Merge dcbe46f0c0 into 6876bfa685

10 years ago · 2fe6f7beda
709 changed files with 186629 additions and 2889 deletions
--- a/.gitignore
+++ b/.gitignore
@ -1,4 +1,4 @@
-go/weed/.goxc*
+weed/weedcmd/.goxc*
 tags
 *.swp
 ### OSX template
@ -75,3 +75,4 @@ crashlytics.properties
 crashlytics-build.properties

 test_data
+bin
--- a/.travis.yml
+++ b/.travis.yml
@ -9,7 +9,7 @@ before_install:
 - export PATH=/home/travis/gopath/bin:$PATH

 install:
- - go get ./go/...
+ - go get ./weed/...

 script:
- - go test ./go/...
+ - go test ./weed/...
--- a/Dockerfile.go_build
+++ b/Dockerfile.go_build
@ -1,5 +1,5 @@
 FROM cydev/go
-RUN go get github.com/chrislusf/seaweedfs/go/weed
+RUN go get github.com/chrislusf/seaweedfs/weed
 EXPOSE 8080
 EXPOSE 9333
 VOLUME /data
--- a/25
+++ b/25
@ -1,22 +1,27 @@
 BINARY = weed
+OUT_DIR = bin

-GO_FLAGS = #-v
-SOURCE_DIR = ./go/weed/
+GO_FLAGS = #-race -v
+SOURCE_DIR = ./weed

 all: build

-.PHONY : clean deps build linux
+.PHONY : clean godep build linux vet

 clean:
 	go clean -i $(GO_FLAGS) $(SOURCE_DIR)
 	rm -f $(BINARY)

-deps:
-	go get $(GO_FLAGS) -d $(SOURCE_DIR)
+fmt:
+	gofmt -w -s $(SOURCE_DIR)

-build: deps
-	go build $(GO_FLAGS) -o $(BINARY) $(SOURCE_DIR)
+vet:
+	go vet $(SOURCE_DIR)/...

-linux: deps
-	mkdir -p linux
-	GOOS=linux GOARCH=amd64 go build $(GO_FLAGS) -o linux/$(BINARY) $(SOURCE_DIR)
+build: fmt
+	mkdir -p $(OUT_DIR)
+	go build $(GO_FLAGS) -o $(OUT_DIR)/$(BINARY) $(SOURCE_DIR)
+
+linux:
+	mkdir -p $(OUT_DIR)/linux-amd64
+	GOOS=linux GOARCH=amd64 go build $(GO_FLAGS) -o $(OUT_DIR)/linux-amd64/$(BINARY) $(SOURCE_DIR)
--- a/README.md
+++ b/README.md
@ -1,7 +1,7 @@
 # SeaweedFS

 [![Build Status](https://travis-ci.org/chrislusf/seaweedfs.svg?branch=master)](https://travis-ci.org/chrislusf/seaweedfs)
-[![GoDoc](https://godoc.org/github.com/chrislusf/seaweedfs/go?status.svg)](https://godoc.org/github.com/chrislusf/seaweedfs/go)
+[![GoDoc](https://godoc.org/github.com/chrislusf/seaweedfs/weed?status.svg)](https://godoc.org/github.com/chrislusf/seaweedfs/weed)
 [![Wiki](https://img.shields.io/badge/docs-wiki-blue.svg)](https://github.com/chrislusf/seaweedfs/wiki)

 ![SeaweedFS Logo](https://raw.githubusercontent.com/chrislusf/seaweedfs/master/note/seaweedfs.png)
@ -287,11 +287,11 @@ http://mercurial.selenic.com/downloads

 step 3: download, compile, and install the project by executing the following command

-go get github.com/chrislusf/seaweedfs/go/weed
+go get github.com/chrislusf/seaweedfs/weed

 once this is done, you should see the executable "weed" under $GOPATH/bin

-step 4: after you modify your code locally, you could start a local build by calling "go install" under $GOPATH/src/github.com/chrislusf/seaweedfs/go/weed
+step 4: after you modify your code locally, you could start a local build by calling "go install" under $GOPATH/src/github.com/chrislusf/seaweedfs/weed

