MAPREDUCE-2837. Ported bug fixes from y-merge to prepare for MAPREDUCE-279 merge.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1157249 13f79535-47bb-0310-9956-ffa450edef68

mapreduce/CHANGES.txt

@@ -388,6 +388,10 @@ Trunk (unreleased changes)
 
     MAPREDUCE-2805. Update RAID for HDFS-2241.  (szetszwo)
     
+    MAPREDUCE-2837. Ported bug fixes from y-merge to prepare for MAPREDUCE-279
+    merge. (acmurthy) 
+
+
 Release 0.22.0 - Unreleased
 
   INCOMPATIBLE CHANGES

mapreduce/src/examples/org/apache/hadoop/examples/terasort/TeraInputFormat.java

@@ -61,19 +61,32 @@ public class TeraInputFormat extends FileInputFormat<Text,Text> {
   private static List<InputSplit> lastResult = null;
 
   static class TeraFileSplit extends FileSplit {
+    static private String[] ZERO_LOCATIONS = new String[0];
+
     private String[] locations;
-    public TeraFileSplit() {}
+
+    public TeraFileSplit() {
+      locations = ZERO_LOCATIONS;
+    }
     public TeraFileSplit(Path file, long start, long length, String[] hosts) {
       super(file, start, length, hosts);
-      locations = hosts;
+      try {
+        locations = super.getLocations();
+      } catch (IOException e) {
+        locations = ZERO_LOCATIONS;
       }
+    }
+
+    // XXXXXX should this also be null-protected?
     protected void setLocations(String[] hosts) {
       locations = hosts;
     }
+
     @Override
     public String[] getLocations() {
       return locations;
     }
+
     public String toString() {
       StringBuffer result = new StringBuffer();
       result.append(getPath());

mapreduce/src/java/org/apache/hadoop/mapred/ACLsManager.java

@@ -36,7 +36,7 @@ import org.apache.hadoop.security.authorize.AccessControlList;
  * QueueManager for queue operations.
  */
 @InterfaceAudience.Private
-class ACLsManager {
+public class ACLsManager {
 
   static Log LOG = LogFactory.getLog(ACLsManager.class);
   // MROwner(user who started this mapreduce cluster)'s ugi
@@ -49,7 +49,7 @@ class ACLsManager {
   
   private final boolean aclsEnabled;
 
-  ACLsManager(Configuration conf, JobACLsManager jobACLsManager,
+  public ACLsManager(Configuration conf, JobACLsManager jobACLsManager,
       QueueManager queueManager) throws IOException {
 
     mrOwner = UserGroupInformation.getCurrentUser();
@@ -68,7 +68,7 @@ class ACLsManager {
     this.queueManager = queueManager;
   }
 
-  UserGroupInformation getMROwner() {
+  public UserGroupInformation getMROwner() {
     return mrOwner;
   }
 
@@ -76,7 +76,7 @@ class ACLsManager {
     return adminAcl;
   }
 
-  JobACLsManager getJobACLsManager() {
+  public JobACLsManager getJobACLsManager() {
     return jobACLsManager;
   }
 
@@ -85,7 +85,7 @@ class ACLsManager {
    * i.e. either cluster owner or cluster administrator
    * @return true, if user is an admin
    */
-  boolean isMRAdmin(UserGroupInformation callerUGI) {
+  public boolean isMRAdmin(UserGroupInformation callerUGI) {
     if (adminAcl.isUserAllowed(callerUGI)) {
       return true;
     }
@@ -111,7 +111,7 @@ class ACLsManager {
    * @param operation  the operation for which authorization is needed
    * @throws AccessControlException
    */
-   void checkAccess(JobInProgress job, UserGroupInformation callerUGI,
+   public void checkAccess(JobInProgress job, UserGroupInformation callerUGI,
        Operation operation) throws AccessControlException {
 
     String queue = job.getProfile().getQueueName();

mapreduce/src/java/org/apache/hadoop/mapred/JobACLsManager.java

@@ -29,7 +29,7 @@ import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.authorize.AccessControlList;
 
 @InterfaceAudience.Private
-class JobACLsManager {
+public class JobACLsManager {
 
   Configuration conf;
 
@@ -37,7 +37,7 @@ class JobACLsManager {
     this.conf = conf;
   }
 
-  boolean areACLsEnabled() {
+  public boolean areACLsEnabled() {
     return conf.getBoolean(MRConfig.MR_ACLS_ENABLED, false);
   }
 
@@ -86,7 +86,7 @@ class JobACLsManager {
    * @param jobACL
    * @throws AccessControlException
    */
-  boolean checkAccess(UserGroupInformation callerUGI,
+  public boolean checkAccess(UserGroupInformation callerUGI,
       JobACL jobOperation, String jobOwner, AccessControlList jobACL) {
 
