diff --git a/README.md b/README.md
index 5a8436b..9e4ee0a 100644
--- a/README.md
+++ b/README.md
@@ -167,18 +167,9 @@ See [Clients](https://github.com/siddontang/ledisdb/wiki/Clients) to find or con
 + `pcall` and `xpcall` are not supported in lua, you can see the readme in [golua](https://github.com/aarzilli/golua).
 
 
-## Thanks
-
-Gmail: cenqichao@gmail.com
-
-Gmail: chendahui007@gmail.com
-
-Gmail: cppgohan@gmail.com
-
-Gmail: tiaotiaoyly@gmail.com
-
-Gmail: wyk4true@gmail.com
+## Requirement
 
++ go version >= 1.3
 
 ## Feedback
 
diff --git a/config/config.toml b/config/config.toml
index 4e04cb1..98da90e 100644
--- a/config/config.toml
+++ b/config/config.toml
@@ -111,7 +111,7 @@ path = ""
 
 # If sync is true, the new log must be sent to some slaves, and then commit. 
 # It will reduce performance but have better high availability. 
-sync = true
+sync = false
 
 # If sync is true, wait at last wait_sync_time milliseconds for slave syncing this log
 wait_sync_time = 500
diff --git a/etc/ledis.conf b/etc/ledis.conf
index 4e04cb1..98da90e 100644
--- a/etc/ledis.conf
+++ b/etc/ledis.conf
@@ -111,7 +111,7 @@ path = ""
 
 # If sync is true, the new log must be sent to some slaves, and then commit. 
 # It will reduce performance but have better high availability. 
-sync = true
+sync = false
 
 # If sync is true, wait at last wait_sync_time milliseconds for slave syncing this log
 wait_sync_time = 500
diff --git a/ledis/batch.go b/ledis/batch.go
index 171a3ea..c9064df 100644
--- a/ledis/batch.go
+++ b/ledis/batch.go
@@ -100,12 +100,13 @@ type commitDataGetter interface {
 
 func (l *Ledis) handleCommit(g commitDataGetter, c commiter) error {
 	l.commitLock.Lock()
-	defer l.commitLock.Unlock()
 
 	var err error
 	if l.r != nil {
 		var rl *rpl.Log
 		if rl, err = l.r.Log(g.Data()); err != nil {
+			l.commitLock.Unlock()
+
 			log.Fatal("write wal error %s", err.Error())
 			return err
 		}
@@ -113,19 +114,25 @@ func (l *Ledis) handleCommit(g commitDataGetter, c commiter) error {
 		l.propagate(rl)
 
 		if err = c.Commit(); err != nil {
+			l.commitLock.Unlock()
+
 			log.Fatal("commit error %s", err.Error())
 			l.noticeReplication()
 			return err
 		}
 
 		if err = l.r.UpdateCommitID(rl.ID); err != nil {
+			l.commitLock.Unlock()
+
 			log.Fatal("update commit id error %s", err.Error())
 			l.noticeReplication()
 			return err
 		}
-
-		return nil
 	} else {
-		return c.Commit()
+		err = c.Commit()
 	}
+
+	l.commitLock.Unlock()
+
+	return err
 }
diff --git a/rpl/file_store.go b/rpl/file_store.go
index 823b1cd..13d86c8 100644
--- a/rpl/file_store.go
+++ b/rpl/file_store.go
@@ -163,8 +163,12 @@ func (s *FileStore) LastID() (uint64, error) {
 
 func (s *FileStore) StoreLog(l *Log) error {
 	s.wm.Lock()
-	defer s.wm.Unlock()
+	err := s.storeLog(l)
+	s.wm.Unlock()
+	return err
+}
 
+func (s *FileStore) storeLog(l *Log) error {
 	err := s.w.StoreLog(l)
 	if err == nil {
 		return nil
@@ -172,23 +176,24 @@ func (s *FileStore) StoreLog(l *Log) error {
 		return err
 	}
 
-	s.rm.Lock()
-
 	var r *tableReader
-	if r, err = s.w.Flush(); err != nil {
+	r, err = s.w.Flush()
+
+	if err != nil {
 		log.Error("write table flush error %s, can not store now", err.Error())
 
 		s.w.Close()
 
