Avoid slow port startup.

weed/server/filer_server.go

@@ -125,9 +125,11 @@ func NewFilerServer(defaultMux, readonlyMux *http.ServeMux, option *FilerOption)
 	// we do not support IP whitelist right now
 	fs.filerGuard = security.NewGuard([]string{}, signingKey, expiresAfterSec, readSigningKey, readExpiresAfterSec)
 
+	go func() {
 		fs.checkWithMaster()
+		stats.LoopPushingMetric("filer", string(fs.option.Host), fs.metricsAddress, fs.metricsIntervalSec)
+	}()
 
-	go stats.LoopPushingMetric("filer", string(fs.option.Host), fs.metricsAddress, fs.metricsIntervalSec)
 	go fs.filer.KeepMasterClientConnected()
 
 	if !util.LoadConfiguration("filer", false) {