference, startFrom string) ([]string, error) {
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	if startFrom == "" {
+		startFrom = "-"
+	} else {
+		startFrom = "(" + startFrom
+	}
+	return nl.client.ZRangeByLex(context.Background(), key, &redis.ZRangeBy{
+		Min: startFrom,
+		Max: "+",
+	}).Result()
+}
+
+func (nl *ItemList) NodeDeleteBeforeExclusive(node *skiplist.SkipListElementReference, stopAt string) error {
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	if stopAt == "" {
+		stopAt = "+"
+	} else {
+		stopAt = "(" + stopAt
+	}
+	return nl.client.ZRemRangeByLex(context.Background(), key, "-", stopAt).Err()
+}
+func (nl *ItemList) NodeDeleteAfterExclusive(node *skiplist.SkipListElementReference, startFrom string) error {
+	key := fmt.Sprintf("%s%dm", nl.prefix, node.ElementPointer)
+	if startFrom == "" {
+		startFrom = "-"
+	} else {
+		startFrom = "(" + startFrom
+	}
+	return nl.client.ZRemRangeByLex(context.Background(), key, startFrom, "+").Err()
+}
+
+func (nl *ItemList) ItemAdd(lookupKey []byte, idIfKnown int64, names ...string) error {
+	if id, err := nl.skipList.InsertByKey(lookupKey, idIfKnown, nil); err != nil {
+		return err
+	} else {
+		if len(names) > 0 {
+			return nl.NodeAddMember(&skiplist.SkipListElementReference{
+				ElementPointer: id,
+				Key:            lookupKey,
+			}, names...)
+		}
+	}
+	return nil
+}
--- a/weed/filer/redis3/item_list_serde.go
+++ b/weed/filer/redis3/item_list_serde.go
@@ -0,0 +1,75 @@
+package redis3
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util/skiplist"
+	"github.com/go-redis/redis/v8"
+	"github.com/golang/protobuf/proto"
+)
+
+func LoadItemList(data []byte, prefix string, client redis.UniversalClient, store skiplist.ListStore, batchSize int) *ItemList {
+
+	nl := &ItemList{
+		skipList:  skiplist.New(store),
+		batchSize: batchSize,
+		client:    client,
+		prefix:    prefix,
+	}
+
+	if len(data) == 0 {
+		return nl
+	}
+
+	message := &skiplist.SkipListProto{}
+	if err := proto.Unmarshal(data, message); err != nil {
+		glog.Errorf("loading skiplist: %v", err)
+	}
+	nl.skipList.MaxNewLevel = int(message.MaxNewLevel)
+	nl.skipList.MaxLevel = int(message.MaxLevel)
+	for i, ref := range message.StartLevels {
+		nl.skipList.StartLevels[i] = &skiplist.SkipListElementReference{
+			ElementPointer: ref.ElementPointer,
+			Key:            ref.Key,
+		}
+	}
+	for i, ref := range message.EndLevels {
+		nl.skipList.EndLevels[i] = &skiplist.SkipListElementReference{
+			ElementPointer: ref.ElementPointer,
+			Key:            ref.Key,
+		}
+	}
+	return nl
+}
+
+func (nl *ItemList) HasChanges() bool {
+	return nl.skipList.HasChanges
+}
+
+func (nl *ItemList) ToBytes() []byte {
+	message := &skiplist.SkipListProto{}
+	message.MaxNewLevel = int32(nl.skipList.MaxNewLevel)
+	message.MaxLevel = int32(nl.skipList.MaxLevel)
+	for _, ref := range nl.skipList.StartLevels {
+		if ref == nil {
+			break
+		}
+		message.StartLevels = append(message.StartLevels, &skiplist.SkipListElementReference{
+			ElementPointer: ref.ElementPointer,
+			Key:            ref.Key,
+		})
+	}
+	for _, ref := range nl.skipList.EndLevels {
+		if ref == nil {
+			break
+		}
+		message.EndLevels = append(message.EndLevels, &skiplist.SkipListElementReference{
+			ElementPointer: ref.ElementPointer,
+			Key:            ref.Key,
+		})
+	}
+	data, err := proto.Marshal(message)
+	if err != nil {
+		glog.Errorf("marshal skiplist: %v", err)
+	}
+	return data
+}
--- a/weed/filer/redis3/kv_directory_children.go
+++ b/weed/filer/redis3/kv_directory_children.go
@@ -0,0 +1,138 @@
+package redis3
+
+import (
+	"context"
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/go-redis/redis/v8"
+)
+
+const maxNameBatchSizeLimit = 1000000
+
+func insertChild(ctx context.Context, redisStore *UniversalRedis3Store, key string, name string) error {
+
+	// lock and unlock
+	mutex := redisStore.redsync.NewMutex(key + "lock")
+	if err := mutex.Lock(); err != nil {
+		return fmt.Errorf("lock %s: %v", key, err)
+	}
+	defer func() {
+		mutex.Unlock()
+	}()
+
+	client := redisStore.Client
+	data, err := client.Get(ctx, key).Result()
+	if err != nil {
+		if err != redis.Nil {
+			return fmt.Errorf("read %s: %v", key, err)
+		}
+	}
+	store := newSkipListElementStore(key, client)
+	nameList := LoadItemList([]byte(data), key, client, store, maxNameBatchSizeLimit)
+
+	if err := nameList.WriteName(name); err != nil {
+		glog.Errorf("add %s %s: %v", key, name, err)
+		return err
+	}
+
+	if !nameList.HasChanges() {
+		return nil
+	}
+
+	if err := client.Set(ctx, key, nameList.ToBytes(), 0).Err(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func removeChild(ctx context.Context, redisStore *UniversalRedis3Store, key string, name string) error {
+
+	// lock and unlock
+	mutex := redisStore.redsync.NewMutex(key + "lock")
+	if err := mutex.Lock(); err != nil {
+		return fmt.Errorf("lock %s: %v", key, err)
+	}
+	defer mutex.Unlock()
+
+	client := redisStore.Client
+	data, err := client.Get(ctx, key).Result()
+	if err != nil {
+		if err != redis.Nil {
+			return fmt.Errorf("read %s: %v", key, err)
+		}
+	}
+	store := newSkipListElementStore(key, client)
+	nameList := LoadItemList([]byte(data), key, client, store, maxNameBatchSizeLimit)
+
+	if err := nameList.DeleteName(name); err != nil {
+		return err
+	}
+	if !nameList.HasChanges() {
+		return nil
+	}
+
+	if err := client.Set(ctx, key, nameList.ToBytes(), 0).Err(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func removeChildren(ctx context.Context, redisStore *UniversalRedis3Store, key string, onDeleteFn func(name string) error) error {
+
+	// lock and unlock
+	mutex := redisStore.redsync.NewMutex(key + "lock")
+	if err := mutex.Lock(); err != nil {
+		return fmt.Errorf("lock %s: %v", key, err)
+	}
+	defer mutex.Unlock()
+
+	client := redisStore.Client
+	data, err := client.Get(ctx, key).Result()
+	if err != nil {
+		if err != redis.Nil {
+			return fmt.Errorf("read %s: %v", key, err)
+		}
+	}
+	store := newSkipListElementStore(key, client)
+	nameList := LoadItemList([]byte(data), key, client, store, maxNameBatchSizeLimit)
+
+	if err = nameList.ListNames("", func(name string) bool {
+		if err := onDeleteFn(name); err != nil {
+			glog.Errorf("delete %s child %s: %v", key, name, err)
+			return false
+		}
+		return true
+	}); err != nil {
+		return err
+	}
+
+	if err = nameList.RemoteAllListElement(); err != nil {
+		return err
+	}
+
+	return nil
+
+}
+
+func listChildren(ctx context.Context, redisStore *UniversalRedis3Store, key string, startFileName string, eachFn func(name string) bool) error {
+	client := redisStore.Client
+	data, err := client.Get(ctx, key).Result()
+	if err != nil {
+		if err != redis.Nil {
+			return fmt.Errorf("read %s: %v", key, err)
+		}
+	}
+	store := newSkipListElementStore(key, client)
+	nameList := LoadItemList([]byte(data), key, client, store, maxNameBatchSizeLimit)
+
+	if err = nameList.ListNames(startFileName, func(name string) bool {
+		return eachFn(name)
+	}); err != nil {
+		return err
+	}
+
+	return nil
+
+}
--- a/weed/filer/redis3/kv_directory_children_test.go
+++ b/weed/filer/redis3/kv_directory_children_test.go
@@ -0,0 +1,210 @@
+package redis3
+
+import (
+	"context"
+	"fmt"
+	"github.com/go-redis/redis/v8"
+	"github.com/stvp/tempredis"
+	"strconv"
+	"testing"
+	"time"
+)
+
+var names = []string{
+	"cassandra.in.sh",
+	"cassandra",
+	"debug-cql.bat",
+	"nodetool",
+	"nodetool.bat",
+	"source-conf.ps1",
+	"sstableloader",
+	"sstableloader.bat",
+	"sstablescrub",
+	"sstablescrub.bat",
+	"sstableupgrade",
+	"sstableupgrade.bat",
+	"sstableutil",
+	"sstableutil.bat",
+	"sstableverify",
+	"sstableverify.bat",
+	"stop-server",
+	"stop-server.bat",
+	"stop-server.ps1",
+	"cassandra.in.bat",
+	"cqlsh.py",
+	"cqlsh",
+	"cassandra.ps1",
+	"cqlsh.bat",
+	"debug-cql",
+	"cassandra.bat",
+}
+
+func yTestNameList(t *testing.T) {
+	server, err := tempredis.Start(tempredis.Config{})
+	if err != nil {
+		panic(err)
+	}
+	defer server.Term()
+
+	client := redis.NewClient(&redis.Options{
+		Network: "unix",
+		Addr:    server.Socket(),
+	})
+
+	store := newSkipListElementStore("/yyy/bin", client)
+	var data []byte
+	for _, name := range names {
+		nameList := LoadItemList(data, "/yyy/bin", client, store, maxNameBatchSizeLimit)
+		nameList.WriteName(name)
+
+		nameList.ListNames("", func(name string) bool {
+			println(name)
+			return true
+		})
+
+		if nameList.HasChanges() {
+			data = nameList.ToBytes()
+		}
+		println()
+	}
+
+	nameList := LoadItemList(data, "/yyy/bin", client, store, maxNameBatchSizeLimit)
+	nameList.ListNames("", func(name string) bool {
+		println(name)
+		return true
+	})
+
+}
+
+func yBenchmarkNameList(b *testing.B) {
+
+	server, err := tempredis.Start(tempredis.Config{})
+	if err != nil {
+		panic(err)
+	}
+	defer server.Term()
+
+	client := redis.NewClient(&redis.Options{
+		Network: "unix",
+		Addr:    server.Socket(),
+	})
+
+	store := newSkipListElementStore("/yyy/bin", client)
+	var data []byte
+	for i := 0; i < b.N; i++ {
+		nameList := LoadItemList(data, "/yyy/bin", client, store, maxNameBatchSizeLimit)
+
+		nameList.WriteName(strconv.Itoa(i) + "namexxxxxxxxxxxxxxxxxxx")
+
+		if nameList.HasChanges() {
+			data = nameList.ToBytes()
+		}
+	}
+}
+
+func BenchmarkRedis(b *testing.B) {
+
+	server, err := tempredis.Start(tempredis.Config{})
+	if err != nil {
+		panic(err)
+	}
+	defer server.Term()
+
+	client := redis.NewClient(&redis.Options{
+		Network: "unix",
+		Addr:    server.Socket(),
+	})
+
+	for i := 0; i < b.N; i++ {
+		client.ZAddNX(context.Background(), "/yyy/bin", &redis.Z{Score: 0, Member: strconv.Itoa(i) + "namexxxxxxxxxxxxxxxxxxx"})
+	}
+}
+
+func xTestNameListAdd(t *testing.T) {
+
+	server, err := tempredis.Start(tempredis.Config{})
+	if err != nil {
+		panic(err)
+	}
+	defer server.Term()
+
+	client := redis.NewClient(&redis.Options{
+		Addr:     "localhost:6379",
+		Password: "",
+		DB:       0,
+	})
+
+	client.FlushAll(context.Background())
+
+	N := 364800
+
+	ts0 := time.Now()
+	store := newSkipListElementStore("/y", client)
+	var data []byte
+	nameList := LoadItemList(data, "/y", client, store, 100000)
+	for i := 0; i < N; i++ {
+		nameList.WriteName(fmt.Sprintf("%8d", i))
+	}
+
+	ts1 := time.Now()
+
+	for i := 0; i < N; i++ {
+		client.ZAddNX(context.Background(), "/x", &redis.Z{Score: 0, Member: fmt.Sprintf("name %8d", i)})
+	}
+	ts2 := time.Now()
+
+	fmt.Printf("%v %v", ts1.Sub(ts0), ts2.Sub(ts1))
+
+	/*
+		keys := client.Keys(context.Background(), "/*m").Val()
+		for _, k := range keys {
+			println("key", k)
+			for i, v := range client.ZRangeByLex(context.Background(), k, &redis.ZRangeBy{
+				Min:    "-",
+				Max:    "+",
+			}).Val() {
+				println(" ", i, v)
+			}
+		}
+	*/
+}
+
+func xBenchmarkNameList(b *testing.B) {
+
+	server, err := tempredis.Start(tempredis.Config{})
+	if err != nil {
+		panic(err)
+	}
+	defer server.Term()
+
+	client := redis.NewClient(&redis.Options{
+		Addr:     "localhost:6379",
+		Password: "",
+		DB:       0,
+	})
+
+	store := newSkipListElementStore("/yyy/bin", client)
+	var data []byte
+	for i := 0; i < b.N; i++ {
+		nameList := LoadItemList(data, "/yyy/bin", client, store, maxNameBatchSizeLimit)
+
+		nameList.WriteName(fmt.Sprintf("name %8d", i))
+
+		if nameList.HasChanges() {
+			data = nameList.ToBytes()
+		}
+	}
+}
+
+func xBenchmarkRedis(b *testing.B) {
+
+	client := redis.NewClient(&redis.Options{
+		Addr:     "localhost:6379",
+		Password: "",
+		DB:       0,
+	})
+
+	for i := 0; i < b.N; i++ {
+		client.ZAddNX(context.Background(), "/xxx/bin", &redis.Z{Score: 0, Member: fmt.Sprintf("name %8d", i)})
+	}
+}
--- a/weed/filer/redis3/redis_cluster_store.go
+++ b/weed/filer/redis3/redis_cluster_store.go
@@ -0,0 +1,45 @@
+package redis3
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/go-redis/redis/v8"
+	"github.com/go-redsync/redsync/v4"
+	"github.com/go-redsync/redsync/v4/redis/goredis/v8"
+)
+
+func init() {
+	filer.Stores = append(filer.Stores, &RedisCluster3Store{})
+}
+
+type RedisCluster3Store struct {
+	UniversalRedis3Store
+}
+
+func (store *RedisCluster3Store) GetName() string {
+	return "redis_cluster3"
+}
+
+func (store *RedisCluster3Store) Initialize(configuration util.Configuration, prefix string) (err error) {
+
+	configuration.SetDefault(prefix+"useReadOnly", false)
+	configuration.SetDefault(prefix+"routeByLatency", false)
+
+	return store.initialize(
+		configuration.GetStringSlice(prefix+"addresses"),
+		configuration.GetString(prefix+"password"),
+		configuration.GetBool(prefix+"useReadOnly"),
+		configuration.GetBool(prefix+"routeByLatency"),
+	)
+}
+
+func (store *RedisCluster3Store) initialize(addresses []string, password string, readOnly, routeByLatency bool) (err error) {
+	store.Client = redis.NewClusterClient(&redis.ClusterOptions{
+		Addrs:          addresses,
+		Password:       password,
+		ReadOnly:       readOnly,
+		RouteByLatency: routeByLatency,
+	})
+	store.redsync = redsync.New(goredis.NewPool(store.Client))
+	return
+}
--- a/weed/filer/redis3/redis_sentinel_store.go
+++ b/weed/filer/redis3/redis_sentinel_store.go
@@ -0,0 +1,49 @@
+package redis3
+
+import (
+	"time"
+
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/go-redis/redis/v8"
+	"github.com/go-redsync/redsync/v4"
+	"github.com/go-redsync/redsync/v4/redis/goredis/v8"
+)
+
+func init() {
+	filer.Stores = append(filer.Stores, &Redis3SentinelStore{})
