org.apache.hadoop.mapreduce.server.jobtracker
Class TaskTracker

java.lang.Object
  org.apache.hadoop.mapreduce.server.jobtracker.TaskTracker

public class TaskTracker
extends Object

The representation of a single TaskTracker as seen by the JobTracker.

Constructor Summary

TaskTracker(String trackerName)
Create a new TaskTracker.

Method Summary

void	cancelAllReservations() Cleanup when the TaskTracker is declared as 'lost/blacklisted' by the JobTracker.
int	getAvailableSlots(TaskType taskType) Get the number of currently available slots on this tasktracker for the given type of the task.
JobInProgress	getJobForFallowSlot(TaskType taskType) Get the JobInProgress for which the fallow slot(s) are held.
TaskTrackerStatus	getStatus() Get the current TaskTrackerStatus of the TaskTracker.
String	getTrackerName() Get the unique identifier for the TaskTracker
void	reserveSlots(TaskType taskType, JobInProgress job, int numSlots) Reserve specified number of slots for a given job.
void	setStatus(TaskTrackerStatus status) Set the current TaskTrackerStatus of the TaskTracker.
void	unreserveSlots(TaskType taskType, JobInProgress job) Free map slots on this TaskTracker which were reserved for taskType.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TaskTracker

public TaskTracker(String trackerName)

Create a new TaskTracker.

Parameters:

trackerName - Unique identifier for the TaskTracker

Method Detail

getTrackerName

public String getTrackerName()

Get the unique identifier for the TaskTracker

Returns:

the unique identifier for the TaskTracker

getStatus

public TaskTrackerStatus getStatus()

Get the current TaskTrackerStatus of the TaskTracker.

Returns:

the current TaskTrackerStatus of the TaskTracker

setStatus

public void setStatus(TaskTrackerStatus status)

Set the current TaskTrackerStatus of the TaskTracker.

Parameters:

status - the current TaskTrackerStatus of the TaskTracker

getAvailableSlots

public int getAvailableSlots(TaskType taskType)

Get the number of currently available slots on this tasktracker for the given type of the task.

Parameters:

taskType - the TaskType to check for number of available slots

Returns:

the number of currently available slots for the given taskType

getJobForFallowSlot

public JobInProgress getJobForFallowSlot(TaskType taskType)

Get the JobInProgress for which the fallow slot(s) are held.

Parameters:

taskType - TaskType of the task

Returns:

the task for which the fallow slot(s) are held, null if there are no fallow slots

reserveSlots

public void reserveSlots(TaskType taskType,
                         JobInProgress job,
                         int numSlots)

Reserve specified number of slots for a given job.

Parameters:

taskType - TaskType of the task

job - the job for which slots on this TaskTracker are to be reserved

numSlots - number of slots to be reserved

unreserveSlots

public void unreserveSlots(TaskType taskType,
                           JobInProgress job)

Free map slots on this TaskTracker which were reserved for taskType.

Parameters:

taskType - TaskType of the task

job - job whose slots are being un-reserved

cancelAllReservations

public void cancelAllReservations()

Cleanup when the TaskTracker is declared as 'lost/blacklisted' by the JobTracker. The method assumes that the lock on the JobTracker is obtained by the caller.