diff --git a/README.md b/README.md
index ffab92ebba3a03f0ce22ef9b66f2f0d0484800de..5bb346e3e2005f20644ea80cc883651715f81e11 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,8 @@ $ docker-compose up -d
 ![dashboard](https://user-images.githubusercontent.com/19553554/78956965-8b9c6180-7b16-11ea-9747-6ed5e62b068d.png)
 
 ## Upgrading
-If upgrade `version<1.4.0` to `v1.4.0`, follow the operating instructions in [v1.4.0](https://github.com/didi/nightingale/releases/tag/V1.4.0) release
+- If upgrade `version<1.4.0` to `v1.4.0`, follow the operating instructions in [v1.4.0](https://github.com/didi/nightingale/releases/tag/V1.4.0) release
+- If upgrade from `version>1.4.0 & version<2.3.0` to `v2.3.0`, need import this [sql](https://github.com/didi/nightingale/blob/master/sql/upgrade_2.3.0.sql) 
 
 
 ## Team
diff --git a/control b/control
index ff087d4307ed9f9c1919c19df6b93e7163b4e05f..d533219232f2fd6463ee5432b2f1df5d42c67f19 100755
--- a/control
+++ b/control
@@ -139,13 +139,13 @@ status()
 build_one()
 {
 	mod=$1
-	go build -ldflags "-X main.version=${version} -X main.buildTime=`date -u '+%Y-%m-%d_%I:%M:%S%p'` -X main.gitHash=`git rev-parse HEAD`" -mod=vendor -o n9e-${mod} --tags "md5" src/modules/${mod}/${mod}.go
+	go build -ldflags "-X main.version=${version} -X main.buildTime=`date -u '+%Y-%m-%d_%I:%M:%S%p'` -X main.gitHash=`git rev-parse HEAD`" -mod=vendor -o n9e-${mod} src/modules/${mod}/${mod}.go
 }
 
 build_docker()
 {
 	mod=$1
-	go build -ldflags "-X main.version=${version} -X main.buildTime=`date -u '+%Y-%m-%d_%I:%M:%S%p'` -X main.gitHash=`git rev-parse HEAD`" -mod=vendor -o bin/n9e-${mod} --tags "md5" src/modules/${mod}/${mod}.go
+	go build -ldflags "-X main.version=${version} -X main.buildTime=`date -u '+%Y-%m-%d_%I:%M:%S%p'` -X main.gitHash=`git rev-parse HEAD`" -mod=vendor -o bin/n9e-${mod}  src/modules/${mod}/${mod}.go
 }
 
 build()
diff --git a/src/modules/tsdb/cache/cache.go b/src/modules/tsdb/cache/cache.go
index c3059e8d95a8c12f66cd895a256480acd540ecbe..dfca2142cd86643ff65cfe3361c76b1a4b056bbb 100644
--- a/src/modules/tsdb/cache/cache.go
+++ b/src/modules/tsdb/cache/cache.go
@@ -38,7 +38,7 @@ type (
 )
 
 type cache struct {
-	Items map[interface{}]*CS // [counter]ts,value
+	Items map[string]*CS // [counter]ts,value
 	sync.RWMutex
 }
 
@@ -64,18 +64,18 @@ func InitChunkSlot() {
 	}
 
 	ChunksSlots = &ChunksSlot{
-		Data: make([]map[interface{}][]*Chunk, size),
+		Data: make([]map[string][]*Chunk, size),
 		Size: size,
 	}
 	for i := 0; i < size; i++ {
-		ChunksSlots.Data[i] = make(map[interface{}][]*Chunk)
+		ChunksSlots.Data[i] = make(map[string][]*Chunk)
 	}
 }
 
 func NewCaches() caches {
 	c := make(caches, SHARD_COUNT)
 	for i := 0; i < SHARD_COUNT; i++ {
-		c[i] = &cache{Items: make(map[interface{}]*CS)}
+		c[i] = &cache{Items: make(map[string]*CS)}
 	}
 	return c
 }
@@ -97,7 +97,7 @@ func StartCleanup() {
 	}
 }
 