 ## Disk Related topics ##

--- a/go/operation/data_struts.go
+++ b/go/operation/data_struts.go
@ -1,7 +0,0 @@
-package operation
-
-type JoinResult struct {
-	VolumeSizeLimit uint64 `json:"VolumeSizeLimit,omitempty"`
-	SecretKey       string `json:"secretKey,omitempty"`
-	Error           string `json:"error,omitempty"`
-}
--- a/go/operation/system_message.pb.go
+++ b/go/operation/system_message.pb.go
@ -1,203 +0,0 @@
-// Code generated by protoc-gen-go.
-// source: system_message.proto
-// DO NOT EDIT!
-
-/*
-Package operation is a generated protocol buffer package.
-
-It is generated from these files:
-	system_message.proto
-
-It has these top-level messages:
-	VolumeInformationMessage
-	JoinMessage
-*/
-package operation
-
-import proto "github.com/golang/protobuf/proto"
-import math "math"
-
-// Reference imports to suppress errors if they are not otherwise used.
-var _ = proto.Marshal
-var _ = math.Inf
-
-type VolumeInformationMessage struct {
-	Id               *uint32 `protobuf:"varint,1,req,name=id" json:"id,omitempty"`
-	Size             *uint64 `protobuf:"varint,2,req,name=size" json:"size,omitempty"`
-	Collection       *string `protobuf:"bytes,3,opt,name=collection" json:"collection,omitempty"`
-	FileCount        *uint64 `protobuf:"varint,4,req,name=file_count" json:"file_count,omitempty"`
-	DeleteCount      *uint64 `protobuf:"varint,5,req,name=delete_count" json:"delete_count,omitempty"`
-	DeletedByteCount *uint64 `protobuf:"varint,6,req,name=deleted_byte_count" json:"deleted_byte_count,omitempty"`
-	ReadOnly         *bool   `protobuf:"varint,7,opt,name=read_only" json:"read_only,omitempty"`
-	ReplicaPlacement *uint32 `protobuf:"varint,8,req,name=replica_placement" json:"replica_placement,omitempty"`
-	Version          *uint32 `protobuf:"varint,9,opt,name=version,def=2" json:"version,omitempty"`
-	Ttl              *uint32 `protobuf:"varint,10,opt,name=ttl" json:"ttl,omitempty"`
-	XXX_unrecognized []byte  `json:"-"`
-}
-
-func (m *VolumeInformationMessage) Reset()         { *m = VolumeInformationMessage{} }
-func (m *VolumeInformationMessage) String() string { return proto.CompactTextString(m) }
-func (*VolumeInformationMessage) ProtoMessage()    {}
-
-const Default_VolumeInformationMessage_Version uint32 = 2
-
-func (m *VolumeInformationMessage) GetId() uint32 {
-	if m != nil && m.Id != nil {
-		return *m.Id
-	}
-	return 0
-}
-
-func (m *VolumeInformationMessage) GetSize() uint64 {
-	if m != nil && m.Size != nil {
-		return *m.Size
-	}
-	return 0
-}
-
-func (m *VolumeInformationMessage) GetCollection() string {
-	if m != nil && m.Collection != nil {
-		return *m.Collection
-	}
-	return ""
-}
-
-func (m *VolumeInformationMessage) GetFileCount() uint64 {
-	if m != nil && m.FileCount != nil {
-		return *m.FileCount
-	}
-	return 0
-}
-
-func (m *VolumeInformationMessage) GetDeleteCount() uint64 {
-	if m != nil && m.DeleteCount != nil {
-		return *m.DeleteCount
-	}
-	return 0
-}
-
-func (m *VolumeInformationMessage) GetDeletedByteCount() uint64 {
-	if m != nil && m.DeletedByteCount != nil {
-		return *m.DeletedByteCount
-	}
-	return 0
-}
-
-func (m *VolumeInformationMessage) GetReadOnly() bool {
-	if m != nil && m.ReadOnly != nil {
-		return *m.ReadOnly
-	}
-	return false
-}
-
-func (m *VolumeInformationMessage) GetReplicaPlacement() uint32 {
-	if m != nil && m.ReplicaPlacement != nil {
-		return *m.ReplicaPlacement
-	}
-	return 0
-}
-
-func (m *VolumeInformationMessage) GetVersion() uint32 {
-	if m != nil && m.Version != nil {
-		return *m.Version
-	}
-	return Default_VolumeInformationMessage_Version
-}
-
-func (m *VolumeInformationMessage) GetTtl() uint32 {
-	if m != nil && m.Ttl != nil {
-		return *m.Ttl
-	}
-	return 0
-}
-
-type JoinMessage struct {
-	IsInit           *bool                       `protobuf:"varint,1,opt,name=is_init" json:"is_init,omitempty"`
-	Ip               *string                     `protobuf:"bytes,2,req,name=ip" json:"ip,omitempty"`
-	Port             *uint32                     `protobuf:"varint,3,req,name=port" json:"port,omitempty"`
-	PublicUrl        *string                     `protobuf:"bytes,4,opt,name=public_url" json:"public_url,omitempty"`
-	MaxVolumeCount   *uint32                     `protobuf:"varint,5,req,name=max_volume_count" json:"max_volume_count,omitempty"`
-	MaxFileKey       *uint64                     `protobuf:"varint,6,req,name=max_file_key" json:"max_file_key,omitempty"`
-	DataCenter       *string                     `protobuf:"bytes,7,opt,name=data_center" json:"data_center,omitempty"`
-	Rack             *string                     `protobuf:"bytes,8,opt,name=rack" json:"rack,omitempty"`
-	Volumes          []*VolumeInformationMessage `protobuf:"bytes,9,rep,name=volumes" json:"volumes,omitempty"`
-	AdminPort        *uint32                     `protobuf:"varint,10,opt,name=admin_port" json:"admin_port,omitempty"`
-	XXX_unrecognized []byte                      `json:"-"`
-}
-
-func (m *JoinMessage) Reset()         { *m = JoinMessage{} }
-func (m *JoinMessage) String() string { return proto.CompactTextString(m) }
-func (*JoinMessage) ProtoMessage()    {}
-
-func (m *JoinMessage) GetIsInit() bool {
-	if m != nil && m.IsInit != nil {
-		return *m.IsInit
-	}
-	return false
-}
-
-func (m *JoinMessage) GetIp() string {
-	if m != nil && m.Ip != nil {
-		return *m.Ip
-	}
-	return ""
-}
-
-func (m *JoinMessage) GetPort() uint32 {
-	if m != nil && m.Port != nil {
-		return *m.Port
-	}
-	return 0
-}
-
-func (m *JoinMessage) GetPublicUrl() string {
-	if m != nil && m.PublicUrl != nil {
-		return *m.PublicUrl
-	}
-	return ""
-}
-
-func (m *JoinMessage) GetMaxVolumeCount() uint32 {
-	if m != nil && m.MaxVolumeCount != nil {
-		return *m.MaxVolumeCount
-	}
-	return 0
-}
-
-func (m *JoinMessage) GetMaxFileKey() uint64 {
-	if m != nil && m.MaxFileKey != nil {
-		return *m.MaxFileKey
-	}
-	return 0
-}
-
-func (m *JoinMessage) GetDataCenter() string {
-	if m != nil && m.DataCenter != nil {
-		return *m.DataCenter
-	}
-	return ""
-}
-
-func (m *JoinMessage) GetRack() string {
-	if m != nil && m.Rack != nil {
-		return *m.Rack
-	}
-	return ""
-}
-
-func (m *JoinMessage) GetVolumes() []*VolumeInformationMessage {
-	if m != nil {
-		return m.Volumes
-	}
-	return nil
-}
-
-func (m *JoinMessage) GetAdminPort() uint32 {
-	if m != nil && m.AdminPort != nil {
-		return *m.AdminPort
-	}
-	return 0
-}
-
-func init() {
-}
--- a/go/proto/system_message.proto
+++ b/go/proto/system_message.proto
@ -1,27 +0,0 @@
-package operation;
-
-message VolumeInformationMessage {
-  required uint32 id = 1;
-  required uint64 size = 2;
-  optional string collection = 3;
-  required uint64 file_count = 4;
-  required uint64 delete_count = 5;
-  required uint64 deleted_byte_count = 6;
-  optional bool read_only = 7;
-  required uint32 replica_placement = 8;
-  optional uint32 version = 9 [default=2];
-  optional uint32 ttl = 10;
-}
-
-message JoinMessage {
-  optional bool   is_init = 1;
-  required string ip = 2;
-  required uint32 port = 3;
-  optional string public_url = 4;
-  required uint32 max_volume_count = 5;
-  required uint64 max_file_key = 6;
-  optional string data_center = 7;
-  optional string rack = 8;
-  repeated VolumeInformationMessage volumes = 9;
-  optional uint32 admin_port = 10;
-}
--- a/go/stats/stats.go
+++ b/go/stats/stats.go
@ -1,113 +0,0 @@
-package stats
-
-import (
-	"time"
-)
-
-type ServerStats struct {
-	Requests       *DurationCounter
-	Connections    *DurationCounter
-	AssignRequests *DurationCounter
-	ReadRequests   *DurationCounter
-	WriteRequests  *DurationCounter
-	DeleteRequests *DurationCounter
-	BytesIn        *DurationCounter
-	BytesOut       *DurationCounter
-}
-
-type Channels struct {
-	Connections    chan *TimedValue
-	Requests       chan *TimedValue
-	AssignRequests chan *TimedValue
-	ReadRequests   chan *TimedValue
-	WriteRequests  chan *TimedValue
-	DeleteRequests chan *TimedValue
-	BytesIn        chan *TimedValue
-	BytesOut       chan *TimedValue
-}
-
-var (
-	Chan *Channels
-)
-
-func init() {
-	Chan = &Channels{
-		Connections:    make(chan *TimedValue, 100),
-		Requests:       make(chan *TimedValue, 100),
-		AssignRequests: make(chan *TimedValue, 100),
-		ReadRequests:   make(chan *TimedValue, 100),
-		WriteRequests:  make(chan *TimedValue, 100),
-		DeleteRequests: make(chan *TimedValue, 100),
-		BytesIn:        make(chan *TimedValue, 100),
-		BytesOut:       make(chan *TimedValue, 100),
-	}
-}
-
-func NewServerStats() *ServerStats {
-	return &ServerStats{
-		Requests:       NewDurationCounter(),
-		Connections:    NewDurationCounter(),
-		AssignRequests: NewDurationCounter(),
-		ReadRequests:   NewDurationCounter(),
-		WriteRequests:  NewDurationCounter(),
-		DeleteRequests: NewDurationCounter(),
-		BytesIn:        NewDurationCounter(),
-		BytesOut:       NewDurationCounter(),
-	}
-}
-
-func ConnectionOpen() {
-	Chan.Connections <- NewTimedValue(time.Now(), 1)
-}
-func ConnectionClose() {
-	Chan.Connections <- NewTimedValue(time.Now(), -1)
-}
-func RequestOpen() {
-	Chan.Requests <- NewTimedValue(time.Now(), 1)
-}
-func RequestClose() {
-	Chan.Requests <- NewTimedValue(time.Now(), -1)
-}
-func AssignRequest() {
-	Chan.AssignRequests <- NewTimedValue(time.Now(), 1)
-}
-func ReadRequest() {
-	Chan.ReadRequests <- NewTimedValue(time.Now(), 1)
-}
-func WriteRequest() {
-	Chan.WriteRequests <- NewTimedValue(time.Now(), 1)
-}
-func DeleteRequest() {
-	Chan.DeleteRequests <- NewTimedValue(time.Now(), 1)
-}
-func BytesIn(val int64) {
-	Chan.BytesIn <- NewTimedValue(time.Now(), val)
-}
-func BytesOut(val int64) {
-	Chan.BytesOut <- NewTimedValue(time.Now(), val)
-}
-
-func (ss *ServerStats) Start() {
-	for {
-		select {
-		case tv := <-Chan.Connections:
-			ss.Connections.Add(tv)
-		case tv := <-Chan.Requests:
-			ss.Requests.Add(tv)
-		case tv := <-Chan.AssignRequests:
-			ss.AssignRequests.Add(tv)
-		case tv := <-Chan.ReadRequests:
-			ss.ReadRequests.Add(tv)
-		case tv := <-Chan.WriteRequests:
-			ss.WriteRequests.Add(tv)
-		case tv := <-Chan.ReadRequests:
-			ss.ReadRequests.Add(tv)
-		case tv := <-Chan.DeleteRequests:
-			ss.DeleteRequests.Add(tv)
-		case tv := <-Chan.BytesIn:
-			ss.BytesIn.Add(tv)
-		case tv := <-Chan.BytesOut:
-			ss.BytesOut.Add(tv)
-		}
-	}
-}
--- a/go/storage/needle_map.go
+++ b/go/storage/needle_map.go
@ -1,123 +0,0 @@
-package storage
-
-import (
-	"fmt"
-	"io/ioutil"
-	"os"
-	"sync"
-
-	"github.com/chrislusf/seaweedfs/go/util"
-)
-
-type NeedleMapType int
-
-const (
-	NeedleMapInMemory NeedleMapType = iota
-	NeedleMapLevelDb
-	NeedleMapBoltDb
-)
-
-type NeedleMapper interface {
-	Put(key uint64, offset uint32, size uint32) error
-	Get(key uint64) (element *NeedleValue, ok bool)
-	Delete(key uint64) error
-	Close()
-	Destroy() error
-	ContentSize() uint64
-	DeletedSize() uint64
-	FileCount() int
-	DeletedCount() int
-	MaxFileKey() uint64
-	IndexFileSize() uint64
-	IndexFileContent() ([]byte, error)
-	IndexFileName() string
-}
-
-type baseNeedleMapper struct {
-	indexFile           *os.File
-	indexFileAccessLock sync.Mutex
-
-	mapMetric
-}
-
-func (nm baseNeedleMapper) IndexFileSize() uint64 {
-	stat, err := nm.indexFile.Stat()
-	if err == nil {
-		return uint64(stat.Size())
-	}
-	return 0
-}
-
-func (nm baseNeedleMapper) IndexFileName() string {
-	return nm.indexFile.Name()
-}
-
-func idxFileEntry(bytes []byte) (key uint64, offset uint32, size uint32) {
-	key = util.BytesToUint64(bytes[:8])
-	offset = util.BytesToUint32(bytes[8:12])
-	size = util.BytesToUint32(bytes[12:16])
-	return
-}
-func (nm baseNeedleMapper) appendToIndexFile(key uint64, offset uint32, size uint32) error {
-	bytes := make([]byte, 16)
-	util.Uint64toBytes(bytes[0:8], key)
-	util.Uint32toBytes(bytes[8:12], offset)
-	util.Uint32toBytes(bytes[12:16], size)
-
-	nm.indexFileAccessLock.Lock()
-	defer nm.indexFileAccessLock.Unlock()
-	if _, err := nm.indexFile.Seek(0, 2); err != nil {
-		return fmt.Errorf("cannot seek end of indexfile %s: %v",
-			nm.indexFile.Name(), err)
-	}
-	_, err := nm.indexFile.Write(bytes)
-	return err
-}
-func (nm baseNeedleMapper) IndexFileContent() ([]byte, error) {
-	nm.indexFileAccessLock.Lock()
-	defer nm.indexFileAccessLock.Unlock()
-	return ioutil.ReadFile(nm.indexFile.Name())
-}
-
-type mapMetric struct {
-	indexFile *os.File
-
-	DeletionCounter     int    `json:"DeletionCounter"`
-	FileCounter         int    `json:"FileCounter"`
-	DeletionByteCounter uint64 `json:"DeletionByteCounter"`
-	FileByteCounter     uint64 `json:"FileByteCounter"`
-	MaximumFileKey      uint64 `json:"MaxFileKey"`
-}
-
-func (mm *mapMetric) logDelete(deletedByteCount uint32) {
-	mm.DeletionByteCounter = mm.DeletionByteCounter + uint64(deletedByteCount)
-	mm.DeletionCounter++
-}
-
-func (mm *mapMetric) logPut(key uint64, oldSize uint32, newSize uint32) {
-	if key > mm.MaximumFileKey {
-		mm.MaximumFileKey = key
-	}
-	mm.FileCounter++
-	mm.FileByteCounter = mm.FileByteCounter + uint64(newSize)
-	if oldSize > 0 {
-		mm.DeletionCounter++
-		mm.DeletionByteCounter = mm.DeletionByteCounter + uint64(oldSize)
-	}
-}
-
-func (mm mapMetric) ContentSize() uint64 {
-	return mm.FileByteCounter
-}
-func (mm mapMetric) DeletedSize() uint64 {
-	return mm.DeletionByteCounter
-}
-func (mm mapMetric) FileCount() int {
-	return mm.FileCounter
-}
-func (mm mapMetric) DeletedCount() int {
-	return mm.DeletionCounter
-}
-func (mm mapMetric) MaxFileKey() uint64 {
-	return mm.MaximumFileKey
-}
--- a/go/storage/store.go
+++ b/go/storage/store.go
@ -1,389 +0,0 @@
-package storage
-
-import (
-	"encoding/json"
-	"errors"
-	"fmt"
-	"io/ioutil"
-	"math/rand"
-	"strconv"
-	"strings"
-
-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/operation"
-	"github.com/chrislusf/seaweedfs/go/security"
-	"github.com/chrislusf/seaweedfs/go/util"
-	"github.com/golang/protobuf/proto"
-)
-
-const (
-	MAX_TTL_VOLUME_REMOVAL_DELAY = 10 // 10 minutes
-)
-
-type DiskLocation struct {
-	Directory      string
-	MaxVolumeCount int
-	volumes        map[VolumeId]*Volume
-}
-
-func (mn *DiskLocation) reset() {
-}
-
-type MasterNodes struct {
-	nodes    []string
-	lastNode int
-}
-
-func (mn *MasterNodes) String() string {
-	return fmt.Sprintf("nodes:%v, lastNode:%d", mn.nodes, mn.lastNode)
-}
-
-func NewMasterNodes(bootstrapNode string) (mn *MasterNodes) {
-	mn = &MasterNodes{nodes: []string{bootstrapNode}, lastNode: -1}
-	return
-}
-func (mn *MasterNodes) reset() {
-	glog.V(4).Infof("Resetting master nodes: %v", mn)
-	if len(mn.nodes) > 1 && mn.lastNode >= 0 {
-		glog.V(0).Infof("Reset master %s from: %v", mn.nodes[mn.lastNode], mn.nodes)
-		mn.lastNode = -mn.lastNode - 1
-	}
-}
-func (mn *MasterNodes) findMaster() (string, error) {
-	if len(mn.nodes) == 0 {
-		return "", errors.New("No master node found!")
-	}
-	if mn.lastNode < 0 {
-		for _, m := range mn.nodes {
-			glog.V(4).Infof("Listing masters on %s", m)
-			if masters, e := operation.ListMasters(m); e == nil {
-				if len(masters) == 0 {
-					continue
-				}
-				mn.nodes = append(masters, m)
-				mn.lastNode = rand.Intn(len(mn.nodes))
-				glog.V(2).Infof("current master nodes is %v", mn)
-				break
-			} else {
-				glog.V(4).Infof("Failed listing masters on %s: %v", m, e)
-			}
-		}
-	}
-	if mn.lastNode < 0 {
-		return "", errors.New("No master node available!")
-	}
-	return mn.nodes[mn.lastNode], nil
-}
-
-/*
- * A VolumeServer contains one Store
- */
-type Store struct {
-	Ip              string
-	Port            int
-	PublicUrl       string
-	Locations       []*DiskLocation
-	dataCenter      string //optional informaton, overwriting master setting if exists
-	rack            string //optional information, overwriting master setting if exists
-	connected       bool
-	volumeSizeLimit uint64 //read from the master
-	masterNodes     *MasterNodes
-}
-
-func (s *Store) String() (str string) {
-	str = fmt.Sprintf("Ip:%s, Port:%d, PublicUrl:%s, dataCenter:%s, rack:%s, connected:%v, volumeSizeLimit:%d, masterNodes:%s", s.Ip, s.Port, s.PublicUrl, s.dataCenter, s.rack, s.connected, s.volumeSizeLimit, s.masterNodes)
-	return
-}
-
-func NewStore(port int, ip, publicUrl string, dirnames []string, maxVolumeCounts []int, needleMapKind NeedleMapType) (s *Store) {
-	s = &Store{Port: port, Ip: ip, PublicUrl: publicUrl}
-	s.Locations = make([]*DiskLocation, 0)
-	for i := 0; i < len(dirnames); i++ {
-		location := &DiskLocation{Directory: dirnames[i], MaxVolumeCount: maxVolumeCounts[i]}
-		location.volumes = make(map[VolumeId]*Volume)
-		location.loadExistingVolumes(needleMapKind)
-		s.Locations = append(s.Locations, location)
-	}
-	return
-}
-func (s *Store) AddVolume(volumeListString string, collection string, needleMapKind NeedleMapType, replicaPlacement string, ttlString string) error {
-	rt, e := NewReplicaPlacementFromString(replicaPlacement)
-	if e != nil {
-		return e
-	}
-	ttl, e := ReadTTL(ttlString)
-	if e != nil {
-		return e
-	}
-	for _, range_string := range strings.Split(volumeListString, ",") {
-		if strings.Index(range_string, "-") < 0 {
-			id_string := range_string
-			id, err := NewVolumeId(id_string)
-			if err != nil {
-				return fmt.Errorf("Volume Id %s is not a valid unsigned integer!", id_string)
-			}
-			e = s.addVolume(VolumeId(id), collection, needleMapKind, rt, ttl)
-		} else {
-			pair := strings.Split(range_string, "-")
-			start, start_err := strconv.ParseUint(pair[0], 10, 64)
-			if start_err != nil {
-				return fmt.Errorf("Volume Start Id %s is not a valid unsigned integer!", pair[0])
-			}
-			end, end_err := strconv.ParseUint(pair[1], 10, 64)
-			if end_err != nil {
-				return fmt.Errorf("Volume End Id %s is not a valid unsigned integer!", pair[1])
-			}
-			for id := start; id <= end; id++ {
-				if err := s.addVolume(VolumeId(id), collection, needleMapKind, rt, ttl); err != nil {
-					e = err
-				}
-			}
-		}
-	}
-	return e
-}
-func (s *Store) DeleteCollection(collection string) (e error) {
-	for _, location := range s.Locations {
-		for k, v := range location.volumes {
-			if v.Collection == collection {
-				e = v.Destroy()
-				if e != nil {
-					return
-				}
-				delete(location.volumes, k)
-			}
-		}
-	}
-	return
-}
-func (s *Store) DeleteVolume(volumes map[VolumeId]*Volume, v *Volume) (e error) {
-	e = v.Destroy()
-	if e != nil {
-		return
-	}
-	delete(volumes, v.Id)
-	return
-}
-func (s *Store) findVolume(vid VolumeId) *Volume {
-	for _, location := range s.Locations {
-		if v, found := location.volumes[vid]; found {
-			return v
-		}
-	}
-	return nil
-}
-func (s *Store) findFreeLocation() (ret *DiskLocation) {
-	max := 0
-	for _, location := range s.Locations {
-		currentFreeCount := location.MaxVolumeCount - len(location.volumes)
-		if currentFreeCount > max {
-			max = currentFreeCount
-			ret = location
-		}
-	}
-	return ret
-}
-func (s *Store) addVolume(vid VolumeId, collection string, needleMapKind NeedleMapType, replicaPlacement *ReplicaPlacement, ttl *TTL) error {
-	if s.findVolume(vid) != nil {
-		return fmt.Errorf("Volume Id %d already exists!", vid)
-	}
-	if location := s.findFreeLocation(); location != nil {
-		glog.V(0).Infof("In dir %s adds volume:%v collection:%s replicaPlacement:%v ttl:%v",
-			location.Directory, vid, collection, replicaPlacement, ttl)
-		if volume, err := NewVolume(location.Directory, collection, vid, needleMapKind, replicaPlacement, ttl); err == nil {
-			location.volumes[vid] = volume
-			return nil
-		} else {
-			return err
-		}
-	}
-	return fmt.Errorf("No more free space left")
-}
-
-func (l *DiskLocation) loadExistingVolumes(needleMapKind NeedleMapType) {
-	if dirs, err := ioutil.ReadDir(l.Directory); err == nil {
-		for _, dir := range dirs {
-			name := dir.Name()
-			if !dir.IsDir() && strings.HasSuffix(name, ".dat") {
-				collection := ""
-				base := name[:len(name)-len(".dat")]
-				i := strings.LastIndex(base, "_")
-				if i > 0 {
-					collection, base = base[0:i], base[i+1:]
-				}
-				if vid, err := NewVolumeId(base); err == nil {
-					if l.volumes[vid] == nil {
-						if v, e := NewVolume(l.Directory, collection, vid, needleMapKind, nil, nil); e == nil {
-							l.volumes[vid] = v
-							glog.V(0).Infof("data file %s, replicaPlacement=%s v=%d size=%d ttl=%s", l.Directory+"/"+name, v.ReplicaPlacement, v.Version(), v.Size(), v.Ttl.String())
-						} else {
-							glog.V(0).Infof("new volume %s error %s", name, e)
-						}
-					}
-				}
-			}
-		}
-	}
-	glog.V(0).Infoln("Store started on dir:", l.Directory, "with", len(l.volumes), "volumes", "max", l.MaxVolumeCount)
-}
-func (s *Store) Status() []*VolumeInfo {
-	var stats []*VolumeInfo
-	for _, location := range s.Locations {
-		for k, v := range location.volumes {
-			s := &VolumeInfo{
-				Id:               VolumeId(k),
-				Size:             v.ContentSize(),
-				Collection:       v.Collection,
-				ReplicaPlacement: v.ReplicaPlacement,
-				Version:          v.Version(),
-				FileCount:        v.nm.FileCount(),
-				DeleteCount:      v.nm.DeletedCount(),
-				DeletedByteCount: v.nm.DeletedSize(),
-				ReadOnly:         v.readOnly,
-				Ttl:              v.Ttl}
-			stats = append(stats, s)
-		}
-	}
-	sortVolumeInfos(stats)
-	return stats
-}
-
-func (s *Store) SetDataCenter(dataCenter string) {
-	s.dataCenter = dataCenter
-}
-func (s *Store) SetRack(rack string) {
-	s.rack = rack
-}
-
-func (s *Store) SetBootstrapMaster(bootstrapMaster string) {
-	s.masterNodes = NewMasterNodes(bootstrapMaster)
-}
-func (s *Store) SendHeartbeatToMaster() (masterNode string, secretKey security.Secret, e error) {
-	masterNode, e = s.masterNodes.findMaster()
-	if e != nil {
-		return
-	}
-	var volumeMessages []*operation.VolumeInformationMessage
-	maxVolumeCount := 0
-	var maxFileKey uint64
-	for _, location := range s.Locations {
-		maxVolumeCount = maxVolumeCount + location.MaxVolumeCount
-		for k, v := range location.volumes {
-			if maxFileKey < v.nm.MaxFileKey() {
-				maxFileKey = v.nm.MaxFileKey()
-			}
-			if !v.expired(s.volumeSizeLimit) {
-				volumeMessage := &operation.VolumeInformationMessage{
-					Id:               proto.Uint32(uint32(k)),
-					Size:             proto.Uint64(uint64(v.Size())),
-					Collection:       proto.String(v.Collection),
-					FileCount:        proto.Uint64(uint64(v.nm.FileCount())),
-					DeleteCount:      proto.Uint64(uint64(v.nm.DeletedCount())),
-					DeletedByteCount: proto.Uint64(v.nm.DeletedSize()),
-					ReadOnly:         proto.Bool(v.readOnly),
-					ReplicaPlacement: proto.Uint32(uint32(v.ReplicaPlacement.Byte())),
-					Version:          proto.Uint32(uint32(v.Version())),
-					Ttl:              proto.Uint32(v.Ttl.ToUint32()),
-				}
-				volumeMessages = append(volumeMessages, volumeMessage)
-			} else {
-				if v.exiredLongEnough(MAX_TTL_VOLUME_REMOVAL_DELAY) {
-					s.DeleteVolume(location.volumes, v)
-					glog.V(0).Infoln("volume", v.Id, "is deleted.")
-				} else {
-					glog.V(0).Infoln("volume", v.Id, "is expired.")
-				}
-			}
-		}
-	}
-
-	joinMessage := &operation.JoinMessage{
-		IsInit:         proto.Bool(!s.connected),
-		Ip:             proto.String(s.Ip),
-		Port:           proto.Uint32(uint32(s.Port)),
-		PublicUrl:      proto.String(s.PublicUrl),
-		MaxVolumeCount: proto.Uint32(uint32(maxVolumeCount)),
-		MaxFileKey:     proto.Uint64(maxFileKey),
-		DataCenter:     proto.String(s.dataCenter),
-		Rack:           proto.String(s.rack),
-		Volumes:        volumeMessages,
-	}
-
-	data, err := proto.Marshal(joinMessage)
-	if err != nil {
-		return "", "", err
-	}
-
-	joinUrl := "http://" + masterNode + "/dir/join"
-	glog.V(4).Infof("Connecting to %s ...", joinUrl)
-
-	jsonBlob, err := util.PostBytes(joinUrl, data)
-	if err != nil {
-		s.masterNodes.reset()
-		return "", "", err
-	}
-	var ret operation.JoinResult
-	if err := json.Unmarshal(jsonBlob, &ret); err != nil {
-		glog.V(0).Infof("Failed to join %s with response: %s", joinUrl, string(jsonBlob))
-		s.masterNodes.reset()
-		return masterNode, "", err
-	}
-	if ret.Error != "" {
-		s.masterNodes.reset()
-		return masterNode, "", errors.New(ret.Error)
-	}
-	s.volumeSizeLimit = ret.VolumeSizeLimit
-	secretKey = security.Secret(ret.SecretKey)
-	s.connected = true
-	return
-}
-func (s *Store) Close() {
-	for _, location := range s.Locations {
-		for _, v := range location.volumes {
-			v.Close()
-		}
-	}
-}
-func (s *Store) Write(i VolumeId, n *Needle) (size uint32, err error) {
-	if v := s.findVolume(i); v != nil {
-		if v.readOnly {
-			err = fmt.Errorf("Volume %d is read only", i)
-			return
-		}
-		if MaxPossibleVolumeSize >= v.ContentSize()+uint64(size) {
-			size, err = v.write(n)
-		} else {
-			err = fmt.Errorf("Volume Size Limit %d Exceeded! Current size is %d", s.volumeSizeLimit, v.ContentSize())
-		}
-		if s.volumeSizeLimit < v.ContentSize()+3*uint64(size) {
-			glog.V(0).Infoln("volume", i, "size", v.ContentSize(), "will exceed limit", s.volumeSizeLimit)
-			if _, _, e := s.SendHeartbeatToMaster(); e != nil {
-				glog.V(0).Infoln("error when reporting size:", e)
-			}
-		}
-		return
-	}
-	glog.V(0).Infoln("volume", i, "not found!")
-	err = fmt.Errorf("Volume %d not found!", i)
-	return
-}
-func (s *Store) Delete(i VolumeId, n *Needle) (uint32, error) {
-	if v := s.findVolume(i); v != nil && !v.readOnly {
-		return v.delete(n)
-	}
-	return 0, nil
-}
-func (s *Store) ReadVolumeNeedle(i VolumeId, n *Needle) (int, error) {
-	if v := s.findVolume(i); v != nil {
-		return v.readNeedle(n)
-	}
-	return 0, fmt.Errorf("Volume %v not found!", i)
-}
-func (s *Store) GetVolume(i VolumeId) *Volume {
-	return s.findVolume(i)
-}
-
-func (s *Store) HasVolume(i VolumeId) bool {
-	v := s.findVolume(i)
-	return v != nil
-}
--- a/go/storage/volume_info.go
+++ b/go/storage/volume_info.go
@ -1,65 +0,0 @@
-package storage
-
-import (
-	"fmt"
-	"github.com/chrislusf/seaweedfs/go/operation"
-	"sort"
-)
-
-type VolumeInfo struct {
-	Id               VolumeId
-	Size             uint64
-	ReplicaPlacement *ReplicaPlacement
-	Ttl              *TTL
-	Collection       string
-	Version          Version
-	FileCount        int
-	DeleteCount      int
-	DeletedByteCount uint64
-	ReadOnly         bool
-}
-
-func NewVolumeInfo(m *operation.VolumeInformationMessage) (vi VolumeInfo, err error) {
-	vi = VolumeInfo{
-		Id:               VolumeId(*m.Id),
-		Size:             *m.Size,
-		Collection:       *m.Collection,
-		FileCount:        int(*m.FileCount),
-		DeleteCount:      int(*m.DeleteCount),
-		DeletedByteCount: *m.DeletedByteCount,
-		ReadOnly:         *m.ReadOnly,
-		Version:          Version(*m.Version),
-	}
-	rp, e := NewReplicaPlacementFromByte(byte(*m.ReplicaPlacement))
-	if e != nil {
-		return vi, e
-	}
-	vi.ReplicaPlacement = rp
-	vi.Ttl = LoadTTLFromUint32(*m.Ttl)
-	return vi, nil
-}
-
-func (vi VolumeInfo) String() string {
-	return fmt.Sprintf("Id:%d, Size:%d, ReplicaPlacement:%s, Collection:%s, Version:%v, FileCount:%d, DeleteCount:%d, DeletedByteCount:%d, ReadOnly:%v",
-		vi.Id, vi.Size, vi.ReplicaPlacement, vi.Collection, vi.Version, vi.FileCount, vi.DeleteCount, vi.DeletedByteCount, vi.ReadOnly)
-}
-
-/*VolumesInfo sorting*/
-
-type volumeInfos []*VolumeInfo
-
-func (vis volumeInfos) Len() int {
-	return len(vis)
-}
-
-func (vis volumeInfos) Less(i, j int) bool {
-	return vis[i].Id < vis[j].Id
-}
-
-func (vis volumeInfos) Swap(i, j int) {
-	vis[i], vis[j] = vis[j], vis[i]
-}
-
-func sortVolumeInfos(vis volumeInfos) {
-	sort.Sort(vis)
-}
--- a/go/topology/collection.go
+++ b/go/topology/collection.go
@ -1,57 +0,0 @@
-package topology
-
-import (
-	"fmt"
-
-	"github.com/chrislusf/seaweedfs/go/storage"
-	"github.com/chrislusf/seaweedfs/go/util"
-)
-
-type Collection struct {
-	Name                     string
-	volumeSizeLimit          uint64
-	storageType2VolumeLayout *util.ConcurrentReadMap
-}
-
-func NewCollection(name string, volumeSizeLimit uint64) *Collection {
-	c := &Collection{Name: name, volumeSizeLimit: volumeSizeLimit}
-	c.storageType2VolumeLayout = util.NewConcurrentReadMap()
-	return c
-}
-
-func (c *Collection) String() string {
-	return fmt.Sprintf("Name:%s, volumeSizeLimit:%d, storageType2VolumeLayout:%v", c.Name, c.volumeSizeLimit, c.storageType2VolumeLayout)
-}
-
-func (c *Collection) GetOrCreateVolumeLayout(rp *storage.ReplicaPlacement, ttl *storage.TTL) *VolumeLayout {
-	keyString := rp.String()
-	if ttl != nil {
-		keyString += ttl.String()
-	}
-	vl := c.storageType2VolumeLayout.Get(keyString, func() interface{} {
-		return NewVolumeLayout(rp, ttl, c.volumeSizeLimit)
-	})
-	return vl.(*VolumeLayout)
-}
-
-func (c *Collection) Lookup(vid storage.VolumeId) []*DataNode {
-	for _, vl := range c.storageType2VolumeLayout.Items {
-		if vl != nil {
-			if list := vl.(*VolumeLayout).Lookup(vid); list != nil {
-				return list
-			}
-		}
-	}
-	return nil
-}
-
-func (c *Collection) ListVolumeServers() (nodes []*DataNode) {
-	for _, vl := range c.storageType2VolumeLayout.Items {
-		if vl != nil {
-			if list := vl.(*VolumeLayout).ListVolumeServers(); list != nil {
-				nodes = append(nodes, list...)
-			}
-		}
-	}
-	return
-}
--- a/go/topology/data_node.go
+++ b/go/topology/data_node.go
@ -1,100 +0,0 @@
-package topology
-
-import (
-	"fmt"
-	"strconv"
-
-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/storage"
-)
-
-type DataNode struct {
-	NodeImpl
-	volumes   map[storage.VolumeId]storage.VolumeInfo
-	Ip        string
-	Port      int
-	PublicUrl string
-	LastSeen  int64 // unix time in seconds
-	Dead      bool
-}
-
-func NewDataNode(id string) *DataNode {
-	s := &DataNode{}
-	s.id = NodeId(id)
-	s.nodeType = "DataNode"
-	s.volumes = make(map[storage.VolumeId]storage.VolumeInfo)
-	s.NodeImpl.value = s
-	return s
-}
-
-func (dn *DataNode) String() string {
-	return fmt.Sprintf("Node:%s, volumes:%v, Ip:%s, Port:%d, PublicUrl:%s, Dead:%v", dn.NodeImpl.String(), dn.volumes, dn.Ip, dn.Port, dn.PublicUrl, dn.Dead)
-}
-
-func (dn *DataNode) AddOrUpdateVolume(v storage.VolumeInfo) {
-	if _, ok := dn.volumes[v.Id]; !ok {
-		dn.volumes[v.Id] = v
-		dn.UpAdjustVolumeCountDelta(1)
-		if !v.ReadOnly {
-			dn.UpAdjustActiveVolumeCountDelta(1)
-		}
-		dn.UpAdjustMaxVolumeId(v.Id)
-	} else {
-		dn.volumes[v.Id] = v
-	}
-}
-
-func (dn *DataNode) UpdateVolumes(actualVolumes []storage.VolumeInfo) (deletedVolumes []storage.VolumeInfo) {
-	actualVolumeMap := make(map[storage.VolumeId]storage.VolumeInfo)
-	for _, v := range actualVolumes {
-		actualVolumeMap[v.Id] = v
-	}
-	for vid, v := range dn.volumes {
-		if _, ok := actualVolumeMap[vid]; !ok {
-			glog.V(0).Infoln("Deleting volume id:", vid)
-			delete(dn.volumes, vid)
-			deletedVolumes = append(deletedVolumes, v)
-			dn.UpAdjustVolumeCountDelta(-1)
-			dn.UpAdjustActiveVolumeCountDelta(-1)
-		}
-	} //TODO: adjust max volume id, if need to reclaim volume ids
-	for _, v := range actualVolumes {
-		dn.AddOrUpdateVolume(v)
-	}
-	return
-}
-
-func (dn *DataNode) GetDataCenter() *DataCenter {
-	return dn.Parent().Parent().(*NodeImpl).value.(*DataCenter)
-}
-
-func (dn *DataNode) GetRack() *Rack {
-	return dn.Parent().(*NodeImpl).value.(*Rack)
-}
-
-func (dn *DataNode) GetTopology() *Topology {
-	p := dn.Parent()
-	for p.Parent() != nil {
-		p = p.Parent()
-	}
-	t := p.(*Topology)
-	return t
-}
-
-func (dn *DataNode) MatchLocation(ip string, port int) bool {
-	return dn.Ip == ip && dn.Port == port
-}
-
-func (dn *DataNode) Url() string {
-	return dn.Ip + ":" + strconv.Itoa(dn.Port)
-}
-
-func (dn *DataNode) ToMap() interface{} {
-	ret := make(map[string]interface{})
-	ret["Url"] = dn.Url()
-	ret["Volumes"] = dn.GetVolumeCount()
-	ret["Max"] = dn.GetMaxVolumeCount()
-	ret["Free"] = dn.FreeSpace()
-	ret["PublicUrl"] = dn.PublicUrl
-	return ret
-}
--- a/go/topology/store_replicate.go
+++ b/go/topology/store_replicate.go
@ -1,126 +0,0 @@
-package topology
-
-import (
-	"bytes"
-	"net/http"
-	"strconv"
-
-	"net/url"
-
-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/operation"
-	"github.com/chrislusf/seaweedfs/go/security"
-	"github.com/chrislusf/seaweedfs/go/storage"
-	"github.com/chrislusf/seaweedfs/go/util"
-)
-
-func ReplicatedWrite(masterNode string, s *storage.Store,
-	volumeId storage.VolumeId, needle *storage.Needle,
-	r *http.Request) (size uint32, errorStatus string) {
-
-	//check JWT
-	jwt := security.GetJwt(r)
-
-	ret, err := s.Write(volumeId, needle)
-	needToReplicate := !s.HasVolume(volumeId)
-	if err != nil {
-		errorStatus = "Failed to write to local disk (" + err.Error() + ")"
-	} else if ret > 0 {
-		needToReplicate = needToReplicate || s.GetVolume(volumeId).NeedToReplicate()
-	} else {
-		errorStatus = "Failed to write to local disk"
-	}
-	if !needToReplicate && ret > 0 {
-		needToReplicate = s.GetVolume(volumeId).NeedToReplicate()
-	}
-	if needToReplicate { //send to other replica locations
-		if r.FormValue("type") != "replicate" {
-
-			if !distributedOperation(masterNode, s, volumeId, func(location operation.Location) bool {
-				u := url.URL{
-					Scheme: "http",
-					Host:   location.Url,
-					Path:   r.URL.Path,
-				}
-				q := url.Values{
-					"type": {"replicate"},
-				}
-				if needle.LastModified > 0 {
-					q.Set("ts", strconv.FormatUint(needle.LastModified, 10))
-				}
-				if needle.IsChunkedManifest() {
-					q.Set("cm", "true")
-				}
-				u.RawQuery = q.Encode()
-				_, err := operation.Upload(u.String(),
-					string(needle.Name), bytes.NewReader(needle.Data), needle.IsGzipped(), string(needle.Mime),
-					jwt)
-				return err == nil
-			}) {
-				ret = 0
-				errorStatus = "Failed to write to replicas for volume " + volumeId.String()
-			}
-		}
-	}
-	size = ret
-	return
-}
-
-func ReplicatedDelete(masterNode string, store *storage.Store,
-	volumeId storage.VolumeId, n *storage.Needle,
-	r *http.Request) (ret uint32) {
-
-	//check JWT
-	jwt := security.GetJwt(r)
-
-	ret, err := store.Delete(volumeId, n)
-	if err != nil {
-		glog.V(0).Infoln("delete error:", err)
-		return
-	}
-
-	needToReplicate := !store.HasVolume(volumeId)
-	if !needToReplicate && ret > 0 {
-		needToReplicate = store.GetVolume(volumeId).NeedToReplicate()
-	}
-	if needToReplicate { //send to other replica locations
-		if r.FormValue("type") != "replicate" {
-			if !distributedOperation(masterNode, store, volumeId, func(location operation.Location) bool {
-				return nil == util.Delete("http://"+location.Url+r.URL.Path+"?type=replicate", jwt)
-			}) {
-				ret = 0
-			}
-		}
-	}
-	return
-}
-
-func distributedOperation(masterNode string, store *storage.Store, volumeId storage.VolumeId, op func(location operation.Location) bool) bool {
-	if lookupResult, lookupErr := operation.Lookup(masterNode, volumeId.String()); lookupErr == nil {
-		length := 0
-		selfUrl := (store.Ip + ":" + strconv.Itoa(store.Port))
-		results := make(chan bool)
-		for _, location := range lookupResult.Locations {
-			if location.Url != selfUrl {
-				length++
-				go func(location operation.Location, results chan bool) {
-					results <- op(location)
-				}(location, results)
-			}
-		}
-		ret := true
-		for i := 0; i < length; i++ {
-			ret = ret && <-results
-		}
-		if volume := store.GetVolume(volumeId); volume != nil {
-			if length+1 < volume.ReplicaPlacement.GetCopyCount() {
-				glog.V(0).Infof("replicating opetations [%d] is less than volume's replication copy count [%d]", length+1, volume.ReplicaPlacement.GetCopyCount())
-				ret = false
-			}
-		}
-		return ret
-	} else {
-		glog.V(0).Infoln("Failed to lookup for", volumeId, lookupErr.Error())
-	}
-	return false
-}
--- a/go/topology/topology.go
+++ b/go/topology/topology.go
@ -1,189 +0,0 @@
-package topology
-
-import (
-	"errors"
-	"io/ioutil"
-	"math/rand"
-
-	"github.com/chrislusf/raft"
-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/operation"
-	"github.com/chrislusf/seaweedfs/go/sequence"
-	"github.com/chrislusf/seaweedfs/go/storage"
-	"github.com/chrislusf/seaweedfs/go/util"
-)
-
-type Topology struct {
-	NodeImpl
-
-	collectionMap *util.ConcurrentReadMap
-
-	pulse int64
-
-	volumeSizeLimit uint64
-
-	Sequence sequence.Sequencer
-
-	chanDeadDataNodes      chan *DataNode
-	chanRecoveredDataNodes chan *DataNode
-	chanFullVolumes        chan storage.VolumeInfo
-
-	configuration *Configuration
-
-	RaftServer raft.Server
-}
-
-func NewTopology(id string, confFile string, seq sequence.Sequencer, volumeSizeLimit uint64, pulse int) (*Topology, error) {
-	t := &Topology{}
-	t.id = NodeId(id)
-	t.nodeType = "Topology"
-	t.NodeImpl.value = t
-	t.children = make(map[NodeId]Node)
-	t.collectionMap = util.NewConcurrentReadMap()
-	t.pulse = int64(pulse)
-	t.volumeSizeLimit = volumeSizeLimit
-
-	t.Sequence = seq
-
-	t.chanDeadDataNodes = make(chan *DataNode)
-	t.chanRecoveredDataNodes = make(chan *DataNode)
-	t.chanFullVolumes = make(chan storage.VolumeInfo)
-
-	err := t.loadConfiguration(confFile)
-
-	return t, err
-}
-
-func (t *Topology) IsLeader() bool {
-	if leader, e := t.Leader(); e == nil {
-		return leader == t.RaftServer.Name()
-	}
-	return false
-}
-
-func (t *Topology) Leader() (string, error) {
-	l := ""
-	if t.RaftServer != nil {
-		l = t.RaftServer.Leader()
-	} else {
-		return "", errors.New("Raft Server not ready yet!")
-	}
-
-	if l == "" {
-		// We are a single node cluster, we are the leader
-		return t.RaftServer.Name(), errors.New("Raft Server not initialized!")
-	}
-
-	return l, nil
-}
-
-func (t *Topology) loadConfiguration(configurationFile string) error {
-	b, e := ioutil.ReadFile(configurationFile)
-	if e == nil {
-		t.configuration, e = NewConfiguration(b)
-		return e
-	}
-	glog.V(0).Infoln("Using default configurations.")
-	return nil
-}
-
-func (t *Topology) Lookup(collection string, vid storage.VolumeId) []*DataNode {
-	//maybe an issue if lots of collections?
-	if collection == "" {
-		for _, c := range t.collectionMap.Items {
-			if list := c.(*Collection).Lookup(vid); list != nil {
-				return list
-			}
-		}
-	} else {
-		if c, ok := t.collectionMap.Items[collection]; ok {
-			return c.(*Collection).Lookup(vid)
-		}
-	}
-	return nil
-}
-
-func (t *Topology) NextVolumeId() storage.VolumeId {
-	vid := t.GetMaxVolumeId()
-	next := vid.Next()
-	go t.RaftServer.Do(NewMaxVolumeIdCommand(next))
-	return next
-}
-
-func (t *Topology) HasWritableVolume(option *VolumeGrowOption) bool {
-	vl := t.GetVolumeLayout(option.Collection, option.ReplicaPlacement, option.Ttl)
-	return vl.GetActiveVolumeCount(option) > 0
-}
-
-func (t *Topology) PickForWrite(count uint64, option *VolumeGrowOption) (string, uint64, *DataNode, error) {
-	vid, count, datanodes, err := t.GetVolumeLayout(option.Collection, option.ReplicaPlacement, option.Ttl).PickForWrite(count, option)
-	if err != nil || datanodes.Length() == 0 {
-		return "", 0, nil, errors.New("No writable volumes available!")
-	}
-	fileId, count := t.Sequence.NextFileId(count)
-	return storage.NewFileId(*vid, fileId, rand.Uint32()).String(), count, datanodes.Head(), nil
-}
-
-func (t *Topology) GetVolumeLayout(collectionName string, rp *storage.ReplicaPlacement, ttl *storage.TTL) *VolumeLayout {
-	return t.collectionMap.Get(collectionName, func() interface{} {
-		return NewCollection(collectionName, t.volumeSizeLimit)
-	}).(*Collection).GetOrCreateVolumeLayout(rp, ttl)
-}
-
-func (t *Topology) GetCollection(collectionName string) (*Collection, bool) {
-	c, hasCollection := t.collectionMap.Items[collectionName]
-	return c.(*Collection), hasCollection
-}
-
-func (t *Topology) DeleteCollection(collectionName string) {
-	delete(t.collectionMap.Items, collectionName)
-}
-
-func (t *Topology) RegisterVolumeLayout(v storage.VolumeInfo, dn *DataNode) {
-	t.GetVolumeLayout(v.Collection, v.ReplicaPlacement, v.Ttl).RegisterVolume(&v, dn)
-}
-func (t *Topology) UnRegisterVolumeLayout(v storage.VolumeInfo, dn *DataNode) {
-	glog.Infof("removing volume info:%+v", v)
-	t.GetVolumeLayout(v.Collection, v.ReplicaPlacement, v.Ttl).UnRegisterVolume(&v, dn)
-}
-
-func (t *Topology) ProcessJoinMessage(joinMessage *operation.JoinMessage) {
-	t.Sequence.SetMax(*joinMessage.MaxFileKey)
-	dcName, rackName := t.configuration.Locate(*joinMessage.Ip, *joinMessage.DataCenter, *joinMessage.Rack)
-	dc := t.GetOrCreateDataCenter(dcName)
-	rack := dc.GetOrCreateRack(rackName)
-	dn := rack.FindDataNode(*joinMessage.Ip, int(*joinMessage.Port))
-	if *joinMessage.IsInit && dn != nil {
-		t.UnRegisterDataNode(dn)
-	}
-	dn = rack.GetOrCreateDataNode(*joinMessage.Ip,
-		int(*joinMessage.Port), *joinMessage.PublicUrl,
-		int(*joinMessage.MaxVolumeCount))
-	var volumeInfos []storage.VolumeInfo
-	for _, v := range joinMessage.Volumes {
-		if vi, err := storage.NewVolumeInfo(v); err == nil {
-			volumeInfos = append(volumeInfos, vi)
-		} else {
-			glog.V(0).Infoln("Fail to convert joined volume information:", err.Error())
-		}
-	}
-	deletedVolumes := dn.UpdateVolumes(volumeInfos)
-	for _, v := range volumeInfos {
-		t.RegisterVolumeLayout(v, dn)
-	}
-	for _, v := range deletedVolumes {
-		t.UnRegisterVolumeLayout(v, dn)
-	}
-}
-
-func (t *Topology) GetOrCreateDataCenter(dcName string) *DataCenter {
-	for _, c := range t.Children() {
-		dc := c.(*DataCenter)
-		if string(dc.Id()) == dcName {
-			return dc
-		}
-	}
-	dc := NewDataCenter(dcName)
-	t.LinkChildNode(dc)
-	return dc
-}
--- a/go/topology/volume_growth.go
+++ b/go/topology/volume_growth.go
@ -1,211 +0,0 @@
-package topology
-
-import (
-	"fmt"
-	"math/rand"
-	"sync"
-
-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/storage"
-)
-
-/*
-This package is created to resolve these replica placement issues:
-1. growth factor for each replica level, e.g., add 10 volumes for 1 copy, 20 volumes for 2 copies, 30 volumes for 3 copies
-2. in time of tight storage, how to reduce replica level
-3. optimizing for hot data on faster disk, cold data on cheaper storage,
-4. volume allocation for each bucket
-*/
-
-type VolumeGrowOption struct {
-	Collection       string
-	ReplicaPlacement *storage.ReplicaPlacement
-	Ttl              *storage.TTL
-	DataCenter       string
-	Rack             string
-	DataNode         string
-}
-
-type VolumeGrowth struct {
-	accessLock sync.Mutex
-}
-
-func (o *VolumeGrowOption) String() string {
-	return fmt.Sprintf("Collection:%s, ReplicaPlacement:%v, Ttl:%v, DataCenter:%s, Rack:%s, DataNode:%s", o.Collection, o.ReplicaPlacement, o.Ttl, o.DataCenter, o.Rack, o.DataNode)
-}
-
-func NewDefaultVolumeGrowth() *VolumeGrowth {
-	return &VolumeGrowth{}
-}
-
-// one replication type may need rp.GetCopyCount() actual volumes
-// given copyCount, how many logical volumes to create
-func (vg *VolumeGrowth) findVolumeCount(copyCount int) (count int) {
-	switch copyCount {
-	case 1:
-		count = 7
-	case 2:
-		count = 6
-	case 3:
-		count = 3
-	default:
-		count = 1
-	}
-	return
-}
-
-func (vg *VolumeGrowth) AutomaticGrowByType(option *VolumeGrowOption, topo *Topology) (count int, err error) {
-	count, err = vg.GrowByCountAndType(vg.findVolumeCount(option.ReplicaPlacement.GetCopyCount()), option, topo)
-	if count > 0 && count%option.ReplicaPlacement.GetCopyCount() == 0 {
-		return count, nil
-	}
-	return count, err
-}
-func (vg *VolumeGrowth) GrowByCountAndType(targetCount int, option *VolumeGrowOption, topo *Topology) (counter int, err error) {
-	vg.accessLock.Lock()
-	defer vg.accessLock.Unlock()
-
-	for i := 0; i < targetCount; i++ {
-		if c, e := vg.findAndGrow(topo, option); e == nil {
-			counter += c
-		} else {
-			return counter, e
-		}
-	}
-	return
-}
-
-func (vg *VolumeGrowth) findAndGrow(topo *Topology, option *VolumeGrowOption) (int, error) {
-	servers, e := vg.findEmptySlotsForOneVolume(topo, option)
-	if e != nil {
-		return 0, e
-	}
-	vid := topo.NextVolumeId()
-	err := vg.grow(topo, vid, option, servers...)
-	return len(servers), err
-}
-
-// 1. find the main data node
-// 1.1 collect all data nodes that have 1 slots
-// 2.2 collect all racks that have rp.SameRackCount+1
-// 2.2 collect all data centers that have DiffRackCount+rp.SameRackCount+1
-// 2. find rest data nodes
-func (vg *VolumeGrowth) findEmptySlotsForOneVolume(topo *Topology, option *VolumeGrowOption) (servers []*DataNode, err error) {
-	//find main datacenter and other data centers
-	rp := option.ReplicaPlacement
-	mainDataCenter, otherDataCenters, dc_err := topo.RandomlyPickNodes(rp.DiffDataCenterCount+1, func(node Node) error {
-		if option.DataCenter != "" && node.IsDataCenter() && node.Id() != NodeId(option.DataCenter) {
-			return fmt.Errorf("Not matching preferred data center:%s", option.DataCenter)
-		}
-		if len(node.Children()) < rp.DiffRackCount+1 {
-			return fmt.Errorf("Only has %d racks, not enough for %d.", len(node.Children()), rp.DiffRackCount+1)
-		}
-		if node.FreeSpace() < rp.DiffRackCount+rp.SameRackCount+1 {
-			return fmt.Errorf("Free:%d < Expected:%d", node.FreeSpace(), rp.DiffRackCount+rp.SameRackCount+1)
-		}
-		possibleRacksCount := 0
-		for _, rack := range node.Children() {
-			possibleDataNodesCount := 0
-			for _, n := range rack.Children() {
-				if n.FreeSpace() >= 1 {
-					possibleDataNodesCount++
-				}
-			}
-			if possibleDataNodesCount >= rp.SameRackCount+1 {
-				possibleRacksCount++
-			}
-		}
-		if possibleRacksCount < rp.DiffRackCount+1 {
-			return fmt.Errorf("Only has %d racks with more than %d free data nodes, not enough for %d.", possibleRacksCount, rp.SameRackCount+1, rp.DiffRackCount+1)
-		}
-		return nil
-	})
-	if dc_err != nil {
-		return nil, dc_err
-	}
-
-	//find main rack and other racks
-	mainRack, otherRacks, rack_err := mainDataCenter.(*DataCenter).RandomlyPickNodes(rp.DiffRackCount+1, func(node Node) error {
-		if option.Rack != "" && node.IsRack() && node.Id() != NodeId(option.Rack) {
-			return fmt.Errorf("Not matching preferred rack:%s", option.Rack)
-		}
-		if node.FreeSpace() < rp.SameRackCount+1 {
-			return fmt.Errorf("Free:%d < Expected:%d", node.FreeSpace(), rp.SameRackCount+1)
-		}
-		if len(node.Children()) < rp.SameRackCount+1 {
-			// a bit faster way to test free racks
-			return fmt.Errorf("Only has %d data nodes, not enough for %d.", len(node.Children()), rp.SameRackCount+1)
-		}
-		possibleDataNodesCount := 0
-		for _, n := range node.Children() {
-			if n.FreeSpace() >= 1 {
-				possibleDataNodesCount++
-			}
-		}
-		if possibleDataNodesCount < rp.SameRackCount+1 {
-			return fmt.Errorf("Only has %d data nodes with a slot, not enough for %d.", possibleDataNodesCount, rp.SameRackCount+1)
-		}
-		return nil
-	})
-	if rack_err != nil {
-		return nil, rack_err
-	}
-
-	//find main rack and other racks
-	mainServer, otherServers, server_err := mainRack.(*Rack).RandomlyPickNodes(rp.SameRackCount+1, func(node Node) error {
-		if option.DataNode != "" && node.IsDataNode() && node.Id() != NodeId(option.DataNode) {
-			return fmt.Errorf("Not matching preferred data node:%s", option.DataNode)
-		}
-		if node.FreeSpace() < 1 {
-			return fmt.Errorf("Free:%d < Expected:%d", node.FreeSpace(), 1)
-		}
-		return nil
-	})
-	if server_err != nil {
-		return nil, server_err
-	}
-
-	servers = append(servers, mainServer.(*DataNode))
-	for _, server := range otherServers {
-		servers = append(servers, server.(*DataNode))
-	}
-	for _, rack := range otherRacks {
-		r := rand.Intn(rack.FreeSpace())
-		if server, e := rack.ReserveOneVolume(r); e == nil {
-			servers = append(servers, server)
-		} else {
-			return servers, e
-		}
-	}
-	for _, datacenter := range otherDataCenters {
-		r := rand.Intn(datacenter.FreeSpace())
-		if server, e := datacenter.ReserveOneVolume(r); e == nil {
-			servers = append(servers, server)
-		} else {
-			return servers, e
-		}
-	}
-	return
-}
-
-func (vg *VolumeGrowth) grow(topo *Topology, vid storage.VolumeId, option *VolumeGrowOption, servers ...*DataNode) error {
-	for _, server := range servers {
-		if err := AllocateVolume(server, vid, option); err == nil {
-			vi := storage.VolumeInfo{
-				Id:               vid,
-				Size:             0,
-				Collection:       option.Collection,
-				ReplicaPlacement: option.ReplicaPlacement,
-				Ttl:              option.Ttl,
-				Version:          storage.CurrentVersion,
-			}
-			server.AddOrUpdateVolume(vi)
-			topo.RegisterVolumeLayout(vi, server)
-			glog.V(0).Infoln("Created Volume", vid, "on", server.NodeImpl.String())
-		} else {
-			glog.V(0).Infoln("Failed to assign volume", vid, "to", servers, "error", err)
-			return fmt.Errorf("Failed to assign %d: %v", vid, err)
-		}
-	}
-	return nil
-}
--- a/go/topology/volume_location_list.go
+++ b/go/topology/volume_location_list.go
@ -1,65 +0,0 @@
-package topology
-
-import (
-	"fmt"
-)
-
-type VolumeLocationList struct {
-	list []*DataNode
-}
-
-func NewVolumeLocationList() *VolumeLocationList {
-	return &VolumeLocationList{}
-}
-
-func (dnll *VolumeLocationList) String() string {
-	return fmt.Sprintf("%v", dnll.list)
-}
-
-func (dnll *VolumeLocationList) Head() *DataNode {
-	//mark first node as master volume
-	return dnll.list[0]
-}
-
-func (dnll *VolumeLocationList) Length() int {
-	return len(dnll.list)
-}
-
-func (dnll *VolumeLocationList) Set(loc *DataNode) {
-	for i := 0; i < len(dnll.list); i++ {
-		if loc.Ip == dnll.list[i].Ip && loc.Port == dnll.list[i].Port {
-			dnll.list[i] = loc
-			return
-		}
-	}
-	dnll.list = append(dnll.list, loc)
-}
-
-func (dnll *VolumeLocationList) Remove(loc *DataNode) bool {
-	for i, dnl := range dnll.list {
-		if loc.Ip == dnl.Ip && loc.Port == dnl.Port {
-			dnll.list = append(dnll.list[:i], dnll.list[i+1:]...)
-			return true
-		}
-	}
-	return false
-}
-
-func (dnll *VolumeLocationList) Refresh(freshThreshHold int64) {
-	var changed bool
-	for _, dnl := range dnll.list {
-		if dnl.LastSeen < freshThreshHold {
-			changed = true
-			break
-		}
-	}
-	if changed {
-		var l []*DataNode
-		for _, dnl := range dnll.list {
-			if dnl.LastSeen >= freshThreshHold {
-				l = append(l, dnl)
-			}
-		}
-		dnll.list = l
-	}
-}
--- a/go/util/concurrent_read_map.go
+++ b/go/util/concurrent_read_map.go
@ -1,38 +0,0 @@
-package util
-
-import (
-	"sync"
-)
-
-// A mostly for read map, which can thread-safely
-// initialize the map entries.
-type ConcurrentReadMap struct {
-	rmutex sync.RWMutex
-	mutex  sync.Mutex
-	Items  map[string]interface{}
-}
-
-func NewConcurrentReadMap() *ConcurrentReadMap {
-	return &ConcurrentReadMap{Items: make(map[string]interface{})}
-}
-
-func (m *ConcurrentReadMap) initMapEntry(key string, newEntry func() interface{}) (value interface{}) {
-	m.mutex.Lock()
-	defer m.mutex.Unlock()
-	if value, ok := m.Items[key]; ok {
-		return value
-	}
-	value = newEntry()
-	m.Items[key] = value
-	return value
-}
-
-func (m *ConcurrentReadMap) Get(key string, newEntry func() interface{}) interface{} {
-	m.rmutex.RLock()
-	if value, ok := m.Items[key]; ok {
-		m.rmutex.RUnlock()
-		return value
-	}
-	m.rmutex.RUnlock()
-	return m.initMapEntry(key, newEntry)
-}
--- a/go/util/http_util.go
+++ b/go/util/http_util.go
@ -1,163 +0,0 @@
-package util
-
-import (
-	"bytes"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"net/http"
-	"net/url"
-	"strings"
-
-	"github.com/chrislusf/seaweedfs/go/security"
-)
-
-var (
-	client    *http.Client
-	Transport *http.Transport
-)
-
-func init() {
-	Transport = &http.Transport{
-		MaxIdleConnsPerHost: 1024,
-	}
-	client = &http.Client{Transport: Transport}
-}
-
-func PostBytes(url string, body []byte) ([]byte, error) {
-	r, err := client.Post(url, "application/octet-stream", bytes.NewReader(body))
-	if err != nil {
-		return nil, fmt.Errorf("Post to %s: %v", url, err)
-	}
-	defer r.Body.Close()
-	b, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		return nil, fmt.Errorf("Read response body: %v", err)
-	}
-	return b, nil
-}
-
-func Post(url string, values url.Values) ([]byte, error) {
-	r, err := client.PostForm(url, values)
-	if err != nil {
-		return nil, err
-	}
-	defer r.Body.Close()
-	b, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		return nil, err
-	}
-	return b, nil
-}
-
-func Get(url string) ([]byte, error) {
-	r, err := client.Get(url)
-	if err != nil {
-		return nil, err
-	}
-	defer r.Body.Close()
-	b, err := ioutil.ReadAll(r.Body)
-	if r.StatusCode != 200 {
-		return nil, fmt.Errorf("%s: %s", url, r.Status)
-	}
-	if err != nil {
-		return nil, err
-	}
-	return b, nil
-}
-
-func Delete(url string, jwt security.EncodedJwt) error {
-	req, err := http.NewRequest("DELETE", url, nil)
-	if jwt != "" {
-		req.Header.Set("Authorization", "BEARER "+string(jwt))
-	}
-	if err != nil {
-		return err
-	}
-	resp, e := client.Do(req)
-	if e != nil {
-		return e
-	}
-	defer resp.Body.Close()
-	body, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		return err
-	}
-	switch resp.StatusCode {
-	case http.StatusNotFound, http.StatusAccepted, http.StatusOK:
-		return nil
-	}
-	m := make(map[string]interface{})
-	if e := json.Unmarshal(body, m); e == nil {
-		if s, ok := m["error"].(string); ok {
-			return errors.New(s)
-		}
-	}
-	return errors.New(string(body))
-}
-
-func GetBufferStream(url string, values url.Values, allocatedBytes []byte, eachBuffer func([]byte)) error {
-	r, err := client.PostForm(url, values)
-	if err != nil {
-		return err
-	}
-	defer r.Body.Close()
-	if r.StatusCode != 200 {
-		return fmt.Errorf("%s: %s", url, r.Status)
-	}
-	bufferSize := len(allocatedBytes)
-	for {
-		n, err := r.Body.Read(allocatedBytes)
-		if n == bufferSize {
-			eachBuffer(allocatedBytes)
-		}
-		if err != nil {
-			if err == io.EOF {
-				return nil
-			}
-			return err
-		}
-	}
-	return nil
-}
-
-func GetUrlStream(url string, values url.Values, readFn func(io.Reader) error) error {
-	r, err := client.PostForm(url, values)
-	if err != nil {
-		return err
-	}
-	defer r.Body.Close()
-	if r.StatusCode != 200 {
-		return fmt.Errorf("%s: %s", url, r.Status)
-	}
-	return readFn(r.Body)
-}
-
-func DownloadUrl(fileUrl string) (filename string, rc io.ReadCloser, e error) {
-	response, err := client.Get(fileUrl)
-	if err != nil {
-		return "", nil, err
-	}
-	contentDisposition := response.Header["Content-Disposition"]
-	if len(contentDisposition) > 0 {
-		if strings.HasPrefix(contentDisposition[0], "filename=") {
-			filename = contentDisposition[0][len("filename="):]
-			filename = strings.Trim(filename, "\"")
-		}
-	}
-	rc = response.Body
-	return
-}
-
-func Do(req *http.Request) (resp *http.Response, err error) {
-	return client.Do(req)
-}
-
-func NormalizeUrl(url string) string {
-	if strings.HasPrefix(url, "http://") || strings.HasPrefix(url, "https://") {
-		return url
-	}
-	return "http://" + url
-}
--- a/go/weed/weed_server/master_server_handlers_ui.go
+++ b/go/weed/weed_server/master_server_handlers_ui.go
@ -1,30 +0,0 @@
-package weed_server
-
-import (
-	"net/http"
-
-	"github.com/chrislusf/seaweedfs/go/stats"
-	"github.com/chrislusf/seaweedfs/go/util"
-	ui "github.com/chrislusf/seaweedfs/go/weed/weed_server/master_ui"
-)
-
-func (ms *MasterServer) uiStatusHandler(w http.ResponseWriter, r *http.Request) {
-	infos := make(map[string]interface{})
-	infos["Version"] = util.VERSION
-	args := struct {
-		Version  string
-		Topology interface{}
-		Leader   string
-		Peers    interface{}
-		Stats    map[string]interface{}
-		Counters *stats.ServerStats
-	}{
-		util.VERSION,
-		ms.Topo.ToMap(),
-		ms.Topo.RaftServer.Leader(),
-		ms.Topo.RaftServer.Peers(),
-		infos,
-		serverStats,
-	}
-	ui.StatusTpl.Execute(w, args)
-}
--- a/go/weed/weed_server/volume_server_handlers_admin.go
+++ b/go/weed/weed_server/volume_server_handlers_admin.go
@ -1,50 +0,0 @@
-package weed_server
-
-import (
-	"net/http"
-	"path/filepath"
-
-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/stats"
-	"github.com/chrislusf/seaweedfs/go/util"
-)
-
-func (vs *VolumeServer) statusHandler(w http.ResponseWriter, r *http.Request) {
-	m := make(map[string]interface{})
-	m["Version"] = util.VERSION
-	m["Volumes"] = vs.store.Status()
-	writeJsonQuiet(w, r, http.StatusOK, m)
-}
-
-func (vs *VolumeServer) assignVolumeHandler(w http.ResponseWriter, r *http.Request) {
-	err := vs.store.AddVolume(r.FormValue("volume"), r.FormValue("collection"), vs.needleMapKind, r.FormValue("replication"), r.FormValue("ttl"))
-	if err == nil {
-		writeJsonQuiet(w, r, http.StatusAccepted, map[string]string{"error": ""})
-	} else {
-		writeJsonError(w, r, http.StatusNotAcceptable, err)
-	}
-	glog.V(2).Infoln("assign volume =", r.FormValue("volume"), ", collection =", r.FormValue("collection"), ", replication =", r.FormValue("replication"), ", error =", err)
-}
-
-func (vs *VolumeServer) deleteCollectionHandler(w http.ResponseWriter, r *http.Request) {
-	err := vs.store.DeleteCollection(r.FormValue("collection"))
-	if err == nil {
-		writeJsonQuiet(w, r, http.StatusOK, map[string]string{"error": ""})
-	} else {
-		writeJsonError(w, r, http.StatusInternalServerError, err)
-	}
-	glog.V(2).Infoln("deleting collection =", r.FormValue("collection"), ", error =", err)
-}
-
-func (vs *VolumeServer) statsDiskHandler(w http.ResponseWriter, r *http.Request) {
-	m := make(map[string]interface{})
-	m["Version"] = util.VERSION
-	var ds []*stats.DiskStatus
-	for _, loc := range vs.store.Locations {
-		if dir, e := filepath.Abs(loc.Directory); e == nil {
-			ds = append(ds, stats.NewDiskStatus(dir))
-		}
-	}
-	m["DiskStatuses"] = ds
-	writeJsonQuiet(w, r, http.StatusOK, m)
-}
--- a/go/weed/weed_server/volume_server_handlers_sync.go
+++ b/go/weed/weed_server/volume_server_handlers_sync.go
@ -1,86 +0,0 @@
-package weed_server
-
-import (
-	"fmt"
-	"net/http"
-
-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/storage"
-	"github.com/chrislusf/seaweedfs/go/util"
-)
-
-func (vs *VolumeServer) getVolumeSyncStatusHandler(w http.ResponseWriter, r *http.Request) {
-	v, err := vs.getVolume("volume", r)
-	if v == nil {
-		writeJsonError(w, r, http.StatusBadRequest, err)
-		return
-	}
-	syncStat := v.GetVolumeSyncStatus()
-	if syncStat.Error != "" {
-		writeJsonError(w, r, http.StatusInternalServerError, fmt.Errorf("Get Volume %d status error: %s", v.Id, syncStat.Error))
-		glog.V(2).Infoln("getVolumeSyncStatusHandler volume =", r.FormValue("volume"), ", error =", err)
-	} else {
-		writeJsonQuiet(w, r, http.StatusOK, syncStat)
-	}
-}
-
-func (vs *VolumeServer) getVolumeIndexContentHandler(w http.ResponseWriter, r *http.Request) {
-	v, err := vs.getVolume("volume", r)
-	if v == nil {
-		writeJsonError(w, r, http.StatusBadRequest, err)
-		return
-	}
-	content, err := v.IndexFileContent()
-	if err != nil {
-		writeJsonError(w, r, http.StatusInternalServerError, err)
-		return
-	}
-	w.Write(content)
-}
-
-func (vs *VolumeServer) getVolumeDataContentHandler(w http.ResponseWriter, r *http.Request) {
-	v, err := vs.getVolume("volume", r)
-	if v == nil {
-		writeJsonError(w, r, http.StatusBadRequest, fmt.Errorf("Not Found volume: %v", err))
-		return
-	}
-	if int(v.SuperBlock.CompactRevision) != util.ParseInt(r.FormValue("revision"), 0) {
-		writeJsonError(w, r, http.StatusExpectationFailed, fmt.Errorf("Requested Volume Revision is %s, but current revision is %d", r.FormValue("revision"), v.SuperBlock.CompactRevision))
-		return
-	}
-	offset := uint32(util.ParseUint64(r.FormValue("offset"), 0))
-	size := uint32(util.ParseUint64(r.FormValue("size"), 0))
-	content, err := storage.ReadNeedleBlob(v.DataFile(), int64(offset)*storage.NeedlePaddingSize, size)
-	if err != nil {
-		writeJsonError(w, r, http.StatusInternalServerError, err)
-		return
-	}
-
-	id := util.ParseUint64(r.FormValue("id"), 0)
-	n := new(storage.Needle)
-	n.ParseNeedleHeader(content)
-	if id != n.Id {
-		writeJsonError(w, r, http.StatusNotFound, fmt.Errorf("Expected file entry id %d, but found %d", id, n.Id))
-		return
-	}
-
-	w.Write(content)
-}
-
-func (vs *VolumeServer) getVolume(volumeParameterName string, r *http.Request) (*storage.Volume, error) {
-	volumeIdString := r.FormValue(volumeParameterName)
-	if volumeIdString == "" {
-		err := fmt.Errorf("Empty Volume Id: Need to pass in %s=the_volume_id.", volumeParameterName)
-		return nil, err
-	}
-	vid, err := storage.NewVolumeId(volumeIdString)
-	if err != nil {
-		err = fmt.Errorf("Volume Id %s is not a valid unsigned integer", volumeIdString)
-		return nil, err
-	}
-	v := vs.store.GetVolume(vid)
-	if v == nil {
-		return nil, fmt.Errorf("Not Found Volume Id %s: %d", volumeIdString, vid)
-	}
-	return v, nil
-}
--- a/unmaintained/fix_dat/fix_dat.go
+++ b/unmaintained/fix_dat/fix_dat.go
@ -8,9 +8,9 @@ import (
 	"path"
 	"strconv"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/storage"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/storage"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 var (
--- a/unmaintained/see_idx/see_idx.go
+++ b/unmaintained/see_idx/see_idx.go
@ -6,8 +6,8 @@ import (
 	"path"
 	"strconv"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/storage"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/storage"
 )

