commit d31ea1a98e2c16c9a9afc9beb9d63568fe32f81e

Author: Arun C Murthy <acmurthy@apache.org>
Date:   Mon Sep 28 13:36:31 2009 -0700

    MAPREDUCE-964. Fixed start and finish times of TaskStatus to be consistent, thereby fixing inconsistencies in metering tasks. Contributed by Sreekanth Ramakrishnan.
    
    from: http://issues.apache.org/jira/secure/attachment/12420539/mapreduce-964-ydist.patch
    
    +++ b/YAHOO-CHANGES.txt
    +57. MAPREDUCE-964. Fixed start and finish times of TaskStatus to be
    +    consistent, thereby fixing inconsistencies in metering tasks.
    +    Contributed by Sreekanth Ramakrishnan.
    +


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20-security-patches@1077006 13f79535-47bb-0310-9956-ffa450edef68

src/mapred/org/apache/hadoop/mapred/TaskStatus.java

@@ -27,6 +27,7 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.io.WritableUtils;
+import org.apache.hadoop.util.StringUtils;
 /**************************************************
  * Describes the current status of a task.  This is
  * not intended to be a comprehensive piece of data.
@@ -130,12 +131,23 @@ abstract class TaskStatus implements Writable, Cloneable {
   }
 
   /**
-   * Sets finishTime. 
+   * Sets finishTime for the task status if and only if the
+   * start time is set and passed finish time is greater than
+   * zero.
+   * 
    * @param finishTime finish time of task.
    */
   void setFinishTime(long finishTime) {
-    this.finishTime = finishTime;
+    if(this.getStartTime() > 0 && finishTime > 0) {
+      this.finishTime = finishTime;
+    } else {
+      //Using String utils to get the stack trace.
+      LOG.error("Trying to set finish time for task " + taskid + 
+          " when no start time is set, stackTrace is : " + 
+          StringUtils.stringifyException(new Exception()));
+    }
   }
+  
   /**
    * Get shuffle finish time for the task. If shuffle finish time was 
    * not set due to shuffle/sort/finish phases ending within same
@@ -181,12 +193,22 @@ abstract class TaskStatus implements Writable, Cloneable {
   }
 
   /**
-   * Set startTime of the task.
+   * Set startTime of the task if start time is greater than zero.
    * @param startTime start time
    */
   void setStartTime(long startTime) {
-    this.startTime = startTime;
+    //Making the assumption of passed startTime to be a positive
+    //long value explicit.
+    if (startTime > 0) {
+      this.startTime = startTime;
+    } else {
+      //Using String utils to get the stack trace.
+      LOG.error("Trying to set illegal startTime for task : " + taskid +
+          ".Stack trace is : " +
+          StringUtils.stringifyException(new Exception()));
+    }
   }
+  
   /**
    * Get current phase of this task. Phase.Map in case of map tasks, 
    * for reduce one of Phase.SHUFFLE, Phase.SORT or Phase.REDUCE. 
@@ -301,11 +323,11 @@ abstract class TaskStatus implements Writable, Cloneable {
 
     setDiagnosticInfo(status.getDiagnosticInfo());
     
-    if (status.getStartTime() != 0) {
+    if (status.getStartTime() > 0) {
       this.startTime = status.getStartTime(); 
     }
-    if (status.getFinishTime() != 0) {
-      this.finishTime = status.getFinishTime(); 
+    if (status.getFinishTime() > 0) {
+      setFinishTime(status.getFinishTime()); 
     }
     
     this.phase = status.getPhase();
@@ -334,8 +356,8 @@ abstract class TaskStatus implements Writable, Cloneable {
     setProgress(progress);
     setStateString(state);
     setPhase(phase);
-    if (finishTime != 0) {
-      this.finishTime = finishTime; 
+    if (finishTime > 0) {
+      setFinishTime(finishTime); 
     }
   }
 

src/test/org/apache/hadoop/mapred/TestTaskStatus.java

@@ -0,0 +1,71 @@
+/**
+ * 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 junit.framework.TestCase;
+
+public class TestTaskStatus extends TestCase {
+
+  public void testMapTaskStatusStartAndFinishTimes() {
+    checkTaskStatues(true);
+  }
+
+  public void testReduceTaskStatusStartAndFinishTimes() {
+    checkTaskStatues(false);
+  }
+
+  /**
+   * Private utility method which ensures uniform testing of newly created
+   * TaskStatus object.
+   * 
+   * @param isMap
+   *          true to test map task status, false for reduce.
+   */
+  private void checkTaskStatues(boolean isMap) {
+
+    TaskStatus status = null;
+    if (isMap) {
+      status = new MapTaskStatus();
+    } else {
+      status = new ReduceTaskStatus();
+    }
+    long currentTime = System.currentTimeMillis();
+    // first try to set the finish time before
+    // start time is set.
+    status.setFinishTime(currentTime);
+    assertEquals("Finish time of the task status set without start time", 0,
+        status.getFinishTime());
+    // Now set the start time to right time.
+    status.setStartTime(currentTime);
+    assertEquals("Start time of the task status not set correctly.",
+        currentTime, status.getStartTime());
+    // try setting wrong start time to task status.
+    long wrongTime = -1;
+    status.setStartTime(wrongTime);
+    assertEquals(
+        "Start time of the task status is set to wrong negative value",
+        currentTime, status.getStartTime());
+    // finally try setting wrong finish time i.e. negative value.
+    status.setFinishTime(wrongTime);
+    assertEquals("Finish time of task status is set to wrong negative value",
+        0, status.getFinishTime());
+    status.setFinishTime(currentTime);
+    assertEquals("Finish time of the task status not set correctly.",
+        currentTime, status.getFinishTime());
+  }
+}