-func (c *caches) Push(seriesID interface{}, ts int64, value float64) error {
+func (c *caches) Push(seriesID string, ts int64, value float64) error {
 	shard := c.getShard(seriesID)
 	existC, exist := Caches.exist(seriesID)
 	if exist {
@@ -114,7 +114,7 @@ func (c *caches) Push(seriesID interface{}, ts int64, value float64) error {
 	return err
 }
 
-func (c *caches) Get(seriesID interface{}, from, to int64) ([]Iter, error) {
+func (c *caches) Get(seriesID string, from, to int64) ([]Iter, error) {
 	existC, exist := Caches.exist(seriesID)
 
 	if !exist {
@@ -129,7 +129,7 @@ func (c *caches) Get(seriesID interface{}, from, to int64) ([]Iter, error) {
 	return res, nil
 }
 
-func (c *caches) SetFlag(seriesID interface{}, flag uint32) error {
+func (c *caches) SetFlag(seriesID string, flag uint32) error {
 	existC, exist := Caches.exist(seriesID)
 	if !exist {
 		return fmt.Errorf("non series exist")
@@ -138,7 +138,7 @@ func (c *caches) SetFlag(seriesID interface{}, flag uint32) error {
 	return nil
 }
 
-func (c *caches) GetFlag(seriesID interface{}) uint32 {
+func (c *caches) GetFlag(seriesID string) uint32 {
 	existC, exist := Caches.exist(seriesID)
 	if !exist {
 		return 0
@@ -146,7 +146,7 @@ func (c *caches) GetFlag(seriesID interface{}) uint32 {
 	return existC.GetFlag()
 }
 
-func (c *caches) create(seriesID interface{}) *CS {
+func (c *caches) create(seriesID string) *CS {
 	atomic.AddInt64(&TotalCount, 1)
 	shard := c.getShard(seriesID)
 	shard.Lock()
@@ -157,7 +157,7 @@ func (c *caches) create(seriesID interface{}) *CS {
 	return newC
 }
 
-func (c *caches) exist(seriesID interface{}) (*CS, bool) {
+func (c *caches) exist(seriesID string) (*CS, bool) {
 	shard := c.getShard(seriesID)
 	shard.RLock()
 	existC, exist := shard.Items[seriesID]
@@ -166,7 +166,7 @@ func (c *caches) exist(seriesID interface{}) (*CS, bool) {
 	return existC, exist
 }
 
-func (c *caches) GetCurrentChunk(seriesID interface{}) (*Chunk, bool) {
+func (c *caches) GetCurrentChunk(seriesID string) (*Chunk, bool) {
 	shard := c.getShard(seriesID)
 	if shard == nil {
 		return nil, false
@@ -185,7 +185,7 @@ func (c caches) Count() int64 {
 	return atomic.LoadInt64(&TotalCount)
 }
 
-func (c caches) Remove(seriesID interface{}) {
+func (c caches) Remove(seriesID string) {
 	atomic.AddInt64(&TotalCount, -1)
 	shard := c.getShard(seriesID)
 	shard.Lock()
@@ -229,14 +229,6 @@ func (c caches) Cleanup(expiresInMinutes int) {
 	logger.Infof("cleanup %v Items, took %.2f ms\n", count, float64(time.Since(now).Nanoseconds())*1e-6)
 }
 