     String user = callerUGI.getShortUserName();

mapreduce/src/java/org/apache/hadoop/mapred/LocalJobRunner.java

@@ -240,7 +240,7 @@ public class LocalJobRunner implements ClientProtocol {
               getShortUserName());
           TaskRunner.setupChildMapredLocalDirs(map, localConf);
 
-          MapOutputFile mapOutput = new MapOutputFile();
+          MapOutputFile mapOutput = new MROutputFiles();
           mapOutput.setConf(localConf);
           mapOutputFiles.put(mapId, mapOutput);
 
@@ -404,7 +404,7 @@ public class LocalJobRunner implements ClientProtocol {
               if (!this.isInterrupted()) {
                 TaskAttemptID mapId = mapIds.get(i);
                 Path mapOut = mapOutputFiles.get(mapId).getOutputFile();
-                MapOutputFile localOutputFile = new MapOutputFile();
+                MapOutputFile localOutputFile = new MROutputFiles();
                 localOutputFile.setConf(localConf);
                 Path reduceIn =
                   localOutputFile.getInputFileForWrite(mapId.getTaskID(),

mapreduce/src/java/org/apache/hadoop/mapred/MROutputFiles.java

@@ -0,0 +1,226 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.mapred;
+
+import java.io.IOException;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.conf.Configurable;
+import org.apache.hadoop.fs.LocalDirAllocator;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.mapreduce.MRConfig;
+
+/**
+ * Manipulate the working area for the transient store for maps and reduces.
+ *
+ * This class is used by map and reduce tasks to identify the directories that
+ * they need to write to/read from for intermediate files. The callers of
+ * these methods are from the Child running the Task.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public class MROutputFiles extends MapOutputFile {
+
+  private LocalDirAllocator lDirAlloc =
+    new LocalDirAllocator(MRConfig.LOCAL_DIR);
+
+  public MROutputFiles() {
+  }
+
+  /**
+   * Return the path to local map output file created earlier
+   *
+   * @return path
+   * @throws IOException
+   */
+  @Override
+  public Path getOutputFile()
+      throws IOException {
+    return lDirAlloc.getLocalPathToRead(TaskTracker.OUTPUT + Path.SEPARATOR
+        + MAP_OUTPUT_FILENAME_STRING, getConf());
+  }
+
+  /**
+   * Create a local map output file name.
+   *
+   * @param size the size of the file
+   * @return path
+   * @throws IOException
+   */
+  @Override
+  public Path getOutputFileForWrite(long size)
+      throws IOException {
+    return lDirAlloc.getLocalPathForWrite(TaskTracker.OUTPUT + Path.SEPARATOR
+        + MAP_OUTPUT_FILENAME_STRING, size, getConf());
+  }
+
+  /**
+   * Create a local map output file name on the same volume.
+   */
+  @Override
+  public Path getOutputFileForWriteInVolume(Path existing) {
+    return new Path(existing.getParent(), MAP_OUTPUT_FILENAME_STRING);
+  }
+
+  /**
+   * Return the path to a local map output index file created earlier
+   *
+   * @return path
+   * @throws IOException
+   */
+  @Override
+  public Path getOutputIndexFile()
+      throws IOException {
+    return lDirAlloc.getLocalPathToRead(TaskTracker.OUTPUT + Path.SEPARATOR
+        + MAP_OUTPUT_FILENAME_STRING + MAP_OUTPUT_INDEX_SUFFIX_STRING,
+        getConf());
+  }
+
+  /**
+   * Create a local map output index file name.
+   *
+   * @param size the size of the file
+   * @return path
+   * @throws IOException
+   */
+  @Override
+  public Path getOutputIndexFileForWrite(long size)
+      throws IOException {
+    return lDirAlloc.getLocalPathForWrite(TaskTracker.OUTPUT + Path.SEPARATOR
+        + MAP_OUTPUT_FILENAME_STRING + MAP_OUTPUT_INDEX_SUFFIX_STRING,
+        size, getConf());
+  }
+
+  /**
+   * Create a local map output index file name on the same volume.
+   */
+  @Override
+  public Path getOutputIndexFileForWriteInVolume(Path existing) {
+    return new Path(existing.getParent(),
+        MAP_OUTPUT_FILENAME_STRING + MAP_OUTPUT_INDEX_SUFFIX_STRING);
+  }
+
+  /**
+   * Return a local map spill file created earlier.
+   *
+   * @param spillNumber the number
+   * @return path
+   * @throws IOException
+   */
+  @Override
+  public Path getSpillFile(int spillNumber)
+      throws IOException {
+    return lDirAlloc.getLocalPathToRead(TaskTracker.OUTPUT + "/spill"
+        + spillNumber + ".out", getConf());
+  }
+
+  /**
+   * Create a local map spill file name.
+   *
+   * @param spillNumber the number
+   * @param size the size of the file
+   * @return path
+   * @throws IOException
+   */
+  @Override
+  public Path getSpillFileForWrite(int spillNumber, long size)
+      throws IOException {
+    return lDirAlloc.getLocalPathForWrite(TaskTracker.OUTPUT + "/spill"
+        + spillNumber + ".out", size, getConf());
+  }
+
+  /**
+   * Return a local map spill index file created earlier
+   *
+   * @param spillNumber the number
+   * @return path
+   * @throws IOException
+   */
+  @Override
+  public Path getSpillIndexFile(int spillNumber)
+      throws IOException {
+    return lDirAlloc.getLocalPathToRead(TaskTracker.OUTPUT + "/spill"
+        + spillNumber + ".out.index", getConf());
+  }
+
+  /**
+   * Create a local map spill index file name.
+   *
+   * @param spillNumber the number
+   * @param size the size of the file
+   * @return path
+   * @throws IOException
+   */
+  @Override
+  public Path getSpillIndexFileForWrite(int spillNumber, long size)
+      throws IOException {
+    return lDirAlloc.getLocalPathForWrite(TaskTracker.OUTPUT + "/spill"
+        + spillNumber + ".out.index", size, getConf());
+  }
+
+  /**
+   * Return a local reduce input file created earlier
+   *
+   * @param mapId a map task id
+   * @return path
+   * @throws IOException
+   */
+  @Override
+  public Path getInputFile(int mapId)
+      throws IOException {
+    return lDirAlloc.getLocalPathToRead(String.format(
+        REDUCE_INPUT_FILE_FORMAT_STRING, TaskTracker.OUTPUT, Integer
+            .valueOf(mapId)), getConf());
+  }
+
+  /**
+   * Create a local reduce input file name.
+   *
+   * @param mapId a map task id
+   * @param size the size of the file
+   * @return path
+   * @throws IOException
+   */
+  @Override
+  public Path getInputFileForWrite(org.apache.hadoop.mapreduce.TaskID mapId,
+                                   long size)
+      throws IOException {
+    return lDirAlloc.getLocalPathForWrite(String.format(
+        REDUCE_INPUT_FILE_FORMAT_STRING, TaskTracker.OUTPUT, mapId.getId()),
+        size, getConf());
+  }
+
+  /** Removes all of the files related to a task. */
+  @Override
+  public void removeAll()
+      throws IOException {
+    ((JobConf)getConf()).deleteLocalFiles(TaskTracker.OUTPUT);
+  }
+
+  @Override
+  public void setConf(Configuration conf) {
+    if (!(conf instanceof JobConf)) {
+      conf = new JobConf(conf);
+    }
+    super.setConf(conf);
+  }
+
+}