+}
+
+type Redis3SentinelStore struct {
+	UniversalRedis3Store
+}
+
+func (store *Redis3SentinelStore) GetName() string {
+	return "redis3_sentinel"
+}
+
+func (store *Redis3SentinelStore) Initialize(configuration util.Configuration, prefix string) (err error) {
+	return store.initialize(
+		configuration.GetStringSlice(prefix+"addresses"),
+		configuration.GetString(prefix+"masterName"),
+		configuration.GetString(prefix+"username"),
+		configuration.GetString(prefix+"password"),
+		configuration.GetInt(prefix+"database"),
+	)
+}
+
+func (store *Redis3SentinelStore) initialize(addresses []string, masterName string, username string, password string, database int) (err error) {
+	store.Client = redis.NewFailoverClient(&redis.FailoverOptions{
+		MasterName:      masterName,
+		SentinelAddrs:   addresses,
+		Username:        username,
+		Password:        password,
+		DB:              database,
+		MinRetryBackoff: time.Millisecond * 100,
+		MaxRetryBackoff: time.Minute * 1,
+		ReadTimeout:     time.Second * 30,
+		WriteTimeout:    time.Second * 5,
+	})
+	store.redsync = redsync.New(goredis.NewPool(store.Client))
+	return
+}
--- a/weed/filer/redis3/redis_store.go
+++ b/weed/filer/redis3/redis_store.go
@@ -0,0 +1,39 @@
+package redis3
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/go-redis/redis/v8"
+	"github.com/go-redsync/redsync/v4"
+	"github.com/go-redsync/redsync/v4/redis/goredis/v8"
+)
+
+func init() {
+	filer.Stores = append(filer.Stores, &Redis3Store{})
+}
+
+type Redis3Store struct {
+	UniversalRedis3Store
+}
+
+func (store *Redis3Store) GetName() string {
+	return "redis3"
+}
+
+func (store *Redis3Store) Initialize(configuration util.Configuration, prefix string) (err error) {
+	return store.initialize(
+		configuration.GetString(prefix+"address"),
+		configuration.GetString(prefix+"password"),
+		configuration.GetInt(prefix+"database"),
+	)
+}
+
+func (store *Redis3Store) initialize(hostPort string, password string, database int) (err error) {
+	store.Client = redis.NewClient(&redis.Options{
+		Addr:     hostPort,
+		Password: password,
+		DB:       database,
+	})
+	store.redsync = redsync.New(goredis.NewPool(store.Client))
+	return
+}
--- a/weed/filer/redis3/skiplist_element_store.go
+++ b/weed/filer/redis3/skiplist_element_store.go
@@ -0,0 +1,62 @@
+package redis3
+
+import (
+	"context"
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util/skiplist"
+	"github.com/go-redis/redis/v8"
+	"github.com/golang/protobuf/proto"
+)
+
+type SkipListElementStore struct {
+	Prefix string
+	client redis.UniversalClient
+}
+
+var _ = skiplist.ListStore(&SkipListElementStore{})
+
+func newSkipListElementStore(prefix string, client redis.UniversalClient) *SkipListElementStore {
+	return &SkipListElementStore{
+		Prefix: prefix,
+		client: client,
+	}
+}
+
+func (m *SkipListElementStore) SaveElement(id int64, element *skiplist.SkipListElement) error {
+	key := fmt.Sprintf("%s%d", m.Prefix, id)
+	data, err := proto.Marshal(element)
+	if err != nil {
+		glog.Errorf("marshal %s: %v", key, err)
+	}
+	return m.client.Set(context.Background(), key, data, 0).Err()
+}
+
+func (m *SkipListElementStore) DeleteElement(id int64) error {
+	key := fmt.Sprintf("%s%d", m.Prefix, id)
+	return m.client.Del(context.Background(), key).Err()
+}
+
+func (m *SkipListElementStore) LoadElement(id int64) (*skiplist.SkipListElement, error) {
+	key := fmt.Sprintf("%s%d", m.Prefix, id)
+	data, err := m.client.Get(context.Background(), key).Result()
+	if err != nil {
+		if err == redis.Nil {
+			return nil, nil
+		}
+		return nil, err
+	}
+	t := &skiplist.SkipListElement{}
+	err = proto.Unmarshal([]byte(data), t)
+	if err == nil {
+		for i := 0; i < len(t.Next); i++ {
+			if t.Next[i].IsNil() {
+				t.Next[i] = nil
+			}
+		}
+		if t.Prev.IsNil() {
+			t.Prev = nil
+		}
+	}
+	return t, err
+}
--- a/weed/filer/redis3/universal_redis_store.go
+++ b/weed/filer/redis3/universal_redis_store.go
@@ -0,0 +1,179 @@
+package redis3
+
+import (
+	"context"
+	"fmt"
+	"github.com/go-redsync/redsync/v4"
+	"time"
+
+	"github.com/go-redis/redis/v8"
+
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+const (
+	DIR_LIST_MARKER = "\x00"
+)
+
+type UniversalRedis3Store struct {
+	Client  redis.UniversalClient
+	redsync *redsync.Redsync
+}
+
+func (store *UniversalRedis3Store) BeginTransaction(ctx context.Context) (context.Context, error) {
+	return ctx, nil
+}
+func (store *UniversalRedis3Store) CommitTransaction(ctx context.Context) error {
+	return nil
+}
+func (store *UniversalRedis3Store) RollbackTransaction(ctx context.Context) error {
+	return nil
+}
+
+func (store *UniversalRedis3Store) InsertEntry(ctx context.Context, entry *filer.Entry) (err error) {
+
+	value, err := entry.EncodeAttributesAndChunks()
+	if err != nil {
+		return fmt.Errorf("encoding %s %+v: %v", entry.FullPath, entry.Attr, err)
+	}
+
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
+		value = util.MaybeGzipData(value)
+	}
+
+	if err = store.Client.Set(ctx, string(entry.FullPath), value, time.Duration(entry.TtlSec)*time.Second).Err(); err != nil {
+		return fmt.Errorf("persisting %s : %v", entry.FullPath, err)
+	}
+
+	dir, name := entry.FullPath.DirAndName()
+
+	if name != "" {
+		if err = insertChild(ctx, store, genDirectoryListKey(dir), name); err != nil {
+			return fmt.Errorf("persisting %s in parent dir: %v", entry.FullPath, err)
+		}
+	}
+
+	return nil
+}
+
+func (store *UniversalRedis3Store) UpdateEntry(ctx context.Context, entry *filer.Entry) (err error) {
+
+	return store.InsertEntry(ctx, entry)
+}
+
+func (store *UniversalRedis3Store) FindEntry(ctx context.Context, fullpath util.FullPath) (entry *filer.Entry, err error) {
+
+	data, err := store.Client.Get(ctx, string(fullpath)).Result()
+	if err == redis.Nil {
+		return nil, filer_pb.ErrNotFound
+	}
+
+	if err != nil {
+		return nil, fmt.Errorf("get %s : %v", fullpath, err)
+	}
+
+	entry = &filer.Entry{
+		FullPath: fullpath,
+	}
+	err = entry.DecodeAttributesAndChunks(util.MaybeDecompressData([]byte(data)))
+	if err != nil {
+		return entry, fmt.Errorf("decode %s : %v", entry.FullPath, err)
+	}
+
+	return entry, nil
+}
+
+func (store *UniversalRedis3Store) DeleteEntry(ctx context.Context, fullpath util.FullPath) (err error) {
+
+	_, err = store.Client.Del(ctx, genDirectoryListKey(string(fullpath))).Result()
+	if err != nil {
+		return fmt.Errorf("delete dir list %s : %v", fullpath, err)
+	}
+
+	_, err = store.Client.Del(ctx, string(fullpath)).Result()
+	if err != nil {
+		return fmt.Errorf("delete %s : %v", fullpath, err)
+	}
+
+	dir, name := fullpath.DirAndName()
+
+	if name != "" {
+		if err = removeChild(ctx, store, genDirectoryListKey(dir), name); err != nil {
+			return fmt.Errorf("DeleteEntry %s in parent dir: %v", fullpath, err)
+		}
+	}
+
+	return nil
+}
+
+func (store *UniversalRedis3Store) DeleteFolderChildren(ctx context.Context, fullpath util.FullPath) (err error) {
+
+	return removeChildren(ctx, store, genDirectoryListKey(string(fullpath)), func(name string) error {
+		path := util.NewFullPath(string(fullpath), name)
+		_, err = store.Client.Del(ctx, string(path)).Result()
+		if err != nil {
+			return fmt.Errorf("DeleteFolderChildren %s in parent dir: %v", fullpath, err)
+		}
+		// not efficient, but need to remove if it is a directory
+		store.Client.Del(ctx, genDirectoryListKey(string(path)))
+		return nil
+	})
+
+}
+
+func (store *UniversalRedis3Store) ListDirectoryPrefixedEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, prefix string, eachEntryFunc filer.ListEachEntryFunc) (lastFileName string, err error) {
+	return lastFileName, filer.ErrUnsupportedListDirectoryPrefixed
+}
+
+func (store *UniversalRedis3Store) ListDirectoryEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, eachEntryFunc filer.ListEachEntryFunc) (lastFileName string, err error) {
+
+	dirListKey := genDirectoryListKey(string(dirPath))
+	counter := int64(0)
+
+	err = listChildren(ctx, store, dirListKey, startFileName, func(fileName string) bool {
+		if startFileName != "" {
+			if !includeStartFile && startFileName == fileName {
+				return true
+			}
+		}
+
+		path := util.NewFullPath(string(dirPath), fileName)
+		entry, err := store.FindEntry(ctx, path)
+		lastFileName = fileName
+		if err != nil {
+			glog.V(0).Infof("list %s : %v", path, err)
+			if err == filer_pb.ErrNotFound {
+				return true
+			}
+		} else {
+			if entry.TtlSec > 0 {
+				if entry.Attr.Crtime.Add(time.Duration(entry.TtlSec) * time.Second).Before(time.Now()) {
+					store.Client.Del(ctx, string(path)).Result()
+					store.Client.ZRem(ctx, dirListKey, fileName).Result()
+					return true
+				}
+			}
+			counter++
+			if !eachEntryFunc(entry) {
+				return false
+			}
+			if counter >= limit {
+				return false
+			}
+		}
+		return true
+	})
+
+	return lastFileName, err
+}
+
+func genDirectoryListKey(dir string) (dirList string) {
+	return dir + DIR_LIST_MARKER
+}
+
+func (store *UniversalRedis3Store) Shutdown() {
+	store.Client.Close()
+}
--- a/weed/filer/redis3/universal_redis_store_kv.go
+++ b/weed/filer/redis3/universal_redis_store_kv.go
@@ -0,0 +1,42 @@
+package redis3
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/go-redis/redis/v8"
+)
+
+func (store *UniversalRedis3Store) KvPut(ctx context.Context, key []byte, value []byte) (err error) {
+
+	_, err = store.Client.Set(ctx, string(key), value, 0).Result()
+
+	if err != nil {
+		return fmt.Errorf("kv put: %v", err)
+	}
+
+	return nil
+}
+
+func (store *UniversalRedis3Store) KvGet(ctx context.Context, key []byte) (value []byte, err error) {
+
+	data, err := store.Client.Get(ctx, string(key)).Result()
+
+	if err == redis.Nil {
+		return nil, filer.ErrKvNotFound
+	}
+
+	return []byte(data), err
+}
+
+func (store *UniversalRedis3Store) KvDelete(ctx context.Context, key []byte) (err error) {
+
+	_, err = store.Client.Del(ctx, string(key)).Result()
+
+	if err != nil {
+		return fmt.Errorf("kv delete: %v", err)
+	}
+
+	return nil
+}
--- a/weed/filer/redis_lua/redis_cluster_store.go
+++ b/weed/filer/redis_lua/redis_cluster_store.go
@@ -0,0 +1,44 @@
+package redis_lua
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/go-redis/redis/v8"
+)
+
+func init() {
+	filer.Stores = append(filer.Stores, &RedisLuaClusterStore{})
+}
+
+type RedisLuaClusterStore struct {
+	UniversalRedisLuaStore
+}
+
+func (store *RedisLuaClusterStore) GetName() string {
+	return "redis_lua_cluster"
+}
+
+func (store *RedisLuaClusterStore) Initialize(configuration util.Configuration, prefix string) (err error) {
+
+	configuration.SetDefault(prefix+"useReadOnly", false)
+	configuration.SetDefault(prefix+"routeByLatency", false)
+
+	return store.initialize(
+		configuration.GetStringSlice(prefix+"addresses"),
+		configuration.GetString(prefix+"password"),
+		configuration.GetBool(prefix+"useReadOnly"),
+		configuration.GetBool(prefix+"routeByLatency"),
+		configuration.GetStringSlice(prefix+"superLargeDirectories"),
+	)
+}
+
+func (store *RedisLuaClusterStore) initialize(addresses []string, password string, readOnly, routeByLatency bool, superLargeDirectories []string) (err error) {
+	store.Client = redis.NewClusterClient(&redis.ClusterOptions{
+		Addrs:          addresses,
+		Password:       password,
+		ReadOnly:       readOnly,
+		RouteByLatency: routeByLatency,
+	})
+	store.loadSuperLargeDirectories(superLargeDirectories)
+	return
+}
--- a/weed/filer/redis_lua/redis_sentinel_store.go
+++ b/weed/filer/redis_lua/redis_sentinel_store.go
@@ -0,0 +1,45 @@
+package redis_lua
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/go-redis/redis/v8"
+	"time"
+)
+
+func init() {
+	filer.Stores = append(filer.Stores, &RedisLuaSentinelStore{})
+}
+
+type RedisLuaSentinelStore struct {
+	UniversalRedisLuaStore
+}
+
+func (store *RedisLuaSentinelStore) GetName() string {
+	return "redis_lua_sentinel"
+}
+
+func (store *RedisLuaSentinelStore) Initialize(configuration util.Configuration, prefix string) (err error) {
+	return store.initialize(
+		configuration.GetStringSlice(prefix+"addresses"),
+		configuration.GetString(prefix+"masterName"),
+		configuration.GetString(prefix+"username"),
+		configuration.GetString(prefix+"password"),
+		configuration.GetInt(prefix+"database"),
+	)
+}
+
+func (store *RedisLuaSentinelStore) initialize(addresses []string, masterName string, username string, password string, database int) (err error) {
+	store.Client = redis.NewFailoverClient(&redis.FailoverOptions{
+		MasterName:      masterName,
+		SentinelAddrs:   addresses,
+		Username:        username,
+		Password:        password,
+		DB:              database,
+		MinRetryBackoff: time.Millisecond * 100,
+		MaxRetryBackoff: time.Minute * 1,
+		ReadTimeout:     time.Second * 30,
+		WriteTimeout:    time.Second * 5,
+	})
+	return
+}
--- a/weed/filer/redis_lua/redis_store.go
+++ b/weed/filer/redis_lua/redis_store.go
@@ -0,0 +1,38 @@
+package redis_lua
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/go-redis/redis/v8"
+)
+
+func init() {
+	filer.Stores = append(filer.Stores, &RedisLuaStore{})
+}
+
+type RedisLuaStore struct {
+	UniversalRedisLuaStore
+}
+
+func (store *RedisLuaStore) GetName() string {
+	return "redis_lua"
+}
+
+func (store *RedisLuaStore) Initialize(configuration util.Configuration, prefix string) (err error) {
+	return store.initialize(
+		configuration.GetString(prefix+"address"),
+		configuration.GetString(prefix+"password"),