-func (c caches) getShard(key interface{}) *cache {
-	switch key.(type) {
-	case uint64:
-		return c[int(key.(uint64)%SHARD_COUNT)]
-	case string:
-		return c[utils.HashKey(key.(string))%SHARD_COUNT]
-	default: //不会出现此种情况
-		return nil
-	}
-	return nil
+func (c caches) getShard(key string) *cache {
+	return c[utils.HashKey(key)%SHARD_COUNT]
 }
diff --git a/src/modules/tsdb/cache/chunk.go b/src/modules/tsdb/cache/chunk.go
index 0babb39a96e89c625d822f9cf3fa8662c1e65719..b5c5bd4f35d14811c50d6644c64bbf59ed9239c1 100644
--- a/src/modules/tsdb/cache/chunk.go
+++ b/src/modules/tsdb/cache/chunk.go
@@ -54,7 +54,7 @@ var ChunksSlots *ChunksSlot
 
 type ChunksSlot struct {
 	sync.RWMutex
-	Data []map[interface{}][]*Chunk
+	Data []map[string][]*Chunk
 	Size int
 }
 
@@ -65,21 +65,21 @@ func (c *ChunksSlot) Len(idx int) int {
 	return len(c.Data[idx])
 }
 
-func (c *ChunksSlot) Get(idx int) map[interface{}][]*Chunk {
+func (c *ChunksSlot) Get(idx int) map[string][]*Chunk {
 	c.Lock()
 	defer c.Unlock()
 
 	items := c.Data[idx]
-	ret := make(map[interface{}][]*Chunk)
+	ret := make(map[string][]*Chunk)
 	for k, v := range items {
 		ret[k] = v
 	}
-	c.Data[idx] = make(map[interface{}][]*Chunk)
+	c.Data[idx] = make(map[string][]*Chunk)
 
 	return ret
 }
 
-func (c *ChunksSlot) GetChunks(key interface{}) ([]*Chunk, bool) {
+func (c *ChunksSlot) GetChunks(key string) ([]*Chunk, bool) {
 	c.Lock()
 	defer c.Unlock()
 
@@ -96,7 +96,7 @@ func (c *ChunksSlot) GetChunks(key interface{}) ([]*Chunk, bool) {
 	return val, ok
 }
 
-func (c *ChunksSlot) PushChunks(key interface{}, vals []*Chunk) {
+func (c *ChunksSlot) PushChunks(key string, vals []*Chunk) {
 	c.Lock()
 	defer c.Unlock()
 	idx, err := GetChunkIndex(key, c.Size)
@@ -115,7 +115,7 @@ func (c *ChunksSlot) PushChunks(key interface{}, vals []*Chunk) {
 	c.Data[idx][key] = vals
 }
 
-func (c *ChunksSlot) Push(key interface{}, val *Chunk) {
+func (c *ChunksSlot) Push(key string, val *Chunk) {
 	c.Lock()
 	defer c.Unlock()
 	idx, err := GetChunkIndex(key, c.Size)
@@ -130,13 +130,6 @@ func (c *ChunksSlot) Push(key interface{}, val *Chunk) {
 	c.Data[idx][key] = append(c.Data[idx][key], val)
 }
 
-func GetChunkIndex(key interface{}, size int) (uint32, error) {
-	switch key.(type) {
-	case uint64:
-		return uint32(key.(uint64)) % uint32(size), nil
-	case string:
-		return utils.HashKey(key.(string)) % uint32(size), nil
-	default:
-		return 0, fmt.Errorf("undefined hashType:%v", key)
-	}
+func GetChunkIndex(key string, size int) (uint32, error) {
+	return utils.HashKey(key) % uint32(size), nil
 }
diff --git a/src/modules/tsdb/cache/chunks.go b/src/modules/tsdb/cache/chunks.go
index f97b2698e72a1fd60ad606cd88fa23228e87d3eb..3996929166f28ed56f4cc296c9ab0d1b3c772fa1 100644
--- a/src/modules/tsdb/cache/chunks.go
+++ b/src/modules/tsdb/cache/chunks.go
@@ -21,7 +21,7 @@ func NewChunks(numOfChunks int) *CS {
 	return &CS{Chunks: cs}
 }
 
