/**
* We lost the task tracker! All task-tracker structures have already been updated. Just process
* the contained tasks and any jobs that might be affected.
*/
void lostTaskTracker(String trackerName) {
LOG.info("Lost tracker '" + trackerName + "'");
TreeSet lostTasks = (TreeSet) trackerToTaskMap.get(trackerName);
trackerToTaskMap.remove(trackerName);
if (lostTasks != null) {
for (Iterator it = lostTasks.iterator(); it.hasNext(); ) {
String taskId = (String) it.next();
TaskInProgress tip = (TaskInProgress) taskidToTIPMap.get(taskId);
// Tell the job to fail the relevant task
JobInProgress job = tip.getJob();
job.failedTask(tip, taskId, trackerName);
}
}
}
/**
* A tracker wants to know if any of its Tasks have been closed (because the job completed,
* whether successfully or not)
*/
public synchronized String pollForTaskWithClosedJob(String taskTracker) {
TreeSet taskIds = (TreeSet) trackerToTaskMap.get(taskTracker);
if (taskIds != null) {
for (Iterator it = taskIds.iterator(); it.hasNext(); ) {
String taskId = (String) it.next();
TaskInProgress tip = (TaskInProgress) taskidToTIPMap.get(taskId);
if (tip.shouldCloseForClosedJob(taskId)) {
//
// This is how the JobTracker ends a task at the TaskTracker.
// It may be successfully completed, or may be killed in
// mid-execution.
//
return taskId;
}
}
}
return null;
}
public synchronized TaskReport[] getReduceTaskReports(String jobid) {
JobInProgress job = (JobInProgress) jobs.get(jobid);
if (job == null) {
return new TaskReport[0];
} else {
Vector reports = new Vector();
Vector completeReduceTasks = job.reportTasksInProgress(false, true);
for (Iterator it = completeReduceTasks.iterator(); it.hasNext(); ) {
TaskInProgress tip = (TaskInProgress) it.next();
reports.add(tip.generateSingleReport());
}
Vector incompleteReduceTasks = job.reportTasksInProgress(false, false);
for (Iterator it = incompleteReduceTasks.iterator(); it.hasNext(); ) {
TaskInProgress tip = (TaskInProgress) it.next();
reports.add(tip.generateSingleReport());
}
return (TaskReport[]) reports.toArray(new TaskReport[reports.size()]);
}
}
/**
* Accept and process a new TaskTracker profile. We might have known about the TaskTracker
* previously, or it might be brand-new. All task-tracker structures have already been updated.
* Just process the contained tasks and any jobs that might be affected.
*/
void updateTaskStatuses(TaskTrackerStatus status) {
for (Iterator it = status.taskReports(); it.hasNext(); ) {
TaskStatus report = (TaskStatus) it.next();
TaskInProgress tip = (TaskInProgress) taskidToTIPMap.get(report.getTaskId());
if (tip == null) {
LOG.info(
"Serious problem. While updating status, cannot find taskid " + report.getTaskId());
} else {
JobInProgress job = tip.getJob();
job.updateTaskStatus(tip, report);
if (report.getRunState() == TaskStatus.SUCCEEDED) {
job.completedTask(tip, report.getTaskId());
} else if (report.getRunState() == TaskStatus.FAILED) {
// Tell the job to fail the relevant task
job.failedTask(tip, report.getTaskId(), status.getTrackerName());
}
}
}
}
/**
* A TaskTracker wants to know the physical locations of completed, but not yet closed, tasks.
* This exists so the reduce task thread can locate map task outputs.
