public void testJobRetire() throws Exception {
    MiniMRCluster mr = null;
    try {
      JobConf conf = new JobConf();
      mr = startCluster(conf, 1);

      JobConf jobConf = mr.createJobConf();
      JobTracker jobtracker = mr.getJobTrackerRunner().getJobTracker();

      Path inDir = new Path(testDir, "input1");
      Path outDir = new Path(testDir, "output1");

      JobID id1 = validateJobRetire(jobConf, inDir, outDir, jobtracker);

      outDir = new Path(testDir, "output2");
      JobID id2 = validateJobRetire(jobConf, inDir, outDir, jobtracker);

      assertNull("Job not removed from cache", jobtracker.getJobStatus(id1));

      assertEquals("Total job in cache not correct", 1, jobtracker.getAllJobs().length);
    } finally {
      if (mr != null) {
        mr.shutdown();
      }
      FileUtil.fullyDelete(new File(testDir.toString()));
    }
  }
  /** (Mock)Test JobTracker.removeJobTasks() which is called only when the job retires. */
  public void testJobRemoval() throws Exception {
    MiniMRCluster mr = null;
    try {
      JobConf conf = new JobConf();
      mr = startCluster(conf, 0);
      JobTracker jobtracker = mr.getJobTrackerRunner().getJobTracker();

      // test map task removal
      testRemoveJobTasks(jobtracker, conf, TaskType.MAP);
      // test reduce task removal
      testRemoveJobTasks(jobtracker, conf, TaskType.REDUCE);
      // test job setup removal
      testRemoveJobTasks(jobtracker, conf, TaskType.JOB_SETUP);
      // test job cleanup removal
      testRemoveJobTasks(jobtracker, conf, TaskType.JOB_CLEANUP);
    } finally {
      if (mr != null) {
        mr.shutdown();
      }
      // cleanup
      FileUtil.fullyDelete(new File(testDir.toString()));
    }
  }
  /** Check refreshNodes for decommissioning blacklisted nodes. */
  public void testBlacklistedNodeDecommissioning() throws Exception {
    LOG.info("Testing blacklisted node decommissioning");
    MiniMRCluster mr = null;
    JobTracker jt = null;

    try {
      // start mini mr
      JobConf jtConf = new JobConf();
      jtConf.set("mapred.max.tracker.blacklists", "1");
      mr = new MiniMRCluster(0, 0, 2, "file:///", 1, null, null, null, jtConf);
      jt = mr.getJobTrackerRunner().getJobTracker();

      assertEquals("Trackers not up", 2, jt.taskTrackers().size());
      // validate the total tracker count
      assertEquals(
          "Active tracker count mismatch", 2, jt.getClusterStatus(false).getTaskTrackers());
      // validate blacklisted count
      assertEquals(
          "Blacklisted tracker count mismatch",
          0,
          jt.getClusterStatus(false).getBlacklistedTrackers());

      // run a failing job to blacklist the tracker
      JobConf jConf = mr.createJobConf();
      jConf.set("mapred.max.tracker.failures", "1");
      jConf.setJobName("test-job-fail-once");
      jConf.setMapperClass(FailOnceMapper.class);
      jConf.setReducerClass(IdentityReducer.class);
      jConf.setNumMapTasks(1);
      jConf.setNumReduceTasks(0);

      RunningJob job =
          UtilsForTests.runJob(jConf, new Path(TEST_DIR, "in"), new Path(TEST_DIR, "out"));
      job.waitForCompletion();

      // validate the total tracker count
      assertEquals(
          "Active tracker count mismatch", 1, jt.getClusterStatus(false).getTaskTrackers());
      // validate blacklisted count
      assertEquals(
          "Blacklisted tracker count mismatch",
          1,
          jt.getClusterStatus(false).getBlacklistedTrackers());

      // find the blacklisted tracker
      String trackerName = null;
      for (TaskTrackerStatus status : jt.taskTrackers()) {
        if (jt.isBlacklisted(status.getTrackerName())) {
          trackerName = status.getTrackerName();
          break;
        }
      }
      // get the hostname
      String hostToDecommission = JobInProgress.convertTrackerNameToHostName(trackerName);
      LOG.info("Decommissioning tracker " + hostToDecommission);

      // decommission the node
      HashSet<String> decom = new HashSet<String>(1);
      decom.add(hostToDecommission);
      jt.decommissionNodes(decom);