-func (cs *CS) Push(seriesID interface{}, ts int64, value float64) error {
+func (cs *CS) Push(seriesID string, ts int64, value float64) error {
 	//找到当前chunk的起始时间
 	t0 := uint32(ts - (ts % int64(Config.SpanInSeconds)))
 
diff --git a/src/modules/tsdb/cache/point.go b/src/modules/tsdb/cache/point.go
index 8c88e1c3f3d11506809e3632689bbc011fc38e77..c0bd58b0c7f253df43353624c65f26c1cbdb7aa9 100644
--- a/src/modules/tsdb/cache/point.go
+++ b/src/modules/tsdb/cache/point.go
@@ -1,7 +1,7 @@
 package cache
 
 type Point struct {
-	Key       interface{} `msg:"key"`
-	Timestamp int64       `msg:"timestamp"`
-	Value     float64     `msg:"value"`
+	Key       string  `msg:"key"`
+	Timestamp int64   `msg:"timestamp"`
+	Value     float64 `msg:"value"`
 }
diff --git a/src/modules/tsdb/index/cache.go b/src/modules/tsdb/index/cache.go
index 5576b189cb85c66debb30f68423048aa89b08764..012b9bc95a206a2d4678b1a75c436dafd631ecf3 100644
--- a/src/modules/tsdb/index/cache.go
+++ b/src/modules/tsdb/index/cache.go
@@ -17,11 +17,11 @@ type DsTypeAndStep struct {
 
 // 索引缓存的元素数据结构
 type IndexCacheItem struct {
-	UUID interface{}
+	UUID string
 	Item *dataobj.TsdbItem
 }
 
-func NewIndexCacheItem(uuid interface{}, item *dataobj.TsdbItem) *IndexCacheItem {
+func NewIndexCacheItem(uuid string, item *dataobj.TsdbItem) *IndexCacheItem {
 	return &IndexCacheItem{UUID: uuid, Item: item}
 }
 
@@ -29,26 +29,26 @@ func NewIndexCacheItem(uuid interface{}, item *dataobj.TsdbItem) *IndexCacheItem
 type IndexCacheBase struct {
 	sync.RWMutex
 	maxSize int
-	data    map[interface{}]*dataobj.TsdbItem
+	data    map[string]*dataobj.TsdbItem
 }
 
 func NewIndexCacheBase(max int) *IndexCacheBase {
-	return &IndexCacheBase{maxSize: max, data: make(map[interface{}]*dataobj.TsdbItem)}
+	return &IndexCacheBase{maxSize: max, data: make(map[string]*dataobj.TsdbItem)}
 }
 
-func (i *IndexCacheBase) Put(key interface{}, item *dataobj.TsdbItem) {
+func (i *IndexCacheBase) Put(key string, item *dataobj.TsdbItem) {
 	i.Lock()
 	defer i.Unlock()
 	i.data[key] = item
 }
 
-func (i *IndexCacheBase) Get(key interface{}) *dataobj.TsdbItem {
+func (i *IndexCacheBase) Get(key string) *dataobj.TsdbItem {
 	i.RLock()
 	defer i.RUnlock()
 	return i.data[key]
 }
 
-func (i *IndexCacheBase) ContainsKey(key interface{}) bool {
+func (i *IndexCacheBase) ContainsKey(key string) bool {
 	i.RLock()
 	defer i.RUnlock()
 	return i.data[key] != nil
@@ -60,16 +60,16 @@ func (i *IndexCacheBase) Size() int {
 	return len(i.data)
 }
 
-func (i *IndexCacheBase) Keys() []interface{} {
+func (i *IndexCacheBase) Keys() []string {
 	i.RLock()
 	defer i.RUnlock()
 
 	count := len(i.data)
 	if count == 0 {
-		return []interface{}{}
+		return []string{}
 	}
 
-	keys := make([]interface{}, 0, count)
+	keys := make([]string, 0, count)
 	for key := range i.data {
 		keys = append(keys, key)
 	}
@@ -77,7 +77,7 @@ func (i *IndexCacheBase) Keys() []interface{} {
 	return keys
 }
 