+		configuration.GetInt(prefix+"database"),
+		configuration.GetStringSlice(prefix+"superLargeDirectories"),
+	)
+}
+
+func (store *RedisLuaStore) initialize(hostPort string, password string, database int, superLargeDirectories []string) (err error) {
+	store.Client = redis.NewClient(&redis.Options{
+		Addr:     hostPort,
+		Password: password,
+		DB:       database,
+	})
+	store.loadSuperLargeDirectories(superLargeDirectories)
+	return
+}
--- a/weed/filer/redis_lua/stored_procedure/delete_entry.lua
+++ b/weed/filer/redis_lua/stored_procedure/delete_entry.lua
@@ -0,0 +1,19 @@
+-- KEYS[1]: full path of entry
+local fullpath = KEYS[1]
+-- KEYS[2]: full path of entry
+local fullpath_list_key = KEYS[2]
+-- KEYS[3]: dir of the entry
+local dir_list_key = KEYS[3]
+
+-- ARGV[1]: isSuperLargeDirectory
+local isSuperLargeDirectory = ARGV[1] == "1"
+-- ARGV[2]: name of the entry
+local name = ARGV[2]
+
+redis.call("DEL", fullpath, fullpath_list_key)
+
+if not isSuperLargeDirectory and name ~= "" then
+    redis.call("ZREM", dir_list_key, name)
+end
+
+return 0
--- a/weed/filer/redis_lua/stored_procedure/delete_folder_children.lua
+++ b/weed/filer/redis_lua/stored_procedure/delete_folder_children.lua
@@ -0,0 +1,15 @@
+-- KEYS[1]: full path of entry
+local fullpath = KEYS[1]
+
+if fullpath ~= "" and string.sub(fullpath, -1) == "/" then
+    fullpath = string.sub(fullpath, 0, -2)
+end
+
+local files = redis.call("ZRANGE", fullpath .. "\0", "0", "-1")
+
+for _, name in ipairs(files) do
+    local file_path = fullpath .. "/" .. name
+    redis.call("DEL", file_path, file_path .. "\0")
+end
+
+return 0
--- a/weed/filer/redis_lua/stored_procedure/init.go
+++ b/weed/filer/redis_lua/stored_procedure/init.go
@@ -0,0 +1,24 @@
+package stored_procedure
+
+import (
+	_ "embed"
+	"github.com/go-redis/redis/v8"
+)
+
+func init() {
+	InsertEntryScript = redis.NewScript(insertEntry)
+	DeleteEntryScript = redis.NewScript(deleteEntry)
+	DeleteFolderChildrenScript = redis.NewScript(deleteFolderChildren)
+}
+
+//go:embed insert_entry.lua
+var insertEntry string
+var InsertEntryScript *redis.Script
+
+//go:embed delete_entry.lua
+var deleteEntry string
+var DeleteEntryScript *redis.Script
+
+//go:embed delete_folder_children.lua
+var deleteFolderChildren string
+var DeleteFolderChildrenScript *redis.Script
--- a/weed/filer/redis_lua/stored_procedure/insert_entry.lua
+++ b/weed/filer/redis_lua/stored_procedure/insert_entry.lua
@@ -0,0 +1,27 @@
+-- KEYS[1]: full path of entry
+local full_path = KEYS[1]
+-- KEYS[2]: dir of the entry
+local dir_list_key = KEYS[2]
+
+-- ARGV[1]: content of the entry
+local entry = ARGV[1]
+-- ARGV[2]: TTL of the entry
+local ttlSec = tonumber(ARGV[2])
+-- ARGV[3]: isSuperLargeDirectory
+local isSuperLargeDirectory = ARGV[3] == "1"
+-- ARGV[4]: zscore of the entry in zset
+local zscore = tonumber(ARGV[4])
+-- ARGV[5]: name of the entry
+local name = ARGV[5]
+
+if ttlSec > 0 then
+    redis.call("SET", full_path, entry, "EX", ttlSec)
+else
+    redis.call("SET", full_path, entry)
+end
+
+if not isSuperLargeDirectory and name ~= "" then
+    redis.call("ZADD", dir_list_key, "NX", zscore, name)
+end
+
+return 0
--- a/weed/filer/redis_lua/universal_redis_store.go
+++ b/weed/filer/redis_lua/universal_redis_store.go
@@ -0,0 +1,191 @@
+package redis_lua
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/go-redis/redis/v8"
+
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/filer/redis_lua/stored_procedure"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+const (
+	DIR_LIST_MARKER = "\x00"
+)
+
+type UniversalRedisLuaStore struct {
+	Client                  redis.UniversalClient
+	superLargeDirectoryHash map[string]bool
+}
+
+func (store *UniversalRedisLuaStore) isSuperLargeDirectory(dir string) (isSuperLargeDirectory bool) {
+	_, isSuperLargeDirectory = store.superLargeDirectoryHash[dir]
+	return
+}
+
+func (store *UniversalRedisLuaStore) loadSuperLargeDirectories(superLargeDirectories []string) {
+	// set directory hash
+	store.superLargeDirectoryHash = make(map[string]bool)
+	for _, dir := range superLargeDirectories {
+		store.superLargeDirectoryHash[dir] = true
+	}
+}
+
+func (store *UniversalRedisLuaStore) BeginTransaction(ctx context.Context) (context.Context, error) {
+	return ctx, nil
+}
+func (store *UniversalRedisLuaStore) CommitTransaction(ctx context.Context) error {
+	return nil
+}
+func (store *UniversalRedisLuaStore) RollbackTransaction(ctx context.Context) error {
+	return nil
+}
+
+func (store *UniversalRedisLuaStore) InsertEntry(ctx context.Context, entry *filer.Entry) (err error) {
+
+	value, err := entry.EncodeAttributesAndChunks()
+	if err != nil {
+		return fmt.Errorf("encoding %s %+v: %v", entry.FullPath, entry.Attr, err)
+	}
+
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
+		value = util.MaybeGzipData(value)
+	}
+
+	dir, name := entry.FullPath.DirAndName()
+
+	err = stored_procedure.InsertEntryScript.Run(ctx, store.Client,
+		[]string{string(entry.FullPath), genDirectoryListKey(dir)},
+		value, entry.TtlSec,
+		store.isSuperLargeDirectory(dir), 0, name).Err()
+
+	if err != nil {
+		return fmt.Errorf("persisting %s : %v", entry.FullPath, err)
+	}
+
+	return nil
+}
+
+func (store *UniversalRedisLuaStore) UpdateEntry(ctx context.Context, entry *filer.Entry) (err error) {
+
+	return store.InsertEntry(ctx, entry)
+}
+
+func (store *UniversalRedisLuaStore) FindEntry(ctx context.Context, fullpath util.FullPath) (entry *filer.Entry, err error) {
+
+	data, err := store.Client.Get(ctx, string(fullpath)).Result()
+	if err == redis.Nil {
+		return nil, filer_pb.ErrNotFound
+	}
+
+	if err != nil {
+		return nil, fmt.Errorf("get %s : %v", fullpath, err)
+	}
+
+	entry = &filer.Entry{
+		FullPath: fullpath,
+	}
+	err = entry.DecodeAttributesAndChunks(util.MaybeDecompressData([]byte(data)))
+	if err != nil {
+		return entry, fmt.Errorf("decode %s : %v", entry.FullPath, err)
+	}
+
+	return entry, nil
+}
+
+func (store *UniversalRedisLuaStore) DeleteEntry(ctx context.Context, fullpath util.FullPath) (err error) {
+
+	dir, name := fullpath.DirAndName()
+
+	err = stored_procedure.DeleteEntryScript.Run(ctx, store.Client,
+		[]string{string(fullpath), genDirectoryListKey(string(fullpath)), genDirectoryListKey(dir)},
+		store.isSuperLargeDirectory(dir), name).Err()
+
+	if err != nil {
+		return fmt.Errorf("DeleteEntry %s : %v", fullpath, err)
+	}
+
+	return nil
+}
+
+func (store *UniversalRedisLuaStore) DeleteFolderChildren(ctx context.Context, fullpath util.FullPath) (err error) {
+
+	if store.isSuperLargeDirectory(string(fullpath)) {
+		return nil
+	}
+
+	err = stored_procedure.DeleteFolderChildrenScript.Run(ctx, store.Client,
+		[]string{string(fullpath)}).Err()
+
+	if err != nil {
+		return fmt.Errorf("DeleteFolderChildren %s : %v", fullpath, err)
+	}
+
+	return nil
+}
+
+func (store *UniversalRedisLuaStore) ListDirectoryPrefixedEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, prefix string, eachEntryFunc filer.ListEachEntryFunc) (lastFileName string, err error) {
+	return lastFileName, filer.ErrUnsupportedListDirectoryPrefixed
+}
+
+func (store *UniversalRedisLuaStore) ListDirectoryEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, eachEntryFunc filer.ListEachEntryFunc) (lastFileName string, err error) {
+
+	dirListKey := genDirectoryListKey(string(dirPath))
+
+	min := "-"
+	if startFileName != "" {
+		if includeStartFile {
+			min = "[" + startFileName
+		} else {
+			min = "(" + startFileName
+		}
+	}
+
+	members, err := store.Client.ZRangeByLex(ctx, dirListKey, &redis.ZRangeBy{
+		Min:    min,
+		Max:    "+",
+		Offset: 0,
+		Count:  limit,
+	}).Result()
+	if err != nil {
+		return lastFileName, fmt.Errorf("list %s : %v", dirPath, err)
+	}
+
+	// fetch entry meta
+	for _, fileName := range members {
+		path := util.NewFullPath(string(dirPath), fileName)
+		entry, err := store.FindEntry(ctx, path)
+		lastFileName = fileName
+		if err != nil {
+			glog.V(0).Infof("list %s : %v", path, err)
+			if err == filer_pb.ErrNotFound {
+				continue
+			}
+		} else {
+			if entry.TtlSec > 0 {
+				if entry.Attr.Crtime.Add(time.Duration(entry.TtlSec) * time.Second).Before(time.Now()) {
+					store.DeleteEntry(ctx, path)
+					continue
+				}
+			}
+			if !eachEntryFunc(entry) {
+				break
+			}
+		}
+	}
+
+	return lastFileName, err
+}
+
+func genDirectoryListKey(dir string) (dirList string) {
+	return dir + DIR_LIST_MARKER
+}
+
+func (store *UniversalRedisLuaStore) Shutdown() {
+	store.Client.Close()
+}
--- a/weed/filer/redis_lua/universal_redis_store_kv.go
+++ b/weed/filer/redis_lua/universal_redis_store_kv.go
@@ -0,0 +1,42 @@
+package redis_lua
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/go-redis/redis/v8"
+)
+
+func (store *UniversalRedisLuaStore) KvPut(ctx context.Context, key []byte, value []byte) (err error) {
+
+	_, err = store.Client.Set(ctx, string(key), value, 0).Result()
+
+	if err != nil {
+		return fmt.Errorf("kv put: %v", err)
+	}
+
+	return nil
+}
+
+func (store *UniversalRedisLuaStore) KvGet(ctx context.Context, key []byte) (value []byte, err error) {
+
+	data, err := store.Client.Get(ctx, string(key)).Result()
+
+	if err == redis.Nil {
+		return nil, filer.ErrKvNotFound
+	}
+
+	return []byte(data), err
+}
+
+func (store *UniversalRedisLuaStore) KvDelete(ctx context.Context, key []byte) (err error) {
+
+	_, err = store.Client.Del(ctx, string(key)).Result()
+
+	if err != nil {
+		return fmt.Errorf("kv delete: %v", err)
+	}
+
+	return nil
+}
--- a/weed/filer/remote_mapping.go
+++ b/weed/filer/remote_mapping.go
@@ -0,0 +1,121 @@
+package filer
+
+import (
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/pb"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/pb/remote_pb"
+	"github.com/golang/protobuf/proto"
+	"google.golang.org/grpc"
+)
+
+func ReadMountMappings(grpcDialOption grpc.DialOption, filerAddress pb.ServerAddress) (mappings *remote_pb.RemoteStorageMapping, readErr error) {
+	var oldContent []byte
+	if readErr = pb.WithFilerClient(false, filerAddress, grpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
+		oldContent, readErr = ReadInsideFiler(client, DirectoryEtcRemote, REMOTE_STORAGE_MOUNT_FILE)
+		return readErr
+	}); readErr != nil {
+		return nil, readErr
+	}
+
+	mappings, readErr = UnmarshalRemoteStorageMappings(oldContent)
+	if readErr != nil {
+		return nil, fmt.Errorf("unmarshal mappings: %v", readErr)
+	}
+
+	return
+}
+
+func InsertMountMapping(filerClient filer_pb.FilerClient, dir string, remoteStorageLocation *remote_pb.RemoteStorageLocation) (err error) {
+
+	// read current mapping
+	var oldContent, newContent []byte
+	err = filerClient.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+		oldContent, err = ReadInsideFiler(client, DirectoryEtcRemote, REMOTE_STORAGE_MOUNT_FILE)
+		return err
+	})
+	if err != nil {
+		if err != filer_pb.ErrNotFound {
+			return fmt.Errorf("read existing mapping: %v", err)
+		}
+	}
+
+	// add new mapping
+	newContent, err = addRemoteStorageMapping(oldContent, dir, remoteStorageLocation)
+	if err != nil {
+		return fmt.Errorf("add mapping %s~%s: %v", dir, remoteStorageLocation, err)
+	}
+
+	// save back
+	err = filerClient.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+		return SaveInsideFiler(client, DirectoryEtcRemote, REMOTE_STORAGE_MOUNT_FILE, newContent)
+	})
+	if err != nil {
+		return fmt.Errorf("save mapping: %v", err)
+	}
+
+	return nil
+}
+
+func DeleteMountMapping(filerClient filer_pb.FilerClient, dir string) (err error) {
+
+	// read current mapping
+	var oldContent, newContent []byte
+	err = filerClient.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+		oldContent, err = ReadInsideFiler(client, DirectoryEtcRemote, REMOTE_STORAGE_MOUNT_FILE)
+		return err
+	})
+	if err != nil {
+		if err != filer_pb.ErrNotFound {
+			return fmt.Errorf("read existing mapping: %v", err)
+		}
+	}
+
+	// add new mapping
+	newContent, err = removeRemoteStorageMapping(oldContent, dir)
+	if err != nil {
+		return fmt.Errorf("delete mount %s: %v", dir, err)
+	}
+
+	// save back
+	err = filerClient.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
+		return SaveInsideFiler(client, DirectoryEtcRemote, REMOTE_STORAGE_MOUNT_FILE, newContent)
+	})
+	if err != nil {
+		return fmt.Errorf("save mapping: %v", err)
+	}
+
+	return nil
+}
+
+func addRemoteStorageMapping(oldContent []byte, dir string, storageLocation *remote_pb.RemoteStorageLocation) (newContent []byte, err error) {
+	mappings, unmarshalErr := UnmarshalRemoteStorageMappings(oldContent)
+	if unmarshalErr != nil {
+		// skip
+	}
+
+	// set the new mapping
+	mappings.Mappings[dir] = storageLocation
+
+	if newContent, err = proto.Marshal(mappings); err != nil {
+		return oldContent, fmt.Errorf("marshal mappings: %v", err)
+	}
+
+	return
+}
+
+func removeRemoteStorageMapping(oldContent []byte, dir string) (newContent []byte, err error) {
+	mappings, unmarshalErr := UnmarshalRemoteStorageMappings(oldContent)
+	if unmarshalErr != nil {
+		return nil, unmarshalErr
+	}
+
+	// set the new mapping
+	delete(mappings.Mappings, dir)
+
+	if newContent, err = proto.Marshal(mappings); err != nil {
+		return oldContent, fmt.Errorf("marshal mappings: %v", err)
+	}
+
+	return
+}
--- a/weed/filer/filer_remote_storage.go
+++ b/weed/filer/filer_remote_storage.go
@@ -131,58 +131,9 @@ func UnmarshalRemoteStorageMappings(oldContent []byte) (mappings *remote_pb.Remo
 	return
 }