*/
public synchronized MapOutputLocation[] locateMapOutputs(
String taskId, String[][] mapTasksNeeded) {
ArrayList v = new ArrayList();
for (int i = 0; i < mapTasksNeeded.length; i++) {
for (int j = 0; j < mapTasksNeeded[i].length; j++) {
TaskInProgress tip = (TaskInProgress) taskidToTIPMap.get(mapTasksNeeded[i][j]);
if (tip != null && tip.isComplete(mapTasksNeeded[i][j])) {
String trackerId = (String) taskidToTrackerMap.get(mapTasksNeeded[i][j]);
TaskTrackerStatus tracker;
synchronized (taskTrackers) {
tracker = (TaskTrackerStatus) taskTrackers.get(trackerId);
}
v.add(new MapOutputLocation(mapTasksNeeded[i][j], tracker.getHost(), tracker.getPort()));
break;
}
}
}
// randomly shuffle results to load-balance map output requests
Collections.shuffle(v);
return (MapOutputLocation[]) v.toArray(new MapOutputLocation[v.size()]);
}
///////////////////////////////////////////////////////
// Maintain lookup tables; called by JobInProgress
// and TaskInProgress
///////////////////////////////////////////////////////
void createTaskEntry(String taskid, String taskTracker, TaskInProgress tip) {
LOG.info(
"Adding task '"
+ taskid
+ "' to tip "
+ tip.getTIPId()
+ ", for tracker '"
+ taskTracker
+ "'");
// taskid --> tracker
taskidToTrackerMap.put(taskid, taskTracker);
// tracker --> taskid
TreeSet taskset = (TreeSet) trackerToTaskMap.get(taskTracker);
if (taskset == null) {
taskset = new TreeSet();
trackerToTaskMap.put(taskTracker, taskset);
}
taskset.add(taskid);
// taskid --> TIP
taskidToTIPMap.put(taskid, tip);
}
private void printFailedAttempts(
JspWriter out,
JobTracker tracker,
JobID jobId,
TaskInProgress tip,
TaskStatus.State failState)
throws IOException {
TaskStatus[] statuses = tip.getTaskStatuses();
TaskID tipId = tip.getTIPId();
for (int i = 0; i < statuses.length; ++i) {
TaskStatus.State taskState = statuses[i].getRunState();
if ((failState == null
&& (taskState == TaskStatus.State.FAILED || taskState == TaskStatus.State.KILLED))
|| taskState == failState) {
String taskTrackerName = statuses[i].getTaskTracker();
TaskTrackerStatus taskTracker = tracker.getTaskTrackerStatus(taskTrackerName);
out.print(
"<tr><td>"
+ statuses[i].getTaskID()
+ "</td><td><a href=\"taskdetails.jsp?jobid="
+ jobId
+ "&tipid="
+ tipId
+ "\">"
+ tipId
+ "</a></td>");
if (taskTracker == null) {
out.print("<td>" + taskTrackerName + "</td>");
} else {
out.print(
"<td><a href=\"http://"
+ taskTracker.getHost()
+ ":"
+ taskTracker.getHttpPort()
+ "\">"
+ taskTracker.getHost()
+ "</a></td>");
}
out.print("<td>" + taskState + "</td>");
out.print("<td><pre>");
String[] failures = tracker.getTaskDiagnostics(statuses[i].getTaskID());
if (failures == null) {
out.print(" ");
} else {
for (int j = 0; j < failures.length; j++) {
out.print(failures[j]);
if (j < (failures.length - 1)) {
out.print("\n-------\n");
}
}
}
out.print("</pre></td>");
out.print("<td>");
String taskLogUrl = null;
if (taskTracker != null) {
taskLogUrl =
TaskLogServlet.getTaskLogUrl(
taskTracker.getHost(),
String.valueOf(taskTracker.getHttpPort()),
statuses[i].getTaskID().toString());
}
if (taskLogUrl != null) {
String tailFourKBUrl = taskLogUrl + "&start=-4097";
String tailEightKBUrl = taskLogUrl + "&start=-8193";
String entireLogUrl = taskLogUrl;
out.print("<a href=\"" + tailFourKBUrl + "\">Last 4KB</a><br/>");
out.print("<a href=\"" + tailEightKBUrl + "\">Last 8KB</a><br/>");
out.print("<a href=\"" + entireLogUrl + "\">All</a><br/>");
} else {
out.print("n/a"); // task tracker was lost
}
out.print("</td>");
out.print("</tr>\n");
}
}
}