mapreduce/src/java/org/apache/hadoop/mapred/MapOutputFile.java

@@ -23,9 +23,8 @@ import java.io.IOException;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.fs.LocalDirAllocator;
+import org.apache.hadoop.conf.Configurable;
 import org.apache.hadoop.fs.Path;
-import org.apache.hadoop.mapreduce.MRConfig;
 
 /**
  * Manipulate the working area for the transient store for maps and reduces.
@@ -38,29 +37,24 @@ import org.apache.hadoop.mapreduce.MRConfig;
  */
 @InterfaceAudience.Private
 @InterfaceStability.Unstable
-public class MapOutputFile {
+public abstract class MapOutputFile implements Configurable {
 
-  private JobConf conf;
+  private Configuration conf;
 
+  static final String MAP_OUTPUT_FILENAME_STRING = "file.out";
+  static final String MAP_OUTPUT_INDEX_SUFFIX_STRING = ".index";
   static final String REDUCE_INPUT_FILE_FORMAT_STRING = "%s/map_%d.out";
 
   public MapOutputFile() {
   }
 
-  private LocalDirAllocator lDirAlloc = 
-    new LocalDirAllocator(MRConfig.LOCAL_DIR);
-  
   /**
    * Return the path to local map output file created earlier
    *
    * @return path
    * @throws IOException
    */
-  public Path getOutputFile()
+  public abstract Path getOutputFile() throws IOException;
-      throws IOException {
-    return lDirAlloc.getLocalPathToRead(TaskTracker.OUTPUT + Path.SEPARATOR
-        + "file.out", conf);
-  }
 
   /**
    * Create a local map output file name.
@@ -69,11 +63,12 @@ public class MapOutputFile {
    * @return path
    * @throws IOException
    */
-  public Path getOutputFileForWrite(long size)
+  public abstract Path getOutputFileForWrite(long size) throws IOException;
-      throws IOException {
+
-    return lDirAlloc.getLocalPathForWrite(TaskTracker.OUTPUT + Path.SEPARATOR
+  /**
-        + "file.out", size, conf);
+   * Create a local map output file name on the same volume.
-  }
+   */
+  public abstract Path getOutputFileForWriteInVolume(Path existing);
 
