private StringBuilder buildRetInfo(StringBuilder sBuffer, boolean isNewVer) {
        int totalCnt = 0;
        ClusterSettingEntity curConf =
                defMetaDataService.getClusterDefSetting(true);
        WebParameterUtils.buildSuccessWithDataRetBegin(sBuffer);
        if (curConf != null) {
            totalCnt++;
            if (isNewVer) {
                curConf.toWebJsonStr(sBuffer, true, true);
            } else {
                curConf.toOldVerFlowCtrlWebJsonStr(sBuffer, true);
            }
        }
        WebParameterUtils.buildSuccessWithDataRetEnd(sBuffer, totalCnt);
        return sBuffer;
    }
add default flow control rule

@param req       Http Servlet Request
@param sBuffer   string buffer
@param result    process result
@param isAddOp   whether add operation
@param isNewVer  whether new version return
@return       process result
inlong-tubemq/tubemq-server/src/main/java/org/apache/inlong/tubemq/server/master/web/handler/WebMasterInfoHandler.java