HDFS-6621. Hadoop Balancer prematurely exits iterations. Contributed by Rafal Wodjdyla and Benjamin Bowman.

(cherry picked from commit d1dab6cc63abf5d44533ad9b39e32c582327627b)

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

@@ -380,6 +380,9 @@ Release 2.6.0 - UNRELEASED
     HDFS-6966. Add additional unit tests for encryption zones.
     (Stephen Chu via wang)
 
+    HDFS-6621. Hadoop Balancer prematurely exits iterations.
+    (Rafal Wojdyla and Benjamin Bowman via wang)
+
     BREAKDOWN OF HDFS-6134 AND HADOOP-10150 SUBTASKS AND RELATED JIRAS
   
       HDFS-6387. HDFS CLI admin tool for creating & deleting an

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

@@ -654,6 +654,8 @@ public class Dispatcher {
           && (!srcBlocks.isEmpty() || blocksToReceive > 0)) {
         final PendingMove p = chooseNextMove();
         if (p != null) {
+          // Reset no pending move counter
+          noPendingMoveIteration=0;
           // move the block
           moveExecutor.execute(new Runnable() {
             @Override