-func (i *IndexCacheBase) Remove(key interface{}) {
+func (i *IndexCacheBase) Remove(key string) {
 	i.Lock()
 	defer i.Unlock()
 	delete(i.data, key)
diff --git a/src/modules/tsdb/index/init.go b/src/modules/tsdb/index/init.go
index 8a32a541432ac8cf5e8562f2fd23124cdba31691..0dd3d0ce5a88e7adab313634eef568a14392bb1d 100644
--- a/src/modules/tsdb/index/init.go
+++ b/src/modules/tsdb/index/init.go
@@ -40,53 +40,28 @@ func Init(cfg IndexSection) {
 	logger.Info("index.Start ok")
 }
 
-func GetItemFronIndex(hash interface{}) *dataobj.TsdbItem {
-	switch hash.(type) {
-	case uint64:
-		indexedItemCache := IndexedItemCacheBigMap[hash.(uint64)%INDEX_SHARD]
-		return indexedItemCache.Get(hash)
-	case string:
-		indexedItemCache := IndexedItemCacheBigMap[utils.HashKey(hash.(string))%INDEX_SHARD]
-		return indexedItemCache.Get(hash)
-	}
-
-	return nil
+func GetItemFronIndex(hash string) *dataobj.TsdbItem {
+	indexedItemCache := IndexedItemCacheBigMap[utils.HashKey(hash)%INDEX_SHARD]
+	return indexedItemCache.Get(hash)
 }
 
-func DeleteItemFronIndex(hash interface{}) *dataobj.TsdbItem {
-	switch hash.(type) {
-	case uint64:
-		indexedItemCache := IndexedItemCacheBigMap[hash.(uint64)%INDEX_SHARD]
-		indexedItemCache.Remove(hash)
-	case string:
-		indexedItemCache := IndexedItemCacheBigMap[utils.HashKey(hash.(string))%INDEX_SHARD]
-		indexedItemCache.Remove(hash)
-	}
-
-	return nil
+func DeleteItemFronIndex(hash string) {
+	indexedItemCache := IndexedItemCacheBigMap[utils.HashKey(hash)%INDEX_SHARD]
+	indexedItemCache.Remove(hash)
+	return
 }
 
 // index收到一条新上报的监控数据,尝试用于增量更新索引
-func ReceiveItem(item *dataobj.TsdbItem, hash interface{}) {
+func ReceiveItem(item *dataobj.TsdbItem, hash string) {
 	if item == nil {
 		return
 	}
 	var indexedItemCache *IndexCacheBase
 	var unIndexedItemCache *IndexCacheBase
 
-	switch hash.(type) {
-	case uint64:
-		indexedItemCache = IndexedItemCacheBigMap[int(hash.(uint64)%INDEX_SHARD)]
-		unIndexedItemCache = UnIndexedItemCacheBigMap[int(hash.(uint64)%INDEX_SHARD)]
-	case string:
-		indexedItemCache = IndexedItemCacheBigMap[int(hashKey(hash.(string))%INDEX_SHARD)]
-		unIndexedItemCache = UnIndexedItemCacheBigMap[int(hashKey(hash.(string))%INDEX_SHARD)]
-	default:
-		logger.Error("undefined hash type", hash)
-		stats.Counter.Set("index.in.err", 1)
+	indexedItemCache = IndexedItemCacheBigMap[int(hashKey(hash)%INDEX_SHARD)]
+	unIndexedItemCache = UnIndexedItemCacheBigMap[int(hashKey(hash)%INDEX_SHARD)]
 