 var (
--- a/weed/Godeps/Godeps.json
+++ b/weed/Godeps/Godeps.json
@ -0,0 +1,190 @@
+{
+	"ImportPath": "github.com/chrislusf/seaweedfs/weed",
+	"GoVersion": "go1.6",
+	"GodepVersion": "v60",
+	"Deps": [
+		{
+			"ImportPath": "bazil.org/fuse",
+			"Rev": "e1ba3783de6cb92c16f72802a4bb94fe639a8049"
+		},
+		{
+			"ImportPath": "bazil.org/fuse/fs",
+			"Rev": "e1ba3783de6cb92c16f72802a4bb94fe639a8049"
+		},
+		{
+			"ImportPath": "bazil.org/fuse/fuseutil",
+			"Rev": "e1ba3783de6cb92c16f72802a4bb94fe639a8049"
+		},
+		{
+			"ImportPath": "github.com/boltdb/bolt",
+			"Comment": "v1.1.0-22-g6e1ca38",
+			"Rev": "6e1ca38c6a73025366cd8705553b404746ee6e63"
+		},
+		{
+			"ImportPath": "github.com/chrislusf/raft",
+			"Rev": "90f631ee823c83f594f27257bab64911190856af"
+		},
+		{
+			"ImportPath": "github.com/chrislusf/raft/protobuf",
+			"Rev": "90f631ee823c83f594f27257bab64911190856af"
+		},
+		{
+			"ImportPath": "github.com/dgrijalva/jwt-go",
+			"Comment": "v2.4.0",
+			"Rev": "f164e17f59b82642a3895ba065c385db6c547344"
+		},
+		{
+			"ImportPath": "github.com/disintegration/imaging",
+			"Rev": "546cb3c5137b3f1232e123a26aa033aade6b3066"
+		},
+		{
+			"ImportPath": "github.com/gocql/gocql",
+			"Comment": "1st_gen_framing-383-g87cc185",
+			"Rev": "87cc1854b57c7a4d8f4ae1d0cc358ed6ecb0f8c3"
+		},
+		{
+			"ImportPath": "github.com/gocql/gocql/internal/lru",
+			"Comment": "1st_gen_framing-383-g87cc185",
+			"Rev": "87cc1854b57c7a4d8f4ae1d0cc358ed6ecb0f8c3"
+		},
+		{
+			"ImportPath": "github.com/gocql/gocql/internal/murmur",
+			"Comment": "1st_gen_framing-383-g87cc185",
+			"Rev": "87cc1854b57c7a4d8f4ae1d0cc358ed6ecb0f8c3"
+		},
+		{
+			"ImportPath": "github.com/gocql/gocql/internal/streams",
+			"Comment": "1st_gen_framing-383-g87cc185",
+			"Rev": "87cc1854b57c7a4d8f4ae1d0cc358ed6ecb0f8c3"
+		},
+		{
+			"ImportPath": "github.com/gogo/protobuf/proto",
+			"Comment": "v0.1-78-gd3235f0",
+			"Rev": "d3235f01ecae4901dd9f7ea6af57a352c0189deb"
+		},
+		{
+			"ImportPath": "github.com/golang/protobuf/proto",
+			"Rev": "8d92cf5fc15a4382f8964b08e1f42a75c0591aa3"
+		},
+		{
+			"ImportPath": "github.com/golang/snappy",
+			"Rev": "723cc1e459b8eea2dea4583200fd60757d40097a"
+		},
+		{
+			"ImportPath": "github.com/gorilla/context",
+			"Rev": "1ea25387ff6f684839d82767c1733ff4d4d15d0a"
+		},
+		{
+			"ImportPath": "github.com/gorilla/mux",
+			"Comment": "v1.1",
+			"Rev": "0eeaf8392f5b04950925b8a69fe70f110fa7cbfc"
+		},
+		{
+			"ImportPath": "github.com/hailocab/go-hostpool",
+			"Rev": "0637eae892be221164aff5fcbccc57171aea6406"
+		},
+		{
+			"ImportPath": "github.com/klauspost/crc32",
+			"Comment": "v1.0",
+			"Rev": "19b0b332c9e4516a6370a0456e6182c3b5036720"
+		},
+		{
+			"ImportPath": "github.com/pierrec/lz4",
+			"Rev": "0b67ae4bb1ab03691079e38dddbc3909d68de64f"
+		},
+		{
+			"ImportPath": "github.com/pierrec/xxHash/xxHash32",
+			"Rev": "122b94d6aa20d9b33d3989da6d7cd6cf641d2277"
+		},
+		{
+			"ImportPath": "github.com/rwcarlsen/goexif/exif",
+			"Rev": "709fab3d192d7c62f86043caff1e7e3fb0f42bd8"
+		},
+		{
+			"ImportPath": "github.com/rwcarlsen/goexif/tiff",
+			"Rev": "709fab3d192d7c62f86043caff1e7e3fb0f42bd8"
+		},
+		{
+			"ImportPath": "github.com/syndtr/goleveldb/leveldb",
+			"Rev": "1a9d62f03ea92815b46fcaab357cfd4df264b1a0"
+		},
+		{
+			"ImportPath": "github.com/syndtr/goleveldb/leveldb/cache",
+			"Rev": "1a9d62f03ea92815b46fcaab357cfd4df264b1a0"
+		},
+		{
+			"ImportPath": "github.com/syndtr/goleveldb/leveldb/comparer",
+			"Rev": "1a9d62f03ea92815b46fcaab357cfd4df264b1a0"
+		},
+		{
+			"ImportPath": "github.com/syndtr/goleveldb/leveldb/errors",
+			"Rev": "1a9d62f03ea92815b46fcaab357cfd4df264b1a0"
+		},
+		{
+			"ImportPath": "github.com/syndtr/goleveldb/leveldb/filter",
+			"Rev": "1a9d62f03ea92815b46fcaab357cfd4df264b1a0"
+		},
+		{
+			"ImportPath": "github.com/syndtr/goleveldb/leveldb/iterator",
+			"Rev": "1a9d62f03ea92815b46fcaab357cfd4df264b1a0"
+		},
+		{
+			"ImportPath": "github.com/syndtr/goleveldb/leveldb/journal",
+			"Rev": "1a9d62f03ea92815b46fcaab357cfd4df264b1a0"
+		},
+		{
+			"ImportPath": "github.com/syndtr/goleveldb/leveldb/memdb",
+			"Rev": "1a9d62f03ea92815b46fcaab357cfd4df264b1a0"
+		},
+		{
+			"ImportPath": "github.com/syndtr/goleveldb/leveldb/opt",
+			"Rev": "1a9d62f03ea92815b46fcaab357cfd4df264b1a0"
+		},
+		{
+			"ImportPath": "github.com/syndtr/goleveldb/leveldb/storage",
+			"Rev": "1a9d62f03ea92815b46fcaab357cfd4df264b1a0"
+		},
+		{
+			"ImportPath": "github.com/syndtr/goleveldb/leveldb/table",
+			"Rev": "1a9d62f03ea92815b46fcaab357cfd4df264b1a0"
+		},
+		{
+			"ImportPath": "github.com/syndtr/goleveldb/leveldb/util",
+			"Rev": "1a9d62f03ea92815b46fcaab357cfd4df264b1a0"
+		},
+		{
+			"ImportPath": "golang.org/x/image/bmp",
+			"Rev": "baddd3465a05d84a6d8d3507547a91cb188c81ea"
+		},
+		{
+			"ImportPath": "golang.org/x/image/tiff",
+			"Rev": "baddd3465a05d84a6d8d3507547a91cb188c81ea"
+		},
+		{
+			"ImportPath": "golang.org/x/image/tiff/lzw",
+			"Rev": "baddd3465a05d84a6d8d3507547a91cb188c81ea"
+		},
+		{
+			"ImportPath": "golang.org/x/net/context",
+			"Rev": "c764672d0ee39ffd83cfcb375804d3181302b62b"
+		},
+		{
+			"ImportPath": "golang.org/x/sys/unix",
+			"Rev": "320cb01ddbbf0473674c2585f9b6e245721de355"
+		},
+		{
+			"ImportPath": "gopkg.in/bufio.v1",
+			"Comment": "v1",
+			"Rev": "567b2bfa514e796916c4747494d6ff5132a1dfce"
+		},
+		{
+			"ImportPath": "gopkg.in/inf.v0",
+			"Rev": "3887ee99ecf07df5b447e9b00d9c0b2adaa9f3e4"
+		},
+		{
+			"ImportPath": "gopkg.in/redis.v2",
+			"Comment": "v2.3.2",
+			"Rev": "e6179049628164864e6e84e973cfb56335748dea"
+		}
+	]
+}
--- a/weed/Godeps/Readme
+++ b/weed/Godeps/Readme
@ -0,0 +1,5 @@
+This directory tree is generated automatically by godep.
+
+Please do not edit.
+
+See https://github.com/tools/godep for more information.
--- a/weed/compress/compression_test.go
+++ b/weed/compress/compression_test.go
--- a/weed/compress/delta_binary_pack32.go
+++ b/weed/compress/delta_binary_pack32.go
--- a/weed/filer/cassandra_store/cassandra_store.go
+++ b/weed/filer/cassandra_store/cassandra_store.go
@ -3,7 +3,7 @@ package cassandra_store
 import (
 	"fmt"

