Revert "HDFS-4937. ReplicationMonitor can infinite-loop in BlockPlacementPolicyDefault#chooseRandom(). Contributed by Kihwal Lee."

This reverts commit c250b21c23945ce2c580186c224cc65ab2b501fc.

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

@@ -89,9 +89,6 @@ Release 2.7.2 - UNRELEASED
     HDFS-9317. Document fsck -blockId and -storagepolicy options in branch-2.7.
     (aajisaka)
 
-    HDFS-4937. ReplicationMonitor can infinite-loop in
-    BlockPlacementPolicyDefault#chooseRandom() (kihwal)
-
 Release 2.7.1 - 2015-07-06
 
   INCOMPATIBLE CHANGES

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

@@ -622,7 +622,6 @@ public class BlockPlacementPolicyDefault extends BlockPlacementPolicy {
       
     int numOfAvailableNodes = clusterMap.countNumOfAvailableNodes(
         scope, excludedNodes);
-    int refreshCounter = numOfAvailableNodes;
     StringBuilder builder = null;
     if (LOG.isDebugEnabled()) {
       builder = debugLoggingBuilder.get();
@@ -676,17 +675,6 @@ public class BlockPlacementPolicyDefault extends BlockPlacementPolicy {
         // If no candidate storage was found on this DN then set badTarget.
         badTarget = (i == storages.length);
       }
-      // Refresh the node count. If the live node count became smaller,
-      // but it is not reflected in this loop, it may loop forever in case
-      // the replicas/rack cannot be satisfied.
-      if (--refreshCounter == 0) {
-        refreshCounter = clusterMap.countNumOfAvailableNodes(scope,
-            excludedNodes);
-        // It has already gone through enough number of nodes.
-        if (refreshCounter <= excludedNodes.size()) {
-          break;
-        }
-      }
     }
       
     if (numOfReplicas>0) {