-		return
-	}
 	if indexedItemCache == nil {
 		stats.Counter.Set("index.in.err", 1)
 		logger.Error("indexedItemCache: ", reflect.TypeOf(hash), hash)
diff --git a/src/modules/tsdb/migrate/init.go b/src/modules/tsdb/migrate/init.go
index cb2d6c218de8ea168d5d7404e80f49580a36daec..1a74592045b188688b4add1384bf699011b295f2 100644
--- a/src/modules/tsdb/migrate/init.go
+++ b/src/modules/tsdb/migrate/init.go
@@ -30,7 +30,7 @@ const (
 
 var (
 	Config     MigrateSection
-	QueueCheck = QueueFilter{Data: make(map[interface{}]struct{})}
+	QueueCheck = QueueFilter{Data: make(map[string]struct{})}
 
 	TsdbQueues    = make(map[string]*list.SafeListLimited)
 	NewTsdbQueues = make(map[string]*list.SafeListLimited)
@@ -45,11 +45,11 @@ var (
 )
 
 type QueueFilter struct {
-	Data map[interface{}]struct{}
+	Data map[string]struct{}
 	sync.RWMutex
 }
 
-func (q *QueueFilter) Exists(key interface{}) bool {
+func (q *QueueFilter) Exists(key string) bool {
 	q.RLock()
 	defer q.RUnlock()
 
@@ -57,7 +57,7 @@ func (q *QueueFilter) Exists(key interface{}) bool {
 	return exsits
 }
 
-func (q *QueueFilter) Set(key interface{}) {
+func (q *QueueFilter) Set(key string) {
 	q.Lock()
 	defer q.Unlock()
 
diff --git a/src/modules/tsdb/rpc/query.go b/src/modules/tsdb/rpc/query.go
index 0b01ba78903261ca35c1da4ec323294d7f2a0f7f..c336fbaf1e43ee918fed7146d2684abbefbcff33 100644
--- a/src/modules/tsdb/rpc/query.go
+++ b/src/modules/tsdb/rpc/query.go
@@ -410,7 +410,7 @@ func getRRD(f dataobj.RRDFile, worker chan struct{}, dataChan chan *dataobj.File
 
 	chunks, exists := cache.ChunksSlots.GetChunks(key)
 	if exists {
-		m := make(map[interface{}][]*cache.Chunk)
+		m := make(map[string][]*cache.Chunk)
 		m[key] = chunks
 		rrdtool.FlushRRD(m)
 	}
diff --git a/src/modules/tsdb/rrdtool/rrdtool.go b/src/modules/tsdb/rrdtool/rrdtool.go
index f6d4d80e2a80c29c9e33278b42a908b281e22388..2fe12a0b794855be4a7e9d634b61f90bf44deb7b 100644
--- a/src/modules/tsdb/rrdtool/rrdtool.go
+++ b/src/modules/tsdb/rrdtool/rrdtool.go
@@ -55,7 +55,7 @@ func update(filename string, items []*dataobj.TsdbItem) error {
 
 // flush to disk from memory
 // 最新的数据在列表的最后面
-func Flushrrd(seriesID interface{}, items []*dataobj.TsdbItem) error {
+func Flushrrd(seriesID string, items []*dataobj.TsdbItem) error {
 	item := index.GetItemFronIndex(seriesID)
 	if items == nil || len(items) == 0 || item == nil {
 		return errors.New("empty items")
diff --git a/src/modules/tsdb/rrdtool/sync_disk.go b/src/modules/tsdb/rrdtool/sync_disk.go
index cd2885e95b27d5e8a41cea28774d0240041a0231..20baefae2dca5065f58a7f79a8daf56450796f93 100644
--- a/src/modules/tsdb/rrdtool/sync_disk.go
+++ b/src/modules/tsdb/rrdtool/sync_disk.go
@@ -1,7 +1,6 @@
 package rrdtool
 
 import (
-	"fmt"
 	"io/ioutil"
 	"sync"
 	"sync/atomic"
@@ -53,7 +52,7 @@ type fetch_t struct {
 }
 
 type flushfile_t struct {
-	seriesID interface{}
+	seriesID string
 	items    []*dataobj.TsdbItem
 }
 