-	"github.com/chrislusf/seaweedfs/go/glog"
+	"github.com/chrislusf/seaweedfs/weed/glog"

 	"github.com/gocql/gocql"
 )
--- a/weed/filer/cassandra_store/schema.cql
+++ b/weed/filer/cassandra_store/schema.cql
--- a/weed/filer/client_operations.go
+++ b/weed/filer/client_operations.go
@ -5,7 +5,7 @@ import (
 	"errors"
 	"fmt"

-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/util"

 	"net/url"
 )
@ -58,7 +58,7 @@ func call(server string, request ApiRequest, ret interface{}) error {
 	}
 	values := make(url.Values)
 	values.Add("request", string(b))
-	jsonBlob, err := util.Post("http://"+server+"/__api__", values)
+	jsonBlob, err := util.Post(server, "/__api__", values)
 	if err != nil {
 		return err
 	}
--- a/weed/filer/embedded_filer/design.txt
+++ b/weed/filer/embedded_filer/design.txt
--- a/weed/filer/embedded_filer/directory.go
+++ b/weed/filer/embedded_filer/directory.go
@ -1,7 +1,7 @@
 package embedded_filer

 import (
-	"github.com/chrislusf/seaweedfs/go/filer"
+	"github.com/chrislusf/seaweedfs/weed/filer"
 )

 type DirectoryManager interface {
--- a/weed/filer/embedded_filer/directory_in_map.go
+++ b/weed/filer/embedded_filer/directory_in_map.go
@ -10,8 +10,8 @@ import (
 	"strings"
 	"sync"

