diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/NetworkTopology.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/NetworkTopology.java
index cf5b17678b..0e6c253c5b 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/NetworkTopology.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/NetworkTopology.java
@@ -813,7 +813,7 @@ private Node chooseRandom(final String scope, String excludedScope,
       }
     }
     if (numOfDatanodes == 0) {
-      LOG.warn("Failed to find datanode (scope=\"{}\" excludedScope=\"{}\").",
+      LOG.debug("Failed to find datanode (scope=\"{}\" excludedScope=\"{}\").",
           String.valueOf(scope), String.valueOf(excludedScope));
       return null;
     }
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyDefault.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyDefault.java
index abfa7824ab..3958c738d9 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyDefault.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockPlacementPolicyDefault.java
@@ -49,8 +49,9 @@
 public class BlockPlacementPolicyDefault extends BlockPlacementPolicy {
 
   private static final String enableDebugLogging =
-    "For more information, please enable DEBUG log level on "
-    + BlockPlacementPolicy.class.getName();
+      "For more information, please enable DEBUG log level on "
+          + BlockPlacementPolicy.class.getName() + " and "
+          + NetworkTopology.class.getName();
 
   private static final ThreadLocal<StringBuilder> debugLoggingBuilder
       = new ThreadLocal<StringBuilder>() {