@Test
public void testChooseSrcDNWithDupECInDecommissioningNode() throws Exception {

  long blockId = -9223372036854775776L; // real ec block id
  Block aBlock = new Block(blockId, 0, 0);
  // RS-3-2 EC policy
  ErasureCodingPolicy ecPolicy =
      SystemErasureCodingPolicies.getPolicies().get(1);
  // striped blockInfo
  BlockInfoStriped aBlockInfoStriped = new BlockInfoStriped(aBlock, ecPolicy);
  // ec storageInfo
  DatanodeStorageInfo ds1 = DFSTestUtil.createDatanodeStorageInfo(
      "storage1", "1.1.1.1", "rack1", "host1");
  DatanodeStorageInfo ds2 = DFSTestUtil.createDatanodeStorageInfo(
      "storage2", "2.2.2.2", "rack2", "host2");
  DatanodeStorageInfo ds3 = DFSTestUtil.createDatanodeStorageInfo(
      "storage3", "3.3.3.3", "rack3", "host3");
  DatanodeStorageInfo ds4 = DFSTestUtil.createDatanodeStorageInfo(
      "storage4", "4.4.4.4", "rack4", "host4");
  DatanodeStorageInfo ds5 = DFSTestUtil.createDatanodeStorageInfo(
      "storage5", "5.5.5.5", "rack5", "host5");
  DatanodeStorageInfo ds6 = DFSTestUtil.createDatanodeStorageInfo(
      "storage6", "6.6.6.6", "rack6", "host6");
  // link block with storage
  aBlockInfoStriped.addStorage(ds1, aBlock);
  aBlockInfoStriped.addStorage(ds2, new Block(blockId + 1, 0, 0));
  aBlockInfoStriped.addStorage(ds3, new Block(blockId + 2, 0, 0));
  aBlockInfoStriped.addStorage(ds4, new Block(blockId + 3, 0, 0));
  aBlockInfoStriped.addStorage(ds5, new Block(blockId + 4, 0, 0));
  // NOTE: duplicate block 0，this DN will replace the decommission ds1 DN
  aBlockInfoStriped.addStorage(ds6, aBlock);
  addEcBlockToBM(blockId, ecPolicy);
  // decommission datanode where store block 0
  ds1.getDatanodeDescriptor().startDecommission();
  List<DatanodeDescriptor> containingNodes =
      new LinkedList<DatanodeDescriptor>();
  List<DatanodeStorageInfo> nodesContainingLiveReplicas =
      new LinkedList<DatanodeStorageInfo>();
  NumberReplicas numReplicas = new NumberReplicas();
  List<Byte> liveBlockIndices = new ArrayList<>();
  List<Byte> liveBusyBlockIndices = new ArrayList<>();
  bm.chooseSourceDatanodes(
      aBlockInfoStriped,
      containingNodes,
      nodesContainingLiveReplicas,
      numReplicas, liveBlockIndices,
      liveBusyBlockIndices,
      LowRedundancyBlocks.QUEUE_HIGHEST_PRIORITY);
  assertEquals("There are 5 live replicas in " +
          "[ds2, ds3, ds4, ds5, ds6] datanodes ",
      5, numReplicas.liveReplicas());
  assertEquals("The ds1 datanode is in decommissioning, " +
          "so there is no redundant replica",
      0, numReplicas.redundantInternalBlocks());
}