MAPREDUCE-5568. Fixed CompletedJob in JHS to show progress percentage correctly in case the number of mappers or reducers is zero. Contributed by MinJi Kim

(cherry picked from commit 78f7cdbfd6)

hadoop-mapreduce-project/CHANGES.txt

@@ -24,6 +24,10 @@ Release 2.7.0 - UNRELEASED
     MAPREDUCE-6049. AM JVM does not exit if MRClientService graceful shutdown
     fails (Rohith via devaraj)
 
+    MAPREDUCE-5568. Fixed CompletedJob in JHS to show progress percentage
+    correctly in case the number of mappers or reducers is zero. (MinJi Kim via
+    jianhe)
+ 
 Release 2.6.0 - 2014-11-18
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-hs/src/main/java/org/apache/hadoop/mapreduce/v2/hs/CompletedJob.java

@@ -141,8 +141,18 @@ public class CompletedJob implements org.apache.hadoop.mapreduce.v2.app.job.Job
     report.setFinishTime(jobInfo.getFinishTime());
     report.setJobName(jobInfo.getJobname());
     report.setUser(jobInfo.getUsername());
-    report.setMapProgress((float) getCompletedMaps() / getTotalMaps());
-    report.setReduceProgress((float) getCompletedReduces() / getTotalReduces());
+
+    if ( getTotalMaps() == 0 ) {
+      report.setMapProgress(1.0f);
+    } else {
+      report.setMapProgress((float) getCompletedMaps() / getTotalMaps());
+    }
+    if ( getTotalReduces() == 0 ) {
+      report.setReduceProgress(1.0f);
+    } else {
+      report.setReduceProgress((float) getCompletedReduces() / getTotalReduces());
+    }
+
     report.setJobFile(getConfFile().toString());
     String historyUrl = "N/A";
     try {

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-hs/src/test/java/org/apache/hadoop/mapreduce/v2/hs/TestJobHistoryEntities.java

@@ -55,14 +55,19 @@ public class TestJobHistoryEntities {
 
   private final String historyFileName =
       "job_1329348432655_0001-1329348443227-user-Sleep+job-1329348468601-10-1-SUCCEEDED-default.jhist";
+  private final String historyFileNameZeroReduceTasks =
+    "job_1416424547277_0002-1416424775281-root-TeraGen-1416424785433-2-0-SUCCEEDED-default-1416424779349.jhist";
   private final String confFileName = "job_1329348432655_0001_conf.xml";
   private final Configuration conf = new Configuration();
   private final JobACLsManager jobAclsManager = new JobACLsManager(conf);
   private boolean loadTasks;
   private JobId jobId = MRBuilderUtils.newJobId(1329348432655l, 1, 1);
-  Path fulleHistoryPath =
+  Path fullHistoryPath =
     new Path(this.getClass().getClassLoader().getResource(historyFileName)
         .getFile());
+  Path fullHistoryPathZeroReduces =
+    new Path(this.getClass().getClassLoader().getResource(historyFileNameZeroReduceTasks)
+        .getFile());
   Path fullConfPath =
     new Path(this.getClass().getClassLoader().getResource(confFileName)
         .getFile());
@@ -87,7 +92,7 @@ public class TestJobHistoryEntities {
     when(info.getConfFile()).thenReturn(fullConfPath);
     //Re-initialize to verify the delayed load.
     completedJob =
-      new CompletedJob(conf, jobId, fulleHistoryPath, loadTasks, "user",
+      new CompletedJob(conf, jobId, fullHistoryPath, loadTasks, "user",
           info, jobAclsManager);
     //Verify tasks loaded based on loadTask parameter.
     assertEquals(loadTasks, completedJob.tasksLoaded.get());
@@ -106,12 +111,27 @@ public class TestJobHistoryEntities {
     assertEquals(JobState.SUCCEEDED, jobReport.getJobState());
   }
   
+  @Test (timeout=100000)
+  public void testCopmletedJobReportWithZeroTasks() throws Exception {
+    HistoryFileInfo info = mock(HistoryFileInfo.class);
+    when(info.getConfFile()).thenReturn(fullConfPath);
+    completedJob =
+      new CompletedJob(conf, jobId, fullHistoryPathZeroReduces, loadTasks, "user",
+          info, jobAclsManager);
+    JobReport jobReport = completedJob.getReport();
+    // Make sure that the number reduces (completed and total) are equal to zero.
+    assertEquals(0, completedJob.getTotalReduces());
+    assertEquals(0, completedJob.getCompletedReduces());
+    // Verify that the reduce progress is 1.0 (not NaN)
+    assertEquals(1.0, jobReport.getReduceProgress(), 0.001);
+  }
+
   @Test (timeout=10000)
   public void testCompletedTask() throws Exception {
     HistoryFileInfo info = mock(HistoryFileInfo.class);
     when(info.getConfFile()).thenReturn(fullConfPath);
     completedJob =
-      new CompletedJob(conf, jobId, fulleHistoryPath, loadTasks, "user",
+      new CompletedJob(conf, jobId, fullHistoryPath, loadTasks, "user",
           info, jobAclsManager);
     TaskId mt1Id = MRBuilderUtils.newTaskId(jobId, 0, TaskType.MAP);
     TaskId rt1Id = MRBuilderUtils.newTaskId(jobId, 0, TaskType.REDUCE);
@@ -140,7 +160,7 @@ public class TestJobHistoryEntities {
     HistoryFileInfo info = mock(HistoryFileInfo.class);
     when(info.getConfFile()).thenReturn(fullConfPath);
     completedJob =
-      new CompletedJob(conf, jobId, fulleHistoryPath, loadTasks, "user",
+      new CompletedJob(conf, jobId, fullHistoryPath, loadTasks, "user",
           info, jobAclsManager);
     TaskId mt1Id = MRBuilderUtils.newTaskId(jobId, 0, TaskType.MAP);
     TaskId rt1Id = MRBuilderUtils.newTaskId(jobId, 0, TaskType.REDUCE);
@@ -179,7 +199,7 @@ public class TestJobHistoryEntities {
     HistoryFileInfo info = mock(HistoryFileInfo.class);
     when(info.getConfFile()).thenReturn(fullConfPath);
     completedJob =
-      new CompletedJob(conf, jobId, fulleHistoryPath, loadTasks, "user",
+      new CompletedJob(conf, jobId, fullHistoryPath, loadTasks, "user",
           info, jobAclsManager);
     TaskCompletionEvent[] events= completedJob.getMapAttemptCompletionEvents(0,1000);
     assertEquals(10, completedJob.getMapAttemptCompletionEvents(0,10).length);