@VisibleForTesting
  static void resetReplChangeManagerInstance() {
    inited = false;
    enabled = false;
    instance = null;
    encryptionZoneToCmrootMapping.clear();
  }
Thread to clear old files of cmroot recursively
standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/ReplChangeManager.java