From d9e4ad78ca284fb92397bcb56e3abd98870e5039 Mon Sep 17 00:00:00 2001
From: Brahma Reddy Battula <brahma@apache.org>
Date: Thu, 6 Oct 2016 17:47:31 +0530
Subject: [PATCH] HDFS-10963. Reduce log level when network topology cannot
 find enough datanodes. Contributed by Xiao chen

(cherry picked from commit b90fc70d671481564e468550c770c925f25d7db0)
---
 .../src/main/java/org/apache/hadoop/net/NetworkTopology.java | 2 +-
 .../server/blockmanagement/BlockPlacementPolicyDefault.java  | 5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

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 cf5b17678b0..0e6c253c5bc 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 @@ public class NetworkTopology {
       }
     }
     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 dc5ed9bcd96..4bc479a6538 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
@@ -48,8 +48,9 @@ import com.google.common.annotations.VisibleForTesting;
 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>() {