From c5a74c5c37a1208b6b0077c723efc8f4c896711a Mon Sep 17 00:00:00 2001
From: Akira Ajisaka <aajisaka@apache.org>
Date: Wed, 9 Sep 2015 17:20:46 +0900
Subject: [PATCH] HDFS-9033. dfsadmin -metasave prints "NaN" for cache used%.
 Contributed by Brahma Reddy Battula.

(cherry picked from commit 0113e4528deda7563b62a29745fbf209ab31b81a)
(cherry picked from commit eb9e06f8e30a6f930db478683739230f8f5ada5d)
---
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt           |  3 +++
 .../org/apache/hadoop/hdfs/protocol/DatanodeInfo.java |  6 ++++--
 .../hadoop/hdfs/server/namenode/TestMetaSave.java     | 11 +++++++++++
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 06b87ec651c..e1785d28f62 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -44,6 +44,9 @@ Release 2.7.2 - UNRELEASED
     HDFS-8384. Allow NN to startup if there are files having a lease but are not
     under construction. (jing9)
 
+    HDFS-9033. dfsadmin -metasave prints "NaN" for cache used%.
+    (Brahma Reddy Battula via aajisaka)
+
 Release 2.7.1 - 2015-07-06
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/DatanodeInfo.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/DatanodeInfo.java
index 1fd001899eb..a40143ce79e 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/DatanodeInfo.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/DatanodeInfo.java
@@ -370,9 +370,11 @@ public String dumpDatanode() {
     long c = getCapacity();
     long r = getRemaining();
     long u = getDfsUsed();
+    float usedPercent = getDfsUsedPercent();
     long cc = getCacheCapacity();
     long cr = getCacheRemaining();
     long cu = getCacheUsed();
+    float cacheUsedPercent = getCacheUsedPercent();
     buffer.append(getName());
     if (!NetworkTopology.DEFAULT_RACK.equals(location)) {
       buffer.append(" "+location);
@@ -386,11 +388,11 @@ public String dumpDatanode() {
     }
     buffer.append(" " + c + "(" + StringUtils.byteDesc(c)+")");
     buffer.append(" " + u + "(" + StringUtils.byteDesc(u)+")");
-    buffer.append(" " + percent2String(u/(double)c));
+    buffer.append(" " + percent2String(usedPercent));
     buffer.append(" " + r + "(" + StringUtils.byteDesc(r)+")");
     buffer.append(" " + cc + "(" + StringUtils.byteDesc(cc)+")");
     buffer.append(" " + cu + "(" + StringUtils.byteDesc(cu)+")");
-    buffer.append(" " + percent2String(cu/(double)cc));
+    buffer.append(" " + percent2String(cacheUsedPercent));
     buffer.append(" " + cr + "(" + StringUtils.byteDesc(cr)+")");
     buffer.append(" " + new Date(lastUpdate));
     return buffer.toString();
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestMetaSave.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestMetaSave.java
index 899cf4103b2..786f83f3fe8 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestMetaSave.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestMetaSave.java
@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.hdfs.server.namenode;
 
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
@@ -158,6 +159,16 @@ public void testMetasaveAfterDelete()
       assertTrue(line.equals("Mis-replicated blocks that have been postponed:"));
       line = reader.readLine();
       assertTrue(line.equals("Metasave: Blocks being replicated: 0"));
+      line = reader.readLine();
+      assertTrue(line.equals("Metasave: Blocks 2 waiting deletion from 1 datanodes."));
+     //skip 2 lines to reach HDFS-9033 scenario.
+      line = reader.readLine();
+      line = reader.readLine();
+      line = reader.readLine();
+      assertTrue(line.equals("Metasave: Number of datanodes: 2"));
+      line = reader.readLine();
+      assertFalse(line.contains("NaN"));
+
     } finally {
       if (reader != null)
         reader.close();