-func AddRemoteStorageMapping(oldContent []byte, dir string, storageLocation *remote_pb.RemoteStorageLocation) (newContent []byte, err error) {
-	mappings, unmarshalErr := UnmarshalRemoteStorageMappings(oldContent)
-	if unmarshalErr != nil {
-		// skip
-	}
-
-	// set the new mapping
-	mappings.Mappings[dir] = storageLocation
-
-	if newContent, err = proto.Marshal(mappings); err != nil {
-		return oldContent, fmt.Errorf("marshal mappings: %v", err)
-	}
-
-	return
-}
-
-func RemoveRemoteStorageMapping(oldContent []byte, dir string) (newContent []byte, err error) {
-	mappings, unmarshalErr := UnmarshalRemoteStorageMappings(oldContent)
-	if unmarshalErr != nil {
-		return nil, unmarshalErr
-	}
-
-	// set the new mapping
-	delete(mappings.Mappings, dir)
-
-	if newContent, err = proto.Marshal(mappings); err != nil {
-		return oldContent, fmt.Errorf("marshal mappings: %v", err)
-	}
-
-	return
-}
-
-func ReadMountMappings(grpcDialOption grpc.DialOption, filerAddress string) (mappings *remote_pb.RemoteStorageMapping, readErr error) {
+func ReadRemoteStorageConf(grpcDialOption grpc.DialOption, filerAddress pb.ServerAddress, storageName string) (conf *remote_pb.RemoteConf, readErr error) {
 	var oldContent []byte
-	if readErr = pb.WithFilerClient(filerAddress, grpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
-		oldContent, readErr = ReadInsideFiler(client, DirectoryEtcRemote, REMOTE_STORAGE_MOUNT_FILE)
-		return readErr
-	}); readErr != nil {
-		return nil, readErr
-	}
-
-	mappings, readErr = UnmarshalRemoteStorageMappings(oldContent)
-	if readErr != nil {
-		return nil, fmt.Errorf("unmarshal mappings: %v", readErr)
-	}
-
-	return
-}
-
-func ReadRemoteStorageConf(grpcDialOption grpc.DialOption, filerAddress string, storageName string) (conf *remote_pb.RemoteConf, readErr error) {
-	var oldContent []byte
-	if readErr = pb.WithFilerClient(filerAddress, grpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
+	if readErr = pb.WithFilerClient(false, filerAddress, grpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
 		oldContent, readErr = ReadInsideFiler(client, DirectoryEtcRemote, storageName+REMOTE_STORAGE_CONF_SUFFIX)
 		return readErr
 	}); readErr != nil {
@@ -199,7 +150,7 @@ func ReadRemoteStorageConf(grpcDialOption grpc.DialOption, filerAddress string,
 	return
 }