@@ -164,7 +163,7 @@ func FlushFinishd2Disk() {
 		case <-ticker:
 			idx = idx % slotNum
 			chunks := cache.ChunksSlots.Get(idx)
-			flushChunks := make(map[interface{}][]*cache.Chunk, 0)
+			flushChunks := make(map[string][]*cache.Chunk, 0)
 			for key, cs := range chunks {
 				if Config.Migrate {
 					item := index.GetItemFronIndex(key)
@@ -205,14 +204,14 @@ func Persist() {
 	return
 }
 
-func FlushRRD(flushChunks map[interface{}][]*cache.Chunk) {
+func FlushRRD(flushChunks map[string][]*cache.Chunk) {
 	sema := semaphore.NewSemaphore(Config.Concurrency)
 	var wg sync.WaitGroup
 	for key, chunks := range flushChunks {
 		//控制并发
 		sema.Acquire()
 		wg.Add(1)
-		go func(seriesID interface{}, chunks []*cache.Chunk) {
+		go func(seriesID string, chunks []*cache.Chunk) {
 			defer sema.Release()
 			defer wg.Done()
 			for _, c := range chunks {
@@ -242,11 +241,11 @@ func FlushRRD(flushChunks map[interface{}][]*cache.Chunk) {
 }
 
 //todo items数据结构优化
-func Commit(seriesID interface{}, items []*dataobj.TsdbItem) {
+func Commit(seriesID string, items []*dataobj.TsdbItem) {
 	FlushFile(seriesID, items)
 }
 
-func FlushFile(seriesID interface{}, items []*dataobj.TsdbItem) error {
+func FlushFile(seriesID string, items []*dataobj.TsdbItem) error {
 	done := make(chan error, 1)
 	index, err := getIndex(seriesID)
 	if err != nil {
@@ -265,7 +264,7 @@ func FlushFile(seriesID interface{}, items []*dataobj.TsdbItem) error {
 	return <-done
 }
 
-func Fetch(filename string, seriesID interface{}, cf string, start, end int64, step int) ([]*dataobj.RRDData, error) {
+func Fetch(filename string, seriesID string, cf string, start, end int64, step int) ([]*dataobj.RRDData, error) {
 	done := make(chan error, 1)
 	task := &io_task_t{
 		method: IO_TASK_M_FETCH,
@@ -288,25 +287,17 @@ func Fetch(filename string, seriesID interface{}, cf string, start, end int64, s
 	return task.args.(*fetch_t).data, err
 }
 
-func getIndex(seriesID interface{}) (index int, err error) {
+func getIndex(seriesID string) (index int, err error) {
 	batchNum := Config.IOWorkerNum
 
 	if batchNum <= 1 {
 		return 0, nil
 	}
 
-	switch seriesID.(type) {
-	case uint64:
-		return int(seriesID.(uint64) % uint64(batchNum)), nil
-	case string:
-		return int(utils.HashKey(seriesID.(string)) % uint32(batchNum)), nil
-	default:
-		return 0, fmt.Errorf("undefined hashType:%v", seriesID)
-	}
-	return
+	return int(utils.HashKey(seriesID) % uint32(batchNum)), nil
 }
 
-func ReadFile(filename string, seriesID interface{}) ([]byte, error) {
+func ReadFile(filename string, seriesID string) ([]byte, error) {
 	done := make(chan error, 1)
 	task := &io_task_t{
 		method: IO_TASK_M_READ,
diff --git a/src/modules/tsdb/utils/utils.go b/src/modules/tsdb/utils/utils.go
index 08af9b3974f179e463f7fda1fc29dbb81ca9ac2c..b16d72768a33a9cffd5df4965beb3ff0f4374d3e 100644
--- a/src/modules/tsdb/utils/utils.go
+++ b/src/modules/tsdb/utils/utils.go
@@ -11,26 +11,12 @@ import (
 