-	"github.com/chrislusf/seaweedfs/go/filer"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 var writeLock sync.Mutex //serialize changes to dir.log
--- a/weed/filer/embedded_filer/directory_test.go
+++ b/weed/filer/embedded_filer/directory_test.go
--- a/weed/filer/embedded_filer/filer_embedded.go
+++ b/weed/filer/embedded_filer/filer_embedded.go
@ -6,8 +6,8 @@ import (
 	"path/filepath"
 	"strings"

-	"github.com/chrislusf/seaweedfs/go/filer"
-	"github.com/chrislusf/seaweedfs/go/operation"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/operation"
 )

 type FilerEmbedded struct {
--- a/weed/filer/embedded_filer/files_in_leveldb.go
+++ b/weed/filer/embedded_filer/files_in_leveldb.go
@ -3,8 +3,8 @@ package embedded_filer
 import (
 	"bytes"

-	"github.com/chrislusf/seaweedfs/go/filer"
-	"github.com/chrislusf/seaweedfs/go/glog"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/syndtr/goleveldb/leveldb"
 	"github.com/syndtr/goleveldb/leveldb/util"
 )
--- a/weed/filer/filer.go
+++ b/weed/filer/filer.go
--- a/weed/filer/flat_namespace/flat_namespace_filer.go
+++ b/weed/filer/flat_namespace/flat_namespace_filer.go
@ -3,7 +3,7 @@ package flat_namespace
 import (
 	"errors"

-	"github.com/chrislusf/seaweedfs/go/filer"
+	"github.com/chrislusf/seaweedfs/weed/filer"
 )

 type FlatNamespaceFiler struct {
--- a/weed/filer/flat_namespace/flat_namespace_store.go
+++ b/weed/filer/flat_namespace/flat_namespace_store.go
@ -1,7 +1,5 @@
 package flat_namespace

-import ()
-
 type FlatNamespaceStore interface {
 	Put(fullFileName string, fid string) (err error)
 	Get(fullFileName string) (fid string, err error)
--- a/weed/filer/redis_store/redis_store.go
+++ b/weed/filer/redis_store/redis_store.go
--- a/weed/glog/LICENSE
+++ b/weed/glog/LICENSE
--- a/weed/glog/README
+++ b/weed/glog/README
--- a/weed/glog/convenient_api.go
+++ b/weed/glog/convenient_api.go
--- a/weed/glog/glog.go
+++ b/weed/glog/glog.go
@ -880,7 +880,7 @@ const flushInterval = 30 * time.Second

 // flushDaemon periodically flushes the log file buffers.
 func (l *loggingT) flushDaemon() {
-	for _ = range time.NewTicker(flushInterval).C {
+	for range time.NewTicker(flushInterval).C {
 		l.lockAndFlushAll()
 	}
 }
--- a/weed/glog/glog_file.go
+++ b/weed/glog/glog_file.go
--- a/weed/glog/glog_test.go
+++ b/weed/glog/glog_test.go
--- a/weed/images/orientation.go
+++ b/weed/images/orientation.go
--- a/weed/images/orientation_test.go
+++ b/weed/images/orientation_test.go
--- a/weed/images/preprocess.go
+++ b/weed/images/preprocess.go
--- a/weed/images/resizing.go
+++ b/weed/images/resizing.go
@ -7,10 +7,12 @@ import (
 	"image/jpeg"
 	"image/png"

-	"github.com/chrislusf/seaweedfs/go/glog"
+	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/disintegration/imaging"
 )

+const defaultJpegQuality = 85
+
 func Resized(ext string, data []byte, width, height int) (resized []byte, w int, h int) {
 	if width == 0 && height == 0 {
 		return data, 0, 0
@ -34,7 +36,7 @@ func Resized(ext string, data []byte, width, height int) (resized []byte, w int,
 		case ".png":
 			png.Encode(&buf, dstImage)
 		case ".jpg", ".jpeg":
-			jpeg.Encode(&buf, dstImage, nil)
+			jpeg.Encode(&buf, dstImage, &jpeg.Options{Quality: defaultJpegQuality})
 		case ".gif":
 			gif.Encode(&buf, dstImage, nil)
 		}
--- a/weed/images/resizing_test.go
+++ b/weed/images/resizing_test.go
@ -0,0 +1,29 @@
+package images
+
+import (
+	"io/ioutil"
+	"testing"
+)
+
+func TestResizing(t *testing.T) {
+	fname := "sample1.png"
+
+	data, _ := ioutil.ReadFile(fname)
+
+	new_data, _, _ := Resized(".jpg", data, 500, 0)
+
+	ioutil.WriteFile("resized.jpg", new_data, 0644)
+}
+
+func BenchmarkResizing(b *testing.B) {
+	fName := "test1.png"
+	data, _ := ioutil.ReadFile(fName)
+	ext := ".jpg"
+	w := 0
+	h := 355
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Resized(ext, data, w, h)
+		b.SetBytes(int64(len(data)))
+	}
+}
--- a/weed/images/sample1.jpg
+++ b/weed/images/sample1.jpg
--- a/weed/main.go
+++ b/weed/main.go
@ -0,0 +1,7 @@
+package main
+
+import "github.com/chrislusf/seaweedfs/weed/weedcmd"
+
+func main() {
+	weedcmd.Main()
+}
--- a/weed/operation/assign_file_id.go
+++ b/weed/operation/assign_file_id.go
@ -7,8 +7,8 @@ import (
 	"net/url"
 	"strconv"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 type AssignResult struct {
@ -31,7 +31,7 @@ func Assign(server string, count uint64, replication string, collection string,
 	if ttl != "" {
 		values.Add("ttl", ttl)
 	}
-	jsonBlob, err := util.Post("http://"+server+"/dir/assign", values)
+	jsonBlob, err := util.Post(server, "/dir/assign", values)
 	glog.V(2).Info("assign result :", string(jsonBlob))
 	if err != nil {
 		return nil, err
--- a/weed/operation/chunked_manifest.go
+++ b/weed/operation/chunked_manifest.go
@ -0,0 +1,61 @@
+package operation
+
+import (
+	"encoding/json"
+	"errors"
+	"sort"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+)
+
+type ChunkInfo struct {
+	Fid    string `json:"fid"`
+	Offset int64  `json:"offset"`
+	Size   int64  `json:"size"`
+}
+
+type ChunkList []*ChunkInfo
+
+type ChunkManifest struct {
+	Name   string    `json:"name,omitempty"`
+	Mime   string    `json:"mime,omitempty"`
+	Size   int64     `json:"size,omitempty"`
+	Chunks ChunkList `json:"chunks,omitempty"`
+}
+
+func (s ChunkList) Len() int           { return len(s) }
+func (s ChunkList) Less(i, j int) bool { return s[i].Offset < s[j].Offset }
+func (s ChunkList) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+
+func LoadChunkManifest(buffer []byte, isGzipped bool) (*ChunkManifest, error) {
+	if isGzipped {
+		var err error
+		if buffer, err = UnGzipData(buffer); err != nil {
+			return nil, err
+		}
+	}
+	cm := ChunkManifest{}
+	if e := json.Unmarshal(buffer, &cm); e != nil {
+		return nil, e
+	}
+	sort.Sort(cm.Chunks)
+	return &cm, nil
+}
+
+func (cm *ChunkManifest) Marshal() ([]byte, error) {
+	return json.Marshal(cm)
+}
+
+func (cm *ChunkManifest) DeleteChunks(master, collection string) error {
+	deleteError := 0
+	for _, ci := range cm.Chunks {
+		if e := DeleteFile(master, ci.Fid, collection, ""); e != nil {
+			deleteError++
+			glog.V(0).Infof("Delete %s error: %v, master: %s", ci.Fid, e, master)
+		}
+	}
+	if deleteError > 0 {
+		return errors.New("Not all chunks deleted.")
+	}
+	return nil
+}
--- a/weed/operation/compress.go
+++ b/weed/operation/compress.go
@ -7,7 +7,7 @@ import (
 	"io/ioutil"
 	"strings"

-	"github.com/chrislusf/seaweedfs/go/glog"
+	"github.com/chrislusf/seaweedfs/weed/glog"
 )

 /*
--- a/weed/operation/delete_content.go
+++ b/weed/operation/delete_content.go
@ -10,8 +10,8 @@ import (

 	"net/http"

-	"github.com/chrislusf/seaweedfs/go/security"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/security"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 type DeleteResult struct {
@ -21,8 +21,8 @@ type DeleteResult struct {
 	Error  string `json:"error,omitempty"`
 }

-func DeleteFile(master string, fileId string, jwt security.EncodedJwt) error {
-	fileUrl, err := LookupFileId(master, fileId)
+func DeleteFile(master, fileId, collection string, jwt security.EncodedJwt) error {
+	fileUrl, err := LookupFileId(master, fileId, collection, false)
 	if err != nil {
 		return fmt.Errorf("Failed to lookup %s:%v", fileId, err)
 	}
@ -97,7 +97,7 @@ func DeleteFiles(master string, fileIds []string) (*DeleteFilesResult, error) {
 			for _, fid := range fidList {
 				values.Add("fid", fid)
 			}
-			jsonBlob, err := util.Post("http://"+server+"/delete", values)
+			jsonBlob, err := util.Post(server, "/delete", values)
 			if err != nil {
 				ret.Errors = append(ret.Errors, err.Error()+" "+string(jsonBlob))
 				return
--- a/weed/operation/list_masters.go
+++ b/weed/operation/list_masters.go
@ -3,8 +3,8 @@ package operation
 import (
 	"encoding/json"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 type ClusterStatusResult struct {
@ -14,7 +14,7 @@ type ClusterStatusResult struct {
 }

 func ListMasters(server string) ([]string, error) {
-	jsonBlob, err := util.Get("http://" + server + "/cluster/status")
+	jsonBlob, err := util.Get(server, "/cluster/status", nil)
 	glog.V(2).Info("list masters result :", string(jsonBlob))
 	if err != nil {
 		return nil, err
--- a/weed/operation/lookup.go
+++ b/weed/operation/lookup.go
@ -9,31 +9,42 @@ import (
 	"strings"
 	"time"

-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 type Location struct {
 	Url       string `json:"url,omitempty"`
 	PublicUrl string `json:"publicUrl,omitempty"`
 }
+
+type Locations []Location
+
 type LookupResult struct {
-	VolumeId  string     `json:"volumeId,omitempty"`
-	Locations []Location `json:"locations,omitempty"`
-	Error     string     `json:"error,omitempty"`
+	VolumeId  string    `json:"volumeId,omitempty"`
+	Locations Locations `json:"locations,omitempty"`
+	Error     string    `json:"error,omitempty"`
 }

 func (lr *LookupResult) String() string {
 	return fmt.Sprintf("VolumeId:%s, Locations:%v, Error:%s", lr.VolumeId, lr.Locations, lr.Error)
 }

+func (ls Locations) Head() *Location {
+	return &ls[0]
+}
+
+func (ls Locations) PickForRead() *Location {
+	return &ls[rand.Intn(len(ls))]
+}
+
 var (
 	vc VidCache // caching of volume locations, re-check if after 10 minutes
 )

-func Lookup(server string, vid string) (ret *LookupResult, err error) {
+func Lookup(server, vid, collection string) (ret *LookupResult, err error) {
 	locations, cache_err := vc.Get(vid)
 	if cache_err != nil {
-		if ret, err = do_lookup(server, vid); err == nil {
+		if ret, err = do_lookup(server, vid, collection); err == nil {
 			vc.Set(vid, ret.Locations, 10*time.Minute)
 		}
 	} else {
@ -42,10 +53,20 @@ func Lookup(server string, vid string) (ret *LookupResult, err error) {
 	return
 }

-func do_lookup(server string, vid string) (*LookupResult, error) {
+func LookupNoCache(server, vid, collection string) (ret *LookupResult, err error) {
+	if ret, err = do_lookup(server, vid, collection); err == nil {
+		vc.Set(vid, ret.Locations, 10*time.Minute)
+	}
+	return
+}
+
+func do_lookup(server, vid, collection string) (*LookupResult, error) {
 	values := make(url.Values)
 	values.Add("volumeId", vid)
-	jsonBlob, err := util.Post("http://"+server+"/dir/lookup", values)
+	if collection != "" {
+		values.Set("collection", collection)
+	}
+	jsonBlob, err := util.Post(server, "/dir/lookup", values)
 	if err != nil {
 		return nil, err
 	}
@ -60,19 +81,25 @@ func do_lookup(server string, vid string) (*LookupResult, error) {
 	return &ret, nil
 }

-func LookupFileId(server string, fileId string) (fullUrl string, err error) {
+func LookupFileId(server, fileId, collection string, readonly bool) (fullUrl string, err error) {
 	parts := strings.Split(fileId, ",")
 	if len(parts) != 2 {
 		return "", errors.New("Invalid fileId " + fileId)
 	}
-	lookup, lookupError := Lookup(server, parts[0])
+	lookup, lookupError := Lookup(server, parts[0], collection)
 	if lookupError != nil {
 		return "", lookupError
 	}
 	if len(lookup.Locations) == 0 {
 		return "", errors.New("File Not Found")
 	}
-	return "http://" + lookup.Locations[rand.Intn(len(lookup.Locations))].Url + "/" + fileId, nil
+	var u string
+	if readonly {
+		u = lookup.Locations.PickForRead().Url
+	} else {
+		u = lookup.Locations.Head().Url
+	}
+	return util.MkUrl(u, "/"+fileId, nil), nil
 }

 // LookupVolumeIds find volume locations by cache and actual lookup
@ -99,7 +126,7 @@ func LookupVolumeIds(server string, vids []string) (map[string]LookupResult, err
 	for _, vid := range unknown_vids {
 		values.Add("volumeId", vid)
 	}
-	jsonBlob, err := util.Post("http://"+server+"/vol/lookup", values)
+	jsonBlob, err := util.Post(server, "/vol/lookup", values)
 	if err != nil {
 		return nil, err
 	}
--- a/weed/operation/lookup_vid_cache.go
+++ b/weed/operation/lookup_vid_cache.go
@ -5,18 +5,22 @@ import (
 	"strconv"
 	"time"

-	"github.com/chrislusf/seaweedfs/go/glog"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"sync"
 )

 type VidInfo struct {
-	Locations       []Location
+	Locations       Locations
 	NextRefreshTime time.Time
 }
 type VidCache struct {
 	cache []VidInfo
+	mutex sync.RWMutex
 }

-func (vc *VidCache) Get(vid string) ([]Location, error) {
+func (vc *VidCache) Get(vid string) (Locations, error) {
+	vc.mutex.RLock()
+	defer vc.mutex.RUnlock()
 	id, err := strconv.Atoi(vid)
 	if err != nil {
 		glog.V(1).Infof("Unknown volume id %s", vid)
@ -33,7 +37,9 @@ func (vc *VidCache) Get(vid string) ([]Location, error) {
 	}
 	return nil, errors.New("Not Found")
 }
-func (vc *VidCache) Set(vid string, locations []Location, duration time.Duration) {
+func (vc *VidCache) Set(vid string, locations Locations, duration time.Duration) {
+	vc.mutex.Lock()
+	defer vc.mutex.Unlock()
 	id, err := strconv.Atoi(vid)
 	if err != nil {
 		glog.V(1).Infof("Unknown volume id %s", vid)
--- a/weed/operation/lookup_vid_cache_test.go
+++ b/weed/operation/lookup_vid_cache_test.go
@ -10,7 +10,7 @@ func TestCaching(t *testing.T) {
 	var (
 		vc VidCache
 	)
-	var locations []Location
+	var locations Locations
 	locations = append(locations, Location{Url: "a.com:8080"})
 	vc.Set("123", locations, time.Second)
 	ret, _ := vc.Get("123")
--- a/weed/operation/submit.go
+++ b/weed/operation/submit.go
@ -10,8 +10,8 @@ import (
 	"strconv"
 	"strings"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/security"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/security"
 )

 type FilePart struct {
@ -46,7 +46,7 @@ func SubmitFiles(master string, files []FilePart,
 	}
 	ret, err := Assign(master, uint64(len(files)), replication, collection, ttl)
 	if err != nil {
-		for index, _ := range files {
+		for index := range files {
 			results[index].Error = err.Error()
 		}
 		return results, err
@ -134,7 +134,7 @@ func (fi FilePart) Upload(maxMB int, master string, secret security.Secret) (ret
 				jwt)
 			if e != nil {
 				// delete all uploaded chunks
-				cm.DeleteChunks(master)
+				cm.DeleteChunks(master, fi.Collection)
 				return 0, e
 			}
 			cm.Chunks = append(cm.Chunks,
@ -149,7 +149,7 @@ func (fi FilePart) Upload(maxMB int, master string, secret security.Secret) (ret
 		err = upload_chunked_file_manifest(fileUrl, &cm, jwt)
 		if err != nil {
 			// delete all uploaded chunks
-			cm.DeleteChunks(master)
+			cm.DeleteChunks(master, fi.Collection)
 		}
 	} else {
 		ret, e := Upload(fileUrl, baseName, fi.Reader, fi.IsGzipped, fi.MimeType, jwt)
--- a/weed/operation/sync_volume.go
+++ b/weed/operation/sync_volume.go
@ -5,12 +5,11 @@ import (
 	"fmt"
 	"net/url"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 type SyncVolumeResponse struct {
-	Replication     string `json:"Replication,omitempty"`
 	Ttl             string `json:"Ttl,omitempty"`
 	TailOffset      uint64 `json:"TailOffset,omitempty"`
 	CompactRevision uint16 `json:"CompactRevision,omitempty"`
@ -21,7 +20,7 @@ type SyncVolumeResponse struct {
 func GetVolumeSyncStatus(server string, vid string) (*SyncVolumeResponse, error) {
 	values := make(url.Values)
 	values.Add("volume", vid)
-	jsonBlob, err := util.Post("http://"+server+"/admin/sync/status", values)
+	jsonBlob, err := util.Post(server, "/admin/sync/status", values)
 	glog.V(2).Info("sync volume result :", string(jsonBlob))
 	if err != nil {
 		return nil, err
--- a/weed/operation/upload_content.go
+++ b/weed/operation/upload_content.go
@ -14,8 +14,8 @@ import (
 	"path/filepath"
 	"strings"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/security"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/security"
 )

 type UploadResult struct {
--- a/weed/security/guard.go
+++ b/weed/security/guard.go
@ -8,7 +8,7 @@ import (
 	"regexp"
 	"strings"

-	"github.com/chrislusf/seaweedfs/go/glog"
+	"github.com/chrislusf/seaweedfs/weed/glog"
 )

 var (
@ -41,19 +41,35 @@ Referenced:
 https://github.com/pkieltyka/jwtauth/blob/master/jwtauth.go

 */
+
+//TODO lock on data access?
 type Guard struct {
 	whiteList []string
-	SecretKey Secret
+	secretKey Secret

 	isActive bool
 }

 func NewGuard(whiteList []string, secretKey string) *Guard {
-	g := &Guard{whiteList: whiteList, SecretKey: Secret(secretKey)}
-	g.isActive = len(g.whiteList) != 0 || len(g.SecretKey) != 0
+	g := &Guard{whiteList: whiteList, secretKey: Secret(secretKey)}
+	g.isActive = len(g.whiteList) != 0 || len(g.secretKey) != 0
 	return g
 }

+func (g *Guard) SetSecretKey(k string) {
+	g.secretKey = Secret(k)
+	g.isActive = len(g.whiteList) != 0 || len(g.secretKey) != 0
+}
+
+func (g *Guard) GetSecretKey() Secret {
+	return g.secretKey
+}
+
+func (g *Guard) SetWhiteList(l []string) {
+	g.whiteList = l
+	g.isActive = len(g.whiteList) != 0 || len(g.secretKey) != 0
+}
+
 func (g *Guard) WhiteList(f func(w http.ResponseWriter, r *http.Request)) func(w http.ResponseWriter, r *http.Request) {
 	if !g.isActive {
 		//if no security needed, just skip all checkings
@ -138,7 +154,7 @@ func (g *Guard) checkJwt(w http.ResponseWriter, r *http.Request) error {
 		return nil
 	}

-	if len(g.SecretKey) == 0 {
+	if len(g.secretKey) == 0 {
 		return nil
 	}

@ -149,7 +165,7 @@ func (g *Guard) checkJwt(w http.ResponseWriter, r *http.Request) error {
 	}

 	// Verify the token
-	token, err := DecodeJwt(g.SecretKey, tokenStr)
+	token, err := DecodeJwt(g.secretKey, tokenStr)
 	if err != nil {
 		glog.V(1).Infof("Token verification error from %s: %v", r.RemoteAddr, err)
 		return ErrUnauthorized
--- a/weed/security/jwt.go
+++ b/weed/security/jwt.go
@ -6,7 +6,7 @@ import (

 	"time"

-	"github.com/chrislusf/seaweedfs/go/glog"
+	"github.com/chrislusf/seaweedfs/weed/glog"
 	jwt "github.com/dgrijalva/jwt-go"
 )

--- a/weed/sequence/memory_sequencer.go
+++ b/weed/sequence/memory_sequencer.go
--- a/weed/sequence/sequence.go
+++ b/weed/sequence/sequence.go
--- a/weed/stats/disk.go
+++ b/weed/stats/disk.go
--- a/weed/stats/disk_notsupported.go
+++ b/weed/stats/disk_notsupported.go
--- a/weed/stats/disk_supported.go
+++ b/weed/stats/disk_supported.go
--- a/weed/stats/duration_counter.go
+++ b/weed/stats/duration_counter.go
@ -1,6 +1,7 @@
 package stats

 import (
+	"sync"
 	"time"
 )

