content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.master.file;
  
  /**
   * The pending Path in the Inode SyncStream traversal order.
   * For general-scale directory, BFS can archive better sync speed. For super-large-scale
   * directory (> 100_000_000), BFS may cause a large amount of memory to be used for
   * ufsStatusCache. DFS can ensure a smaller ufsStatusCache size to make the memory
   * smaller and the gc time shorter.
   *
   * If the size of ufsStatusCache is still large, consider setting
   * PropertyKey.MASTER_METADATA_SYNC_PREFETCH_CHILDREN_UFS_STATUS to false.
   */
  public enum MetadataSyncTraversalOrder {
    BFS,
    DFS
  }
  