HDFS-15911 : Provide blocks moved count in Balancer iteration result (#2799)

Contributed by Viraj Jasani.

Signed-off-by: Mingliang Liu <liuml07@apache.org>
Signed-off-by: Ayush Saxena <ayushsaxena@apache.org>

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/balancer/Balancer.java

@@ -578,36 +578,60 @@ public class Balancer {
   }
 
   static class Result {
-    final ExitStatus exitStatus;
-    final long bytesLeftToMove;
-    final long bytesBeingMoved;
-    final long bytesAlreadyMoved;
+    private final ExitStatus exitStatus;
+    private final long bytesLeftToMove;
+    private final long bytesBeingMoved;
+    private final long bytesAlreadyMoved;
+    private final long blocksMoved;
 
     Result(ExitStatus exitStatus, long bytesLeftToMove, long bytesBeingMoved,
-        long bytesAlreadyMoved) {
+           long bytesAlreadyMoved, long blocksMoved) {
       this.exitStatus = exitStatus;
       this.bytesLeftToMove = bytesLeftToMove;
       this.bytesBeingMoved = bytesBeingMoved;
       this.bytesAlreadyMoved = bytesAlreadyMoved;
+      this.blocksMoved = blocksMoved;
+    }
+
+    public ExitStatus getExitStatus() {
+      return exitStatus;
+    }
+
+    public long getBytesLeftToMove() {
+      return bytesLeftToMove;
+    }
+
+    public long getBytesBeingMoved() {
+      return bytesBeingMoved;
+    }
+
+    public long getBytesAlreadyMoved() {
+      return bytesAlreadyMoved;
+    }
+
+    public long getBlocksMoved() {
+      return blocksMoved;
     }
 
     void print(int iteration, NameNodeConnector nnc, PrintStream out) {
-      out.printf("%-24s %10d  %19s  %18s  %17s  %s%n",
+      out.printf("%-24s %10d  %19s  %18s  %17s  %17s  %s%n",
           DateFormat.getDateTimeInstance().format(new Date()), iteration,
           StringUtils.byteDesc(bytesAlreadyMoved),
           StringUtils.byteDesc(bytesLeftToMove),
           StringUtils.byteDesc(bytesBeingMoved),
+          blocksMoved,
           nnc.getNameNodeUri());
     }
   }
 
   Result newResult(ExitStatus exitStatus, long bytesLeftToMove, long bytesBeingMoved) {
     return new Result(exitStatus, bytesLeftToMove, bytesBeingMoved,
-        dispatcher.getBytesMoved());
+        dispatcher.getBytesMoved(), dispatcher.getBblocksMoved());
   }
 
   Result newResult(ExitStatus exitStatus) {
-    return new Result(exitStatus, -1, -1, dispatcher.getBytesMoved());
+    return new Result(exitStatus, -1, -1, dispatcher.getBytesMoved(),
+        dispatcher.getBblocksMoved());
   }
 
   /** Run an iteration for all datanodes. */

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/balancer/TestBalancer.java

@@ -1022,14 +1022,14 @@ public class TestBalancer {
 
           // clean all lists
           b.resetData(conf);
-          if (r.exitStatus == ExitStatus.IN_PROGRESS) {
+          if (r.getExitStatus() == ExitStatus.IN_PROGRESS) {
             done = false;
-          } else if (r.exitStatus != ExitStatus.SUCCESS) {
+          } else if (r.getExitStatus() != ExitStatus.SUCCESS) {
             //must be an error statue, return.
-            return r.exitStatus.getExitCode();
+            return r.getExitStatus().getExitCode();
           } else {
             if (iteration > 0) {
-              assertTrue(r.bytesAlreadyMoved > 0);
+              assertTrue(r.getBytesAlreadyMoved() > 0);
             }
           }
         }
@@ -1655,7 +1655,8 @@ public class TestBalancer {
           // When a block move is not canceled in 2 seconds properly and then
           // a block is moved unexpectedly, IN_PROGRESS will be reported.
           assertEquals("We expect ExitStatus.NO_MOVE_PROGRESS to be reported.",
-              ExitStatus.NO_MOVE_PROGRESS, r.exitStatus);
+              ExitStatus.NO_MOVE_PROGRESS, r.getExitStatus());
+          assertEquals(0, r.getBlocksMoved());
         }
       } finally {
         for (NameNodeConnector nnc : connectors) {