From 51950f149ecc0b6f03849865031b12cdb5eecd5d Mon Sep 17 00:00:00 2001
From: Bharat Viswanadham <bharat@apache.org>
Date: Tue, 19 Feb 2019 17:01:07 -0800
Subject: [PATCH] Logging stale datanode information. Contributed by  Karthik
 Palanisamy.

---
 .../hadoop/hdfs/server/blockmanagement/HeartbeatManager.java   | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/HeartbeatManager.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/HeartbeatManager.java
index d2c279f8b4a..46444bc9b26 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/HeartbeatManager.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/HeartbeatManager.java
@@ -379,6 +379,9 @@ class HeartbeatManager implements DatanodeStatistics {
             dead = d;
           }
           if (d.isStale(dm.getStaleInterval())) {
+            LOG.warn(String.format("Stale datanode {}."
+                    + " No heartbeat received since last {} milliseconds"),
+                    d.getName(), dm.getStaleInterval());
             numOfStaleNodes++;
           }
           DatanodeStorageInfo[] storageInfos = d.getStorageInfos();