HDFS-9033. dfsadmin -metasave prints "NaN" for cache used%. Contributed by Brahma Reddy Battula.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/DatanodeInfo.java

@@ -371,9 +371,11 @@ public class DatanodeInfo extends DatanodeID implements Node {
     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);
@@ -387,11 +389,11 @@ public class DatanodeInfo extends DatanodeID implements Node {
     }
     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();

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -1358,6 +1358,9 @@ Release 2.7.2 - UNRELEASED
     HDFS-8995. Flaw in registration bookeeping can make DN die on reconnect.
     (Kihwal Lee via yliu)
 
+    HDFS-9033. dfsadmin -metasave prints "NaN" for cache used%.
+    (Brahma Reddy Battula via aajisaka)
+
 Release 2.7.1 - 2015-07-06
 
   INCOMPATIBLE CHANGES

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;
 
@@ -149,6 +150,16 @@ public class TestMetaSave {
       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();