@ -14,28 +15,33 @@ func NewTimedValue(t time.Time, val int64) *TimedValue {
 }

 type RoundRobinCounter struct {
-	LastIndex int
-	Values    []int64
-	Counts    []int64
+	lastIndex int
+	values    []int64
+	counts    []int64
+	mutex     sync.RWMutex
 }

 func NewRoundRobinCounter(slots int) *RoundRobinCounter {
-	return &RoundRobinCounter{LastIndex: -1, Values: make([]int64, slots), Counts: make([]int64, slots)}
+	return &RoundRobinCounter{lastIndex: -1, values: make([]int64, slots), counts: make([]int64, slots)}
 }
 func (rrc *RoundRobinCounter) Add(index int, val int64) {
-	if index >= len(rrc.Values) {
+	rrc.mutex.Lock()
+	defer rrc.mutex.Unlock()
+	if index >= len(rrc.values) {
 		return
 	}
-	for rrc.LastIndex != index {
-		rrc.LastIndex = (rrc.LastIndex + 1) % len(rrc.Values)
-		rrc.Values[rrc.LastIndex] = 0
-		rrc.Counts[rrc.LastIndex] = 0
+	for rrc.lastIndex != index {
+		rrc.lastIndex = (rrc.lastIndex + 1) % len(rrc.values)
+		rrc.values[rrc.lastIndex] = 0
+		rrc.counts[rrc.lastIndex] = 0
 	}
-	rrc.Values[index] += val
-	rrc.Counts[index]++
+	rrc.values[index] += val
+	rrc.counts[index]++
 }
 func (rrc *RoundRobinCounter) Max() (max int64) {
-	for _, val := range rrc.Values {
+	rrc.mutex.RLock()
+	defer rrc.mutex.RUnlock()
+	for _, val := range rrc.values {
 		if max < val {
 			max = val
 		}
@ -43,28 +49,34 @@ func (rrc *RoundRobinCounter) Max() (max int64) {
 	return
 }
 func (rrc *RoundRobinCounter) Count() (cnt int64) {
-	for _, c := range rrc.Counts {
+	rrc.mutex.RLock()
+	defer rrc.mutex.RUnlock()
+	for _, c := range rrc.counts {
 		cnt += c
 	}
 	return
 }
 func (rrc *RoundRobinCounter) Sum() (sum int64) {
-	for _, val := range rrc.Values {
+	rrc.mutex.RLock()
+	defer rrc.mutex.RUnlock()
+	for _, val := range rrc.values {
 		sum += val
 	}
 	return
 }

 func (rrc *RoundRobinCounter) ToList() (ret []int64) {
-	index := rrc.LastIndex
-	step := len(rrc.Values)
+	rrc.mutex.RLock()
+	defer rrc.mutex.RUnlock()
+	index := rrc.lastIndex
+	step := len(rrc.values)
 	for step > 0 {
 		step--
 		index++
-		if index >= len(rrc.Values) {
+		if index >= len(rrc.values) {
 			index = 0
 		}
-		ret = append(ret, rrc.Values[index])
+		ret = append(ret, rrc.values[index])
 	}
 	return
 }
--- a/weed/stats/duration_counter_test.go
+++ b/weed/stats/duration_counter_test.go
@ -7,10 +7,10 @@ func TestRobinCounter(t *testing.T) {
 	rrc.Add(0, 1)
 	rrc.Add(50, 2)
 	if rrc.Count() != 2 {
-		t.Fatal()
+		t.Fatal("faild1")
 	}
 	if rrc.Sum() != 3 {
-		t.Fatal()
+		t.Fatal("faild2")
 	}
 	/*
 		index out of range
--- a/weed/stats/memory.go
+++ b/weed/stats/memory.go
--- a/weed/stats/memory_notsupported.go
+++ b/weed/stats/memory_notsupported.go
--- a/weed/stats/memory_supported.go
+++ b/weed/stats/memory_supported.go
--- a/weed/stats/stats.go
+++ b/weed/stats/stats.go
@ -0,0 +1,65 @@
+package stats
+
+import (
+	"time"
+)
+
+type ServerStats struct {
+	Requests       *DurationCounter
+	Connections    *DurationCounter
+	AssignRequests *DurationCounter
+	ReadRequests   *DurationCounter
+	WriteRequests  *DurationCounter
+	DeleteRequests *DurationCounter
+	BytesIn        *DurationCounter
+	BytesOut       *DurationCounter
+}
+
+var (
+	ServStats = NewServerStats()
+)
+
+func NewServerStats() *ServerStats {
+	return &ServerStats{
+		Requests:       NewDurationCounter(),
+		Connections:    NewDurationCounter(),
+		AssignRequests: NewDurationCounter(),
+		ReadRequests:   NewDurationCounter(),
+		WriteRequests:  NewDurationCounter(),
+		DeleteRequests: NewDurationCounter(),
+		BytesIn:        NewDurationCounter(),
+		BytesOut:       NewDurationCounter(),
+	}
+}
+
+func ConnectionOpen() {
+	ServStats.Connections.Add(NewTimedValue(time.Now(), 1))
+}
+func ConnectionClose() {
+	ServStats.Connections.Add(NewTimedValue(time.Now(), -1))
+}
+func RequestOpen() {
+	ServStats.Requests.Add(NewTimedValue(time.Now(), 1))
+}
+func RequestClose() {
+	ServStats.Requests.Add(NewTimedValue(time.Now(), 1))
+
+}
+func AssignRequest() {
+	ServStats.AssignRequests.Add(NewTimedValue(time.Now(), 1))
+}
+func ReadRequest() {
+	ServStats.ReadRequests.Add(NewTimedValue(time.Now(), 1))
+}
+func WriteRequest() {
+	ServStats.WriteRequests.Add(NewTimedValue(time.Now(), 1))
+}
+func DeleteRequest() {
+	ServStats.DeleteRequests.Add(NewTimedValue(time.Now(), 1))
+}
+func BytesIn(val int64) {
+	ServStats.BytesIn.Add(NewTimedValue(time.Now(), 1))
+}
+func BytesOut(val int64) {
+	ServStats.BytesOut.Add(NewTimedValue(time.Now(), 1))
+}
--- a/weed/storage/chunked_file_reader.go
+++ b/weed/storage/chunked_file_reader.go
@ -1,17 +1,14 @@
-package operation
+package storage

 import (
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
 	"net/http"
-	"sort"
-
 	"sync"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/operation"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 var (
@ -21,69 +18,43 @@ var (
 	ErrInvalidRange = errors.New("Invalid range")
 )

-type ChunkInfo struct {
-	Fid    string `json:"fid"`
-	Offset int64  `json:"offset"`
-	Size   int64  `json:"size"`
-}
-
-type ChunkList []*ChunkInfo
-
-type ChunkManifest struct {
-	Name   string    `json:"name,omitempty"`
-	Mime   string    `json:"mime,omitempty"`
-	Size   int64     `json:"size,omitempty"`
-	Chunks ChunkList `json:"chunks,omitempty"`
-}
-
 // seekable chunked file reader
 type ChunkedFileReader struct {
-	Manifest *ChunkManifest
-	Master   string
-	pos      int64
-	pr       *io.PipeReader
-	pw       *io.PipeWriter
-	mutex    sync.Mutex
+	Manifest   *operation.ChunkManifest
+	Master     string
+	Collection string
+	Store      *Store
+	pos        int64
+	pr         *io.PipeReader
+	pw         *io.PipeWriter
+	mutex      sync.Mutex
 }

-func (s ChunkList) Len() int           { return len(s) }
-func (s ChunkList) Less(i, j int) bool { return s[i].Offset < s[j].Offset }
-func (s ChunkList) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
-
-func LoadChunkManifest(buffer []byte, isGzipped bool) (*ChunkManifest, error) {
-	if isGzipped {
-		var err error
-		if buffer, err = UnGzipData(buffer); err != nil {
-			return nil, err
-		}
+func (cf *ChunkedFileReader) Seek(offset int64, whence int) (int64, error) {
+	var err error
+	switch whence {
+	case 0:
+	case 1:
+		offset += cf.pos
+	case 2:
+		offset = cf.Manifest.Size - offset
 	}
-	cm := ChunkManifest{}
-	if e := json.Unmarshal(buffer, &cm); e != nil {
-		return nil, e
+	if offset > cf.Manifest.Size {
+		err = ErrInvalidRange
 	}
-	sort.Sort(cm.Chunks)
-	return &cm, nil
-}
-
-func (cm *ChunkManifest) Marshal() ([]byte, error) {
-	return json.Marshal(cm)
+	if cf.pos != offset {
+		cf.Close()
+	}
+	cf.pos = offset
+	return cf.pos, err
 }

-func (cm *ChunkManifest) DeleteChunks(master string) error {
-	deleteError := 0
-	for _, ci := range cm.Chunks {
-		if e := DeleteFile(master, ci.Fid, ""); e != nil {
-			deleteError++
-			glog.V(0).Infof("Delete %s error: %v, master: %s", ci.Fid, e, master)
-		}
+func (cf *ChunkedFileReader) readRemoteChunkNeedle(fid string, w io.Writer, offset int64) (written int64, e error) {
+	fileUrl, lookupError := operation.LookupFileId(cf.Master, fid, cf.Collection, true)
+	if lookupError != nil {
+		return 0, lookupError
 	}
-	if deleteError > 0 {
-		return errors.New("Not all chunks deleted.")
-	}
-	return nil
-}

-func readChunkNeedle(fileUrl string, w io.Writer, offset int64) (written int64, e error) {
 	req, err := http.NewRequest("GET", fileUrl, nil)
 	if err != nil {
 		return written, err
@ -92,7 +63,7 @@ func readChunkNeedle(fileUrl string, w io.Writer, offset int64) (written int64,
 		req.Header.Set("Range", fmt.Sprintf("bytes=%d-", offset))
 	}

-	resp, err := util.Do(req)
+	resp, err := util.HttpDo(req)
 	if err != nil {
 		return written, err
 	}
@ -114,23 +85,21 @@ func readChunkNeedle(fileUrl string, w io.Writer, offset int64) (written int64,
 	return io.Copy(w, resp.Body)
 }

-func (cf *ChunkedFileReader) Seek(offset int64, whence int) (int64, error) {
-	var err error
-	switch whence {
-	case 0:
-	case 1:
-		offset += cf.pos
-	case 2:
-		offset = cf.Manifest.Size - offset
+func (cf *ChunkedFileReader) readLocalChunkNeedle(fid *FileId, w io.Writer, offset int64) (written int64, e error) {
+	n := &Needle{
+		Id:     fid.Key,
+		Cookie: fid.Hashcode,
 	}
-	if offset > cf.Manifest.Size {
-		err = ErrInvalidRange
+	cookie := n.Cookie
+	count, e := cf.Store.ReadVolumeNeedle(fid.VolumeId, n)
+	if e != nil || count <= 0 {
+		return 0, e
 	}
-	if cf.pos != offset {
-		cf.Close()
+	if n.Cookie != cookie {
+		return 0, fmt.Errorf("read error: with unmaching cookie seen: %x expected: %x", cookie, n.Cookie)
 	}
-	cf.pos = offset
-	return cf.pos, err
+	wn, e := w.Write(n.Data[offset:])
+	return int64(wn), e
 }

 func (cf *ChunkedFileReader) WriteTo(w io.Writer) (n int64, err error) {
@ -149,12 +118,18 @@ func (cf *ChunkedFileReader) WriteTo(w io.Writer) (n int64, err error) {
 	}
 	for ; chunkIndex < cm.Chunks.Len(); chunkIndex++ {
 		ci := cm.Chunks[chunkIndex]
-		// if we need read date from local volume server first?
-		fileUrl, lookupError := LookupFileId(cf.Master, ci.Fid)
-		if lookupError != nil {
-			return n, lookupError
+		fid, e := ParseFileId(ci.Fid)
+		if e != nil {
+			return n, e
 		}
-		if wn, e := readChunkNeedle(fileUrl, w, chunkStartOffset); e != nil {
+		var wn int64
+		if cf.Store != nil && cf.Store.HasVolume(fid.VolumeId) {
+			wn, e = cf.readLocalChunkNeedle(fid, w, chunkStartOffset)
+		} else {
+			wn, e = cf.readRemoteChunkNeedle(ci.Fid, w, chunkStartOffset)
+		}
+
+		if e != nil {
 			return n, e
 		} else {
 			n += wn
--- a/weed/storage/collection_settings.go
+++ b/weed/storage/collection_settings.go
@ -0,0 +1,117 @@
+package storage
+
+import "github.com/chrislusf/seaweedfs/weed/weedpb"
+
+type SettingKey int
+
+const (
+	keyReplicatePlacement SettingKey = iota
+	keyGarbageThreshold
+)
+
+type CollectionSettings struct {
+	settings map[string]map[SettingKey]interface{}
+}
+
+func NewCollectionSettings(defaultReplicatePlacement, defaultGarbageThreshold string) *CollectionSettings {
+	rp, e := NewReplicaPlacementFromString(defaultReplicatePlacement)
+	if e != nil {
+		rp, _ = NewReplicaPlacementFromString("000")
+	}
+	c := &CollectionSettings{
+		settings: make(map[string]map[SettingKey]interface{}),
+	}
+	c.set("", keyReplicatePlacement, rp)
+	c.set("", keyGarbageThreshold, defaultGarbageThreshold)
+	return c
+}
+
+func NewCollectionSettingsFromPbMessage(msg []*weedpb.CollectionSetting) *CollectionSettings {
+	c := &CollectionSettings{
+		settings: make(map[string]map[SettingKey]interface{}),
+	}
+	for _, m := range msg {
+		c.SetGarbageThreshold(m.Collection, m.VacuumGarbageThreshold)
+		c.SetReplicaPlacement(m.Collection, m.ReplicaPlacement)
+	}
+	return c
+}
+
+func (cs *CollectionSettings) ToPbMessage() []*weedpb.CollectionSetting {
+	msg := make([]*weedpb.CollectionSetting, 0, len(cs.settings))
+	for collection, m := range cs.settings {
+		setting := &weedpb.CollectionSetting{
+			Collection: collection,
+		}
+		if v, ok := m[keyReplicatePlacement]; ok && v != nil {
+			setting.ReplicaPlacement = v.(*ReplicaPlacement).String()
+		}
+		if v, ok := m[keyGarbageThreshold]; ok && v != nil {
+			setting.VacuumGarbageThreshold = v.(string)
+		}
+		msg = append(msg, setting)
+	}
+	return msg
+}
+
+func (cs *CollectionSettings) get(collection string, key SettingKey) interface{} {
+	if m, ok := cs.settings[collection]; ok {
+		if v, ok := m[key]; ok {
+			return v
+		}
+	}
+	if m, ok := cs.settings[""]; ok {
+		return m[key]
+	}
+	return nil
+}
+
+func (cs *CollectionSettings) set(collection string, key SettingKey, value interface{}) {
+	m := cs.settings[collection]
+	if m == nil {
+		m = make(map[SettingKey]interface{})
+		cs.settings[collection] = m
+	}
+	if value == nil {
+		//mustn't delete default setting
+		if collection != "" {
+			delete(m, key)
+		}
+	} else {
+		m[key] = value
+	}
+}
+
+func (cs *CollectionSettings) GetGarbageThreshold(collection string) string {
+	return cs.get(collection, keyGarbageThreshold).(string)
+}
+
+func (cs *CollectionSettings) SetGarbageThreshold(collection string, gt string) {
+	if gt == "" {
+		cs.set(collection, keyGarbageThreshold, nil)
+	} else {
+		cs.set(collection, keyGarbageThreshold, gt)
+
+	}
+}
+
+func (cs *CollectionSettings) GetReplicaPlacement(collection string) *ReplicaPlacement {
+	v := cs.get(collection, keyReplicatePlacement)
+	if v == nil {
+		return nil
+	} else {
+		return v.(*ReplicaPlacement)
+	}
+}
+
+func (cs *CollectionSettings) SetReplicaPlacement(collection, t string) error {
+	if t == "" {
+		cs.set(collection, keyReplicatePlacement, nil)
+		return nil
+	}
+	rp, e := NewReplicaPlacementFromString(t)
+	if e == nil {
+		cs.set(collection, keyReplicatePlacement, rp)
+	}
+	return e
+}
--- a/weed/storage/collection_settings_test.go
+++ b/weed/storage/collection_settings_test.go
@ -0,0 +1,32 @@
+package storage
+
+import (
+	"encoding/json"
+	"reflect"
+	"testing"
+)
+
+func TestCollectionSettings(t *testing.T) {
+	cs1 := NewCollectionSettings("000", "0.3")
+	cs1.SetReplicaPlacement("col1", "001")
+	cs1.SetGarbageThreshold("col2", "0.5")
+
+	if cs1.GetGarbageThreshold("col1") != "0.3" ||
+		cs1.GetGarbageThreshold("col2") != "0.5" ||
+		cs1.GetGarbageThreshold("") != "0.3" ||
+		cs1.GetReplicaPlacement("").String() != "000" ||
+		cs1.GetReplicaPlacement("col1").String() != "001" ||
+		cs1.GetReplicaPlacement("col2").String() != "000" {
+		t.Fatal("Value incorrect.")
+	}
+	pb := cs1.ToPbMessage()
+	if buf, e := json.MarshalIndent(pb, "", "\t"); e == nil {
+		t.Log(string(buf))
+	} else {
+		t.Fatal(e)
+	}
+	cs2 := NewCollectionSettingsFromPbMessage(pb)
+	if !reflect.DeepEqual(cs1, cs2) {
+		t.Fatal("PbMessage convert incorrect.")
+	}
+}
--- a/weed/storage/compact_map.go
+++ b/weed/storage/compact_map.go
@ -1,6 +1,9 @@
 package storage

-import "strconv"
+import (
+	"strconv"
+	"sync"
+)

 type NeedleValue struct {
 	Key    Key
@ -18,6 +21,7 @@ func (k Key) String() string {
 	return strconv.FormatUint(uint64(k), 10)
 }

+//CompactSection is not concurrent safe,you should lock it when access in multi-thread
 type CompactSection struct {
 	values   []NeedleValue
 	overflow map[Key]NeedleValue
@ -78,6 +82,7 @@ func (cs *CompactSection) Delete(key Key) uint32 {
 	}
 	return ret
 }
+
 func (cs *CompactSection) Get(key Key) (*NeedleValue, bool) {
 	if v, ok := cs.overflow[key]; ok {
 		return &v, true
@ -87,6 +92,7 @@ func (cs *CompactSection) Get(key Key) (*NeedleValue, bool) {
 	}
 	return nil, false
 }
+
 func (cs *CompactSection) binarySearchValues(key Key) int {
 	l, h := 0, cs.counter-1
 	if h >= 0 && cs.values[h].Key < key {
@ -109,15 +115,19 @@ func (cs *CompactSection) binarySearchValues(key Key) int {
 }

 //This map assumes mostly inserting increasing keys
+//It is concurrent safe
 type CompactMap struct {
 	list []*CompactSection
+	lock sync.RWMutex
 }

-func NewCompactMap() CompactMap {
-	return CompactMap{}
+func NewCompactMap() *CompactMap {
+	return &CompactMap{}
 }

 func (cm *CompactMap) Set(key Key, offset uint32, size uint32) uint32 {
+	cm.lock.Lock()
+	defer cm.lock.Unlock()
 	x := cm.binarySearchCompactSection(key)
 	if x < 0 {
 		//println(x, "creating", len(cm.list), "section, starting", key)
@ -135,14 +145,20 @@ func (cm *CompactMap) Set(key Key, offset uint32, size uint32) uint32 {
 	}
 	return cm.list[x].Set(key, offset, size)
 }
+
 func (cm *CompactMap) Delete(key Key) uint32 {
+	cm.lock.Lock()
+	defer cm.lock.Unlock()
 	x := cm.binarySearchCompactSection(key)
 	if x < 0 {
 		return uint32(0)
 	}
 	return cm.list[x].Delete(key)
 }
+
 func (cm *CompactMap) Get(key Key) (*NeedleValue, bool) {
+	cm.lock.RLock()
+	defer cm.lock.RUnlock()
 	x := cm.binarySearchCompactSection(key)
 	if x < 0 {
 		return nil, false
@ -176,7 +192,10 @@ func (cm *CompactMap) binarySearchCompactSection(key Key) int {
 }

 // Visit visits all entries or stop if any error when visiting
+// You should NOT add or delete item in visit func
 func (cm *CompactMap) Visit(visit func(NeedleValue) error) error {
+	cm.lock.RLock()
+	defer cm.lock.RUnlock()
 	for _, cs := range cm.list {
 		for _, v := range cs.overflow {
 			if err := visit(v); err != nil {
--- a/weed/storage/compact_map_perf_test.go
+++ b/weed/storage/compact_map_perf_test.go
@ -5,8 +5,8 @@ import (
 	"os"
 	"testing"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 func TestMemoryUsage(t *testing.T) {
@ -19,7 +19,7 @@ func TestMemoryUsage(t *testing.T) {

 }

-func LoadNewNeedleMap(file *os.File) CompactMap {
+func LoadNewNeedleMap(file *os.File) *CompactMap {
 	m := NewCompactMap()
 	bytes := make([]byte, 16*1024)
 	count, e := file.Read(bytes)
--- a/weed/storage/compact_map_test.go
+++ b/weed/storage/compact_map_test.go
--- a/weed/storage/crc.go
+++ b/weed/storage/crc.go
@ -4,7 +4,7 @@ import (
 	"fmt"
 	"github.com/klauspost/crc32"