      // validate
      // check the cluster status and tracker size
      assertEquals(
          "Tracker is not lost upon host decommissioning",
          1,
          jt.getClusterStatus(false).getTaskTrackers());
      assertEquals(
          "Blacklisted tracker count incorrect in cluster status " + "after decommissioning",
          0,
          jt.getClusterStatus(false).getBlacklistedTrackers());
      assertEquals("Tracker is not lost upon host decommissioning", 1, jt.taskTrackers().size());
    } finally {
      if (mr != null) {
        mr.shutdown();
        mr = null;
        jt = null;
        FileUtil.fullyDelete(new File(TEST_DIR.toString()));
      }
    }
  }
  /**
   * Test job retire with tasks that report their *first* status only after the job retires. Steps :
   * - Start a mini-mr cluster with 1 task-tracker having only map slots. Note that this
   * task-tracker will take care of setup/cleanup and the map tasks. - Submit a job with 1 map task
   * and 1 reduce task - Wait for the job to finish the map task - Start a 2nd tracker that waits
   * for a long time after contacting the JT. - Wait for the 2nd tracker to get stuck - Kill the job
   * - Wait for the job to retire - Check if the tip mappings are cleaned up.
   */
  public void testJobRetireWithUnreportedTasks() throws Exception {
    MiniMRCluster mr = null;
    try {
      JobConf conf = new JobConf();
      // set the num-map-slots to 1 so that no reduce tasks but setup/cleanup
      // can run on it
      conf.setInt("mapred.tasktracker.map.tasks.maximum", 1);
      conf.setInt("mapred.tasktracker.reduce.tasks.maximum", 0);

      mr = startCluster(conf, 1);
      JobTracker jobtracker = mr.getJobTrackerRunner().getJobTracker();

      RunningJob job =
          UtilsForTests.runJob(
              mr.createJobConf(), new Path(testDir, "in-1"), new Path(testDir, "out-1"), 1, 1);
      JobID id = JobID.downgrade(job.getID());
      JobInProgress jip = jobtracker.getJob(id);

      // wait 100 secs for the job to complete its map task
      for (int i = 0; i < 1000 && jip.finishedMaps() < 1; i++) {
        UtilsForTests.waitFor(100);
      }
      assertEquals(jip.finishedMaps(), 1);

      // start a tracker that will wait
      LOG.info("Adding a waiting tracker");
      TaskTrackerRunner testTrackerRunner =
          mr.new TaskTrackerRunner(1, 1, null, mr.createJobConf()) {
            @Override
            TaskTracker createTaskTracker(JobConf conf) throws InterruptedException, IOException {
              return new WaitingTaskTracker(conf);
            }
          };
      mr.addTaskTracker(testTrackerRunner);
      LOG.info("Waiting tracker added");

      WaitingTaskTracker testTT = (WaitingTaskTracker) testTrackerRunner.getTaskTracker();

      // wait 100 secs for the newly started task-tracker to join
      for (int i = 0; i < 1000 && jobtracker.taskTrackers().size() < 2; i++) {
        UtilsForTests.waitFor(100);
      }
      assertEquals(jobtracker.taskTrackers().size(), 2);
      LOG.info("Cluster is now up with 2 trackers");
      // stop the test-tt as its no longer required
      mr.stopTaskTracker(mr.getTaskTrackerID(testTT.getName()));

      // 1 reduce task should be scheduled
      assertEquals("TestTT contacted but no reduce task scheduled on it", 1, jip.runningReduces());

      // kill the job
      LOG.info("Killing job " + id);
      job.killJob();

      // check if the reduce task attempt status is missing
      TaskInProgress tip = jip.getTasks(TaskType.REDUCE)[0];
      assertNull(tip.getTaskStatus(tip.getAllTaskAttemptIDs()[0]));

      // wait for the job to retire
      waitTillRetire(id, jobtracker);

      // check the taskidToTIPMap
      for (TaskAttemptID tid : jobtracker.taskidToTIPMap.keySet()) {
        LOG.info("TaskidToTIP : " + tid);
      }
      assertEquals("'taskid' to TIP mapping still exists", 0, jobtracker.taskidToTIPMap.size());
    } finally {
      if (mr != null) {
        mr.shutdown();
      }
      // cleanup
      FileUtil.fullyDelete(new File(testDir.toString()));
    }
  }