-func DetectMountInfo(grpcDialOption grpc.DialOption, filerAddress string, dir string) (*remote_pb.RemoteStorageMapping, string, *remote_pb.RemoteStorageLocation, *remote_pb.RemoteConf, error) {
+func DetectMountInfo(grpcDialOption grpc.DialOption, filerAddress pb.ServerAddress, dir string) (*remote_pb.RemoteStorageMapping, string, *remote_pb.RemoteStorageLocation, *remote_pb.RemoteConf, error) {

 	mappings, listErr := ReadMountMappings(grpcDialOption, filerAddress)
 	if listErr != nil {
--- a/weed/filer/filer_remote_storage_test.go
+++ b/weed/filer/filer_remote_storage_test.go
--- a/weed/filer/rocksdb/rocksdb_store.go
+++ b/weed/filer/rocksdb/rocksdb_store.go
@@ -10,7 +10,7 @@ import (
 	"io"
 	"os"

-	"github.com/tecbot/gorocksdb"
+	gorocksdb "github.com/linxGnu/grocksdb"

 	"github.com/chrislusf/seaweedfs/weed/filer"
 	"github.com/chrislusf/seaweedfs/weed/glog"
--- a/weed/filer/rocksdb/rocksdb_store_test.go
+++ b/weed/filer/rocksdb/rocksdb_store_test.go
@@ -1,3 +1,4 @@
+//go:build rocksdb
 // +build rocksdb

 package rocksdb
@@ -5,7 +6,6 @@ package rocksdb
 import (
 	"context"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"testing"
 	"time"
@@ -16,8 +16,7 @@ import (

 func TestCreateAndFind(t *testing.T) {
 	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
-	dir, _ := ioutil.TempDir("", "seaweedfs_filer_test")
-	defer os.RemoveAll(dir)
+	dir := t.TempDir()
 	store := &RocksDBStore{}
 	store.initialize(dir)
 	testFiler.SetStore(store)
@@ -35,7 +34,7 @@ func TestCreateAndFind(t *testing.T) {
 		},
 	}

-	if err := testFiler.CreateEntry(ctx, entry1, false, false, nil); err != nil {
+	if err := testFiler.CreateEntry(ctx, entry1, false, false, nil, false); err != nil {
 		t.Errorf("create entry %v: %v", entry1.FullPath, err)
 		return
 	}
@@ -70,8 +69,7 @@ func TestCreateAndFind(t *testing.T) {

 func TestEmptyRoot(t *testing.T) {
 	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
-	dir, _ := ioutil.TempDir("", "seaweedfs_filer_test2")
-	defer os.RemoveAll(dir)
+	dir := t.TempDir()
 	store := &RocksDBStore{}
 	store.initialize(dir)
 	testFiler.SetStore(store)
@@ -93,8 +91,7 @@ func TestEmptyRoot(t *testing.T) {

 func BenchmarkInsertEntry(b *testing.B) {
 	testFiler := filer.NewFiler(nil, nil, "", 0, "", "", "", nil)
-	dir, _ := ioutil.TempDir("", "seaweedfs_filer_bench")
-	defer os.RemoveAll(dir)
+	dir := b.TempDir()
 	store := &RocksDBStore{}
 	store.initialize(dir)
 	testFiler.SetStore(store)
--- a/weed/filer/rocksdb/rocksdb_ttl.go
+++ b/weed/filer/rocksdb/rocksdb_ttl.go
@@ -5,7 +5,7 @@ package rocksdb
 import (
 	"time"

-	"github.com/tecbot/gorocksdb"
+	gorocksdb "github.com/linxGnu/grocksdb"

 	"github.com/chrislusf/seaweedfs/weed/filer"
 )
@@ -38,3 +38,8 @@ func (t *TTLFilter) Filter(level int, key, val []byte) (remove bool, newVal []by
 func (t *TTLFilter) Name() string {
 	return "TTLFilter"
 }
+func (t *TTLFilter) SetIgnoreSnapshots(value bool) {
+}
+
+func (t *TTLFilter) Destroy() {
+}
--- a/weed/filer/s3iam_conf.go
+++ b/weed/filer/s3iam_conf.go
@@ -2,13 +2,12 @@ package filer

 import (
 	"bytes"
-	"github.com/chrislusf/seaweedfs/weed/pb/iam_pb"
 	"github.com/golang/protobuf/jsonpb"
 	"github.com/golang/protobuf/proto"
 	"io"
 )

-func ParseS3ConfigurationFromBytes(content []byte, config *iam_pb.S3ApiConfiguration) error {
+func ParseS3ConfigurationFromBytes[T proto.Message](content []byte, config T) error {
 	if err := jsonpb.Unmarshal(bytes.NewBuffer(content), config); err != nil {
 		return err
 	}
--- a/weed/filer/sqlite/doc.go
+++ b/weed/filer/sqlite/doc.go
@@ -0,0 +1,9 @@
+/*
+
+Package sqlite is for sqlite filer store.
+
+The referenced "modernc.org/sqlite" library is too big when compiled.
+So this is only compiled in "make full_install".
+
+*/
+package sqlite
--- a/weed/filer/sqlite/sqlite_store.go
+++ b/weed/filer/sqlite/sqlite_store.go
@@ -1,4 +1,6 @@
+//go:build (linux || darwin || windows) && sqlite
 // +build linux darwin windows
+// +build sqlite

 // limited GOOS due to modernc.org/libc/unistd

--- a/weed/filer/sqlite/sqlite_store_unsupported.go
+++ b/weed/filer/sqlite/sqlite_store_unsupported.go
@@ -1,4 +1,5 @@
-// +build !linux,!darwin,!windows,!s390,!ppc64le,!mips64
+//go:build !linux && !darwin && !windows && !s390 && !ppc64le && !mips64 && !sqlite
+// +build !linux,!darwin,!windows,!s390,!ppc64le,!mips64,!sqlite

 // limited GOOS due to modernc.org/libc/unistd

--- a/weed/filer/store_test/test_suite.go
+++ b/weed/filer/store_test/test_suite.go
@@ -0,0 +1,55 @@
+package store_test
+
+import (
+	"context"
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/stretchr/testify/assert"
+	"os"
+	"testing"
+)
+
+func TestFilerStore(t *testing.T, store filer.FilerStore) {
+	ctx := context.Background()
+
+	store.InsertEntry(ctx, makeEntry(util.FullPath("/"), true))
+	store.InsertEntry(ctx, makeEntry(util.FullPath("/a"), true))
+	store.InsertEntry(ctx, makeEntry(util.FullPath("/a/b"), true))
+	store.InsertEntry(ctx, makeEntry(util.FullPath("/a/b/c"), true))
+	for i := 0; i < 2000; i++ {
+		store.InsertEntry(ctx, makeEntry(util.FullPath(fmt.Sprintf("/a/b/c/f%05d", i)), false))
+	}
+
+	{
+		var counter int
+		lastFileName, err := store.ListDirectoryEntries(ctx, util.FullPath("/a/b/c"), "", false, 3, func(entry *filer.Entry) bool {
+			counter++
+			return true
+		})
+		assert.Nil(t, err, "list directory")
+		assert.Equal(t, 3, counter, "directory list counter")
+		assert.Equal(t, "f00003", lastFileName, "directory list last file")
+		lastFileName, err = store.ListDirectoryEntries(ctx, util.FullPath("/a/b/c"), lastFileName, false, 1024, func(entry *filer.Entry) bool {
+			counter++
+			return true
+		})
+		assert.Nil(t, err, "list directory")
+		assert.Equal(t, 1027, counter, "directory list counter")
+		assert.Equal(t, "f01027", lastFileName, "directory list last file")
+	}
+
+}
+
+func makeEntry(fullPath util.FullPath, isDirectory bool) *filer.Entry {
+	var mode os.FileMode
+	if isDirectory {
+		mode = os.ModeDir
+	}
+	return &filer.Entry{
+		FullPath: fullPath,
+		Attr: filer.Attr{
+			Mode: mode,
+		},
+	}
+}
--- a/weed/filer/stream.go
+++ b/weed/filer/stream.go
@@ -3,6 +3,7 @@ package filer
 import (
 	"bytes"
 	"fmt"
+	"golang.org/x/exp/slices"
 	"io"
 	"math"
 	"sort"
@@ -39,11 +40,11 @@ func isSameChunks(a, b []*filer_pb.FileChunk) bool {
 	if len(a) != len(b) {
 		return false
 	}
-	sort.Slice(a, func(i, j int) bool {
-		return strings.Compare(a[i].ETag, a[j].ETag) < 0
+	slices.SortFunc(a, func(i, j *filer_pb.FileChunk) bool {
+		return strings.Compare(i.ETag, j.ETag) < 0
 	})
-	sort.Slice(b, func(i, j int) bool {
-		return strings.Compare(b[i].ETag, b[j].ETag) < 0
+	slices.SortFunc(b, func(i, j *filer_pb.FileChunk) bool {
+		return strings.Compare(i.ETag, j.ETag) < 0
 	})
 	for i := 0; i < len(a); i++ {
 		if a[i].ETag != b[i].ETag {
@@ -62,7 +63,7 @@ func NewFileReader(filerClient filer_pb.FilerClient, entry *filer_pb.Entry) io.R

 func StreamContent(masterClient wdclient.HasLookupFileIdFunction, writer io.Writer, chunks []*filer_pb.FileChunk, offset int64, size int64) error {

-	glog.V(9).Infof("start to stream content for chunks: %+v\n", chunks)
+	glog.V(4).Infof("start to stream content for chunks: %+v", chunks)
 	chunkViews := ViewFromChunks(masterClient.GetLookupFileIdFunction(), chunks, offset, size)

 	fileId2Url := make(map[string][]string)
@@ -80,11 +81,23 @@ func StreamContent(masterClient wdclient.HasLookupFileIdFunction, writer io.Writ
 		fileId2Url[chunkView.FileId] = urlStrings
 	}