-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 var table = crc32.MakeTable(crc32.Castagnoli)
--- a/weed/storage/disk_location.go
+++ b/weed/storage/disk_location.go
@ -0,0 +1,126 @@
+package storage
+
+import (
+	"io/ioutil"
+	"strings"
+	"sync"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+)
+
+// DiskLocation is concurrent safe
+type DiskLocation struct {
+	Directory      string
+	MaxVolumeCount int
+	volumes        map[VolumeId]*Volume
+	mutex          sync.RWMutex
+}
+
+func NewDiskLocation(dir string, maxVolCount int) *DiskLocation {
+	return &DiskLocation{
+		Directory:      dir,
+		MaxVolumeCount: maxVolCount,
+		volumes:        make(map[VolumeId]*Volume),
+	}
+}
+
+func (l *DiskLocation) LoadExistingVolumes(needleMapKind NeedleMapType) {
+	if dirs, err := ioutil.ReadDir(l.Directory); err == nil {
+		for _, dir := range dirs {
+			name := dir.Name()
+			if !dir.IsDir() && strings.HasSuffix(name, ".dat") {
+				collection := ""
+				base := name[:len(name)-len(".dat")]
+				i := strings.LastIndex(base, "_")
+				if i > 0 {
+					collection, base = base[0:i], base[i+1:]
+				}
+				if vid, err := NewVolumeId(base); err == nil {
+					if !l.HasVolume(vid) {
+						if v, e := NewVolume(l.Directory, collection, vid, needleMapKind, nil); e == nil {
+							l.AddVolume(vid, v)
+							glog.V(1).Infof("data file %s, v=%d size=%d ttl=%s", l.Directory+"/"+name, v.Version(), v.Size(), v.Ttl.String())
+						} else {
+							glog.V(0).Infof("new volume %s error %s", name, e)
+						}
+					}
+				}
+			}
+		}
+	}
+	glog.V(0).Infoln("Store started on dir:", l.Directory, "with", l.VolumeCount(), "volumes", "max", l.MaxVolumeCount)
+}
+
+func (l *DiskLocation) AddVolume(vid VolumeId, v *Volume) {
+	l.mutex.Lock()
+	defer l.mutex.Unlock()
+	l.volumes[vid] = v
+}
+
+func (l *DiskLocation) DeleteVolume(vid VolumeId) (e error) {
+	l.mutex.Lock()
+	defer l.mutex.Unlock()
+	if v, ok := l.volumes[vid]; ok {
+		e = v.Destroy()
+	}
+	delete(l.volumes, vid)
+	return
+}
+
+func (l *DiskLocation) DeleteCollection(collection string) (e error) {
+	l.mutex.Lock()
+	defer l.mutex.Unlock()
+	for k, v := range l.volumes {
+		if v.Collection == collection {
+			e = v.Destroy()
+			if e != nil {
+				return
+			}
+			delete(l.volumes, k)
+		}
+	}
+	return
+}
+
+func (l *DiskLocation) HasVolume(vid VolumeId) bool {
+	l.mutex.RLock()
+	defer l.mutex.RUnlock()
+	_, ok := l.volumes[vid]
+	return ok
+}
+
+func (l *DiskLocation) GetVolume(vid VolumeId) (v *Volume, ok bool) {
+	l.mutex.RLock()
+	defer l.mutex.RUnlock()
+	v, ok = l.volumes[vid]
+	return
+}
+
+func (l *DiskLocation) VolumeCount() int {
+	l.mutex.RLock()
+	defer l.mutex.RUnlock()
+	return len(l.volumes)
+}
+
+func (l *DiskLocation) CloseAllVolume() {
+	l.mutex.RLock()
+	defer l.mutex.RUnlock()
+	for _, v := range l.volumes {
+		v.Close()
+	}
+}
+
+// break walk when walker fuc return an error
+type VolumeWalker func(v *Volume) (e error)
+
+// must not add or delete volume in walker
+func (l *DiskLocation) WalkVolume(vw VolumeWalker) (e error) {
+	l.mutex.RLock()
+	defer l.mutex.RUnlock()
+	for _, v := range l.volumes {
+		if e = vw(v); e != nil {
+			return e
+		}
+	}
+	return
+}
--- a/weed/storage/file_id.go
+++ b/weed/storage/file_id.go
@ -1,12 +1,10 @@
 package storage

 import (
-	"encoding/hex"
 	"errors"
 	"strings"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/glog"
 )

 type FileId struct {
@ -22,22 +20,27 @@ func NewFileId(VolumeId VolumeId, Key uint64, Hashcode uint32) *FileId {
 	return &FileId{VolumeId: VolumeId, Key: Key, Hashcode: Hashcode}
 }
 func ParseFileId(fid string) (*FileId, error) {
-	a := strings.Split(fid, ",")
+	var a []string
+	if strings.Contains(fid, ",") {
+		a = strings.Split(fid, ",")
+	} else {
+		a = strings.Split(fid, "/")
+	}
 	if len(a) != 2 {
 		glog.V(1).Infoln("Invalid fid ", fid, ", split length ", len(a))
 		return nil, errors.New("Invalid fid " + fid)
 	}
+
 	vid_string, key_hash_string := a[0], a[1]
 	volumeId, _ := NewVolumeId(vid_string)
-	key, hash, e := ParseKeyHash(key_hash_string)
+	key, hash, e := ParseIdCookie(key_hash_string)
 	return &FileId{VolumeId: volumeId, Key: key, Hashcode: hash}, e
 }
+
 func (n *FileId) String() string {
-	bytes := make([]byte, 12)
-	util.Uint64toBytes(bytes[0:8], n.Key)
-	util.Uint32toBytes(bytes[8:12], n.Hashcode)
-	nonzero_index := 0
-	for ; bytes[nonzero_index] == 0; nonzero_index++ {
-	}
-	return n.VolumeId.String() + "," + hex.EncodeToString(bytes[nonzero_index:])
+	return n.VolumeId.String() + "," + n.Nid()
+}
+
+func (n *FileId) Nid() string {
+	return ToNid(n.Key, n.Hashcode)
 }
--- a/weed/storage/needle.go
+++ b/weed/storage/needle.go
@ -12,10 +12,10 @@ import (
 	"strings"
 	"time"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/images"
-	"github.com/chrislusf/seaweedfs/go/operation"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/images"
+	"github.com/chrislusf/seaweedfs/weed/operation"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 const (
@ -179,50 +179,66 @@ func NewNeedle(r *http.Request, fixJpgOrientation bool) (n *Needle, e error) {

 	commaSep := strings.LastIndex(r.URL.Path, ",")
 	dotSep := strings.LastIndex(r.URL.Path, ".")
-	fid := r.URL.Path[commaSep+1:]
+	nid := r.URL.Path[commaSep+1:]
 	if dotSep > 0 {
-		fid = r.URL.Path[commaSep+1 : dotSep]
+		nid = r.URL.Path[commaSep+1 : dotSep]
 	}

-	e = n.ParsePath(fid)
+	e = n.ParseNid(nid)

 	return
 }
-func (n *Needle) ParsePath(fid string) (err error) {
-	length := len(fid)
+func (n *Needle) ParseNid(nid string) (err error) {
+	length := len(nid)
 	if length <= 8 {
-		return errors.New("Invalid fid:" + fid)
+		return errors.New("Invalid nid:" + nid)
 	}
+	n.Id, n.Cookie, err = ParseIdCookie(nid)
+	if err != nil {
+		return err
+	}
+	return err
+}
+
+func (n *Needle) Nid() string {
+	return ToNid(n.Id, n.Cookie)
+}
+
+func ParseIdCookie(nid string) (uint64, uint32, error) {
 	delta := ""
-	deltaIndex := strings.LastIndex(fid, "_")
+	deltaIndex := strings.LastIndex(nid, "_")
 	if deltaIndex > 0 {
-		fid, delta = fid[0:deltaIndex], fid[deltaIndex+1:]
+		nid, delta = nid[0:deltaIndex], nid[deltaIndex+1:]
 	}
-	n.Id, n.Cookie, err = ParseKeyHash(fid)
-	if err != nil {
-		return err
+
+	if len(nid)%2 == 1 {
+		nid = "0" + nid
 	}
+	key_hash_bytes, khe := hex.DecodeString(nid)
+	key_hash_len := len(key_hash_bytes)
+	if khe != nil || key_hash_len <= 4 {
+		glog.V(0).Infoln("Invalid key_hash", nid, "length:", key_hash_len, "error", khe)
+		return 0, 0, errors.New("Invalid key and hash:" + nid)
+	}
+	id := util.BytesToUint64(key_hash_bytes[0 : key_hash_len-4])
+	cookie := util.BytesToUint32(key_hash_bytes[key_hash_len-4 : key_hash_len])
+
 	if delta != "" {
 		if d, e := strconv.ParseUint(delta, 10, 64); e == nil {
-			n.Id += d
+			id += d
 		} else {
-			return e
+			return 0, 0, e
 		}
 	}
-	return err
+	return id, cookie, nil
 }

-func ParseKeyHash(key_hash_string string) (uint64, uint32, error) {
-	if len(key_hash_string)%2 == 1 {
-		key_hash_string = "0" + key_hash_string
-	}
-	key_hash_bytes, khe := hex.DecodeString(key_hash_string)
-	key_hash_len := len(key_hash_bytes)
-	if khe != nil || key_hash_len <= 4 {
-		glog.V(0).Infoln("Invalid key_hash", key_hash_string, "length:", key_hash_len, "error", khe)
-		return 0, 0, errors.New("Invalid key and hash:" + key_hash_string)
+func ToNid(key uint64, cookie uint32) string {
+	bytes := make([]byte, 12)
+	util.Uint64toBytes(bytes[0:8], key)
+	util.Uint32toBytes(bytes[8:12], cookie)
+	nonzero_index := 0
+	for ; bytes[nonzero_index] == 0; nonzero_index++ {
 	}
-	key := util.BytesToUint64(key_hash_bytes[0 : key_hash_len-4])
-	hash := util.BytesToUint32(key_hash_bytes[key_hash_len-4 : key_hash_len])
-	return key, hash, nil
+	return hex.EncodeToString(bytes[nonzero_index:])
 }
--- a/weed/storage/needle_map.go
+++ b/weed/storage/needle_map.go
@ -0,0 +1,134 @@
+package storage
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"sync"
+
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+type NeedleMapType int
+
+const (
+	NeedleMapInMemory NeedleMapType = iota
+	NeedleMapLevelDb
+	NeedleMapBoltDb
+)
+
+type NeedleMapper interface {
+	Put(key uint64, offset uint32, size uint32) error
+	Get(key uint64) (element *NeedleValue, ok bool)
+	Delete(key uint64) error
+	Close()
+	Destroy() error
+	ContentSize() uint64
+	DeletedSize() uint64
+	FileCount() int
+	DeletedCount() int
+	MaxFileKey() uint64
+	IndexFileSize() uint64
+	IndexFileContent() ([]byte, error)
+	IndexFileName() string
+}
+
+type baseNeedleMapper struct {
+	indexFile           *os.File
+	mutex               sync.RWMutex
+	deletionCounter     int
+	fileCounter         int
+	deletionByteCounter uint64
+	fileByteCounter     uint64
+	maximumFileKey      uint64
+}
+
+func (nm *baseNeedleMapper) IndexFileSize() uint64 {
+	nm.mutex.RLock()
+	defer nm.mutex.RUnlock()
+	stat, err := nm.indexFile.Stat()
+	if err == nil {
+		return uint64(stat.Size())
+	}
+	return 0
+}
+
+func (nm *baseNeedleMapper) IndexFileName() string {
+	nm.mutex.RLock()
+	defer nm.mutex.RUnlock()
+	return nm.indexFile.Name()
+}
+
+func idxFileEntry(bytes []byte) (key uint64, offset uint32, size uint32) {
+	key = util.BytesToUint64(bytes[:8])
+	offset = util.BytesToUint32(bytes[8:12])
+	size = util.BytesToUint32(bytes[12:16])
+	return
+}
+func (nm *baseNeedleMapper) appendToIndexFile(key uint64, offset uint32, size uint32) error {
+	bytes := make([]byte, 16)
+	util.Uint64toBytes(bytes[0:8], key)
+	util.Uint32toBytes(bytes[8:12], offset)
+	util.Uint32toBytes(bytes[12:16], size)
+
+	nm.mutex.Lock()
+	defer nm.mutex.Unlock()
+	if _, err := nm.indexFile.Seek(0, 2); err != nil {
+		return fmt.Errorf("cannot seek end of indexfile %s: %v",
+			nm.indexFile.Name(), err)
+	}
+	_, err := nm.indexFile.Write(bytes)
+	return err
+}
+func (nm *baseNeedleMapper) IndexFileContent() ([]byte, error) {
+	nm.mutex.RLock()
+	defer nm.mutex.RUnlock()
+	return ioutil.ReadFile(nm.indexFile.Name())
+}
+
+func (nm *baseNeedleMapper) logDelete(deletedByteCount uint32) {
+	nm.mutex.Lock()
+	defer nm.mutex.Unlock()
+	nm.deletionByteCounter = nm.deletionByteCounter + uint64(deletedByteCount)
+	nm.deletionCounter++
+}
+
+func (nm *baseNeedleMapper) logPut(key uint64, oldSize uint32, newSize uint32) {
+	nm.mutex.Lock()
+	defer nm.mutex.Unlock()
+	if key > nm.maximumFileKey {
+		nm.maximumFileKey = key
+	}
+	nm.fileCounter++
+	nm.fileByteCounter = nm.fileByteCounter + uint64(newSize)
+	if oldSize > 0 {
+		nm.deletionCounter++
+		nm.deletionByteCounter = nm.deletionByteCounter + uint64(oldSize)
+	}
+}
+
+func (nm *baseNeedleMapper) ContentSize() uint64 {
+	nm.mutex.RLock()
+	defer nm.mutex.RUnlock()
+	return nm.fileByteCounter
+}
+func (nm *baseNeedleMapper) DeletedSize() uint64 {
+	nm.mutex.RLock()
+	defer nm.mutex.RUnlock()
+	return nm.deletionByteCounter
+}
+func (nm *baseNeedleMapper) FileCount() int {
+	nm.mutex.RLock()
+	defer nm.mutex.RUnlock()
+	return nm.fileCounter
+}
+func (nm *baseNeedleMapper) DeletedCount() int {
+	nm.mutex.RLock()
+	defer nm.mutex.RUnlock()
+	return nm.deletionCounter
+}
+func (nm *baseNeedleMapper) MaxFileKey() uint64 {
+	nm.mutex.RLock()
+	defer nm.mutex.RUnlock()
+	return nm.maximumFileKey
+}
--- a/weed/storage/needle_map_boltdb.go
+++ b/weed/storage/needle_map_boltdb.go
@ -6,8 +6,8 @@ import (

 	"github.com/boltdb/bolt"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 type BoltDbNeedleMap struct {
@ -35,7 +35,7 @@ func NewBoltDbNeedleMap(dbFileName string, indexFile *os.File) (m *BoltDbNeedleM
 	if indexLoadError != nil {
 		return nil, indexLoadError
 	}
-	m.mapMetric = nm.mapMetric
+	m.baseNeedleMapper = nm.baseNeedleMapper
 	return
 }

--- a/weed/storage/needle_map_leveldb.go
+++ b/weed/storage/needle_map_leveldb.go
@ -5,8 +5,8 @@ import (
 	"os"
 	"path/filepath"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util"
 	"github.com/syndtr/goleveldb/leveldb"
 )

@ -33,7 +33,7 @@ func NewLevelDbNeedleMap(dbFileName string, indexFile *os.File) (m *LevelDbNeedl
 	if indexLoadError != nil {
 		return nil, indexLoadError
 	}
-	m.mapMetric = nm.mapMetric
+	m.baseNeedleMapper = nm.baseNeedleMapper
 	return
 }

--- a/weed/storage/needle_map_memory.go
+++ b/weed/storage/needle_map_memory.go
@ -4,11 +4,11 @@ import (
 	"io"
 	"os"

-	"github.com/chrislusf/seaweedfs/go/glog"
+	"github.com/chrislusf/seaweedfs/weed/glog"
 )

 type NeedleMap struct {
-	m CompactMap
+	m *CompactMap

 	baseNeedleMapper
 }
@ -28,27 +28,27 @@ const (
 func LoadNeedleMap(file *os.File) (*NeedleMap, error) {
 	nm := NewNeedleMap(file)
 	e := WalkIndexFile(file, func(key uint64, offset, size uint32) error {
-		if key > nm.MaximumFileKey {
-			nm.MaximumFileKey = key
+		if key > nm.maximumFileKey {
+			nm.maximumFileKey = key
 		}
-		nm.FileCounter++
-		nm.FileByteCounter = nm.FileByteCounter + uint64(size)
+		nm.fileCounter++
+		nm.fileByteCounter = nm.fileByteCounter + uint64(size)
 		if offset > 0 {
 			oldSize := nm.m.Set(Key(key), offset, size)
 			glog.V(3).Infoln("reading key", key, "offset", offset*NeedlePaddingSize, "size", size, "oldSize", oldSize)
 			if oldSize > 0 {
-				nm.DeletionCounter++
-				nm.DeletionByteCounter = nm.DeletionByteCounter + uint64(oldSize)
+				nm.deletionCounter++
+				nm.deletionByteCounter = nm.deletionByteCounter + uint64(oldSize)
 			}
 		} else {
 			oldSize := nm.m.Delete(Key(key))
 			glog.V(3).Infoln("removing key", key, "offset", offset*NeedlePaddingSize, "size", size, "oldSize", oldSize)
-			nm.DeletionCounter++
-			nm.DeletionByteCounter = nm.DeletionByteCounter + uint64(oldSize)
+			nm.deletionCounter++
+			nm.deletionByteCounter = nm.deletionByteCounter + uint64(oldSize)
 		}
 		return nil
 	})
-	glog.V(1).Infoln("max file key:", nm.MaximumFileKey)
+	glog.V(1).Infoln("max file key:", nm.maximumFileKey)
 	return nm, e
 }

@ -98,7 +98,9 @@ func (nm *NeedleMap) Delete(key uint64) error {
 	return nm.appendToIndexFile(key, 0, 0)
 }
 func (nm *NeedleMap) Close() {
-	_ = nm.indexFile.Close()
+	nm.mutex.Lock()
+	nm.indexFile.Close()
+	nm.mutex.Unlock()
 }
 func (nm *NeedleMap) Destroy() error {
 	nm.Close()
--- a/weed/storage/needle_read_write.go
+++ b/weed/storage/needle_read_write.go
@ -6,8 +6,8 @@ import (
 	"io"
 	"os"

-	"github.com/chrislusf/seaweedfs/go/glog"
-	"github.com/chrislusf/seaweedfs/go/util"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )

