HDFS-7165. Separate block metrics for files with replication count 1. Contributed by Zhe Zhang.

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -45,6 +45,9 @@ Release 2.7.0 - UNRELEASED
 
     HDFS-6824. Additional user documentation for HDFS encryption. (wang)
 
+    HDFS-7165. Separate block metrics for files with replication count 1.
+    (Zhe Zhang via wang)
+
     HDFS-7222. Expose DataNode network errors as a metric. (Charles Lamb via wang)
 
     HDFS-7257. Add the time of last HA state transition to NN's /jmx page.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSClient.java

@@ -2363,6 +2363,16 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
     return namenode.getStats()[ClientProtocol.GET_STATS_MISSING_BLOCKS_IDX];
   }
   
+  /**
+   * Returns count of blocks with replication factor 1 and have
+   * lost the only replica.
+   * @throws IOException
+   */
+  public long getMissingReplOneBlocksCount() throws IOException {
+    return namenode.getStats()[ClientProtocol.
+        GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX];
+  }
+
   /**
    * Returns count of blocks with one of more replica missing.
    * @throws IOException

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java

@@ -974,6 +974,16 @@ public class DistributedFileSystem extends FileSystem {
     return dfs.getMissingBlocksCount();
   }
 
+  /**
+   * Returns count of blocks with replication factor 1 and have
+   * lost the only replica.
+   *
+   * @throws IOException
+   */
+  public long getMissingReplOneBlocksCount() throws IOException {
+    return dfs.getMissingReplOneBlocksCount();
+  }
+
   /**
    * Returns count of blocks with one of more replica missing.
    * 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java

@@ -652,6 +652,7 @@ public interface ClientProtocol {
   public int GET_STATS_UNDER_REPLICATED_IDX = 3;
   public int GET_STATS_CORRUPT_BLOCKS_IDX = 4;
   public int GET_STATS_MISSING_BLOCKS_IDX = 5;
+  public int GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX = 6;
   
   /**
    * Get a set of statistics about the filesystem.
@@ -663,7 +664,8 @@ public interface ClientProtocol {
    * <li> [3] contains number of under replicated blocks in the system.</li>
    * <li> [4] contains number of blocks with a corrupt replica. </li>
    * <li> [5] contains number of blocks without any good replicas left. </li>
-   * <li> [6] contains the total used space of the block pool. </li>
+   * <li> [6] contains number of blocks which have replication factor
+   *          1 and have lost the only replica. </li>
    * </ul>
    * Use public constants like {@link #GET_STATS_CAPACITY_IDX} in place of 
    * actual numbers to index into the array.

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

@@ -1548,13 +1548,15 @@ public class PBHelper {
   }
 
   public static long[] convert(GetFsStatsResponseProto res) {
-    long[] result = new long[6];
+    long[] result = new long[7];
     result[ClientProtocol.GET_STATS_CAPACITY_IDX] = res.getCapacity();
     result[ClientProtocol.GET_STATS_USED_IDX] = res.getUsed();
     result[ClientProtocol.GET_STATS_REMAINING_IDX] = res.getRemaining();
     result[ClientProtocol.GET_STATS_UNDER_REPLICATED_IDX] = res.getUnderReplicated();
     result[ClientProtocol.GET_STATS_CORRUPT_BLOCKS_IDX] = res.getCorruptBlocks();
     result[ClientProtocol.GET_STATS_MISSING_BLOCKS_IDX] = res.getMissingBlocks();
+    result[ClientProtocol.GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX] =
+        res.getMissingReplOneBlocks();
     return result;
   }
   
@@ -1576,6 +1578,9 @@ public class PBHelper {
     if (fsStats.length >= ClientProtocol.GET_STATS_MISSING_BLOCKS_IDX + 1)
       result.setMissingBlocks(
           fsStats[ClientProtocol.GET_STATS_MISSING_BLOCKS_IDX]);
+    if (fsStats.length >= ClientProtocol.GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX + 1)
+      result.setMissingReplOneBlocks(
+          fsStats[ClientProtocol.GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX]);
     return result.build();
   }
   

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

@@ -3443,6 +3443,11 @@ public class BlockManager {
     return this.neededReplications.getCorruptBlockSize();
   }
 
+  public long getMissingReplOneBlocksCount() {
+    // not locking
+    return this.neededReplications.getCorruptReplOneBlockSize();
+  }
+
   public BlockInfo addBlockCollection(BlockInfo block, BlockCollection bc) {
     return blocksMap.addBlockCollection(block, bc);
   }

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

@@ -179,7 +179,7 @@ class HeartbeatManager implements DatanodeStatistics {
                        -1L,
                        -1L,
                        -1L,
-                       getBlockPoolUsed()};
+                       -1L};
   }
 
