private void upgrade() {
    File consensusDir = new File(CONF.getConsensusDir());
    if (consensusDir.exists()) {
      File oldWalDir = new File(consensusDir, "simple");
      if (oldWalDir.exists() && !oldWalDir.renameTo(new File(getConfigRegionDir()))) {
        LOGGER.warn(
            "upgrade ConfigNode consensus wal dir for SimpleConsensus from version/1.0 to version/1.1 failed, "
                + "you maybe need to rename the simple dir to 0_0 manually.");
      }
    }
  }
In version 1.1, we fixed a 1.0 SimpleConsensus bug that incorrectly set the consensus
directory. For backward compatibility, we added this function, which we may remove in version
2.x
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/manager/consensus/ConsensusManager.java