case UNAUTHORIZED:
                    logger.warn("[{}] Unauthorized access: {}", i, SystemUtil.getSearchEngineHttpAddress(), cause);
                    break;
                default:
                    logger.debug("[{}][{}] Failed to access to Fesen ({})", i, status, SystemUtil.getSearchEngineHttpAddress(), cause);
                    break;
                }
            } else if (logger.isDebugEnabled()) {