public static boolean isSequenceIdFile(final Path file) {
    return file.getName().endsWith(SEQUENCE_ID_FILE_SUFFIX)
      || file.getName().endsWith(OLD_SEQUENCE_ID_FILE_SUFFIX);
  }
Is the given file a region open sequence id file.
hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WALSplitUtil.java