buf.append("-Xlog:gc*,gc+age=trace,safepoint:file=");
        if (logFilePath != null) {
            buf.append(logFilePath);
        } else {
            buf.append(ComponentUtil.getSystemHelper().getLogFilePath());
        }
        buf.append(File.separator);
        buf.append("gc-").append(getExecuteType()).append(".log");
        buf.append(":utctime,pid,tags:filecount=5,filesize=64m");

            logger.warn("Failed to access system.properties.", e);
        }
    }

    protected void writeLogFiles(final ZipOutputStream zos, final String id) {
        final String logFilePath = systemHelper.getLogFilePath();
        if (StringUtil.isNotBlank(logFilePath)) {
            final Path logDirPath = Paths.get(logFilePath);
            try (Stream<Path> stream = Files.list(logDirPath)) {

        final Instant instant = Instant.ofEpochMilli(getCurrentTimeAsLong());
        return LocalDateTime.ofInstant(instant, ZoneId.systemDefault());
    }

    public String getLogFilePath() {
        final String value = System.getProperty("fess.log.path");
        if (value != null) {
            return value;
        }
        final String userDir = System.getProperty("user.dir");