diff --git a/contrib/config/apollo/apollo.go b/contrib/config/apollo/apollo.go
index 1734fdb02..3d312b1b6 100644
--- a/contrib/config/apollo/apollo.go
+++ b/contrib/config/apollo/apollo.go
@@ -25,7 +25,12 @@ const (
 	properties = "properties"
 )
 
-var formats map[string]struct{}
+var formats = map[string]struct{}{
+	yaml:       {},
+	yml:        {},
+	json:       {},
+	properties: {},
+}
 
 // Option is apollo option
 type Option func(*options)
@@ -130,8 +135,10 @@ func NewSource(opts ...Option) config.Source {
 }
 
 func format(ns string) string {
-	arr := strings.Split(ns, ".")
-	suffix := arr[len(arr)-1]
+	var (
+		arr    = strings.Split(ns, ".")
+		suffix = arr[len(arr)-1]
+	)
 	if len(arr) <= 1 || suffix == properties {
 		return json
 	}
@@ -144,8 +151,10 @@ func format(ns string) string {
 }
 
 func (e *apollo) load() []*config.KeyValue {
-	kvs := make([]*config.KeyValue, 0)
-	namespaces := strings.Split(e.opt.namespace, ",")
+	var (
+		kvs        = make([]*config.KeyValue, 0)
+		namespaces = strings.Split(e.opt.namespace, ",")
+	)
 
 	for _, ns := range namespaces {
 		if !e.opt.originConfig {
@@ -225,10 +234,12 @@ func (e *apollo) Watch() (config.Watcher, error) {
 // resolve convert kv pair into one map[string]interface{} by split key into different
 // map level. such as: app.name = "application" => map[app][name] = "application"
 func resolve(key string, value interface{}, target map[string]interface{}) {
-	// expand key "aaa.bbb" into map[aaa]map[bbb]interface{}
-	keys := strings.Split(key, ".")
-	last := len(keys) - 1
-	cursor := target
+	var (
+		// expand key "aaa.bbb" into map[aaa]map[bbb]interface{}
+		keys   = strings.Split(key, ".")
+		last   = len(keys) - 1
+		cursor = target
+	)
 
 	for i, k := range keys {
 		if i == last {
@@ -275,12 +286,3 @@ func genKey(ns, sub string) string {
 
 	return ns + "." + sub
 }
-
-func init() {
-	formats = make(map[string]struct{})
-
-	formats[yaml] = struct{}{}
-	formats[yml] = struct{}{}
-	formats[json] = struct{}{}
-	formats[properties] = struct{}{}
-}
diff --git a/contrib/log/aliyun/aliyun.go b/contrib/log/aliyun/aliyun.go
index 836960e06..8d1ef0672 100644
--- a/contrib/log/aliyun/aliyun.go
+++ b/contrib/log/aliyun/aliyun.go
@@ -102,7 +102,7 @@ func (a *aliyunLog) Log(level log.Level, keyvals ...interface{}) error {
 	return a.producer.SendLog(a.opts.project, a.opts.logstore, "", "", logInst)
 }
 
-// NewAliyunLog new a aliyun logger with options.
+// NewAliyunLog new an aliyun logger with options.
 func NewAliyunLog(options ...Option) Logger {
 	opts := defaultOptions()
 	for _, o := range options {
diff --git a/transport/http/server.go b/transport/http/server.go
index 8bece9afe..343afaea2 100644
--- a/transport/http/server.go
+++ b/transport/http/server.go
@@ -127,7 +127,7 @@ func Listener(lis net.Listener) ServerOption {
 	}
 }
 
-// PathPrefix with mux's PathPrefix, router will replaced by a subrouter that start with prefix.
+// PathPrefix with mux's PathPrefix, router will be replaced by a subroutine that start with prefix.
 func PathPrefix(prefix string) ServerOption {
 	return func(s *Server) {
 		s.router = s.router.PathPrefix(prefix).Subrouter()