// There is a good chance the client hit a different server, so a tight retry is good for client responsiveness.
			waitGroupWriteRetryAfterToResponse(w)
			return
		}

		defer wg.Done()
		handler.ServeHTTP(w, req)
	})
}

func waitGroupWriteRetryAfterToResponse(w http.ResponseWriter) {
	w.Header().Add("Retry-After", "1")
	w.Header().Set("Content-Type", runtime.ContentTypeJSON)

		if err := wg.Add(1); err != nil {
			// When apiserver is shutting down, signal clients to retry
			// There is a good chance the client hit a different server, so a tight retry is good for client responsiveness.
			waitGroupWriteRetryAfterToResponse(w)
			return
		}

		// attach ServerShutdownSignal to the watch request so that the
		// watch handler loop can return as soon as the server signals
		// that it is shutting down.