   @Override

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

@@ -87,7 +87,9 @@ class UnderReplicatedBlocks implements Iterable<Block> {
 
   /** Stores the replication index for each priority */
   private Map<Integer, Integer> priorityToReplIdx = new HashMap<Integer, Integer>(LEVEL);
-  
+  /** The number of corrupt blocks with replication factor 1 */
+  private int corruptReplOneBlocks = 0;
+
   /** Create an object. */
   UnderReplicatedBlocks() {
     for (int i = 0; i < LEVEL; i++) {
@@ -130,6 +132,11 @@ class UnderReplicatedBlocks implements Iterable<Block> {
     return priorityQueues.get(QUEUE_WITH_CORRUPT_BLOCKS).size();
   }
 
+  /** Return the number of corrupt blocks with replication factor 1 */
+  synchronized int getCorruptReplOneBlockSize() {
+    return corruptReplOneBlocks;
+  }
+
   /** Check if a block is in the neededReplication queue */
   synchronized boolean contains(Block block) {
     for(LightWeightLinkedSet<Block> set : priorityQueues) {
@@ -191,6 +198,10 @@ class UnderReplicatedBlocks implements Iterable<Block> {
     int priLevel = getPriority(block, curReplicas, decomissionedReplicas,
                                expectedReplicas);
     if(priorityQueues.get(priLevel).add(block)) {
+      if (priLevel == QUEUE_WITH_CORRUPT_BLOCKS &&
+          expectedReplicas == 1) {
+        corruptReplOneBlocks++;
+      }
       if(NameNode.blockStateChangeLog.isDebugEnabled()) {
         NameNode.blockStateChangeLog.debug(
           "BLOCK* NameSystem.UnderReplicationBlock.add:"
@@ -213,7 +224,16 @@ class UnderReplicatedBlocks implements Iterable<Block> {
     int priLevel = getPriority(block, oldReplicas, 
                                decommissionedReplicas,
                                oldExpectedReplicas);
-    return remove(block, priLevel);
+    boolean removedBlock = remove(block, priLevel);
+    if (priLevel == QUEUE_WITH_CORRUPT_BLOCKS &&
+        oldExpectedReplicas == 1 &&
+        removedBlock) {
+      corruptReplOneBlocks--;
+      assert corruptReplOneBlocks >= 0 :
+          "Number of corrupt blocks with replication factor 1 " +
+              "should be non-negative";
+    }
+    return removedBlock;
   }
 
   /**
@@ -307,6 +327,18 @@ class UnderReplicatedBlocks implements Iterable<Block> {
           + " at priority level " + curPri);
       }
     }
+    if (oldPri != curPri || expectedReplicasDelta != 0) {
+      // corruptReplOneBlocks could possibly change
+      if (curPri == QUEUE_WITH_CORRUPT_BLOCKS &&
+          curExpectedReplicas == 1) {
+        // add a new corrupt block with replication factor 1
+        corruptReplOneBlocks++;
+      } else if (oldPri == QUEUE_WITH_CORRUPT_BLOCKS &&
+          curExpectedReplicas - expectedReplicasDelta == 1) {
+        // remove an existing corrupt block with replication factor 1
+        corruptReplOneBlocks--;
+      }
+    }
   }
   
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -5310,6 +5310,13 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     // not locking
     return blockManager.getMissingBlocksCount();
   }
+
+  @Metric({"MissingReplOneBlocks", "Number of missing blocks " +
+      "with replication factor 1"})
+  public long getMissingReplOneBlocksCount() {
+    // not locking
+    return blockManager.getMissingReplOneBlocksCount();
+  }
   
   @Metric({"ExpiredHeartbeats", "Number of expired heartbeats"})
   public int getExpiredHeartbeats() {
@@ -5351,6 +5358,8 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     stats[ClientProtocol.GET_STATS_UNDER_REPLICATED_IDX] = getUnderReplicatedBlocks();
     stats[ClientProtocol.GET_STATS_CORRUPT_BLOCKS_IDX] = getCorruptReplicaBlocks();
     stats[ClientProtocol.GET_STATS_MISSING_BLOCKS_IDX] = getMissingBlocksCount();
+    stats[ClientProtocol.GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX] =
+        getMissingReplOneBlocksCount();
     return stats;
   }
 
@@ -7617,6 +7626,11 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     return getMissingBlocksCount();
   }
   
+  @Override // NameNodeMXBean
+  public long getNumberOfMissingBlocksWithReplicationFactorOne() {
+    return getMissingReplOneBlocksCount();
+  }
+
   @Override // NameNodeMXBean
   public int getThreads() {
     return ManagementFactory.getThreadMXBean().getThreadCount();

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNodeMXBean.java

@@ -147,10 +147,19 @@ public interface NameNodeMXBean {
   /**
    * Gets the total number of missing blocks on the cluster
    * 
-   * @return the total number of files and blocks on the cluster
+   * @return the total number of missing blocks on the cluster
    */
   public long getNumberOfMissingBlocks();
   
+  /**
+   * Gets the total number of missing blocks on the cluster with
+   * replication factor 1
+   *
+   * @return the total number of missing blocks on the cluster with
+   * replication factor 1
+   */
+  public long getNumberOfMissingBlocksWithReplicationFactorOne();
+
   /**
    * Gets the number of threads.
    * 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSAdmin.java

