Make discovery refresh period less aggressive

cmd/kube-apiserver/app/server.go

@@ -579,7 +579,7 @@ func BuildAdmissionPluginInitializers(
 
 	admissionPostStartHook := func(context genericapiserver.PostStartHookContext) error {
 		discoveryRESTMapper.Reset()
-		go utilwait.Until(discoveryRESTMapper.Reset, 10*time.Second, context.StopCh)
+		go utilwait.Until(discoveryRESTMapper.Reset, 30*time.Second, context.StopCh)
 		return nil
 	}