How to use

selectReplicaToDelete

method

in

org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.BlockPoolSlice

  selectReplicaToDelete(replica1, replica2);
final ReplicaInfo replicaToKeep =
  (replicaToDelete != replica1) ? replica1 : replica2;

  selectReplicaToDelete(replica1, replica2);
final ReplicaInfo replicaToKeep =
  (replicaToDelete != replica1) ? replica1 : replica2;

  selectReplicaToDelete(replica1, replica2);
final ReplicaInfo replicaToKeep =
  (replicaToDelete != replica1) ? replica1 : replica2;

@Test
public void testDuplicateReplicaResolution() throws IOException {
 FsVolumeImpl fsv1 = Mockito.mock(FsVolumeImpl.class);
 FsVolumeImpl fsv2 = Mockito.mock(FsVolumeImpl.class);
 File f1 = new File("d1/block");
 File f2 = new File("d2/block");
 ReplicaInfo replicaOlder = new FinalizedReplica(1,1,1,fsv1,f1);
 ReplicaInfo replica = new FinalizedReplica(1,2,2,fsv1,f1);
 ReplicaInfo replicaSame = new FinalizedReplica(1,2,2,fsv1,f1);
 ReplicaInfo replicaNewer = new FinalizedReplica(1,3,3,fsv1,f1);
 ReplicaInfo replicaOtherOlder = new FinalizedReplica(1,1,1,fsv2,f2);
 ReplicaInfo replicaOtherSame = new FinalizedReplica(1,2,2,fsv2,f2);
 ReplicaInfo replicaOtherNewer = new FinalizedReplica(1,3,3,fsv2,f2);
 // equivalent path so don't remove either
 assertNull(BlockPoolSlice.selectReplicaToDelete(replicaSame, replica));
 assertNull(BlockPoolSlice.selectReplicaToDelete(replicaOlder, replica));
 assertNull(BlockPoolSlice.selectReplicaToDelete(replicaNewer, replica));
 // keep latest found replica
 assertSame(replica,
   BlockPoolSlice.selectReplicaToDelete(replicaOtherSame, replica));
 assertSame(replicaOtherOlder,
   BlockPoolSlice.selectReplicaToDelete(replicaOtherOlder, replica));
 assertSame(replica,
   BlockPoolSlice.selectReplicaToDelete(replicaOtherNewer, replica));
}