diff --git a/get_config.go b/get_config.go
index f175fdc..165ccd5 100644
--- a/get_config.go
+++ b/get_config.go
@@ -28,9 +28,6 @@ func (d *Diamond) GetConfig(args *GetConfigRequest) ([]byte, error) {
 	if err := d.withUsual(args.Tenant, args.Group)(header); err != nil {
 		return nil, err
 	}
-	if err != nil {
-		return nil, err
-	}
 	request := d.c.NewRequest().
 		WithTimeout(apiTimeout).
 		WithPath(acmConfig.String(ip)).
diff --git a/long_pull.go b/long_pull.go
index 1c21dbb..d1af44d 100644
--- a/long_pull.go
+++ b/long_pull.go
@@ -18,44 +18,8 @@ func (d *Diamond) LongPull(unit Unit, contentMD5 string) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	headerSetters := []headerSetter{
-		d.withLongPollingTimeout(),
-		d.withUsual(d.option.tenant, unit.Group),
-	}
-	header := make(http.Header)
-	for _, setter := range headerSetters {
-		if err := setter(header); err != nil {
-			return "", err
-		}
-	}
-	var longPollRequest struct {
-		ProbeModifyRequest string `url:"Probe-Modify-Request"`
-	}
-	longPollRequest.ProbeModifyRequest = strings.Join([]string{unit.DataID, unit.Group, contentMD5, d.option.tenant}, wordSeparator) + lineSeparator
-	request := d.c.NewRequest().
-		WithPath(acmLongPull.String(ip)).
-		WithFormURLEncodedBody(longPollRequest).
-		WithHeader(header).
-		Post()
-	response, err := d.c.Do(request)
-	if err != nil {
-		return "", err
-	}
-
-	switch response.StatusCode() {
-	case http.StatusServiceUnavailable:
-		return "", serviceUnavailableErr
-	case http.StatusInternalServerError:
-		return "", internalServerErr
-	}
-
-	if !response.Success() {
-		return "", errors.New(response.String())
-	}
-
-	ret := url.QueryEscape(strings.Join([]string{unit.DataID, unit.Group, d.option.tenant}, wordSeparator) + lineSeparator)
-	if contentMD5 == "" ||
-		ret == strings.TrimSpace(response.String()) {
+	switch contentMD5 {
+	case "":
 		args := new(GetConfigRequest)
 		args.Tenant = d.option.tenant
 		args.Group = unit.Group
@@ -64,12 +28,62 @@ func (d *Diamond) LongPull(unit Unit, contentMD5 string) (string, error) {
 		if err != nil {
 			return "", err
 		}
-		contentMD5 := Md5(string(content))
+		contentMD5 = Md5(string(content))
 		config := Config{
 			Content: content,
 		}
 		unit.ch <- config
 		return contentMD5, nil
+	default:
+		headerSetters := []headerSetter{
+			d.withLongPollingTimeout(),
+			d.withUsual(d.option.tenant, unit.Group),
+		}
+		header := make(http.Header)
+		for _, setter := range headerSetters {
+			if err := setter(header); err != nil {
+				return "", err
+			}
+		}
+		var longPollRequest struct {
+			ProbeModifyRequest string `url:"Probe-Modify-Request"`
+		}
+		longPollRequest.ProbeModifyRequest = strings.Join([]string{unit.DataID, unit.Group, contentMD5, d.option.tenant}, wordSeparator) + lineSeparator
+		request := d.c.NewRequest().
+			WithPath(acmLongPull.String(ip)).
+			WithFormURLEncodedBody(longPollRequest).
+			WithHeader(header).
+			Post()
+		response, err := d.c.Do(request)
+		if err != nil {
+			return "", err
+		}
+		switch response.StatusCode() {
+		case http.StatusServiceUnavailable:
+			return "", serviceUnavailableErr
+		case http.StatusInternalServerError:
+			return "", internalServerErr
+		}
+		if !response.Success() {
+			return "", errors.New(response.String())
+		}
+		ret := url.QueryEscape(strings.Join([]string{unit.DataID, unit.Group, d.option.tenant}, wordSeparator) + lineSeparator)
+		if  ret == strings.TrimSpace(response.String()) {
+			args := new(GetConfigRequest)
+			args.Tenant = d.option.tenant
+			args.Group = unit.Group
+			args.DataID = unit.DataID
+			content, err := d.GetConfig(args)
+			if err != nil {
+				return "", err
+			}
+			contentMD5 := Md5(string(content))
+			config := Config{
+				Content: content,
+			}
+			unit.ch <- config
+			return contentMD5, nil
+		}
+		return contentMD5, nil
 	}
-	return contentMD5, nil
 }