HDFS-2335. svn merge -c 1220510 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1220513 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -58,6 +58,9 @@ Release 0.23.1 - UNRELEASED
     HDFS-2675. Reduce warning verbosity when double-closing edit logs
     (todd)
 
+    HDFS-2335. DataNodeCluster and NNStorage always pull fresh entropy.
+    (Uma Maheswara Rao G via eli)
+
   OPTIMIZATIONS
 
     HDFS-2130. Switch default checksum to CRC32C. (todd)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSUtil.java

@@ -30,6 +30,7 @@ import java.io.UnsupportedEncodingException;
 import java.net.InetSocketAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Comparator;
@@ -73,11 +74,23 @@ public class DFSUtil {
     }
   };
   
-  /** @return a pseudorandom number generator. */
+  private static final ThreadLocal<SecureRandom> SECURE_RANDOM = new ThreadLocal<SecureRandom>() {
+    @Override
+    protected SecureRandom initialValue() {
+      return new SecureRandom();
+    }
+  };
+
+  /** @return a pseudo random number generator. */
   public static Random getRandom() {
     return RANDOM.get();
   }
   
+  /** @return a pseudo secure random number generator. */
+  public static SecureRandom getSecureRandom() {
+    return SECURE_RANDOM.get();
+  }
+
   /**
    * Compartor for sorting DataNodeInfo[] based on decommissioned states.
    * Decommissioned nodes are moved to the end of the array on sorting with

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java

@@ -65,7 +65,6 @@ import java.net.UnknownHostException;
 import java.nio.channels.ServerSocketChannel;
 import java.nio.channels.SocketChannel;
 import java.security.PrivilegedExceptionAction;
-import java.security.SecureRandom;
 import java.util.AbstractList;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -1056,7 +1055,7 @@ public class DataNode extends Configured
       LOG.warn("Could not find ip address of \"default\" inteface.");
     }
     
-    int rand = new SecureRandom().nextInt(Integer.MAX_VALUE);
+    int rand = DFSUtil.getSecureRandom().nextInt(Integer.MAX_VALUE);
     return "DS-" + rand + "-" + ip + "-" + port + "-"
         + System.currentTimeMillis();
   }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NNStorage.java

@@ -26,8 +26,6 @@ import java.io.RandomAccessFile;
 import java.io.OutputStream;
 import java.net.URI;
 import java.net.UnknownHostException;
-import java.security.NoSuchAlgorithmException;
-import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
@@ -955,13 +953,7 @@ public class NNStorage extends Storage implements Closeable {
       throw e;
     }
     
-    int rand = 0;
-    try {
-      rand = SecureRandom.getInstance("SHA1PRNG").nextInt(Integer.MAX_VALUE);
-    } catch (NoSuchAlgorithmException e) {
-      LOG.warn("Could not use SecureRandom");
-      rand = DFSUtil.getRandom().nextInt(Integer.MAX_VALUE);
-    }
+    int rand = DFSUtil.getSecureRandom().nextInt(Integer.MAX_VALUE);
     String bpid = "BP-" + rand + "-"+ ip + "-" + System.currentTimeMillis();
     return bpid;
   }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/DataNodeCluster.java

@@ -19,10 +19,7 @@ package org.apache.hadoop.hdfs;
 
 import java.io.IOException;
 import java.net.UnknownHostException;
-import java.security.NoSuchAlgorithmException;
-import java.security.SecureRandom;
 import java.util.Arrays;
-import java.util.Random;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
@@ -234,12 +231,7 @@ public class DataNodeCluster {
       System.out.println("Could not find ip address of \"default\" inteface.");
     }
     
-    int rand = 0;
-    try {
-      rand = SecureRandom.getInstance("SHA1PRNG").nextInt(Integer.MAX_VALUE);
-    } catch (NoSuchAlgorithmException e) {
-      rand = (new Random()).nextInt(Integer.MAX_VALUE);
-    }
+    int rand = DFSUtil.getSecureRandom().nextInt(Integer.MAX_VALUE);
     return "/Rack-" + rand + "-"+ ip  + "-" + 
                       System.currentTimeMillis();
   }