From 8719cdd4f68abb91bf9459bca2a5467dafb6b5ae Mon Sep 17 00:00:00 2001
From: Akira Ajisaka <aajisaka@apache.org>
Date: Fri, 27 Feb 2015 12:17:34 -0800
Subject: [PATCH] HDFS-7685. Document dfs.namenode.heartbeat.recheck-interval
 in hdfs-default.xml. Contributed by Kai Sasaki.

---
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt           |  3 +++
 .../hadoop-hdfs/src/main/resources/hdfs-default.xml   | 11 +++++++++++
 2 files changed, 14 insertions(+)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index b2422d60154..b4b0087dc00 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -685,6 +685,9 @@ Release 2.7.0 - UNRELEASED
     HDFS-7308. Change the packet chunk size computation in DFSOutputStream in
     order to enforce packet size <= 64kB.  (Takuya Fukudome via szetszwo)
 
+    HDFS-7685. Document dfs.namenode.heartbeat.recheck-interval in
+    hdfs-default.xml. (Kai Sasaki via aajisaka)
+
   OPTIMIZATIONS
 
     HDFS-7454. Reduce memory footprint for AclEntries in NameNode.
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml b/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml
index 85d2273ea33..66fe86c56ec 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml
@@ -144,6 +144,17 @@
   </description>
 </property>
 
+<property>
+  <name>dfs.namenode.heartbeat.recheck-interval</name>
+  <value>300000</value>
+  <description>
+    This time decides the interval to check for expired datanodes.
+    With this value and dfs.heartbeat.interval, the interval of
+    deciding the datanode is stale or not is also calculated.
+    The unit of this configuration is millisecond.
+  </description>
+</property>
+
 <property>
   <name>dfs.http.policy</name>
   <value>HTTP_ONLY</value>