proxy: add a todo for logging

proxy/reverse.go

@@ -68,6 +68,7 @@ func (p *reverseProxy) ServeHTTP(rw http.ResponseWriter, clientreq *http.Request
 	endpoints := p.director.endpoints()
 	if len(endpoints) == 0 {
 		msg := "proxy: zero endpoints currently available"
+		// TODO: limit the rate of the error logging.
 		log.Printf(msg)
 		e := httptypes.NewHTTPError(http.StatusServiceUnavailable, msg)
 		e.WriteTo(rw)
@@ -91,6 +92,7 @@ func (p *reverseProxy) ServeHTTP(rw http.ResponseWriter, clientreq *http.Request
 	}
 
 	if res == nil {
+		// TODO: limit the rate of the error logging.
 		msg := fmt.Sprintf("proxy: unable to get response from %d endpoint(s)", len(endpoints))
 		log.Printf(msg)
 		e := httptypes.NewHTTPError(http.StatusBadGateway, msg)