code: private void handleHttpClientErrorsForBackend(final HttpRequest clientRequest, final Exception e) {
                  /* Notify error handler that we got an error. */
          errorHandler.accept(e);
  
                  /* Increment our error count. */
          errorCount.incrementAndGet();
  
                  /* Create the error message. */
          final String errorMessage = String.format("Unable to make request %s ",
                  clientRequest.address());
  
  
                          /* Log the error. */
          logger.error(errorMessage, e);
  
          /* Don't send the error to the client if we already handled this, i.e., timedout already. */
          if (!clientRequest.isHandled()) {
              clientRequest.handled();
              /* Notify the client that there was an error. */
              clientRequest.getReceiver().error(String.format("\"%s\"", errorMessage));
          }
  
      }
docs: Handle errors.
  
  @param clientRequest clientRequest
  @param e             exception