-		s.rm.Unlock()
-
 		return err
 	}
 
+	s.rm.Lock()
 	s.rs = append(s.rs, r)
 	s.rm.Unlock()
 
-	return s.w.StoreLog(l)
+	err = s.w.StoreLog(l)
+
+	return err
 }
 
 func (s *FileStore) PurgeExpired(n int64) error {
diff --git a/rpl/file_table.go b/rpl/file_table.go
index 814475e..7b37cd8 100644
--- a/rpl/file_table.go
+++ b/rpl/file_table.go
@@ -546,13 +546,18 @@ func (t *tableWriter) Flush() (*tableReader, error) {
 }
 
 func (t *tableWriter) StoreLog(l *Log) error {
+	t.Lock()
+	err := t.storeLog(l)
+	t.Unlock()
+
+	return err
+}
+
+func (t *tableWriter) storeLog(l *Log) error {
 	if l.ID == 0 {
 		return ErrStoreLogID
 	}
 
-	t.Lock()
-	defer t.Unlock()
-
 	if t.closed {
 		return fmt.Errorf("table writer is closed")
 	}
@@ -588,9 +593,11 @@ func (t *tableWriter) StoreLog(l *Log) error {
 
 	offsetPos := t.offsetPos
 
-	if err := l.Encode(t.wb); err != nil {
+	if err = l.Encode(t.wb); err != nil {
 		return err
-	} else if err = t.wb.Flush(); err != nil {
+	}
+
+	if err = t.wb.Flush(); err != nil {
 		return err
 	}
 
@@ -652,12 +659,14 @@ func (t *tableWriter) GetLog(id uint64, l *Log) error {
 
 func (t *tableWriter) Sync() error {
 	t.Lock()
-	defer t.Unlock()
 
+	var err error
 	if t.wf != nil {
-		return t.wf.Sync()
+		err = t.wf.Sync()
 	}
-	return nil
+	t.Unlock()
+
+	return err
 }
 
 func (t *tableWriter) getLog(l *Log, pos int64) error {
diff --git a/rpl/log.go b/rpl/log.go
index 8500fbf..0b10fd4 100644
--- a/rpl/log.go
+++ b/rpl/log.go
@@ -4,8 +4,11 @@ import (
 	"bytes"
 	"encoding/binary"
 	"io"
+	"sync"
 )
 
+const LogHeadSize = 17
+
 type Log struct {
 	ID          uint64
 	CreateTime  uint32
@@ -15,7 +18,7 @@ type Log struct {
 }
 
 func (l *Log) HeadSize() int {
-	return 17
+	return LogHeadSize
 }
 
 func (l *Log) Size() int {
@@ -23,7 +26,7 @@ func (l *Log) Size() int {
 }
 
 func (l *Log) Marshal() ([]byte, error) {
-	buf := bytes.NewBuffer(make([]byte, l.HeadSize()+len(l.Data)))
+	buf := bytes.NewBuffer(make([]byte, l.Size()))
 	buf.Reset()
 
 	if err := l.Encode(buf); err != nil {
@@ -39,25 +42,32 @@ func (l *Log) Unmarshal(b []byte) error {
 	return l.Decode(buf)
 }
 
+var headPool = sync.Pool{
+	New: func() interface{} { return make([]byte, LogHeadSize) },
+}
+
 func (l *Log) Encode(w io.Writer) error {
-	if err := binary.Write(w, binary.BigEndian, l.ID); err != nil {
+	b := headPool.Get().([]byte)
+	pos := 0
+
+	binary.BigEndian.PutUint64(b[pos:], l.ID)
+	pos += 8
+	binary.BigEndian.PutUint32(b[pos:], uint32(l.CreateTime))
+	pos += 4
+	b[pos] = l.Compression
+	pos++
+	binary.BigEndian.PutUint32(b[pos:], uint32(len(l.Data)))
+
+	n, err := w.Write(b)
+	headPool.Put(b)
+
+	if err != nil {
 		return err
+	} else if n != LogHeadSize {
+		return io.ErrShortWrite
 	}
 