+	remaining := size
 	for _, chunkView := range chunkViews {
-
+		if offset < chunkView.LogicOffset {
+			gap := chunkView.LogicOffset - offset
+			remaining -= gap
+			glog.V(4).Infof("zero [%d,%d)", offset, chunkView.LogicOffset)
+			err := writeZero(writer, gap)
+			if err != nil {
+				return fmt.Errorf("write zero [%d,%d)", offset, chunkView.LogicOffset)
+			}
+			offset = chunkView.LogicOffset
+		}
 		urlStrings := fileId2Url[chunkView.FileId]
 		start := time.Now()
 		err := retriedStreamFetchChunkData(writer, urlStrings, chunkView.CipherKey, chunkView.IsGzipped, chunkView.IsFullChunk(), chunkView.Offset, int(chunkView.Size))
+		offset += int64(chunkView.Size)
+		remaining -= int64(chunkView.Size)
 		stats.FilerRequestHistogram.WithLabelValues("chunkDownload").Observe(time.Since(start).Seconds())
 		if err != nil {
 			stats.FilerRequestCounter.WithLabelValues("chunkDownloadError").Inc()
@@ -92,6 +105,13 @@ func StreamContent(masterClient wdclient.HasLookupFileIdFunction, writer io.Writ
 		}
 		stats.FilerRequestCounter.WithLabelValues("chunkDownload").Inc()
 	}
+	if remaining > 0 {
+		glog.V(4).Infof("zero [%d,%d)", offset, offset+remaining)
+		err := writeZero(writer, remaining)
+		if err != nil {
+			return fmt.Errorf("write zero [%d,%d)", offset, offset+remaining)
+		}
+	}

 	return nil

@@ -99,42 +119,59 @@ func StreamContent(masterClient wdclient.HasLookupFileIdFunction, writer io.Writ

 // ----------------  ReadAllReader ----------------------------------

-func ReadAll(masterClient *wdclient.MasterClient, chunks []*filer_pb.FileChunk) ([]byte, error) {
+func writeZero(w io.Writer, size int64) (err error) {
+	zeroPadding := make([]byte, 1024)
+	var written int
+	for size > 0 {
+		if size > 1024 {
+			written, err = w.Write(zeroPadding)
+		} else {
+			written, err = w.Write(zeroPadding[:size])
+		}
+		size -= int64(written)
+		if err != nil {
+			return
+		}
+	}
+	return
+}

-	buffer := bytes.Buffer{}
+func ReadAll(buffer []byte, masterClient *wdclient.MasterClient, chunks []*filer_pb.FileChunk) error {

 	lookupFileIdFn := func(fileId string) (targetUrls []string, err error) {
 		return masterClient.LookupFileId(fileId)
 	}

-	chunkViews := ViewFromChunks(lookupFileIdFn, chunks, 0, math.MaxInt64)
+	chunkViews := ViewFromChunks(lookupFileIdFn, chunks, 0, int64(len(buffer)))
+
+	idx := 0

 	for _, chunkView := range chunkViews {
 		urlStrings, err := lookupFileIdFn(chunkView.FileId)
 		if err != nil {
 			glog.V(1).Infof("operation LookupFileId %s failed, err: %v", chunkView.FileId, err)
-			return nil, err
+			return err
 		}

-		data, err := retriedFetchChunkData(urlStrings, chunkView.CipherKey, chunkView.IsGzipped, chunkView.IsFullChunk(), chunkView.Offset, int(chunkView.Size))
+		n, err := retriedFetchChunkData(buffer[idx:idx+int(chunkView.Size)], urlStrings, chunkView.CipherKey, chunkView.IsGzipped, chunkView.IsFullChunk(), chunkView.Offset)
 		if err != nil {
-			return nil, err
+			return err
 		}
-		buffer.Write(data)
+		idx += n
 	}
-	return buffer.Bytes(), nil
+	return nil
 }

 // ----------------  ChunkStreamReader ----------------------------------
 type ChunkStreamReader struct {
-	chunkViews         []*ChunkView
-	totalSize          int64
-	logicOffset        int64
-	buffer             []byte
-	bufferOffset       int64
-	bufferLock         sync.Mutex
-	chunk              string
-	lookupFileId       wdclient.LookupFileIdFunctionType
+	chunkViews   []*ChunkView
+	totalSize    int64
+	logicOffset  int64
+	buffer       []byte
+	bufferOffset int64
+	bufferLock   sync.Mutex
+	chunk        string
+	lookupFileId wdclient.LookupFileIdFunctionType
 }

 var _ = io.ReadSeeker(&ChunkStreamReader{})
@@ -143,8 +180,8 @@ var _ = io.ReaderAt(&ChunkStreamReader{})
 func doNewChunkStreamReader(lookupFileIdFn wdclient.LookupFileIdFunctionType, chunks []*filer_pb.FileChunk) *ChunkStreamReader {

 	chunkViews := ViewFromChunks(lookupFileIdFn, chunks, 0, math.MaxInt64)
-	sort.Slice(chunkViews, func(i, j int) bool {
-		return chunkViews[i].LogicOffset < chunkViews[j].LogicOffset
+	slices.SortFunc(chunkViews, func(a, b *ChunkView) bool {
+		return a.LogicOffset < b.LogicOffset
 	})

 	var totalSize int64
@@ -206,7 +243,7 @@ func (c *ChunkStreamReader) doRead(p []byte) (n int, err error) {
 }

 func (c *ChunkStreamReader) isBufferEmpty() bool {
-	return len(c.buffer) <= int(c.logicOffset - c.bufferOffset)
+	return len(c.buffer) <= int(c.logicOffset-c.bufferOffset)
 }

 func (c *ChunkStreamReader) Seek(offset int64, whence int) (int64, error) {
@@ -261,7 +298,7 @@ func (c *ChunkStreamReader) prepareBufferFor(offset int64) (err error) {
 	} else if currentChunkIndex > 0 {
 		if insideChunk(offset, c.chunkViews[currentChunkIndex]) {
 			// good hit
-		} else if insideChunk(offset, c.chunkViews[currentChunkIndex-1]){
+		} else if insideChunk(offset, c.chunkViews[currentChunkIndex-1]) {
 			currentChunkIndex -= 1
 			// fmt.Printf("select -1 chunk %d %s\n", currentChunkIndex, c.chunkViews[currentChunkIndex].FileId)
 		} else {
@@ -297,7 +334,7 @@ func (c *ChunkStreamReader) fetchChunkToBuffer(chunkView *ChunkView) error {
 	var buffer bytes.Buffer
 	var shouldRetry bool
 	for _, urlString := range urlStrings {
-		shouldRetry, err = util.ReadUrlAsStream(urlString, chunkView.CipherKey, chunkView.IsGzipped, chunkView.IsFullChunk(), chunkView.Offset, int(chunkView.Size), func(data []byte) {
+		shouldRetry, err = util.ReadUrlAsStream(urlString+"?readDeleted=true", chunkView.CipherKey, chunkView.IsGzipped, chunkView.IsFullChunk(), chunkView.Offset, int(chunkView.Size), func(data []byte) {
 			buffer.Write(data)
 		})
 		if !shouldRetry {
--- a/weed/filer/tikv/tikv_store.go
+++ b/weed/filer/tikv/tikv_store.go
@@ -1,5 +1,3 @@
-// +build tikv
-
 package tikv

 import (
@@ -14,7 +12,6 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
 	"github.com/chrislusf/seaweedfs/weed/util"
-	"github.com/tikv/client-go/v2/tikv"
 	"github.com/tikv/client-go/v2/txnkv"
 )

@@ -27,8 +24,9 @@ func init() {
 }

 type TikvStore struct {
-	client                 *tikv.KVStore
+	client                 *txnkv.Client
 	deleteRangeConcurrency int
+	onePC                  bool
 }

 // Basic APIs
@@ -46,12 +44,13 @@ func (store *TikvStore) Initialize(config util.Configuration, prefix string) err
 	if drc <= 0 {
 		drc = 1
 	}
+	store.onePC = config.GetBool(prefix + "enable_1pc")
 	store.deleteRangeConcurrency = drc
 	return store.initialize(pdAddrs)
 }

 func (store *TikvStore) initialize(pdAddrs []string) error {
-	client, err := tikv.NewTxnClient(pdAddrs)
+	client, err := txnkv.NewClient(pdAddrs)
 	store.client = client
 	return err
 }
@@ -298,6 +297,9 @@ func (store *TikvStore) BeginTransaction(ctx context.Context) (context.Context,
 	if err != nil {
 		return ctx, err
 	}
+	if store.onePC {
+		tx.SetEnable1PC(store.onePC)
+	}
 	return context.WithValue(ctx, "tx", tx), nil
 }

@@ -344,6 +346,9 @@ func (store *TikvStore) getTxn(ctx context.Context) (*TxnWrapper, error) {
 	if err != nil {
 		return nil, err
 	}
+	if store.onePC {
+		txn.SetEnable1PC(store.onePC)
+	}
 	return &TxnWrapper{txn, false}, nil
 }

--- a/weed/filer/tikv/tikv_store_kv.go
+++ b/weed/filer/tikv/tikv_store_kv.go
@@ -1,5 +1,3 @@
-// +build tikv
-
 package tikv

