HDFS-12182. BlockManager.metaSave does not distinguish between "under replicated" and "missing" blocks. Contributed by Wellington Chevreuil.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java

@@ -705,17 +705,36 @@ public void metaSave(PrintWriter out) {
     datanodeManager.fetchDatanodes(live, dead, false);
     out.println("Live Datanodes: " + live.size());
     out.println("Dead Datanodes: " + dead.size());
+
     //
-    // Dump contents of neededReconstruction
+    // Need to iterate over all queues from neededReplications
+    // except for the QUEUE_WITH_CORRUPT_BLOCKS)
     //
     synchronized (neededReconstruction) {
       out.println("Metasave: Blocks waiting for reconstruction: "
-          + neededReconstruction.size());
-      for (Block block : neededReconstruction) {
+          + neededReconstruction.getLowRedundancyBlockCount());
+      for (int i = 0; i < neededReconstruction.LEVEL; i++) {
+        if (i != neededReconstruction.QUEUE_WITH_CORRUPT_BLOCKS) {
+          for (Iterator<BlockInfo> it = neededReconstruction.iterator(i);
+               it.hasNext();) {
+            Block block = it.next();
+            dumpBlockMeta(block, out);
+          }
+        }
+      }
+      //
+      // Now prints corrupt blocks separately
+      //
+      out.println("Metasave: Blocks currently missing: " +
+          neededReconstruction.getCorruptBlockSize());
+      for (Iterator<BlockInfo> it = neededReconstruction.
+          iterator(neededReconstruction.QUEUE_WITH_CORRUPT_BLOCKS);
+           it.hasNext();) {
+        Block block = it.next();
         dumpBlockMeta(block, out);
       }
     }
-    
+
     // Dump any postponed over-replicated blocks
     out.println("Mis-replicated blocks that have been postponed:");
     for (Block block : postponedMisreplicatedBlocks) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockManager.java

@@ -1459,4 +1459,58 @@ private void verifyPlacementPolicy(final MiniDFSCluster cluster,
     }
   }
 
+  @Test
+  public void testMetaSaveMissingReplicas() throws Exception {
+    List<DatanodeStorageInfo> origStorages = getStorages(0, 1);
+    List<DatanodeDescriptor> origNodes = getNodes(origStorages);
+    BlockInfo block = makeBlockReplicasMissing(0, origNodes);
+    File file = new File("test.log");
+    PrintWriter out = new PrintWriter(file);
+    bm.metaSave(out);
+    out.flush();
+    FileInputStream fstream = new FileInputStream(file);
+    DataInputStream in = new DataInputStream(fstream);
+    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
+    StringBuffer buffer = new StringBuffer();
+    String line;
+    try {
+      while ((line = reader.readLine()) != null) {
+        buffer.append(line);
+      }
+      String output = buffer.toString();
+      assertTrue("Metasave output should have reported missing blocks.",
+          output.contains("Metasave: Blocks currently missing: 1"));
+      assertTrue("There should be 0 blocks waiting for reconstruction",
+          output.contains("Metasave: Blocks waiting for reconstruction: 0"));
+      String blockNameGS = block.getBlockName() + "_" +
+          block.getGenerationStamp();
+      assertTrue("Block " + blockNameGS + " should be MISSING.",
+          output.contains(blockNameGS + " MISSING"));
+    } finally {
+      reader.close();
+      file.delete();
+    }
+  }
+
+  private BlockInfo makeBlockReplicasMissing(long blockId,
+      List<DatanodeDescriptor> nodesList) throws IOException {
+    long inodeId = ++mockINodeId;
+    final INodeFile bc = TestINodeFile.createINodeFile(inodeId);
+
+    BlockInfo blockInfo = blockOnNodes(blockId, nodesList);
+    blockInfo.setReplication((short) 3);
+    blockInfo.setBlockCollectionId(inodeId);
+
+    Mockito.doReturn(bc).when(fsn).getBlockCollection(inodeId);
+    bm.blocksMap.addBlockCollection(blockInfo, bc);
+    bm.markBlockReplicasAsCorrupt(blockInfo, blockInfo,
+        blockInfo.getGenerationStamp() + 1,
+        blockInfo.getNumBytes(),
+        new DatanodeStorageInfo[]{});
+    BlockCollection mockedBc = Mockito.mock(BlockCollection.class);
+    Mockito.when(mockedBc.getBlocks()).thenReturn(new BlockInfo[]{blockInfo});
+    bm.checkRedundancy(mockedBc);
+    return blockInfo;
+  }
+
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestMetaSave.java

@@ -155,6 +155,8 @@ public void testMetasaveAfterDelete()
       line = reader.readLine();
       assertTrue(line.equals("Metasave: Blocks waiting for reconstruction: 0"));
       line = reader.readLine();
+      assertTrue(line.equals("Metasave: Blocks currently missing: 0"));
+      line = reader.readLine();
       assertTrue(line.equals("Mis-replicated blocks that have been postponed:"));
       line = reader.readLine();
       assertTrue(line.equals("Metasave: Blocks being reconstructed: 0"));