HDFS-15113. Addendum: Missing IBR when NameNode restart if open processCommand async feature. Contributed by Xiaoqiao He.

Signed-off-by: Wei-Chiu Chuang <weichiu@apache.org>
(cherry picked from commit af64ce2f4a72705c5b68ddfe4d29f0d208fd38e7)
(cherry picked from commit 4944dafa297e9aad93d39e861b5dc2835b7cbb5f)

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

@@ -286,23 +286,30 @@ public class TestBPOfferService {
   public void testMissBlocksWhenReregister() throws Exception {
     BPOfferService bpos = setupBPOSForNNs(mockNN1, mockNN2);
     bpos.start();
+    int totalTestBlocks = 4000;
+    Thread addNewBlockThread = null;
+    final AtomicInteger count = new AtomicInteger(0);
+
     try {
       waitForBothActors(bpos);
       waitForInitialization(bpos);
-
       DataNodeFaultInjector.set(new DataNodeFaultInjector() {
         public void blockUtilSendFullBlockReport() {
           try {
-            Thread.sleep(200);
-          } catch (InterruptedException e) {
+            GenericTestUtils.waitFor(() -> {
+              if(count.get() > 2000) {
+                return true;
+              }
+              return false;
+            }, 100, 1000);
+          } catch (Exception e) {
             e.printStackTrace();
           }
         }
       });
 
       countBlockReportItems(FAKE_BLOCK, mockNN1);
-      int totalTestBlocks = 4000;
-      Thread addNewBlockThread = new Thread(() -> {
+      addNewBlockThread = new Thread(() -> {
         for (int i = 0; i < totalTestBlocks; i++) {
           SimulatedFSDataset fsDataset = (SimulatedFSDataset) mockFSDataset;
           SimulatedStorage simulatedStorage = fsDataset.getStorages().get(0);
@@ -312,6 +319,7 @@ public class TestBPOfferService {
             fsDataset.createRbw(StorageType.DEFAULT, storageId, b, false);
             bpos.notifyNamenodeReceivingBlock(b, storageId);
             fsDataset.finalizeBlock(b, false);
+            count.addAndGet(1);
             Thread.sleep(1);
           } catch (Exception e) {
             e.printStackTrace();
@@ -321,7 +329,13 @@ public class TestBPOfferService {
       addNewBlockThread.start();
 
       // Make sure that generate blocks for DataNode and IBR not empty now.
-      Thread.sleep(200);
+      GenericTestUtils.waitFor(() -> {
+        if(count.get() > 0) {
+          return true;
+        }
+        return false;
+      }, 100, 1000);
+
       // Trigger re-register using DataNode Command.
       datanodeCommands[0] = new DatanodeCommand[]{RegisterCommand.REGISTER};
       bpos.triggerHeartbeatForTests();
@@ -340,6 +354,7 @@ public class TestBPOfferService {
       assertTrue(fullBlockReportCount == totalTestBlocks ||
           incrBlockReportCount == totalTestBlocks);
     } finally {
+      addNewBlockThread.join();
       bpos.stop();
       bpos.join();
 
@@ -698,12 +713,17 @@ public class TestBPOfferService {
     }
   }
 
+  /**
+   * Record blocks counts of block report and total adding blocks count of IBR
+   * which assume no deleting blocks here.
+   */
   private void countBlockReportItems(final ExtendedBlock fakeBlock,
       final DatanodeProtocolClientSideTranslatorPB mockNN) throws Exception {
     final String fakeBlockPoolId = fakeBlock.getBlockPoolId();
     final ArgumentCaptor<StorageBlockReport[]> captor =
         ArgumentCaptor.forClass(StorageBlockReport[].class);
 
+    // Record blocks count about the last time block report.
     Mockito.doAnswer((Answer<Object>) invocation -> {
       Object[] arguments = invocation.getArguments();
       StorageBlockReport[] list = (StorageBlockReport[])arguments[2];
@@ -716,6 +736,7 @@ public class TestBPOfferService {
         Mockito.any()
     );
 
+    // Record total adding blocks count and assume no deleting blocks here.
     Mockito.doAnswer((Answer<Object>) invocation -> {
       Object[] arguments = invocation.getArguments();
       StorageReceivedDeletedBlocks[] list =