diff --git a/weed/server/filer_server.go b/weed/server/filer_server.go
index 18809162a..fcab017bf 100644
--- a/weed/server/filer_server.go
+++ b/weed/server/filer_server.go
@@ -62,6 +62,10 @@ type FilerServer struct {
 	filer          *filer.Filer
 	grpcDialOption grpc.DialOption
 
+	// metrics read from the master
+	metricsAddress     string
+	metricsIntervalSec int
+
 	// notifying clients
 	listenersLock sync.Mutex
 	listenersCond *sync.Cond
@@ -88,7 +92,7 @@ func NewFilerServer(defaultMux, readonlyMux *http.ServeMux, option *FilerOption)
 	})
 	fs.filer.Cipher = option.Cipher
 
-	maybeStartMetrics(fs, option)
+	fs.maybeStartMetrics()
 
 	go fs.filer.KeepConnectedToMaster()
 
@@ -131,9 +135,9 @@ func NewFilerServer(defaultMux, readonlyMux *http.ServeMux, option *FilerOption)
 	return fs, nil
 }
 
-func maybeStartMetrics(fs *FilerServer, option *FilerOption) {
+func (fs *FilerServer) maybeStartMetrics() {
 
-	for _, master := range option.Masters {
+	for _, master := range fs.option.Masters {
 		_, err := pb.ParseFilerGrpcAddress(master)
 		if err != nil {
 			glog.Fatalf("invalid master address %s: %v", master, err)
@@ -141,12 +145,10 @@ func maybeStartMetrics(fs *FilerServer, option *FilerOption) {
 	}
 
 	isConnected := false
-	var metricsAddress string
-	var metricsIntervalSec int
 	var readErr error
 	for !isConnected {
-		for _, master := range option.Masters {
-			metricsAddress, metricsIntervalSec, readErr = readFilerConfiguration(fs.grpcDialOption, master)
+		for _, master := range fs.option.Masters {
+			fs.metricsAddress, fs.metricsIntervalSec, readErr = readFilerConfiguration(fs.grpcDialOption, master)
 			if readErr == nil {
 				isConnected = true
 			} else {
@@ -154,10 +156,10 @@ func maybeStartMetrics(fs *FilerServer, option *FilerOption) {
 			}
 		}
 	}
-	if metricsAddress == "" && metricsIntervalSec <= 0 {
+	if fs.metricsAddress == "" && fs.metricsIntervalSec <= 0 {
 		return
 	}
-	go stats.LoopPushingMetric("filer", stats.SourceName(option.Port), stats.FilerGather, metricsAddress, metricsIntervalSec)
+	go stats.LoopPushingMetric("filer", stats.SourceName(fs.option.Port), stats.FilerGather, fs.metricsAddress, fs.metricsIntervalSec)
 }
 
 func readFilerConfiguration(grpcDialOption grpc.DialOption, masterAddress string) (metricsAddress string, metricsIntervalSec int, err error) {