 import (
--- a/weed/filer/ydb/doc.go
+++ b/weed/filer/ydb/doc.go
@@ -0,0 +1,9 @@
+/*
+
+Package ydb is for YDB filer store.
+
+The referenced "github.com/ydb-platform/ydb-go-sdk/v3" library is too big when compiled.
+So this is only compiled in "make full_install".
+
+*/
+package ydb
--- a/weed/filer/ydb/readme.md
+++ b/weed/filer/ydb/readme.md
@@ -0,0 +1,27 @@
+## YDB
+
+database: https://github.com/ydb-platform/ydb
+
+go driver: https://github.com/ydb-platform/ydb-go-sdk
+
+options:
+
+```
+[ydb]
+enabled=true
+dsn=grpcs://ydb-ru.yandex.net:2135/?database=/ru/home/username/db
+prefix="seaweedfs"
+useBucketPrefix=true
+poolSizeLimit=50
+dialTimeOut = 10
+```
+
+Authenticate produced with one of next environment variables:
+ * `YDB_SERVICE_ACCOUNT_KEY_FILE_CREDENTIALS=<path/to/sa_key_file>` — used service account key file by path
+ * `YDB_ANONYMOUS_CREDENTIALS="1"` — used for authenticate with anonymous access. Anonymous access needs for connect to testing YDB installation
+ * `YDB_METADATA_CREDENTIALS="1"` — used metadata service for authenticate to YDB from yandex cloud virtual machine or from yandex function
+ * `YDB_ACCESS_TOKEN_CREDENTIALS=<access_token>` — used for authenticate to YDB with short-life access token. For example, access token may be IAM token
+ * `YDB_CONNECTION_STRING="grpcs://endpoint/?database=database"`
+
+ * i test using this dev database:
+`make dev_ydb`
--- a/weed/filer/ydb/ydb_queries.go
+++ b/weed/filer/ydb/ydb_queries.go
@@ -0,0 +1,72 @@
+//go:build ydb
+// +build ydb
+
+package ydb
+
+import asql "github.com/chrislusf/seaweedfs/weed/filer/abstract_sql"
+
+const (
+	upsertQuery = `
+		PRAGMA TablePathPrefix("%v");
+		DECLARE $dir_hash AS int64;
+		DECLARE $directory AS Utf8;
+		DECLARE $name AS Utf8;
+		DECLARE $meta AS String;
+		DECLARE $expire_at AS Optional<uint32>;
+
+		UPSERT INTO ` + asql.DEFAULT_TABLE + `
+			(dir_hash, name, directory, meta, expire_at)
+		VALUES
+			($dir_hash, $name, $directory, $meta, $expire_at);`
+
+	deleteQuery = `
+		PRAGMA TablePathPrefix("%v");
+		DECLARE $dir_hash AS int64;
+		DECLARE $name AS Utf8;
+
+		DELETE FROM ` + asql.DEFAULT_TABLE + ` 
+		WHERE dir_hash = $dir_hash AND name = $name;`
+
+	findQuery = `
+		PRAGMA TablePathPrefix("%v");
+		DECLARE $dir_hash AS int64;
+		DECLARE $name AS Utf8;
+		
+		SELECT meta
+		FROM ` + asql.DEFAULT_TABLE + ` 
+		WHERE dir_hash = $dir_hash AND name = $name;`
+
+	deleteFolderChildrenQuery = `
+		PRAGMA TablePathPrefix("%v");
+		DECLARE $dir_hash AS int64;
+		DECLARE $directory AS Utf8;
+
+		DELETE FROM ` + asql.DEFAULT_TABLE + ` 
+		WHERE dir_hash = $dir_hash AND directory = $directory;`
+
+	listDirectoryQuery = `
+		PRAGMA TablePathPrefix("%v");
+		DECLARE $dir_hash AS int64;
+		DECLARE $directory AS Utf8;
+		DECLARE $start_name AS Utf8;
+		DECLARE $prefix AS Utf8;
+		DECLARE $limit AS Uint64;
+		
+		SELECT name, meta
+		FROM ` + asql.DEFAULT_TABLE + `
+		WHERE dir_hash = $dir_hash AND directory = $directory and name > $start_name and name LIKE $prefix
+		ORDER BY name ASC LIMIT $limit;`
+
+	listInclusiveDirectoryQuery = `
+		PRAGMA TablePathPrefix("%v");
+		DECLARE $dir_hash AS int64;
+		DECLARE $directory AS Utf8;
+		DECLARE $start_name AS Utf8;
+		DECLARE $prefix AS Utf8;
+		DECLARE $limit AS Uint64;
+		
+		SELECT name, meta
+		FROM ` + asql.DEFAULT_TABLE + `
+		WHERE dir_hash = $dir_hash AND directory = $directory and name >= $start_name and name LIKE $prefix
+		ORDER BY name ASC LIMIT $limit;`
+)
--- a/weed/filer/ydb/ydb_store.go
+++ b/weed/filer/ydb/ydb_store.go
@@ -0,0 +1,413 @@
+//go:build ydb
+// +build ydb
+
+package ydb
+
+import (
+	"context"
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/filer/abstract_sql"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	environ "github.com/ydb-platform/ydb-go-sdk-auth-environ"
+	"github.com/ydb-platform/ydb-go-sdk/v3"
+	"github.com/ydb-platform/ydb-go-sdk/v3/sugar"
+	"github.com/ydb-platform/ydb-go-sdk/v3/table"
+	"github.com/ydb-platform/ydb-go-sdk/v3/table/result"
+	"github.com/ydb-platform/ydb-go-sdk/v3/table/result/named"
+	"github.com/ydb-platform/ydb-go-sdk/v3/table/types"
+	"os"
+	"path"
+	"strings"
+	"sync"
+	"time"
+)
+
+const (
+	defaultDialTimeOut = 10
+)
+
+var (
+	roTX = table.TxControl(
+		table.BeginTx(table.WithOnlineReadOnly()),
+		table.CommitTx(),
+	)
+	rwTX = table.DefaultTxControl()
+)
+
+type YdbStore struct {
+	DB                 ydb.Connection
+	dirBuckets         string
+	tablePathPrefix    string
+	SupportBucketTable bool
+	dbs                map[string]bool
+	dbsLock            sync.Mutex
+}
+
+func init() {
+	filer.Stores = append(filer.Stores, &YdbStore{})
+}
+
+func (store *YdbStore) GetName() string {
+	return "ydb"
+}
+
+func (store *YdbStore) Initialize(configuration util.Configuration, prefix string) (err error) {
+	return store.initialize(
+		configuration.GetString("filer.options.buckets_folder"),
+		configuration.GetString(prefix+"dsn"),
+		configuration.GetString(prefix+"prefix"),
+		configuration.GetBool(prefix+"useBucketPrefix"),
+		configuration.GetInt(prefix+"dialTimeOut"),
+		configuration.GetInt(prefix+"poolSizeLimit"),
+	)
+}
+
+func (store *YdbStore) initialize(dirBuckets string, dsn string, tablePathPrefix string, useBucketPrefix bool, dialTimeOut int, poolSizeLimit int) (err error) {
+	store.dirBuckets = dirBuckets
+	store.SupportBucketTable = useBucketPrefix
+	if store.SupportBucketTable {
+		glog.V(0).Infof("enabled BucketPrefix")
+	}
+	store.dbs = make(map[string]bool)
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	if dialTimeOut == 0 {
+		dialTimeOut = defaultDialTimeOut
+	}
+	opts := []ydb.Option{
+		ydb.WithDialTimeout(time.Duration(dialTimeOut) * time.Second),
+		environ.WithEnvironCredentials(ctx),
+	}
+	if poolSizeLimit > 0 {
+		opts = append(opts, ydb.WithSessionPoolSizeLimit(poolSizeLimit))
+	}
+	if dsn == "" {
+		dsn = os.Getenv("YDB_CONNECTION_STRING")
+	}
+	store.DB, err = ydb.Open(ctx, dsn, opts...)
+	if err != nil {
+		if store.DB != nil {
+			_ = store.DB.Close(ctx)
+			store.DB = nil
+		}
+		return fmt.Errorf("can not connect to %s error: %v", dsn, err)
+	}
+
+	store.tablePathPrefix = path.Join(store.DB.Name(), tablePathPrefix)
+	if err = sugar.MakeRecursive(ctx, store.DB, store.tablePathPrefix); err != nil {
+		return fmt.Errorf("MakeRecursive %s : %v", store.tablePathPrefix, err)
+	}
+
+	if err = store.createTable(ctx, store.tablePathPrefix); err != nil {
+		glog.Errorf("createTable %s: %v", store.tablePathPrefix, err)
+	}
+	return err
+}
+
+func (store *YdbStore) doTxOrDB(ctx context.Context, query *string, params *table.QueryParameters, tc *table.TransactionControl, processResultFunc func(res result.Result) error) (err error) {
+	var res result.Result
+	if tx, ok := ctx.Value("tx").(table.Transaction); ok {
+		res, err = tx.Execute(ctx, *query, params)
+		if err != nil {
+			return fmt.Errorf("execute transaction: %v", err)
+		}
+	} else {
+		err = store.DB.Table().Do(ctx, func(ctx context.Context, s table.Session) (err error) {
+			_, res, err = s.Execute(ctx, tc, *query, params)
+			if err != nil {
+				return fmt.Errorf("execute statement: %v", err)
+			}
+			return nil
+		})
+	}
+	if err != nil {
+		return err
+	}
+	if res != nil {
+		defer func() { _ = res.Close() }()
+		if processResultFunc != nil {
+			if err = processResultFunc(res); err != nil {
+				return fmt.Errorf("process result: %v", err)
+			}
+		}
+	}
+	return err
+}
+
+func (store *YdbStore) insertOrUpdateEntry(ctx context.Context, entry *filer.Entry) (err error) {
+	dir, name := entry.FullPath.DirAndName()
+	meta, err := entry.EncodeAttributesAndChunks()
+	if err != nil {
+		return fmt.Errorf("encode %s: %s", entry.FullPath, err)
+	}
+
+	if len(entry.Chunks) > filer.CountEntryChunksForGzip {
+		meta = util.MaybeGzipData(meta)
+	}
+	tablePathPrefix, shortDir := store.getPrefix(ctx, &dir)
+	fileMeta := FileMeta{util.HashStringToLong(dir), name, *shortDir, meta}
+	return store.doTxOrDB(ctx, withPragma(tablePathPrefix, upsertQuery), fileMeta.queryParameters(entry.TtlSec), rwTX, nil)
+}
+
+func (store *YdbStore) InsertEntry(ctx context.Context, entry *filer.Entry) (err error) {
+	return store.insertOrUpdateEntry(ctx, entry)
+}
+
+func (store *YdbStore) UpdateEntry(ctx context.Context, entry *filer.Entry) (err error) {
+	return store.insertOrUpdateEntry(ctx, entry)
+}
+
+func (store *YdbStore) FindEntry(ctx context.Context, fullpath util.FullPath) (entry *filer.Entry, err error) {
+	dir, name := fullpath.DirAndName()
+	var data []byte
+	entryFound := false
+	tablePathPrefix, shortDir := store.getPrefix(ctx, &dir)
+	query := withPragma(tablePathPrefix, findQuery)
+	queryParams := table.NewQueryParameters(
+		table.ValueParam("$dir_hash", types.Int64Value(util.HashStringToLong(*shortDir))),
+		table.ValueParam("$name", types.UTF8Value(name)))
+
+	err = store.doTxOrDB(ctx, query, queryParams, roTX, func(res result.Result) error {
+		if !res.NextResultSet(ctx) || !res.HasNextRow() {
+			return nil
+		}
+		for res.NextRow() {
+			if err = res.ScanNamed(named.OptionalWithDefault("meta", &data)); err != nil {
+				return fmt.Errorf("scanNamed %s : %v", fullpath, err)
+			}
+			entryFound = true
+			return nil
+		}
+		return res.Err()
+	})
+	if err != nil {
+		return nil, err
+	}
+	if !entryFound {
+		return nil, filer_pb.ErrNotFound
+	}
+
+	entry = &filer.Entry{
+		FullPath: fullpath,
+	}
+	if err := entry.DecodeAttributesAndChunks(util.MaybeDecompressData(data)); err != nil {
+		return nil, fmt.Errorf("decode %s : %v", fullpath, err)
+	}
+
+	return entry, nil
+}
+
+func (store *YdbStore) DeleteEntry(ctx context.Context, fullpath util.FullPath) (err error) {
+	dir, name := fullpath.DirAndName()
+	tablePathPrefix, shortDir := store.getPrefix(ctx, &dir)
+	query := withPragma(tablePathPrefix, deleteQuery)
+	queryParams := table.NewQueryParameters(
+		table.ValueParam("$dir_hash", types.Int64Value(util.HashStringToLong(*shortDir))),
+		table.ValueParam("$name", types.UTF8Value(name)))
+
+	return store.doTxOrDB(ctx, query, queryParams, rwTX, nil)
+}
+
+func (store *YdbStore) DeleteFolderChildren(ctx context.Context, fullpath util.FullPath) (err error) {
+	dir, _ := fullpath.DirAndName()
+	tablePathPrefix, shortDir := store.getPrefix(ctx, &dir)
+	query := withPragma(tablePathPrefix, deleteFolderChildrenQuery)
+	queryParams := table.NewQueryParameters(
+		table.ValueParam("$dir_hash", types.Int64Value(util.HashStringToLong(*shortDir))),
+		table.ValueParam("$directory", types.UTF8Value(*shortDir)))
+
+	return store.doTxOrDB(ctx, query, queryParams, rwTX, nil)
+}
+
+func (store *YdbStore) ListDirectoryEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, eachEntryFunc filer.ListEachEntryFunc) (lastFileName string, err error) {
+	return store.ListDirectoryPrefixedEntries(ctx, dirPath, startFileName, includeStartFile, limit, "", eachEntryFunc)