@@ -462,6 +462,8 @@ public class DFSAdmin extends FsShell {
                        dfs.getCorruptBlocksCount());
     System.out.println("Missing blocks: " + 
                        dfs.getMissingBlocksCount());
+    System.out.println("Missing blocks (with replication factor 1): " +
+                      dfs.getMissingReplOneBlocksCount());
 
     System.out.println();
 

hadoop-hdfs-project/hadoop-hdfs/src/main/proto/ClientNamenodeProtocol.proto

@@ -283,6 +283,7 @@ message GetFsStatsResponseProto {
   required uint64 under_replicated = 4;
   required uint64 corrupt_blocks = 5;
   required uint64 missing_blocks = 6;
+  optional uint64 missing_repl_one_blocks = 7;
 }
 
 enum DatanodeReportTypeProto {  // type of the datanode report

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestMissingBlocksAlert.java

@@ -77,7 +77,6 @@ public class TestMissingBlocksAlert {
       Path corruptFile = new Path("/testMissingBlocks/corruptFile");
       DFSTestUtil.createFile(dfs, corruptFile, fileLen, (short)3, 0);
 
-
       // Corrupt the block
       ExtendedBlock block = DFSTestUtil.getFirstBlock(dfs, corruptFile);
       assertTrue(TestDatanodeBlockScanner.corruptReplica(block, 0));
@@ -120,6 +119,24 @@ public class TestMissingBlocksAlert {
 
       Assert.assertEquals(0, (long)(Long) mbs.getAttribute(mxbeanName,
               "NumberOfMissingBlocks"));
+
+      Path replOneFile = new Path("/testMissingBlocks/replOneFile");
+      DFSTestUtil.createFile(dfs, replOneFile, fileLen, (short)1, 0);
+      ExtendedBlock replOneBlock = DFSTestUtil.getFirstBlock(
+          dfs, replOneFile);
+      assertTrue(TestDatanodeBlockScanner.corruptReplica(
+          replOneBlock, 0));
+
+      // read the file so that the corrupt block is reported to NN
+      in = dfs.open(replOneFile);
+      try {
+        in.readFully(new byte[fileLen]);
+      } catch (ChecksumException ignored) { // checksum error is expected.
+      }
+      in.close();
+      assertEquals(1, dfs.getMissingReplOneBlocksCount());
+      Assert.assertEquals(1, (long)(Long) mbs.getAttribute(mxbeanName,
+          "NumberOfMissingBlocksWithReplicationFactorOne"));
     } finally {
       if (cluster != null) {
         cluster.shutdown();

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

@@ -19,10 +19,14 @@
 package org.apache.hadoop.hdfs.server.blockmanagement;
 
 import org.apache.hadoop.hdfs.protocol.Block;
-import org.junit.Assert;
 import org.junit.Test;
 
-public class TestUnderReplicatedBlockQueues extends Assert {
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.fail;
+
+public class TestUnderReplicatedBlockQueues {
 
   /**
    * Test that adding blocks with different replication counts puts them
@@ -36,6 +40,7 @@ public class TestUnderReplicatedBlockQueues extends Assert {
     Block block2 = new Block(2);
     Block block_very_under_replicated = new Block(3);
     Block block_corrupt = new Block(4);
+    Block block_corrupt_repl_one = new Block(5);
 
     //add a block with a single entry
     assertAdded(queues, block1, 1, 0, 3);
@@ -64,6 +69,16 @@ public class TestUnderReplicatedBlockQueues extends Assert {
     assertInLevel(queues, block_very_under_replicated,
                   UnderReplicatedBlocks.QUEUE_VERY_UNDER_REPLICATED);
 
+    //insert a corrupt block with replication factor 1
+    assertAdded(queues, block_corrupt_repl_one, 0, 0, 1);
+    assertEquals(2, queues.getCorruptBlockSize());
+    assertEquals(1, queues.getCorruptReplOneBlockSize());
+    queues.update(block_corrupt_repl_one, 0, 0, 3, 0, 2);
+    assertEquals(0, queues.getCorruptReplOneBlockSize());
+    queues.update(block_corrupt, 0, 0, 1, 0, -2);
+    assertEquals(1, queues.getCorruptReplOneBlockSize());
+    queues.update(block_very_under_replicated, 0, 0, 1, -4, -24);
+    assertEquals(2, queues.getCorruptReplOneBlockSize());
   }
 
   private void assertAdded(UnderReplicatedBlocks queues,

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

@@ -289,6 +289,7 @@ public class TestNameNodeMetrics {
     MetricsRecordBuilder rb = getMetrics(NS_METRICS);
     assertGauge("UnderReplicatedBlocks", 1L, rb);
     assertGauge("MissingBlocks", 1L, rb);
+    assertGauge("MissingReplOneBlocks", 1L, rb);
     fs.delete(file, true);
     waitForDnMetricValue(NS_METRICS, "UnderReplicatedBlocks", 0L);
   }