   /**
    * Return the path to a local map output index file created earlier
@@ -81,11 +76,7 @@ public class MapOutputFile {
    * @return path
    * @throws IOException
    */
-  public Path getOutputIndexFile()
+  public abstract Path getOutputIndexFile() throws IOException;
-      throws IOException {
-    return lDirAlloc.getLocalPathToRead(TaskTracker.OUTPUT + Path.SEPARATOR
-        + "file.out.index", conf);
-  }
 
   /**
    * Create a local map output index file name.
@@ -94,11 +85,12 @@ public class MapOutputFile {
    * @return path
    * @throws IOException
    */
-  public Path getOutputIndexFileForWrite(long size)
+  public abstract Path getOutputIndexFileForWrite(long size) throws IOException;
-      throws IOException {
+
-    return lDirAlloc.getLocalPathForWrite(TaskTracker.OUTPUT + Path.SEPARATOR
+  /**
-        + "file.out.index", size, conf);
+   * Create a local map output index file name on the same volume.
-  }
+   */
+  public abstract Path getOutputIndexFileForWriteInVolume(Path existing);
 
   /**
    * Return a local map spill file created earlier.
@@ -107,11 +99,7 @@ public class MapOutputFile {
    * @return path
    * @throws IOException
    */
-  public Path getSpillFile(int spillNumber)
+  public abstract Path getSpillFile(int spillNumber) throws IOException;
-      throws IOException {
-    return lDirAlloc.getLocalPathToRead(TaskTracker.OUTPUT + "/spill"
-        + spillNumber + ".out", conf);
-  }
 
   /**
    * Create a local map spill file name.
@@ -121,11 +109,8 @@ public class MapOutputFile {
    * @return path
    * @throws IOException
    */
-  public Path getSpillFileForWrite(int spillNumber, long size)
+  public abstract Path getSpillFileForWrite(int spillNumber, long size)
-      throws IOException {
+      throws IOException;
-    return lDirAlloc.getLocalPathForWrite(TaskTracker.OUTPUT + "/spill"
-        + spillNumber + ".out", size, conf);
-  }
 
   /**
    * Return a local map spill index file created earlier
@@ -134,11 +119,7 @@ public class MapOutputFile {
    * @return path
    * @throws IOException
    */
-  public Path getSpillIndexFile(int spillNumber)
+  public abstract Path getSpillIndexFile(int spillNumber) throws IOException;
-      throws IOException {
-    return lDirAlloc.getLocalPathToRead(TaskTracker.OUTPUT + "/spill"
-        + spillNumber + ".out.index", conf);
-  }
 
   /**
    * Create a local map spill index file name.
@@ -148,11 +129,8 @@ public class MapOutputFile {
    * @return path
    * @throws IOException
    */
-  public Path getSpillIndexFileForWrite(int spillNumber, long size)
+  public abstract Path getSpillIndexFileForWrite(int spillNumber, long size)
-      throws IOException {
+      throws IOException;
-    return lDirAlloc.getLocalPathForWrite(TaskTracker.OUTPUT + "/spill"
-        + spillNumber + ".out.index", size, conf);
-  }
 
   /**
    * Return a local reduce input file created earlier
@@ -161,12 +139,7 @@ public class MapOutputFile {
    * @return path
    * @throws IOException
    */
-  public Path getInputFile(int mapId)
+  public abstract Path getInputFile(int mapId) throws IOException;
-      throws IOException {
-    return lDirAlloc.getLocalPathToRead(String.format(
-        REDUCE_INPUT_FILE_FORMAT_STRING, TaskTracker.OUTPUT, Integer
-            .valueOf(mapId)), conf);
-  }
 
   /**
    * Create a local reduce input file name.
@@ -176,26 +149,20 @@ public class MapOutputFile {
    * @return path
    * @throws IOException
    */
-  public Path getInputFileForWrite(org.apache.hadoop.mapreduce.TaskID mapId, 
+  public abstract Path getInputFileForWrite(
-                                   long size)
+      org.apache.hadoop.mapreduce.TaskID mapId, long size) throws IOException;
-      throws IOException {
-    return lDirAlloc.getLocalPathForWrite(String.format(
-        REDUCE_INPUT_FILE_FORMAT_STRING, TaskTracker.OUTPUT, mapId.getId()),
-        size, conf);
-  }
 
   /** Removes all of the files related to a task. */
-  public void removeAll()
+  public abstract void removeAll() throws IOException;
-      throws IOException {
+
-    conf.deleteLocalFiles(TaskTracker.OUTPUT);
+  @Override
+  public void setConf(Configuration conf) {
+    this.conf = conf;
   }
 