 const (
@ -16,6 +16,7 @@ const (
 	FlagHasMime             = 0x04
 	FlagHasLastModifiedDate = 0x08
 	FlagHasTtl              = 0x10
+	FlagIsExtendNeedle      = 0x40 // TODO: Reserve flag, use extent file to save big needle
 	FlagIsChunkManifest     = 0x80
 	LastModifiedBytesLength = 5
 	TtlBytesLength          = 2
@ -238,13 +239,24 @@ func (n *Needle) ReadNeedleBody(r *os.File, version Version, offset int64, bodyL
 		}
 		n.Data = bytes[:n.Size]
 		n.Checksum = NewCRC(n.Data)
+		checksum := util.BytesToUint32(bytes[n.Size : n.Size+NeedleChecksumSize])
+		if n.Checksum.Value() != checksum {
+			glog.V(0).Infof("CRC error! Data On Disk Corrupted, needle id = %x", n.Id)
+		}
 	case Version2:
 		bytes := make([]byte, bodyLength)
 		if _, err = r.ReadAt(bytes, offset); err != nil {
 			return
 		}
 		n.readNeedleDataVersion2(bytes[0:n.Size])
+		if n.DataSize == 0 {
+			return
+		}
 		n.Checksum = NewCRC(n.Data)
+		checksum := util.BytesToUint32(bytes[n.Size : n.Size+NeedleChecksumSize])
+		if n.Checksum.Value() != checksum {
+			glog.V(0).Infof("CRC error! Data On Disk Corrupted, needle id = %x", n.Id)
+		}
 	default:
 		err = fmt.Errorf("Unsupported Version! (%d)", version)
 	}
--- a/weed/storage/replica_placement.go
+++ b/weed/storage/replica_placement.go
@ -51,3 +51,17 @@ func (rp *ReplicaPlacement) String() string {
 func (rp *ReplicaPlacement) GetCopyCount() int {
 	return rp.DiffDataCenterCount + rp.DiffRackCount + rp.SameRackCount + 1
 }
+
+func (rp *ReplicaPlacement) Compare(rp1 *ReplicaPlacement) int {
+	if rp.SameRackCount == rp1.SameRackCount &&
+		rp.DiffRackCount == rp1.DiffRackCount &&
+		rp.DiffDataCenterCount == rp1.DiffDataCenterCount {
+		return 0
+	} else if rp.SameRackCount < rp1.SameRackCount ||
+		rp.DiffRackCount < rp1.DiffRackCount ||
+		rp.DiffDataCenterCount < rp1.DiffDataCenterCount {
+		return -1
+	} else {
+		return 1
+	}
+}
--- a/weed/storage/replica_placement_test.go
+++ b/weed/storage/replica_placement_test.go
--- a/weed/storage/store.go
+++ b/weed/storage/store.go
@ -0,0 +1,450 @@
+package storage
+
+import (
+	"errors"
+	"fmt"
+	"math/rand"
+	"strconv"
+	"strings"
+
+	"sync"
+
+	"encoding/json"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/operation"
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/chrislusf/seaweedfs/weed/weedpb"
+)
+
+const (
+	MAX_TTL_VOLUME_REMOVAL_DELAY = 10 // 10 minutes
+)
+
+type MasterNodes struct {
+	nodes  []string
+	master string
+	mutex  sync.RWMutex
+}
+
+func NewMasterNodes(bootstrapNode string) (mn *MasterNodes) {
+	mn = &MasterNodes{nodes: []string{bootstrapNode}}
+	return
+}
+
+func (mn *MasterNodes) String() string {
+	mn.mutex.RLock()
+	defer mn.mutex.RUnlock()
+	return fmt.Sprintf("nodes:%v, master:%s", mn.nodes, mn.master)
+}
+
+func (mn *MasterNodes) Reset() {
+	glog.V(4).Infof("Resetting master nodes: %v", mn)
+	mn.mutex.Lock()
+	defer mn.mutex.Unlock()
+	if len(mn.nodes) > 1 && mn.master != "" {
+		glog.V(0).Infof("Reset master %s from: %v", mn.master, mn.nodes)
+		mn.master = ""
+	}
+}
+
+func (mn *MasterNodes) findMaster() (string, error) {
+	master := mn.GetMaster()
+	if master != "" {
+		return master, nil
+	}
+	mn.mutex.Lock()
+	defer mn.mutex.Unlock()
+	if len(mn.nodes) == 0 {
+		return "", errors.New("No master node found!")
+	}
+	if mn.master == "" {
+		for _, m := range mn.nodes {
+			glog.V(4).Infof("Listing masters on %s", m)
+			if masters, e := operation.ListMasters(m); e == nil {
+				if len(masters) == 0 {
+					continue
+				}
+				mn.nodes = append(masters, m)
+				mn.master = mn.nodes[rand.Intn(len(mn.nodes))]
+				glog.V(2).Infof("current master nodes is (nodes:%v, master:%s)", mn.nodes, mn.master)
+				break
+			} else {
+				glog.V(4).Infof("Failed listing masters on %s: %v", m, e)
+			}
+		}
+	}
+	if mn.master == "" {
+		return "", errors.New("No master node available!")
+	}
+	return mn.master, nil
+}
+
+func (mn *MasterNodes) GetMaster() string {
+	mn.mutex.RLock()
+	defer mn.mutex.RUnlock()
+	return mn.master
+}
+
+/*
+ * A VolumeServer contains one Store
+ */
+type Store struct {
+	joinKey         string
+	ip              string
+	Port            int
+	PublicUrl       string
+	Locations       []*DiskLocation
+	colSettings     *CollectionSettings
+	dataCenter      string //optional informaton, overwriting master setting if exists
+	rack            string //optional information, overwriting master setting if exists
+	volumeSizeLimit uint64 //read from the master
+	masterNodes     *MasterNodes
+	needleMapKind   NeedleMapType
+	TaskManager     *TaskManager
+	mutex           sync.RWMutex
+}
+
+func (s *Store) String() (str string) {
+	str = fmt.Sprintf("Ip:%s, Port:%d, PublicUrl:%s, dataCenter:%s, rack:%s, joinKey:%v, volumeSizeLimit:%d, masterNodes:%s",
+		s.GetIP(), s.Port, s.PublicUrl, s.dataCenter, s.rack, s.GetJoinKey(), s.GetVolumeSizeLimit(), s.masterNodes)
+	return
+}
+
+func NewStore(port int, ip, publicUrl string, dirnames []string, maxVolumeCounts []int, needleMapKind NeedleMapType) (s *Store) {
+	s = &Store{
+		Port:          port,
+		ip:            ip,
+		PublicUrl:     publicUrl,
+		TaskManager:   NewTaskManager(),
+		needleMapKind: needleMapKind,
+	}
+	s.Locations = make([]*DiskLocation, 0)
+	for i := 0; i < len(dirnames); i++ {
+		location := NewDiskLocation(dirnames[i], maxVolumeCounts[i])
+		location.LoadExistingVolumes(needleMapKind)
+		s.Locations = append(s.Locations, location)
+	}
+	return
+}
+func (s *Store) AddVolume(volumeListString string, collection string, ttlString string) error {
+	ttl, e := ReadTTL(ttlString)
+	if e != nil {
+		return e
+	}
+	for _, range_string := range strings.Split(volumeListString, ",") {
+		if strings.Index(range_string, "-") < 0 {
+			id_string := range_string
+			id, err := NewVolumeId(id_string)
+			if err != nil {
+				return fmt.Errorf("Volume Id %s is not a valid unsigned integer!", id_string)
+			}
+			e = s.addVolume(VolumeId(id), collection, ttl)
+		} else {
+			pair := strings.Split(range_string, "-")
+			start, start_err := strconv.ParseUint(pair[0], 10, 64)
+			if start_err != nil {
+				return fmt.Errorf("Volume Start Id %s is not a valid unsigned integer!", pair[0])
+			}
+			end, end_err := strconv.ParseUint(pair[1], 10, 64)
+			if end_err != nil {
+				return fmt.Errorf("Volume End Id %s is not a valid unsigned integer!", pair[1])
+			}
+			for id := start; id <= end; id++ {
+				if err := s.addVolume(VolumeId(id), collection, ttl); err != nil {
+					e = err
+				}
+			}
+		}
+	}
+	return e
+}
+func (s *Store) DeleteCollection(collection string) (e error) {
+	for _, location := range s.Locations {
+		location.DeleteCollection(collection)
+	}
+	return
+}
+
+func (s *Store) findVolume(vid VolumeId) *Volume {
+	for _, location := range s.Locations {
+		if v, found := location.GetVolume(vid); found {
+			return v
+		}
+	}
+	return nil
+}
+func (s *Store) findFreeLocation() (ret *DiskLocation) {
+	max := 0
+	for _, location := range s.Locations {
+		currentFreeCount := location.MaxVolumeCount - location.VolumeCount()
+		if currentFreeCount > max {
+			max = currentFreeCount
+			ret = location
+		}
+	}
+	return ret
+}
+func (s *Store) addVolume(vid VolumeId, collection string, ttl *TTL) error {
+	if s.findVolume(vid) != nil {
+		return fmt.Errorf("Volume Id %d already exists!", vid)
+	}
+	if location := s.findFreeLocation(); location != nil {
+		glog.V(0).Infof("In dir %s adds volume:%v collection:%s ttl:%v",
+			location.Directory, vid, collection, ttl)
+		if volume, err := NewVolume(location.Directory, collection, vid, s.needleMapKind, ttl); err == nil {
+			location.AddVolume(vid, volume)
+			return nil
+		} else {
+			return err
+		}
+	}
+	return fmt.Errorf("No more free space left")
+}
+
+func (s *Store) Status() []*VolumeInfo {
+	var stats []*VolumeInfo
+	for _, location := range s.Locations {
+		location.WalkVolume(func(v *Volume) (e error) {
+			s := &VolumeInfo{
+				Id:               VolumeId(v.Id),
+				Size:             v.ContentSize(),
+				Collection:       v.Collection,
+				Version:          v.Version(),
+				FileCount:        v.nm.FileCount(),
+				DeleteCount:      v.nm.DeletedCount(),
+				DeletedByteCount: v.nm.DeletedSize(),
+				ReadOnly:         v.IsReadOnly(),
+				Ttl:              v.Ttl}
+			stats = append(stats, s)
+			return nil
+		})
+	}
+	sortVolumeInfos(stats)
+	return stats
+}
+
+func (s *Store) SetDataCenter(dataCenter string) {
+	s.dataCenter = dataCenter
+}
+func (s *Store) SetRack(rack string) {
+	s.rack = rack
+}
+
+func (s *Store) SetBootstrapMaster(bootstrapMaster string) {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+	s.masterNodes = NewMasterNodes(bootstrapMaster)
+}
+
+type SettingChanged func(s *weedpb.JoinResponse)
+
+func (s *Store) SendHeartbeatToMaster(callback SettingChanged) error {
+	masterNode, err := s.masterNodes.findMaster()
+	if err != nil {
+		return err
+	}
+	var volumeMessages []*weedpb.VolumeInformationMessage
+	maxVolumeCount := 0
+	var maxFileKey uint64
+	for _, location := range s.Locations {
+		maxVolumeCount = maxVolumeCount + location.MaxVolumeCount
+		volumeToDelete := []VolumeId{}
+		location.WalkVolume(func(v *Volume) (e error) {
+			if maxFileKey < v.nm.MaxFileKey() {
+				maxFileKey = v.nm.MaxFileKey()
+			}
+			if !v.expired(s.GetVolumeSizeLimit()) {
+				volumeMessage := &weedpb.VolumeInformationMessage{
+					Id:               uint32(v.Id),
+					Size:             uint64(v.Size()),
+					Collection:       v.Collection,
+					FileCount:        uint64(v.nm.FileCount()),
+					DeleteCount:      uint64(v.nm.DeletedCount()),
+					DeletedByteCount: v.nm.DeletedSize(),
+					ReadOnly:         v.IsReadOnly(),
+					Version:          uint32(v.Version()),
+					Ttl:              v.Ttl.ToUint32(),
+				}
+				volumeMessages = append(volumeMessages, volumeMessage)
+			} else {
+				if v.expiredLongEnough(MAX_TTL_VOLUME_REMOVAL_DELAY) {
+					volumeToDelete = append(volumeToDelete, v.Id)
+					glog.V(0).Infoln("volume", v.Id, "is deleted.")
+				} else {
+					glog.V(0).Infoln("volume", v.Id, "is expired.")
+				}
+			}
+			return nil
+		})
+		for _, vid := range volumeToDelete {
+			location.DeleteVolume(vid)
+		}
+	}
+
+	joinMsgV2 := &weedpb.JoinMessageV2{
+		JoinKey:        s.GetJoinKey(),
+		Ip:             s.GetIP(),
+		Port:           uint32(s.Port),
+		PublicUrl:      s.PublicUrl,
+		MaxVolumeCount: uint32(maxVolumeCount),
+		MaxFileKey:     maxFileKey,
+		DataCenter:     s.dataCenter,
+		Rack:           s.rack,
+		Volumes:        volumeMessages,
+	}
+	ret := &weedpb.JoinResponse{}
+	joinUrl := util.MkUrl(masterNode, "/dir/join2", nil)
+	glog.V(4).Infof("Sending heartbeat to %s ...", joinUrl)
+	if err = util.PostPbMsg(joinUrl, joinMsgV2, ret); err != nil {
+		s.masterNodes.Reset()
+		return err
+	}
+
+	if ret.Error != "" {
+		s.masterNodes.Reset()
+		return errors.New(ret.Error)
+	}
+	if ret.JoinKey != s.GetJoinKey() {
+		if glog.V(4) {
+			jsonData, _ := json.Marshal(ret)
+			glog.V(4).Infof("dir join sync settings: %v", string(jsonData))
+		}
+		s.SetJoinKey(ret.JoinKey)
+		if ret.JoinIp != "" {
+			s.SetIP(ret.JoinIp)
+		}
+		if ret.VolumeSizeLimit != 0 {
+			s.SetVolumeSizeLimit(ret.VolumeSizeLimit)
+		}
+		if callback != nil {
+			callback(ret)
+		}
+		if len(ret.CollectionSettings) > 0 {
+			cs := NewCollectionSettingsFromPbMessage(ret.CollectionSettings)
+			s.SetCollectionSettings(cs)
+		}
+	}
+	return nil
+}
+func (s *Store) Close() {
+	for _, location := range s.Locations {
+		location.CloseAllVolume()
+	}
+}
+func (s *Store) Write(i VolumeId, n *Needle) (size uint32, err error) {
+	if v := s.findVolume(i); v != nil {
+		if v.IsReadOnly() {
+			err = fmt.Errorf("Volume %d is read only", i)
+			return
+		}
+		if MaxPossibleVolumeSize >= v.ContentSize()+uint64(size) {
+			size, err = v.write(n)
+		} else {
+			err = fmt.Errorf("Volume Size Limit %d Exceeded! Current size is %d", s.GetVolumeSizeLimit(), v.ContentSize())
+		}
+		if s.GetVolumeSizeLimit() < v.ContentSize()+3*uint64(size) {
+			glog.V(0).Infoln("volume", i, "size", v.ContentSize(), "will exceed limit", s.GetVolumeSizeLimit())
+			if e := s.SendHeartbeatToMaster(nil); e != nil {
+				glog.V(0).Infoln("error when reporting size:", e)
+			}
+		}
+		return
+	}
+	glog.V(0).Infoln("volume", i, "not found!")
+	err = fmt.Errorf("Volume %d not found!", i)
+	return
+}
+func (s *Store) Delete(i VolumeId, n *Needle) (uint32, error) {
+	if v := s.findVolume(i); v != nil && !v.IsReadOnly() {
+		return v.delete(n)
+	}
+	return 0, nil
+}
+func (s *Store) ReadVolumeNeedle(i VolumeId, n *Needle) (int, error) {
+	if v := s.findVolume(i); v != nil {
+		return v.readNeedle(n)
+	}
+	return 0, fmt.Errorf("Volume %v not found!", i)
+}
+func (s *Store) GetVolume(i VolumeId) *Volume {
+	return s.findVolume(i)
+}
+
+func (s *Store) HasVolume(i VolumeId) bool {
+	v := s.findVolume(i)
+	return v != nil
+}
+
+func (s *Store) WalkVolume(walker VolumeWalker) error {
+	for _, location := range s.Locations {
+		if e := location.WalkVolume(walker); e != nil {
+			return e
+		}
+	}
+	return nil
+}
+
+func (s *Store) GetVolumeSizeLimit() uint64 {
+	s.mutex.RLock()
+	defer s.mutex.RUnlock()
+	return s.volumeSizeLimit
+}
+
+func (s *Store) SetVolumeSizeLimit(sz uint64) {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+	s.volumeSizeLimit = sz
+}
+
+func (s *Store) GetIP() string {
+	s.mutex.RLock()
+	defer s.mutex.RUnlock()
+	return s.ip
+}
+
+func (s *Store) SetIP(ip string) {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+	s.ip = ip
+}
+
+func (s *Store) GetJoinKey() string {
+	s.mutex.RLock()
+	defer s.mutex.RUnlock()
+	return s.joinKey
+}
+
+func (s *Store) SetJoinKey(k string) {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+	s.joinKey = k
+}
+
+func (s *Store) GetMaster() string {
+	return s.masterNodes.GetMaster()
+}
+
+func (s *Store) GetCollectionSettings() *CollectionSettings {
+	s.mutex.RLock()
+	defer s.mutex.RUnlock()
+	return s.colSettings
+}
+
+func (s *Store) SetCollectionSettings(cs *CollectionSettings) {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+	s.colSettings = cs
+}
+
+func (s *Store) GetVolumeReplicaPlacement(volumeId VolumeId) *ReplicaPlacement {
+	cs := s.GetCollectionSettings()
+	if cs == nil {
+		return nil
+	}
+	collection := ""
+	if v := s.GetVolume(volumeId); v != nil {
+		collection = v.Collection
+	}
+	return cs.GetReplicaPlacement(collection)
+}
--- a/weed/storage/store_task.go
+++ b/weed/storage/store_task.go
@ -0,0 +1,160 @@
+package storage
+
+import (
+	"errors"
+	"net/url"
+	"time"
+
+	"sync"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+)
+
+const (
+	TaskVacuum    = "vacuum"
+	TaskReplicate = "replicate"
+	TaskBalance   = "balance"
+)
+
+var (
+	ErrTaskNotFinish = errors.New("TaskNotFinish")
+	ErrTaskNotFound  = errors.New("TaskNotFound")
+	ErrTaskInvalid   = errors.New("TaskInvalid")
+	ErrTaskExists    = errors.New("TaskExists")
+)
+
+type TaskWorker interface {
+	Run() error
+	Commit() error
+	Clean() error
+	Info() url.Values
+}
+
+type task struct {
+	Id              string
+	startTime       time.Time
+	worker          TaskWorker
+	ch              chan bool
+	result          error
+	cleanWhenFinish bool
+}
+
+type TaskManager struct {
+	taskList map[string]*task
+	lock     sync.RWMutex
+}
+
+func newTask(worker TaskWorker, id string) *task {
+	t := &task{
+		Id:        id,
+		worker:    worker,
+		startTime: time.Now(),
+		result:    ErrTaskNotFinish,
+		ch:        make(chan bool, 1),
+	}
+	go func(t *task) {
+		t.result = t.worker.Run()
+		if t.cleanWhenFinish {
+			glog.V(0).Infof("clean task (%s) when finish.", t.Id)
+			t.worker.Clean()
+		}
+		t.ch <- true
+
+	}(t)
+	return t
+}
+
+func (t *task) queryResult(waitDuration time.Duration) error {
+	if t.result == ErrTaskNotFinish && waitDuration > 0 {
+		select {
+		case <-time.After(waitDuration):
+		case <-t.ch:
+		}
+	}
+	return t.result
+}
+
+func NewTaskManager() *TaskManager {
+	return &TaskManager{
+		taskList: make(map[string]*task),
+	}
+}
+
+func (tm *TaskManager) NewTask(s *Store, args url.Values) (tid string, e error) {
+	tm.lock.Lock()
+	defer tm.lock.Unlock()
+	tt := args.Get("task")
+	vid := args.Get("volume")
+	tid = tt + "-" + vid
+	if _, ok := tm.taskList[tid]; ok {
+		return tid, ErrTaskExists
+	}
+
+	var tw TaskWorker
+	switch tt {
+	case TaskVacuum:
+		tw, e = NewVacuumTask(s, args)
+	case TaskReplicate:
+		tw, e = NewReplicaTask(s, args)
+	case TaskBalance:
+	}
+	if e != nil {
+		return
+	}
+	if tw == nil {
+		return "", ErrTaskInvalid
+	}
+	tm.taskList[tid] = newTask(tw, tid)
+	return tid, nil
+}
+
+func (tm *TaskManager) QueryResult(tid string, waitDuration time.Duration) (e error) {
+	tm.lock.RLock()
+	defer tm.lock.RUnlock()
+	t, ok := tm.taskList[tid]
+	if !ok {
+		return ErrTaskNotFound
+	}
+	return t.queryResult(waitDuration)
+}
+
+func (tm *TaskManager) Commit(tid string) (e error) {
+	tm.lock.Lock()
+	defer tm.lock.Unlock()
+	t, ok := tm.taskList[tid]
+	if !ok {
+		return ErrTaskNotFound
+	}
+	if t.queryResult(time.Second*30) == ErrTaskNotFinish {
+		return ErrTaskNotFinish
+	}
+	delete(tm.taskList, tid)
+	return t.worker.Commit()
+}
+
+func (tm *TaskManager) Clean(tid string) error {
+	tm.lock.Lock()
+	defer tm.lock.Unlock()
+	t, ok := tm.taskList[tid]
+	if !ok {
+		return ErrTaskNotFound
+	}
+	delete(tm.taskList, tid)
+	if t.queryResult(time.Second*30) == ErrTaskNotFinish {
+		t.cleanWhenFinish = true
+		glog.V(0).Infof("task (%s) is not finish, clean it later.", tid)
+	} else {
+		t.worker.Clean()
+	}
+	return nil
+}
+
+func (tm *TaskManager) ElapsedDuration(tid string) (time.Duration, error) {
+	tm.lock.RLock()
+	defer tm.lock.RUnlock()
+	t, ok := tm.taskList[tid]
+	if !ok {
+		return 0, ErrTaskNotFound
+	}
+	return time.Since(t.startTime), nil
+}
--- a/weed/storage/store_task_cli.go
+++ b/weed/storage/store_task_cli.go
@ -0,0 +1,87 @@
+package storage
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"time"
+
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+type TaskParams map[string]string
+
+var (
+	ErrTaskTimeout = errors.New("TaskTimeout")
+)
+
+type TaskCli struct {
+	TID      string
+	DataNode string
+}
+
+func NewTaskCli(dataNode string, taskType string, params TaskParams) (*TaskCli, error) {
+	args := url.Values{}
+	args.Set("task", taskType)
+	for k, v := range params {
+		args.Set(k, v)
+	}
+	m, e := util.RemoteApiCall(dataNode, "/admin/task/new", args)
+	if e != nil {
+		return nil, e
+	}
+	tid := m["tid"].(string)
+	if tid == "" {
+		return nil, fmt.Errorf("Empty %s task", taskType)
+	}
+	return &TaskCli{
+		TID:      tid,
+		DataNode: dataNode,
+	}, nil
+}
+
+func (c *TaskCli) WaitAndQueryResult(timeout time.Duration) error {
+	startTime := time.Now()
+	args := url.Values{}
+	args.Set("tid", c.TID)
+	args.Set("timeout", time.Minute.String())
+	tryTimes := 0
+	for time.Since(startTime) < timeout {
+		_, e := util.RemoteApiCall(c.DataNode, "/admin/task/query", args)
+		if e == nil {
+			//task have finished and have no error
+			return nil
+		}
+		if util.IsRemoteApiError(e) {
+			if e.Error() == ErrTaskNotFinish.Error() {
+				tryTimes = 0
+				continue
+			}
+			return e
+		} else {
+			tryTimes++
+			if tryTimes >= 10 {
+				return e
+			}
+			glog.V(0).Infof("query task (%s) error %v, wait 1 minute then retry %d times", c.TID, e, tryTimes)
+			time.Sleep(time.Minute)
+		}
+
+	}
+	return ErrTaskTimeout
+}
+
+func (c *TaskCli) Commit() error {
+	args := url.Values{}
+	args.Set("tid", c.TID)
+	_, e := util.RemoteApiCall(c.DataNode, "/admin/task/commit", args)
+	return e
+}
+
+func (c *TaskCli) Clean() error {
+	args := url.Values{}
+	args.Set("tid", c.TID)
+	_, e := util.RemoteApiCall(c.DataNode, "/admin/task/clean", args)
+	return e
+}
--- a/weed/storage/store_task_replication.go
+++ b/weed/storage/store_task_replication.go
@ -0,0 +1,115 @@
+package storage
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"os"
+	"path"
+
+	"github.com/chrislusf/seaweedfs/weed/util"
+)
+
+type ReplicaTask struct {
+	VID         VolumeId
+	Collection  string
+	SrcDataNode string
+	s           *Store
+	location    *DiskLocation
+}
+
+func NewReplicaTask(s *Store, args url.Values) (*ReplicaTask, error) {
+	volumeIdString := args.Get("volume")
+	vid, err := NewVolumeId(volumeIdString)
+	if err != nil {
+		return nil, fmt.Errorf("Volume Id %s is not a valid unsigned integer", volumeIdString)
+	}
+	source := args.Get("source")
+	if source == "" {
+		return nil, errors.New("Invalid source data node.")
+
+	}
+	location := s.findFreeLocation()
+	if location == nil {
+		return nil, errors.New("No more free space left")
+	}
+	collection := args.Get("collection")
+	return &ReplicaTask{
+		VID:         vid,
+		Collection:  collection,
+		SrcDataNode: source,
+		s:           s,
+		location:    location,
+	}, nil
+}
+
+func (t *ReplicaTask) Run() error {
+	ch := make(chan error)
+	go func() {
+		idxUrl := util.MkUrl(t.SrcDataNode, "/admin/sync/index", url.Values{"volume": {t.VID.String()}})
+		e := util.DownloadToFile(idxUrl, t.FileName()+".repx")
+		if e != nil {
+			e = fmt.Errorf("Replicat error: %s, %v", idxUrl, e)
+		}
+		ch <- e
+	}()
+	go func() {
+		datUrl := util.MkUrl(t.SrcDataNode, "/admin/sync/vol_data", url.Values{"volume": {t.VID.String()}})
+		e := util.DownloadToFile(datUrl, t.FileName()+".repd")
+		if e != nil {
+			e = fmt.Errorf("Replicat error: %s, %v", datUrl, e)
+		}
+		ch <- e
+	}()
+	errs := make([]error, 0)
+	for i := 0; i < 2; i++ {
+		if e := <-ch; e != nil {
+			errs = append(errs, e)
+		}
+	}
+	if len(errs) == 0 {
+		return nil
+	} else {
+		return fmt.Errorf("%v", errs)
+	}
+}
+
+func (t *ReplicaTask) Commit() error {
+	var (
+		volume *Volume
+		e      error
+	)
+
+	if e = os.Rename(t.FileName()+".repd", t.FileName()+".dat"); e != nil {
+		return e
+	}
+	if e = os.Rename(t.FileName()+".repx", t.FileName()+".idx"); e != nil {
+		return e
+	}
+	volume, e = NewVolume(t.location.Directory, t.Collection, t.VID, t.s.needleMapKind, nil)
+	if e == nil {
+		t.location.AddVolume(t.VID, volume)
+		t.s.SendHeartbeatToMaster(nil)
+	}
+	return e
+}
+
+func (t *ReplicaTask) Clean() error {
+	os.Remove(t.FileName() + ".repx")
+	os.Remove(t.FileName() + ".repd")
+	return nil
+}
+
+func (t *ReplicaTask) Info() url.Values {
+	//TODO
+	return url.Values{}
+}
+
+func (t *ReplicaTask) FileName() (fileName string) {
+	if t.Collection == "" {
+		fileName = path.Join(t.location.Directory, t.VID.String())
+	} else {
+		fileName = path.Join(t.location.Directory, t.Collection+"_"+t.VID.String())
+	}
+	return
+}