HDFS-15135. EC : ArrayIndexOutOfBoundsException in BlockRecoveryWorker#RecoveryTaskStriped. Contributed by Ravuri Sushma sree.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/DatanodeProtocolClientSideTranslatorPB.java

@@ -319,6 +319,9 @@ public class DatanodeProtocolClientSideTranslatorPB implements
         .setNewLength(newlength).setCloseFile(closeFile)
         .setDeleteBlock(deleteblock);
     for (int i = 0; i < newtargets.length; i++) {
+      if (newtargets[i] == null) {
+        continue;
+      }
       builder.addNewTaragets(PBHelperClient.convert(newtargets[i]));
       builder.addNewTargetStorages(newtargetstorages[i]);
     }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockRecoveryWorker.java

@@ -467,7 +467,7 @@ public class BlockRecoveryWorker {
       // notify Namenode the new size and locations
       final DatanodeID[] newLocs = new DatanodeID[totalBlkNum];
       final String[] newStorages = new String[totalBlkNum];
-      for (int i = 0; i < totalBlkNum; i++) {
+      for (int i = 0; i < blockIndices.length; i++) {
         newLocs[blockIndices[i]] = DatanodeID.EMPTY_DATANODE_ID;
         newStorages[blockIndices[i]] = "";
       }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestBlockRecovery.java

@@ -32,6 +32,8 @@ import static org.mockito.ArgumentMatchers.anyList;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.mock;
@@ -42,6 +44,7 @@ import static org.mockito.Mockito.when;
 
 import java.io.File;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.net.InetSocketAddress;
 import java.net.URISyntaxException;
 import java.util.ArrayList;
@@ -96,6 +99,7 @@ import org.apache.hadoop.hdfs.server.protocol.DatanodeRegistration;
 import org.apache.hadoop.hdfs.server.protocol.HeartbeatResponse;
 import org.apache.hadoop.hdfs.server.protocol.InterDatanodeProtocol;
 import org.apache.hadoop.hdfs.server.protocol.NNHAStatusHeartbeat;
+import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocols;
 import org.apache.hadoop.hdfs.server.protocol.NamespaceInfo;
 import org.apache.hadoop.hdfs.server.protocol.ReplicaRecoveryInfo;
 import org.apache.hadoop.test.GenericTestUtils;
@@ -704,6 +708,66 @@ public class TestBlockRecovery {
     }
   }
 
+  @Test(timeout = 60000)
+  public void testEcRecoverBlocks() throws Throwable {
+    // Stop the Mocked DN started in startup()
+    tearDown();
+    ErasureCodingPolicy ecPolicy = StripedFileTestUtil.getDefaultECPolicy();
+    MiniDFSCluster cluster =
+        new MiniDFSCluster.Builder(conf).numDataNodes(8).build();
+
+    try {
+      cluster.waitActive();
+      NamenodeProtocols preSpyNN = cluster.getNameNodeRpc();
+      NamenodeProtocols spyNN = spy(preSpyNN);
+
+      // Delay completeFile
+      GenericTestUtils.DelayAnswer delayer =
+          new GenericTestUtils.DelayAnswer(LOG);
+      doAnswer(delayer).when(spyNN).complete(anyString(), anyString(), any(),
+          anyLong());
+      String topDir = "/myDir";
+      DFSClient client = new DFSClient(null, spyNN, conf, null);
+      Path file = new Path(topDir + "/testECLeaseRecover");
+      client.mkdirs(topDir, null, false);
+      client.enableErasureCodingPolicy(ecPolicy.getName());
+      client.setErasureCodingPolicy(topDir, ecPolicy.getName());
+      OutputStream stm = client.create(file.toString(), true);
+
+      // write 5MB File
+      AppendTestUtil.write(stm, 0, 1024 * 1024 * 5);
+      final AtomicReference<Throwable> err = new AtomicReference<Throwable>();
+      Thread t = new Thread() {
+        @Override
+        public void run() {
+          try {
+            stm.close();
+          } catch (Throwable t) {
+            err.set(t);
+          }
+        }
+      };
+      t.start();
+
+      // Waiting for close to get to latch
+      delayer.waitForCall();
+      GenericTestUtils.waitFor(new Supplier<Boolean>() {
+        @Override
+        public Boolean get() {
+          try {
+            return client.getNamenode().recoverLease(file.toString(),
+                client.getClientName());
+          } catch (IOException e) {
+            return false;
+          }
+        }
+      }, 5000, 24000);
+      delayer.proceed();
+    } finally {
+      cluster.shutdown();
+    }
+  }
+
   /**
    * Test to verify the race between finalizeBlock and Lease recovery
    *