-  public void setConf(Configuration conf) {
+  @Override
-    if (conf instanceof JobConf) {
+  public Configuration getConf() {
-      this.conf = (JobConf) conf;
+    return conf;
-    } else {
-      this.conf = new JobConf(conf);
-    }
   }
 
 }

mapreduce/src/java/org/apache/hadoop/mapred/MapTask.java

@@ -1735,13 +1735,13 @@ class MapTask extends Task {
       }
       if (numSpills == 1) { //the spill is the final output
         rfs.rename(filename[0],
-            new Path(filename[0].getParent(), "file.out"));
+            mapOutputFile.getOutputFileForWriteInVolume(filename[0]));
         if (indexCacheList.size() == 0) {
           rfs.rename(mapOutputFile.getSpillIndexFile(0),
-              new Path(filename[0].getParent(),"file.out.index"));
+            mapOutputFile.getOutputIndexFileForWriteInVolume(filename[0]));
         } else {
           indexCacheList.get(0).writeToFile(
-                new Path(filename[0].getParent(),"file.out.index"), job);
+            mapOutputFile.getOutputIndexFileForWriteInVolume(filename[0]), job);
         }
         return;
       }

mapreduce/src/java/org/apache/hadoop/mapred/ReduceTask.java

@@ -362,7 +362,8 @@ public class ReduceTask extends Task {
                     shuffledMapsCounter,
                     reduceShuffleBytes, failedShuffleCounter,
                     mergedMapOutputsCounter,
-                    taskStatus, copyPhase, sortPhase, this);
+                    taskStatus, copyPhase, sortPhase, this,
+                    mapOutputFile);
       rIter = shuffle.run();
     } else {
       // local job runner doesn't have a copy phase

mapreduce/src/java/org/apache/hadoop/mapred/Task.java

@@ -146,7 +146,7 @@ abstract public class Task implements Writable, Configurable {
   private long initCpuCumulativeTime = 0;
 
   protected JobConf conf;
-  protected MapOutputFile mapOutputFile = new MapOutputFile();
+  protected MapOutputFile mapOutputFile;
   protected LocalDirAllocator lDirAlloc;
   private final static int MAX_RETRIES = 10;
   protected JobContext jobContext;
@@ -1150,7 +1150,9 @@ abstract public class Task implements Writable, Configurable {
     } else {
       this.conf = new JobConf(conf);
     }
-    this.mapOutputFile.setConf(this.conf);
+    this.mapOutputFile = ReflectionUtils.newInstance(
+        conf.getClass(MRConfig.TASK_LOCAL_OUTPUT_CLASS,
+          MROutputFiles.class, MapOutputFile.class), conf);
     this.lDirAlloc = new LocalDirAllocator(MRConfig.LOCAL_DIR);
     // add the static resolutions (this is required for the junit to
     // work on testcases that simulate multiple nodes on a single physical

mapreduce/src/java/org/apache/hadoop/mapred/TaskMemoryManagerThread.java

@@ -227,8 +227,12 @@ class TaskMemoryManagerThread extends Thread {
             continue; // processTree cannot be tracked
           }
 
-          if (taskTracker.runningTasks.get(tid).wasKilled()) {
+          TaskInProgress tip = taskTracker.getRunningTask(tid);
-            continue; // this task has been killed already
+          if (tip == null) {
+            continue;
+          }
+          if (tip.wasKilled()) {
+            continue;
           }
 
           LOG.debug("Constructing ProcessTree for : PID = " + pId + " TID = "
@@ -514,6 +518,12 @@ class TaskMemoryManagerThread extends Thread {
    * @param msg diagnostics message
    */
   private void killTask(TaskAttemptID tid, String msg) {
+    TaskInProgress tip = taskTracker.getRunningTask(tid);
+    if (tip != null) {
+      //for the task identified to be killed update taskDiagnostic 
+      TaskStatus taskStatus = tip.getStatus();
+      taskStatus.setDiagnosticInfo(msg);
+    }
     // Kill the task and mark it as killed.
     taskTracker.cleanUpOverMemoryTask(tid, false, msg);
     // Now destroy the ProcessTree, remove it from monitoring map.
@@ -530,7 +540,7 @@ class TaskMemoryManagerThread extends Thread {
    * @return true if the task can be killed
    */
   private boolean isKillable(TaskAttemptID tid) {
-      TaskInProgress tip = taskTracker.runningTasks.get(tid);
+      TaskInProgress tip = taskTracker.getRunningTask(tid);
       return tip != null && !tip.wasKilled() &&
              (tip.getRunState() == TaskStatus.State.RUNNING ||
               tip.getRunState() == TaskStatus.State.COMMIT_PENDING);

