Add NormalUnderReplBlocksCount and BadlyDistributedBlocksCount to getStats() NN RPC

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

@@ -2103,11 +2103,29 @@
         GET_STATS_CORRUPT_BLOCKS_IDX);
   }
 
+  /**
+   * Returns count of blocks with one or more replicas missing.
+   * @throws IOException
+   */
+  public long getNormalLowRedundancyBlocksCount() throws IOException {
+    return getStateByIndex(ClientProtocol.
+        GET_STATS_NORMAL_LOW_REDUNDANCY_BLOCKS_IDX);
+  }
+
+  /**
+   * Returns count of blocks that are badly distributed as per BPP.
+   * @throws IOException
+   */
+  public long getBadlyDistributedBlocksCount() throws IOException {
+    return getStateByIndex(ClientProtocol.
+        GET_STATS_BADLY_DISTRIBUTED_BLOCKS_IDX);
+  }
+
   /**
    * Returns number of bytes that reside in Blocks with future generation
    * stamps.
    * @return Bytes in Blocks with future generation stamps.
    * @throws IOException
    */
   public long getBytesInFutureBlocks() throws IOException {
     return getStateByIndex(ClientProtocol.

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

@@ -804,7 +804,9 @@ SnapshotStatus[] getSnapshotListing(String snapshotRoot)
   int GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX = 6;
   int GET_STATS_BYTES_IN_FUTURE_BLOCKS_IDX = 7;
   int GET_STATS_PENDING_DELETION_BLOCKS_IDX = 8;
-  int STATS_ARRAY_LENGTH = 9;
+  int GET_STATS_BADLY_DISTRIBUTED_BLOCKS_IDX = 9;
+  int GET_STATS_NORMAL_LOW_REDUNDANCY_BLOCKS_IDX = 10;
+  int STATS_ARRAY_LENGTH = 11;
 
   /**
    * Get an array of aggregated statistics combining blocks of both type

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

@@ -210,6 +210,8 @@ public synchronized long[] getStats() {
                        -1L,
                        -1L,
                        -1L,
+                       -1L,
+                       -1L,
                        -1L};
   }
 

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

@@ -4848,6 +4848,13 @@ long[] getStats() {
         blockManager.getBytesInFuture();
     stats[ClientProtocol.GET_STATS_PENDING_DELETION_BLOCKS_IDX] =
         blockManager.getPendingDeletionBlocksCount();
+    stats[ClientProtocol.GET_STATS_BADLY_DISTRIBUTED_BLOCKS_IDX] =
+        getBadlyDistributedBlocksCount();
+    // GET_STATS_LOW_REDUNDANCY_IDX uses getLowRedundancyBlocksCount() which gives us the count of
+    // all types of low redundancy blocks. GET_STATS_NORMAL_LOW_REDUNDANCY_BLOCKS_IDX will give the count
+    // of normal low redundancy blocks only using getLowRedundancyBlocks().
+    stats[ClientProtocol.GET_STATS_NORMAL_LOW_REDUNDANCY_BLOCKS_IDX] =
+        blockManager.getLowRedundancyBlocks();
     return stats;
   }