 const RRDDIRS uint64 = 1000
 
-func QueryRrdFile(seriesID interface{}, dsType string, step int) string {
-	switch seriesID.(type) {
-	case uint64:
-		return strconv.FormatUint(seriesID.(uint64)%RRDDIRS, 10) + "/" +
-			strconv.FormatUint(seriesID.(uint64), 10) + "_" + dsType + "_" + strconv.Itoa(step) + ".rrd"
-	case string:
-		return seriesID.(string)[0:2] + "/" + seriesID.(string) + "_" + dsType + "_" + strconv.Itoa(step) + ".rrd"
-	}
-	return ""
+func QueryRrdFile(seriesID string, dsType string, step int) string {
+	return seriesID[0:2] + "/" + seriesID + "_" + dsType + "_" + strconv.Itoa(step) + ".rrd"
 }
 
-func RrdFileName(baseDir string, seriesID interface{}, dsType string, step int) string {
-	switch seriesID.(type) {
-	case uint64:
-		return baseDir + "/" + strconv.FormatUint(seriesID.(uint64)%RRDDIRS, 10) + "/" +
-			strconv.FormatUint(seriesID.(uint64), 10) + "_" + dsType + "_" + strconv.Itoa(step) + ".rrd"
-	case string:
-		return baseDir + "/" + seriesID.(string)[0:2] + "/" + seriesID.(string) + "_" + dsType + "_" + strconv.Itoa(step) + ".rrd"
-	}
-	return ""
+func RrdFileName(baseDir string, seriesID string, dsType string, step int) string {
+	return baseDir + "/" + seriesID[0:2] + "/" + seriesID + "_" + dsType + "_" + strconv.Itoa(step) + ".rrd"
 }
 
 // WriteFile writes data to a file named by filename.
diff --git a/src/toolkits/str/checksum_md5.go b/src/toolkits/str/checksum.go
similarity index 96%
rename from src/toolkits/str/checksum_md5.go
rename to src/toolkits/str/checksum.go
index de28ff90e4dd77a9be0008c2cdbbd10d722b988a..7db3a218829ad42a80a98bd9a772db6423ce23df 100644
--- a/src/toolkits/str/checksum_md5.go
+++ b/src/toolkits/str/checksum.go
@@ -1,5 +1,3 @@
-// +build md5
-
 package str
 
 import (
diff --git a/src/toolkits/str/checksum_xxhash.go b/src/toolkits/str/checksum_xxhash.go
deleted file mode 100644
index 9fcea21eb97fe6faa2b1392541bc6b129633b742..0000000000000000000000000000000000000000
--- a/src/toolkits/str/checksum_xxhash.go
+++ /dev/null
@@ -1,47 +0,0 @@
-// +build xxhash
-
-package str
-
-import (
-	"bytes"
-	"strconv"
-	"strings"
-
-	"github.com/cespare/xxhash"
-)
-
-func Checksum(strs ...string) uint64 {
-	ret := bufferPool.Get().(*bytes.Buffer)
-	ret.Reset()
-	defer bufferPool.Put(ret)
-	count := len(strs)
-	if count == 0 {
-		return 0
-	}
-
-	ret.WriteString(strs[0])
-	for i := 1; i < count-1; i++ {
-		ret.WriteString(SEPERATOR)
-		ret.WriteString(strs[i])
-	}
-
-	if strs[count-1] != "" {
-		ret.WriteString(SEPERATOR)
-		ret.WriteString(strs[count-1])
-	}
-
-	return xxhash.Sum64(ret.Bytes())
-}
-
-func GetKey(filename string) uint64 {
-	arr := strings.Split(filename, "/")
-	if len(arr) < 2 {
-		return 0
-	}
-	a := strings.Split(arr[1], "_")
-	if len(a) > 1 {
-		key, _ := strconv.ParseUint(a[0], 10, 64)
-		return key
-	}
-	return 0
-}