code: private void ajaxReloadExecutors(final HttpServletRequest req,
        final HttpServletResponse resp, final HashMap<String, Object> returnMap, final User user) {
      boolean wasSuccess = false;
      if (HttpRequestUtils.hasPermission(this.userManager, user, Type.ADMIN)) {
        try {
          this.executorManagerAdapter.setupExecutors();
          returnMap.put(ConnectorParams.STATUS_PARAM,
              ConnectorParams.RESPONSE_SUCCESS);
          wasSuccess = true;
        } catch (final ExecutorManagerException e) {
          returnMap.put(ConnectorParams.RESPONSE_ERROR,
              "Failed to refresh the executors " + e.getMessage());
        }
      } else {
        returnMap.put(ConnectorParams.RESPONSE_ERROR,
            "Only Admins are allowed to refresh the executors");
      }
      if (!wasSuccess) {
        returnMap.put(ConnectorParams.STATUS_PARAM,
            ConnectorParams.RESPONSE_ERROR);
      }
    }
docs: /* Reloads executors from DB and azkaban.properties via executorManager