mapreduce/src/java/org/apache/hadoop/mapred/TaskTracker.java

@@ -4218,4 +4218,8 @@ public class TaskTracker
     ACLsManager getACLsManager() {
       return aclsManager;
     }
+
+    synchronized TaskInProgress getRunningTask(TaskAttemptID tid) {
+      return runningTasks.get(tid);
+    }
 }

mapreduce/src/java/org/apache/hadoop/mapreduce/Job.java

@@ -360,8 +360,11 @@ public class Job extends JobContextImpl implements JobContext {
   @Override
   public String toString() {
     ensureState(JobState.RUNNING);
+    String reasonforFailure = " ";
     try {
       updateStatus();
+      if (status.getState().equals(JobStatus.State.FAILED))
+        reasonforFailure = getTaskFailureEventString();
     } catch (IOException e) {
     } catch (InterruptedException ie) {
     }
@@ -378,10 +381,34 @@ public class Job extends JobContextImpl implements JobContext {
     sb.append(status.getState()).append("\n");
     sb.append("history URL: ");
     sb.append(status.getHistoryFile()).append("\n");
-    sb.append("retired: ").append(status.isRetired());
+    sb.append("retired: ").append(status.isRetired()).append("\n");
+    sb.append("reason for failure: ").append(reasonforFailure);
     return sb.toString();
   }
 
+  /**
+   * @return taskid which caused job failure
+   * @throws IOException
+   * @throws InterruptedException
+   */
+  String getTaskFailureEventString() throws IOException,
+      InterruptedException {
+    int failCount = 1;
+    TaskCompletionEvent lastEvent = null;
+    for (TaskCompletionEvent event : cluster.getClient().getTaskCompletionEvents(
+        status.getJobID(), 0, 10)) {
+      if (event.getStatus().equals(TaskCompletionEvent.Status.FAILED)) {
+        failCount++;
+        lastEvent = event;
+      }
+    }
+    String[] taskAttemptID = lastEvent.getTaskAttemptId().toString().split("_", 2);
+    String taskID = taskAttemptID[1].substring(0, taskAttemptID[1].length()-2);
+    return (" task " + taskID + " failed " +
+      failCount + " times " + "For details check tasktracker at: " +
+      lastEvent.getTaskTrackerHttp());
+  }
+
   /**
    * Get the information of the current state of the tasks of a job.
    * 

mapreduce/src/java/org/apache/hadoop/mapreduce/MRConfig.java

@@ -59,4 +59,6 @@ public interface MRConfig {
     7*24*60*60*1000; // 7 days
   
   public static final String FRAMEWORK_NAME  = "mapreduce.framework.name";
+  public static final String TASK_LOCAL_OUTPUT_CLASS =
+  "mapreduce.task.local.output.class";
 }

mapreduce/src/java/org/apache/hadoop/mapreduce/jobhistory/JobHistoryParser.java

@@ -262,6 +262,8 @@ public class JobHistoryParser {
     taskInfo.finishTime = event.getFinishTime();
     taskInfo.error = event.getError();
     taskInfo.failedDueToAttemptId = event.getFailedAttemptID();
+    info.errorInfo = "Task " + taskInfo.taskId +" failed " +
+    taskInfo.attemptsMap.size() + " times ";
   }
 
   private void handleTaskStartedEvent(TaskStartedEvent event) {
@@ -321,6 +323,7 @@ public class JobHistoryParser {
    * The class where job information is aggregated into after parsing
    */
   public static class JobInfo {
+    String errorInfo = "None";
     long submitTime;
     long finishTime;
     JobID jobid;
@@ -406,6 +409,7 @@ public class JobHistoryParser {
     public long getFinishedReduces() { return finishedReduces; }
     /** Get the job status */
     public String getJobStatus() { return jobStatus; }
+    public String getErrorInfo() { return errorInfo; }
     /** Get the counters for the job */
     public Counters getTotalCounters() { return totalCounters; }
     /** Get the map counters for the job */

mapreduce/src/java/org/apache/hadoop/mapreduce/jobhistory/TaskFinishedEvent.java

@@ -67,7 +67,7 @@ public class TaskFinishedEvent implements HistoryEvent {
   /** Get the task finish time */
   public long getFinishTime() { return datum.finishTime; }
   /** Get task counters */
-  Counters getCounters() { return EventReader.fromAvro(datum.counters); }
+  public Counters getCounters() { return EventReader.fromAvro(datum.counters); }
   /** Get task type */
   public TaskType getTaskType() {
     return TaskType.valueOf(datum.taskType.toString());

mapreduce/src/java/org/apache/hadoop/mapreduce/security/TokenCache.java

@@ -34,10 +34,10 @@ import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifie
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.mapred.JobConf;
+import org.apache.hadoop.mapred.JobTracker;
 import org.apache.hadoop.mapreduce.security.token.JobTokenIdentifier;
 import org.apache.hadoop.mapreduce.server.jobtracker.JTConfig;
 import org.apache.hadoop.security.Credentials;
-import org.apache.hadoop.security.KerberosName;
 import org.apache.hadoop.security.SecurityUtil;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.token.Token;
@@ -92,6 +92,13 @@ public class TokenCache {
     }
   }
   