-	if err := binary.Write(w, binary.BigEndian, l.CreateTime); err != nil {
-		return err
-	}
-
-	if _, err := w.Write([]byte{l.Compression}); err != nil {
-		return err
-	}
-
-	dataLen := uint32(len(l.Data))
-	if err := binary.Write(w, binary.BigEndian, dataLen); err != nil {
-		return err
-	}
-
-	if n, err := w.Write(l.Data); err != nil {
+	if n, err = w.Write(l.Data); err != nil {
 		return err
 	} else if n != len(l.Data) {
 		return io.ErrShortWrite
@@ -86,9 +96,10 @@ func (l *Log) Decode(r io.Reader) error {
 }
 
 func (l *Log) DecodeHead(r io.Reader) (uint32, error) {
-	buf := make([]byte, l.HeadSize())
+	buf := headPool.Get().([]byte)
 
 	if _, err := io.ReadFull(r, buf); err != nil {
+		headPool.Put(buf)
 		return 0, err
 	}
 
@@ -104,5 +115,7 @@ func (l *Log) DecodeHead(r io.Reader) (uint32, error) {
 
 	length := binary.BigEndian.Uint32(buf[pos:])
 
+	headPool.Put(buf)
+
 	return length, nil
 }
diff --git a/rpl/rpl.go b/rpl/rpl.go
index 1e15b6f..d232992 100644
--- a/rpl/rpl.go
+++ b/rpl/rpl.go
@@ -114,10 +114,10 @@ func (r *Replication) Log(data []byte) (*Log, error) {
 	}
 
 	r.m.Lock()
-	defer r.m.Unlock()
 
 	lastID, err := r.s.LastID()
 	if err != nil {
+		r.m.Unlock()
 		return nil, err
 	}
 
@@ -125,6 +125,7 @@ func (r *Replication) Log(data []byte) (*Log, error) {
 	if lastID < commitId {
 		lastID = commitId
 	} else if lastID > commitId {
+		r.m.Unlock()
 		return nil, ErrCommitIDBehind
 	}
 
@@ -141,9 +142,12 @@ func (r *Replication) Log(data []byte) (*Log, error) {
 	l.Data = data
 
 	if err = r.s.StoreLog(l); err != nil {
+		r.m.Unlock()
 		return nil, err
 	}
 
+	r.m.Unlock()
+
 	r.ncm.Lock()
 	close(r.nc)
 	r.nc = make(chan struct{})
@@ -161,22 +165,24 @@ func (r *Replication) WaitLog() <-chan struct{} {
 
 func (r *Replication) StoreLog(log *Log) error {
 	r.m.Lock()
-	defer r.m.Unlock()
+	err := r.s.StoreLog(log)
+	r.m.Unlock()
 
-	return r.s.StoreLog(log)
+	return err
 }
 
 func (r *Replication) FirstLogID() (uint64, error) {
 	r.m.Lock()
-	defer r.m.Unlock()
 	id, err := r.s.FirstID()
+	r.m.Unlock()
+
 	return id, err
 }
 
 func (r *Replication) LastLogID() (uint64, error) {
 	r.m.Lock()
-	defer r.m.Unlock()
 	id, err := r.s.LastID()
+	r.m.Unlock()
 	return id, err
 }
 
@@ -189,9 +195,10 @@ func (r *Replication) LastCommitID() (uint64, error) {
 
 func (r *Replication) UpdateCommitID(id uint64) error {
 	r.m.Lock()
-	defer r.m.Unlock()
+	err := r.updateCommitID(id, r.cfg.Replication.SyncLog == 2)
+	r.m.Unlock()
 
-	return r.updateCommitID(id, r.cfg.Replication.SyncLog == 2)
+	return err
 }
 
 func (r *Replication) Stat() (*Stat, error) {
@@ -231,14 +238,17 @@ func (r *Replication) updateCommitID(id uint64, force bool) error {
 
 func (r *Replication) CommitIDBehind() (bool, error) {
 	r.m.Lock()
-	defer r.m.Unlock()
 
 	id, err := r.s.LastID()
 	if err != nil {
+		r.m.Unlock()
 		return false, err
 	}
 
-	return id > r.commitID, nil
+	behind := id > r.commitID
+	r.m.Unlock()
+
+	return behind, nil
 }
 
 func (r *Replication) GetLog(id uint64, log *Log) error {