public static boolean isAlive(long time, long dataTTL) {
    return dataTTL == Long.MAX_VALUE || (CommonDateTimeUtils.currentTime() - time) <= dataTTL;
  }
Check whether the time falls in TTL.

@return whether the given time falls in ttl
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/utils/CommonUtils.java