+  static String getJTPrincipal(Configuration conf) throws IOException {
+    String jtHostname = JobTracker.getAddress(conf).getHostName();
+    // get jobtracker principal for use as delegation token renewer
+    return SecurityUtil.getServerPrincipal(conf.get(JTConfig.JT_USER_NAME),
+        jtHostname);
+  }
+  
   /**
    * get delegation token for a specific FS
    * @param fs
@@ -102,12 +109,11 @@ public class TokenCache {
    */
   static void obtainTokensForNamenodesInternal(FileSystem fs, 
       Credentials credentials, Configuration conf) throws IOException {
-
+    String delegTokenRenewer = getJTPrincipal(conf);
-    // get jobtracker principal id (for the renewer)
+    if (delegTokenRenewer == null || delegTokenRenewer.length() == 0) {
-    KerberosName jtKrbName = 
+      throw new IOException(
-      new KerberosName(conf.get(JTConfig.JT_USER_NAME,""));
+          "Can't get JobTracker Kerberos principal for use as renewer");
-    
+    }
-    String delegTokenRenewer = jtKrbName.getShortName();
     boolean readFile = true;
 
     String fsName = fs.getCanonicalServiceName();

mapreduce/src/java/org/apache/hadoop/mapreduce/task/reduce/MergeManager.java

@@ -133,7 +133,7 @@ public class MergeManager<K, V> {
                       Counters.Counter reduceCombineInputCounter,
                       Counters.Counter mergedMapOutputsCounter,
                       ExceptionReporter exceptionReporter,
-                      Progress mergePhase) {
+                      Progress mergePhase, MapOutputFile mapOutputFile) {
     this.reduceId = reduceId;
     this.jobConf = jobConf;
     this.localDirAllocator = localDirAllocator;
@@ -146,7 +146,7 @@ public class MergeManager<K, V> {
     this.reduceCombineInputCounter = reduceCombineInputCounter;
     this.spilledRecordsCounter = spilledRecordsCounter;
     this.mergedMapOutputsCounter = mergedMapOutputsCounter;
-    this.mapOutputFile = new MapOutputFile();
+    this.mapOutputFile = mapOutputFile;
     this.mapOutputFile.setConf(jobConf);
     
     this.localFS = localFS;

mapreduce/src/java/org/apache/hadoop/mapreduce/task/reduce/Shuffle.java

@@ -28,6 +28,7 @@ import org.apache.hadoop.fs.LocalDirAllocator;
 import org.apache.hadoop.io.compress.CompressionCodec;
 import org.apache.hadoop.mapred.Counters;
 import org.apache.hadoop.mapred.JobConf;
+import org.apache.hadoop.mapred.MapOutputFile;
 import org.apache.hadoop.mapred.RawKeyValueIterator;
 import org.apache.hadoop.mapred.Reducer;
 import org.apache.hadoop.mapred.Reporter;
@@ -75,7 +76,8 @@ public class Shuffle<K, V> implements ExceptionReporter {
                  TaskStatus status,
                  Progress copyPhase,
                  Progress mergePhase,
-                 Task reduceTask) {
+                 Task reduceTask,
+                 MapOutputFile mapOutputFile) {
     this.reduceId = reduceId;
     this.jobConf = jobConf;
     this.umbilical = umbilical;
@@ -95,7 +97,7 @@ public class Shuffle<K, V> implements ExceptionReporter {
                                     spilledRecordsCounter, 
                                     reduceCombineInputCounter, 
                                     mergedMapOutputsCounter, 
-                                    this, mergePhase);
+                                    this, mergePhase, mapOutputFile);
   }
 
   @SuppressWarnings("unchecked")

mapreduce/src/test/mapred-site.xml

@@ -48,4 +48,8 @@
   <name>mapreduce.jobtracker.persist.jobstatus.active</name>
   <value>false</value>
 </property>
+<property>
+  <name>mapreduce.task.local.output.class</name>
+  <value>org.apache.hadoop.mapred.MROutputFiles</value>
+</property>
 </configuration>

mapreduce/src/test/mapred/org/apache/hadoop/mapred/TestMapRed.java

@@ -293,7 +293,7 @@ public class TestMapRed extends Configured implements Tool {
                        ) throws IOException {
       if (first) {
         first = false;
-        MapOutputFile mapOutputFile = new MapOutputFile();
+        MapOutputFile mapOutputFile = new MROutputFiles();
         mapOutputFile.setConf(conf);
         Path input = mapOutputFile.getInputFile(0);
         FileSystem fs = FileSystem.get(conf);

mapreduce/src/test/mapred/org/apache/hadoop/mapreduce/security/TestBinaryTokenFile.java

