diff --git a/cluster/router/chain/chain.go b/cluster/router/chain/chain.go
index 4c3cf8c2a77e95f802e4cd644f53b818d70d3389..3efed158686322e80bc56166993d9d39da8169ce 100644
--- a/cluster/router/chain/chain.go
+++ b/cluster/router/chain/chain.go
@@ -290,7 +290,7 @@ func isInvokersChanged(left []protocol.Invoker, right []protocol.Invoker) bool {
 		rurl := r.GetUrl()
 		for _, l := range left {
 			lurl := l.GetUrl()
-			if common.GetURLTool().CompareURLEqual(&lurl, &rurl, constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY) {
+			if common.GetURLComparator().CompareURLEqual(&lurl, &rurl, constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY) {
 				found = true
 				break
 			}
diff --git a/common/url_tool_extension.go b/common/url_tool_extension.go
index 84899fca51deb47ca0194983db6afbd265c746ba..e446f7ee69a8f95aacee5fda3208db84350bc988 100644
--- a/common/url_tool_extension.go
+++ b/common/url_tool_extension.go
@@ -17,50 +17,30 @@
 
 package common
 
-import "sync"
-
-var urlTool URLTool
-var lock sync.Mutex
+var urlComparator URLComparator
 
 // Define some func for URL, such as comparison of URL.
-// Your can define your own implements, and invoke SetURLTool for high priority.
-type URLTool interface {
-	// The higher of the number, the higher of the priority.
-	Priority() uint8
-	// comparison of two URL, excluding some params
+// Your can define your own implements, and invoke SetURLComparator.
+type URLComparator interface {
 	CompareURLEqual(*URL, *URL, ...string) bool
 }
 
-func SetURLTool(tool URLTool) {
-	lock.Lock()
-	defer lock.Unlock()
-	if urlTool == nil {
-		urlTool = tool
-		return
-	}
-	if urlTool.Priority() < tool.Priority() {
-		urlTool = tool
-	}
+func SetURLComparator(comparator URLComparator) {
+	urlComparator = comparator
 }
-func GetURLTool() URLTool {
-	return urlTool
+func GetURLComparator() URLComparator {
+	return urlComparator
 }
 
-// Config default urlTools.
+// Config default defaultURLComparator.
 func init() {
-	SetURLTool(defaultURLTool{})
-}
-
-type defaultURLTool struct {
+	SetURLComparator(defaultURLComparator{})
 }
 
-// default priority is 16.
-func (defaultURLTool) Priority() uint8 {
-	//default is 16.
-	return 16
+type defaultURLComparator struct {
 }
 
 // default comparison implements
-func (defaultURLTool) CompareURLEqual(l *URL, r *URL, execludeParam ...string) bool {
-	return IsEquals(*l, *r, execludeParam...)
+func (defaultURLComparator) CompareURLEqual(l *URL, r *URL, excludeParam ...string) bool {
+	return IsEquals(*l, *r, excludeParam...)
 }
diff --git a/common/url_tool_extension_test.go b/common/url_tool_extension_test.go
index 8254c18aaa5c4eba110280db79f13b9e7c707075..6a5a3cf9b2b5f970c46b24fcfe7ee6213b59d6f4 100644
--- a/common/url_tool_extension_test.go
+++ b/common/url_tool_extension_test.go
@@ -34,8 +34,8 @@ func TestDefaultURLTool(t *testing.T) {
 		"environment=dev&interface=com.ikurento.user.UserProvider&ip=192.168.56.1&methods=GetUser%2C&" +
 		"module=dubbogo+user-info+server&org=ikurento.com&owner=ZX&pid=1447&revision=0.0.1&" +
 		"side=provider&timeout=3000&timestamp=155650979798")
-	assert.False(t, GetURLTool().CompareURLEqual(&url1, &url2))
-	assert.True(t, GetURLTool().CompareURLEqual(&url1, &url2, constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY))
+	assert.False(t, GetURLComparator().CompareURLEqual(&url1, &url2))
+	assert.True(t, GetURLComparator().CompareURLEqual(&url1, &url2, constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY))
 }
 
 func TestNewCustomURLTool(t *testing.T) {
@@ -49,10 +49,10 @@ func TestNewCustomURLTool(t *testing.T) {
 		"environment=dev&interface=com.ikurento.user.UserProvider&ip=192.168.56.1&methods=GetUser%2C&" +
 		"module=dubbogo+user-info+server&org=ikurento.com&owner=ZX&pid=1447&revision=0.0.1&" +
 		"side=provider&timeout=3000&timestamp=155650979798")
-	assert.True(t, GetURLTool().CompareURLEqual(&url1, &url2, constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY))
-	SetURLTool(customURLTool{})
-	assert.False(t, GetURLTool().CompareURLEqual(&url1, &url2))
-	assert.False(t, GetURLTool().CompareURLEqual(&url1, &url2, constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY))
+	assert.True(t, GetURLComparator().CompareURLEqual(&url1, &url2, constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY))
+	SetURLComparator(customURLTool{})
+	assert.False(t, GetURLComparator().CompareURLEqual(&url1, &url2))
+	assert.False(t, GetURLComparator().CompareURLEqual(&url1, &url2, constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY))
 
 	url1, _ = NewURL("dubbo://127.0.0.1:20000/com.ikurento.user.UserProvider?anyhost=true&" +
 		"application=BDTService&category=providers&default.timeout=10000&dubbo=dubbo-provider-golang-1.0.0&" +
@@ -64,11 +64,11 @@ func TestNewCustomURLTool(t *testing.T) {
 		"environment=dev&interface=com.ikurento.user.UserProvider&ip=192.168.56.1&methods=GetUser%2C&" +
 		"module=dubbogo+user-info+server&org=ikurento.com&owner=ZX&pid=1447&revision=0.0.1&" +
 		"side=provider&timeout=3000")
-	assert.True(t, GetURLTool().CompareURLEqual(&url1, &url2))
-	assert.True(t, GetURLTool().CompareURLEqual(&url1, &url2, constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY))
-	SetURLTool(customURLTool{})
-	assert.True(t, GetURLTool().CompareURLEqual(&url1, &url2))
-	assert.True(t, GetURLTool().CompareURLEqual(&url1, &url2, constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY))
+	assert.True(t, GetURLComparator().CompareURLEqual(&url1, &url2))
+	assert.True(t, GetURLComparator().CompareURLEqual(&url1, &url2, constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY))
+	SetURLComparator(customURLTool{})
+	assert.True(t, GetURLComparator().CompareURLEqual(&url1, &url2))
+	assert.True(t, GetURLComparator().CompareURLEqual(&url1, &url2, constant.TIMESTAMP_KEY, constant.REMOTE_TIMESTAMP_KEY))
 }
 
 // just for no timestamp, it depend on write data.
diff --git a/registry/directory/directory.go b/registry/directory/directory.go
index 2d75fe71d209f2f42319b6513a984e9ec5fd94fa..aaf699bdef621065dfe3e7bdce8386445bbbec83 100644
--- a/registry/directory/directory.go
+++ b/registry/directory/directory.go
@@ -304,7 +304,7 @@ func (dir *RegistryDirectory) cacheInvoker(url *common.URL) protocol.Invoker {
 			// if cached invoker has the same URL with the new URL, then no need to re-refer, and no need to destroy
 			// the old invoker.
 			urlTmp := cacheInvoker.(protocol.Invoker).GetUrl()
-			if common.GetURLTool().CompareURLEqual(newUrl, &urlTmp) {
+			if common.GetURLComparator().CompareURLEqual(newUrl, &urlTmp) {
 				return nil
 			}