diff --git a/README.MD b/README.MD
index d631d14..c6967a3 100644
--- a/README.MD
+++ b/README.MD
@@ -19,8 +19,6 @@ Similar as [dnsmasq](http://www.thekelleys.org.uk/dnsmasq/doc.html) ,but support
 
 
 
-
-
 ## Configuration
 
 All the configuration on `godns.conf` a TOML formating config file.   
@@ -46,6 +44,8 @@ If multi `namerserver` set at resolv.conf, the upsteam server will try in order
 
 #### cache
 
+Only the local memory storage backend implemented now.  The redis backend is in todo list
+
 
 
 
diff --git a/cache.go b/cache.go
index 9a996cf..490dc5e 100644
--- a/cache.go
+++ b/cache.go
@@ -4,6 +4,7 @@ import (
 	"crypto/md5"
 	"encoding/json"
 	"fmt"
+	"github.com/hoisie/redis"
 	"github.com/miekg/dns"
 	"time"
 )
@@ -47,10 +48,9 @@ type Cache interface {
 }
 
 type MemoryCache struct {
-	backend    map[string]*dns.Msg
-	serializer *JsonSerializer
-	expire     time.Duration
-	maxcount   int
+	backend  map[string]*dns.Msg
+	expire   time.Duration
+	maxcount int
 }
 
 func (c *MemoryCache) Get(key string) (*dns.Msg, error) {
@@ -60,11 +60,6 @@ func (c *MemoryCache) Get(key string) (*dns.Msg, error) {
 		return nil, KeyNotFound{key}
 	}
 
-	// mesg := new(dns.Msg)
-	// if err := c.serializer.Loads([]byte(data), &mesg); err != nil {
-	// 	fmt.Println(err)
-	// 	return nil, SerializerError{}
-	// }
 	return mesg, nil
 
 }
@@ -73,13 +68,6 @@ func (c *MemoryCache) Set(key string, mesg *dns.Msg) error {
 	if c.Full() && !c.Exists(key) {
 		return CacheIsFull{}
 	}
-	// data, err := c.serializer.Dumps(mesg)
-
-	// if err != nil {
-	// 	return SerializerError{}
-	// }
-
-	// c.backend[key] = string(data)
 	c.backend[key] = mesg
 	return nil
 }
@@ -105,21 +93,28 @@ func (c *MemoryCache) Full() bool {
 	return c.Length() >= c.maxcount
 }
 
-// type RedisCache struct{
-// backend redis.client
-// }
+/*
+TODO: Redis cache backend
+*/
 
-// func (c *RedisCache) Get(key string) {
+type RedisCache struct {
+	backend    *redis.Client
+	serializer JsonSerializer
+	expire     time.Duration
+	maxcount   int
+}
 
-// }
+func (c *RedisCache) Get() {
 
-// func (c *RedisCache) Set() {
+}
 
-// }
+func (c *RedisCache) Set() {
 
-// func (c &RedisCache) Remove(){
+}
 
-// }
+func (c *RedisCache) Remove() {
+
+}
 
 func KeyGen(q Question) string {
 	h := md5.New()
diff --git a/godns.conf b/godns.conf
index 85285e0..d6bd407 100644
--- a/godns.conf
+++ b/godns.conf
@@ -28,6 +28,7 @@ file = ""
 
 [cache]
 # backend option [memory|redis]	
+# redis backend not implemented yet
 backend = "memory"  
 expire = 600  # 10 minutes
 maxcount = 100000
diff --git a/handler.go b/handler.go
index d2877ce..adb7e69 100644
--- a/handler.go
+++ b/handler.go
@@ -42,18 +42,18 @@ func NewHandler() *GODNSHandler {
 	switch cacheConfig.Backend {
 	case "memory":
 		cache = &MemoryCache{
-			backend:    make(map[string]*dns.Msg),
-			serializer: new(JsonSerializer),
-			expire:     cacheConfig.Expire,
-			maxcount:   cacheConfig.Maxcount,
+			backend:  make(map[string]*dns.Msg),
+			expire:   cacheConfig.Expire,
+			maxcount: cacheConfig.Maxcount,
 		}
 	case "redis":
-		cache = &MemoryCache{
-			backend:    make(map[string]*dns.Msg),
-			serializer: new(JsonSerializer),
-			expire:     cacheConfig.Expire,
-			maxcount:   cacheConfig.Maxcount,
-		}
+		// cache = &MemoryCache{
+		// 	backend:    make(map[string]*dns.Msg),
+		// 	serializer: new(JsonSerializer),
+		// 	expire:     cacheConfig.Expire,
+		// 	maxcount:   cacheConfig.Maxcount,
+		// }
+		panic("Redis cache backend not implement yet")
 	default:
 		logger.Printf("Invalid cache backend %s", cacheConfig.Backend)
 		panic("Invalid cache backend")