+}
+
+func (store *YdbStore) ListDirectoryPrefixedEntries(ctx context.Context, dirPath util.FullPath, startFileName string, includeStartFile bool, limit int64, prefix string, eachEntryFunc filer.ListEachEntryFunc) (lastFileName string, err error) {
+	dir := string(dirPath)
+	tablePathPrefix, shortDir := store.getPrefix(ctx, &dir)
+	var query *string
+	if includeStartFile {
+		query = withPragma(tablePathPrefix, listInclusiveDirectoryQuery)
+	} else {
+		query = withPragma(tablePathPrefix, listDirectoryQuery)
+	}
+	truncated := true
+	eachEntryFuncIsNotBreake := true
+	entryCount := int64(0)
+	for truncated && eachEntryFuncIsNotBreake {
+		if lastFileName != "" {
+			startFileName = lastFileName
+			if includeStartFile {
+				query = withPragma(tablePathPrefix, listDirectoryQuery)
+			}
+		}
+		restLimit := limit - entryCount
+		queryParams := table.NewQueryParameters(
+			table.ValueParam("$dir_hash", types.Int64Value(util.HashStringToLong(*shortDir))),
+			table.ValueParam("$directory", types.UTF8Value(*shortDir)),
+			table.ValueParam("$start_name", types.UTF8Value(startFileName)),
+			table.ValueParam("$prefix", types.UTF8Value(prefix+"%")),
+			table.ValueParam("$limit", types.Uint64Value(uint64(restLimit))),
+		)
+		err = store.doTxOrDB(ctx, query, queryParams, roTX, func(res result.Result) error {
+			var name string
+			var data []byte
+			if !res.NextResultSet(ctx) || !res.HasNextRow() {
+				truncated = false
+				return nil
+			}
+			truncated = res.CurrentResultSet().Truncated()
+			for res.NextRow() {
+				if err := res.ScanNamed(
+					named.OptionalWithDefault("name", &name),
+					named.OptionalWithDefault("meta", &data)); err != nil {
+					return fmt.Errorf("list scanNamed %s : %v", dir, err)
+				}
+				lastFileName = name
+				entry := &filer.Entry{
+					FullPath: util.NewFullPath(dir, name),
+				}
+				if err = entry.DecodeAttributesAndChunks(util.MaybeDecompressData(data)); err != nil {
+					return fmt.Errorf("scan decode %s : %v", entry.FullPath, err)
+				}
+				if !eachEntryFunc(entry) {
+					eachEntryFuncIsNotBreake = false
+					break
+				}
+				entryCount += 1
+			}
+			return res.Err()
+		})
+	}
+	if err != nil {
+		return lastFileName, err
+	}
+	return lastFileName, nil
+}
+
+func (store *YdbStore) BeginTransaction(ctx context.Context) (context.Context, error) {
+	session, err := store.DB.Table().CreateSession(ctx)
+	if err != nil {
+		return ctx, err
+	}
+	tx, err := session.BeginTransaction(ctx, table.TxSettings(table.WithSerializableReadWrite()))
+	if err != nil {
+		return ctx, err
+	}
+	return context.WithValue(ctx, "tx", tx), nil
+}
+
+func (store *YdbStore) CommitTransaction(ctx context.Context) error {
+	if tx, ok := ctx.Value("tx").(table.Transaction); ok {
+		_, err := tx.CommitTx(ctx)
+		return err
+	}
+	return nil
+}
+
+func (store *YdbStore) RollbackTransaction(ctx context.Context) error {
+	if tx, ok := ctx.Value("tx").(table.Transaction); ok {
+		return tx.Rollback(ctx)
+	}
+	return nil
+}
+
+func (store *YdbStore) Shutdown() {
+	_ = store.DB.Close(context.Background())
+}
+
+func (store *YdbStore) CanDropWholeBucket() bool {
+	return store.SupportBucketTable
+}
+
+func (store *YdbStore) OnBucketCreation(bucket string) {
+	store.dbsLock.Lock()
+	defer store.dbsLock.Unlock()
+
+	if err := store.createTable(context.Background(),
+		path.Join(store.tablePathPrefix, bucket)); err != nil {
+		glog.Errorf("createTable %s: %v", bucket, err)
+	}
+
+	if store.dbs == nil {
+		return
+	}
+	store.dbs[bucket] = true
+}
+
+func (store *YdbStore) OnBucketDeletion(bucket string) {
+	store.dbsLock.Lock()
+	defer store.dbsLock.Unlock()
+
+	if err := store.deleteTable(context.Background(),
+		path.Join(store.tablePathPrefix, bucket)); err != nil {
+		glog.Errorf("deleteTable %s: %v", bucket, err)
+	}
+
+	if store.dbs == nil {
+		return
+	}
+	delete(store.dbs, bucket)
+}
+
+func (store *YdbStore) createTable(ctx context.Context, prefix string) error {
+	return store.DB.Table().Do(ctx, func(ctx context.Context, s table.Session) error {
+		return s.CreateTable(ctx, path.Join(prefix, abstract_sql.DEFAULT_TABLE), createTableOptions()...)
+	})
+}
+
+func (store *YdbStore) deleteTable(ctx context.Context, prefix string) error {
+	if !store.SupportBucketTable {
+		return nil
+	}
+	if err := store.DB.Table().Do(ctx, func(ctx context.Context, s table.Session) error {
+		return s.DropTable(ctx, path.Join(prefix, abstract_sql.DEFAULT_TABLE))
+	}); err != nil {
+		return err
+	}
+	glog.V(4).Infof("deleted table %s", prefix)
+
+	return nil
+}
+
+func (store *YdbStore) getPrefix(ctx context.Context, dir *string) (tablePathPrefix *string, shortDir *string) {
+	tablePathPrefix = &store.tablePathPrefix
+	shortDir = dir
+	if !store.SupportBucketTable {
+		return
+	}
+
+	prefixBuckets := store.dirBuckets + "/"
+	if strings.HasPrefix(*dir, prefixBuckets) {
+		// detect bucket
+		bucketAndDir := (*dir)[len(prefixBuckets):]
+		var bucket string
+		if t := strings.Index(bucketAndDir, "/"); t > 0 {
+			bucket = bucketAndDir[:t]
+		} else if t < 0 {
+			bucket = bucketAndDir
+		}
+		if bucket == "" {
+			return
+		}
+
+		store.dbsLock.Lock()
+		defer store.dbsLock.Unlock()
+
+		tablePathPrefixWithBucket := path.Join(store.tablePathPrefix, bucket)
+		if _, found := store.dbs[bucket]; !found {
+			if err := store.createTable(ctx, tablePathPrefixWithBucket); err == nil {
+				store.dbs[bucket] = true
+				glog.V(4).Infof("created table %s", tablePathPrefixWithBucket)
+			} else {
+				glog.Errorf("createTable %s: %v", tablePathPrefixWithBucket, err)
+			}
+		}
+		tablePathPrefix = &tablePathPrefixWithBucket
+	}
+	return
+}
--- a/weed/filer/ydb/ydb_store_kv.go
+++ b/weed/filer/ydb/ydb_store_kv.go
@@ -0,0 +1,75 @@
+//go:build ydb
+// +build ydb
+
+package ydb
+
+import (
+	"context"
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/filer/abstract_sql"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/ydb-platform/ydb-go-sdk/v3/table"
+	"github.com/ydb-platform/ydb-go-sdk/v3/table/result/named"
+	"github.com/ydb-platform/ydb-go-sdk/v3/table/types"
+)
+
+func (store *YdbStore) KvPut(ctx context.Context, key []byte, value []byte) (err error) {
+	dirStr, dirHash, name := abstract_sql.GenDirAndName(key)
+	fileMeta := FileMeta{dirHash, name, dirStr, value}
+	return store.DB.Table().Do(ctx, func(ctx context.Context, s table.Session) (err error) {
+		_, _, err = s.Execute(ctx, rwTX, *withPragma(&store.tablePathPrefix, upsertQuery),
+			fileMeta.queryParameters(0))
+		if err != nil {
+			return fmt.Errorf("kv put execute %s: %v", util.NewFullPath(dirStr, name).Name(), err)
+		}
+		return nil
+	})
+}
+
+func (store *YdbStore) KvGet(ctx context.Context, key []byte) (value []byte, err error) {
+	dirStr, dirHash, name := abstract_sql.GenDirAndName(key)
+	valueFound := false
+	err = store.DB.Table().Do(ctx, func(ctx context.Context, s table.Session) error {
+		_, res, err := s.Execute(ctx, roTX, *withPragma(&store.tablePathPrefix, findQuery),
+			table.NewQueryParameters(
+				table.ValueParam("$dir_hash", types.Int64Value(dirHash)),
+				table.ValueParam("$name", types.UTF8Value(name))))
+		if err != nil {
+			return fmt.Errorf("kv get execute %s: %v", util.NewFullPath(dirStr, name).Name(), err)
+		}
+		defer func() { _ = res.Close() }()
+		if !res.NextResultSet(ctx) || !res.HasNextRow() {
+			return nil
+		}
+		for res.NextRow() {
+			if err := res.ScanNamed(named.OptionalWithDefault("meta", &value)); err != nil {
+				return fmt.Errorf("scanNamed %s : %v", util.NewFullPath(dirStr, name).Name(), err)
+			}
+			valueFound = true
+			return nil
+		}
+		return res.Err()
+	})
+
+	if !valueFound {
+		return nil, filer.ErrKvNotFound
+	}
+
+	return value, nil
+}
+
+func (store *YdbStore) KvDelete(ctx context.Context, key []byte) (err error) {
+	dirStr, dirHash, name := abstract_sql.GenDirAndName(key)
+	return store.DB.Table().Do(ctx, func(ctx context.Context, s table.Session) (err error) {
+		_, _, err = s.Execute(ctx, rwTX, *withPragma(&store.tablePathPrefix, deleteQuery),
+			table.NewQueryParameters(
+				table.ValueParam("$dir_hash", types.Int64Value(dirHash)),
+				table.ValueParam("$name", types.UTF8Value(name))))
+		if err != nil {
+			return fmt.Errorf("kv delete %s: %v", util.NewFullPath(dirStr, name).Name(), err)
+		}
+		return nil
+	})
+
+}
--- a/weed/filer/ydb/ydb_store_test.go
+++ b/weed/filer/ydb/ydb_store_test.go
@@ -0,0 +1,19 @@
+//go:build ydb
+// +build ydb
+
+package ydb
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/filer/store_test"
+	"testing"
+)
+
+func TestStore(t *testing.T) {
+	// run "make test_ydb" under docker folder.
+	// to set up local env
+	if false {
+		store := &YdbStore{}
+		store.initialize("/buckets", "grpc://localhost:2136/?database=local", "seaweedfs", true, 10, 50)
+		store_test.TestFilerStore(t, store)
+	}
+}
--- a/weed/filer/ydb/ydb_types.go
+++ b/weed/filer/ydb/ydb_types.go
@@ -0,0 +1,56 @@
+//go:build ydb
+// +build ydb
+
+package ydb
+
+import (
+	"fmt"
+	"github.com/ydb-platform/ydb-go-sdk/v3/table"
+	"github.com/ydb-platform/ydb-go-sdk/v3/table/options"
+	"github.com/ydb-platform/ydb-go-sdk/v3/table/types"
+)
+
+type FileMeta struct {
+	DirHash   int64  `ydb:"type:int64"`
+	Name      string `ydb:"type:utf8"`
+	Directory string `ydb:"type:utf8"`
+	Meta      []byte `ydb:"type:string"`
+}
+
+type FileMetas []FileMeta
+
+func (fm *FileMeta) queryParameters(ttlSec int32) *table.QueryParameters {
+	var expireAtValue types.Value
+	if ttlSec > 0 {
+		expireAtValue = types.Uint32Value(uint32(ttlSec))
+	} else {
+		expireAtValue = types.NullValue(types.TypeUint32)
+	}
+	return table.NewQueryParameters(
+		table.ValueParam("$dir_hash", types.Int64Value(fm.DirHash)),
+		table.ValueParam("$directory", types.UTF8Value(fm.Directory)),
+		table.ValueParam("$name", types.UTF8Value(fm.Name)),
+		table.ValueParam("$meta", types.StringValue(fm.Meta)),
+		table.ValueParam("$expire_at", expireAtValue))
+}
+
+func createTableOptions() []options.CreateTableOption {
+	columnUnit := options.TimeToLiveUnitSeconds
+	return []options.CreateTableOption{
+		options.WithColumn("dir_hash", types.Optional(types.TypeInt64)),
+		options.WithColumn("directory", types.Optional(types.TypeUTF8)),
+		options.WithColumn("name", types.Optional(types.TypeUTF8)),
+		options.WithColumn("meta", types.Optional(types.TypeString)),
+		options.WithColumn("expire_at", types.Optional(types.TypeUint32)),
+		options.WithPrimaryKeyColumn("dir_hash", "name"),
+		options.WithTimeToLiveSettings(options.TimeToLiveSettings{
+			ColumnName: "expire_at",
+			ColumnUnit: &columnUnit,
+			Mode:       options.TimeToLiveModeValueSinceUnixEpoch},
+		),
+	}
+}
+func withPragma(prefix *string, query string) *string {
+	queryWithPragma := fmt.Sprintf(query, *prefix)
+	return &queryWithPragma
+}