diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/PartitionedGSet.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/PartitionedGSet.java
index f493402959031..d874f428d633d 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/PartitionedGSet.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/PartitionedGSet.java
@@ -25,6 +25,8 @@
 import java.util.Set;
 import java.util.TreeMap;
 import java.util.NoSuchElementException;
+import java.util.concurrent.atomic.AtomicInteger;
+
 import org.apache.hadoop.HadoopIllegalArgumentException;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.util.LightWeightGSet.LinkedElement;
@@ -61,7 +63,7 @@ public class PartitionedGSet<K, E extends K> implements GSet<K, E> {
   /**
    * The number of elements in the set.
    */
-  protected volatile int size;
+  private AtomicInteger size;
 
   /**
    * A single partition of the {@link PartitionedGSet}.
@@ -84,7 +86,7 @@ public PartitionedGSet(final int capacity,
     this.latchLock = latchLock;
     // addNewPartition(rootKey).put(rootKey);
     // this.size = 1;
-    this.size = 0;
+    this.size = new AtomicInteger(0);
     LOG.info("Partition capacity = {}", DEFAULT_PARTITION_CAPACITY);
     LOG.info("Partition overflow factor = {}", DEFAULT_PARTITION_OVERFLOW);
   }
@@ -108,7 +110,7 @@ public PartitionEntry addNewPartition(final K key) {
     assert oldPart == null :
       "RangeMap already has a partition associated with " + key;
 
-    LOG.debug("Total GSet size = {}", size);
+    LOG.debug("Total GSet size = {}", size.get());
     LOG.debug("Number of partitions = {}", partitions.size());
     LOG.debug("Previous partition size = {}",
         lastPart == null ? 0 : lastPart.size());
@@ -118,7 +120,7 @@ public PartitionEntry addNewPartition(final K key) {
 
   @Override
   public int size() {
-    return size;
+    return size.get();
   }
 
   public PartitionEntry getPartition(final K key) {
@@ -130,7 +132,7 @@ public PartitionEntry getPartition(final K key) {
     if(part == null) {
       throw new IllegalStateException("Null partition for key: " + key);
     }
-    assert size == 0 || part.partLock.isReadTopLocked() ||
+    assert size.get() == 0 || part.partLock.isReadTopLocked() ||
         part.partLock.hasReadChildLock() : "Must hold read Lock: key = " + key;
     return part;
   }
@@ -162,7 +164,7 @@ public E put(final E element) {
     if(part == null) {
       throw new HadoopIllegalArgumentException("Illegal key: " + key);
     }
-    assert size == 0 || part.partLock.isWriteTopLocked() ||
+    assert size.get() == 0 || part.partLock.isWriteTopLocked() ||
         part.partLock.hasWriteChildLock() :
           "Must hold write Lock: key = " + key;
     LOG.debug("put key: {}", key);
@@ -173,11 +175,11 @@ public E put(final E element) {
     }
     E result = part.put(element);
     if(result == null) {  // new element
-      size++;
-      LOG.debug("partitionPGSet.put: added key {}, size is now {} ", key, size);
+      size.incrementAndGet();
+      LOG.debug("partitionPGSet.put: added key {}, size is now {} ", key, size.get());
     } else {
       LOG.debug("partitionPGSet.put: replaced key {}, size is now {}",
-          key, size);
+          key, size.get());
     }
     return result;
   }
@@ -199,20 +201,20 @@ public E remove(final K key) {
     }
     E result = part.remove(key);
     if(result != null) {
-      size--;
+      size.decrementAndGet();
     }
     return result;
   }
 
   @Override
   public void clear() {
-    LOG.error("Total GSet size = {}", size);
+    LOG.error("Total GSet size = {}", size.get());
     LOG.error("Number of partitions = {}", partitions.size());
     printStats();
     // assert latchLock.hasWriteTopLock() : "Must hold write topLock";
     // SHV May need to clear all partitions?
     partitions.clear();
-    size = 0;
+    size.set(0);
   }
 
   private void printStats() {