[HDFS-15658] Improve datanode capability balancing

• Type: Improvement
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Component/s: hdfs
• Assignee: Unassigned
• Reporter: chuanjie.duan
• Created: 28/Oct/20 06:39
• Updated: 28/Oct/20 09:52

Description

How about adjust the order of choosing replication to deletion? 

Is there any other meaning, choosing "oldestHeartbeatStorage" first?

 

  public DatanodeStorageInfo chooseReplicaToDelete(

      Collection<DatanodeStorageInfo> moreThanOne,

      Collection<DatanodeStorageInfo> exactlyOne,

      final List<StorageType> excessTypes,

      Map<String, List<DatanodeStorageInfo>> rackMap) {

    ......

    final DatanodeStorageInfo storage;

    if (minSpaceStorage != null)

{       storage = minSpaceStorage;     }

else if (oldestHeartbeatStorage != null)

{       storage = oldestHeartbeatStorage;     }

else

{       return null;     }

    excessTypes.remove(storage.getStorageType());

    return storage;

  }