@@ -178,7 +178,7 @@ public class TestBinaryTokenFile {
     jConf = mrCluster.createJobConf();
     
     // provide namenodes names for the job to get the delegation tokens for
-    String nnUri = dfsCluster.getURI().toString();
+    String nnUri = dfsCluster.getURI(0).toString();
     jConf.set(MRJobConfig.JOB_NAMENODES, nnUri + "," + nnUri);
     // job tracker principla id..
     jConf.set(JTConfig.JT_USER_NAME, "jt_id");

mapreduce/src/test/mapred/org/apache/hadoop/mapreduce/security/TestTokenCache.java

@@ -150,6 +150,7 @@ public class TestTokenCache {
   @BeforeClass
   public static void setUp() throws Exception {
     Configuration conf = new Configuration();
+    conf.set("hadoop.security.auth_to_local", "RULE:[2:$1]");
     dfsCluster = new MiniDFSCluster(conf, numSlaves, true, null);
     jConf = new JobConf(conf);
     mrCluster = new MiniMRCluster(0, 0, numSlaves, 
@@ -224,10 +225,10 @@ public class TestTokenCache {
     jConf = mrCluster.createJobConf();
     
     // provide namenodes names for the job to get the delegation tokens for
-    String nnUri = dfsCluster.getURI().toString();
+    String nnUri = dfsCluster.getURI(0).toString();
     jConf.set(MRJobConfig.JOB_NAMENODES, nnUri + "," + nnUri);
     // job tracker principla id..
-    jConf.set(JTConfig.JT_USER_NAME, "jt_id");
+    jConf.set(JTConfig.JT_USER_NAME, "jt_id/foo@BAR");
     
     // using argument to pass the file name
     String[] args = {
@@ -361,4 +362,20 @@ public class TestTokenCache {
     }
   }
 
+  /** 
+   * verify _HOST substitution
+   * @throws IOException
+   */
+  @Test
+  public void testGetJTPrincipal() throws IOException {
+    String serviceName = "jt/";
+    String hostName = "foo";
+    String domainName = "@BAR";
+    Configuration conf = new Configuration();
+    conf.set(JTConfig.JT_IPC_ADDRESS, hostName + ":8888");
+    conf.set(JTConfig.JT_USER_NAME, serviceName + SecurityUtil.HOSTNAME_PATTERN
+        + domainName);
+    assertEquals("Failed to substitute HOSTNAME_PATTERN with hostName",
+        serviceName + hostName + domainName, TokenCache.getJTPrincipal(conf));
+  }
 }

mapreduce/src/test/mapred/org/apache/hadoop/security/TestMapredGroupMappingServiceRefresh.java

@@ -108,7 +108,7 @@ public class TestMapredGroupMappingServiceRefresh {
     cluster = new MiniDFSCluster(0, config, 1, true, true, true,  null, null, 
         null, null);
     cluster.waitActive();
-    URI uri = cluster.getURI();
+    URI uri = cluster.getURI(0);
     
     MiniMRCluster miniMRCluster = new MiniMRCluster(0, uri.toString() , 
       3, null, null, config);

mapreduce/src/webapps/job/jobdetailshistory.jsp

@@ -45,6 +45,7 @@
 <%! static SimpleDateFormat dateFormat = new SimpleDateFormat("d-MMM-yyyy HH:mm:ss") ; %>
 <%
     String logFile = request.getParameter("logFile");
+    String reasonforFailure = " ";
     final Path jobFile = new Path(logFile);
     String jobid = JobHistory.getJobIDFromHistoryFilePath(jobFile).toString();
 
@@ -55,6 +56,8 @@
     if (job == null) {
       return;
     }
+    if (job.getJobStatus().equals("FAILED")) 
+      reasonforFailure = job.getErrorInfo();
 %>
 
 <html>
@@ -78,6 +81,7 @@
 <b>Launched At: </b> <%=StringUtils.getFormattedTimeWithDiff(dateFormat, job.getLaunchTime(), job.getSubmitTime()) %><br/>
 <b>Finished At: </b>  <%=StringUtils.getFormattedTimeWithDiff(dateFormat, job.getFinishTime(), job.getLaunchTime()) %><br/>
 <b>Status: </b> <%= ((job.getJobStatus()) == null ? "Incomplete" :job.getJobStatus()) %><br/> 
+<b>ReasonForFailure: </b> <%=reasonforFailure %><br/>
 <%
     HistoryViewer.SummarizedJob sj = new HistoryViewer.SummarizedJob(job);
 %>