org.apache.hadoop.mapreduce.v2.app.speculate

Class NullTaskRuntimesEngine

java.lang.Object

org.apache.hadoop.mapreduce.v2.app.speculate.NullTaskRuntimesEngine

All Implemented Interfaces:

TaskRuntimeEstimator

public class NullTaskRuntimesEngine
extends Object
implements TaskRuntimeEstimator

Constructor Summary

Constructors

Constructor and Description
NullTaskRuntimesEngine()

Method Summary

Methods

Modifier and Type	Method and Description
long	attemptEnrolledTime(TaskAttemptId attemptID)
void	contextualize(Configuration conf, AppContext context)
void	enrollAttempt(TaskAttemptStatusUpdateEvent.TaskAttemptStatus status, long timestamp)
long	estimatedNewAttemptRuntime(TaskId id) Estimates how long a new attempt on this task will take if we start one now
long	estimatedRuntime(TaskAttemptId id) Estimate a task attempt's total runtime.
long	runtimeEstimateVariance(TaskAttemptId id) Computes the width of the error band of our estimate of the task runtime as returned by TaskRuntimeEstimator.estimatedRuntime(TaskAttemptId)
long	thresholdRuntime(TaskId id) Find a maximum reasonable execution wallclock time.
void	updateAttempt(TaskAttemptStatusUpdateEvent.TaskAttemptStatus status, long timestamp)

Methods inherited from class java.lang.Object

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

Constructor Detail

NullTaskRuntimesEngine

public NullTaskRuntimesEngine()

Method Detail

enrollAttempt

public void enrollAttempt(TaskAttemptStatusUpdateEvent.TaskAttemptStatus status,
                 long timestamp)

Specified by:

enrollAttempt in interface TaskRuntimeEstimator

attemptEnrolledTime

public long attemptEnrolledTime(TaskAttemptId attemptID)

Specified by:

attemptEnrolledTime in interface TaskRuntimeEstimator

updateAttempt

public void updateAttempt(TaskAttemptStatusUpdateEvent.TaskAttemptStatus status,
                 long timestamp)

Specified by:

updateAttempt in interface TaskRuntimeEstimator

contextualize

public void contextualize(Configuration conf,
                 AppContext context)

Specified by:

contextualize in interface TaskRuntimeEstimator

thresholdRuntime

public long thresholdRuntime(TaskId id)

Description copied from interface: TaskRuntimeEstimator

Find a maximum reasonable execution wallclock time. Includes the time already elapsed. Find a maximum reasonable execution time. Includes the time already elapsed. If the projected total execution time for this task ever exceeds its reasonable execution time, we may speculate it.

Specified by:

thresholdRuntime in interface TaskRuntimeEstimator

Parameters:

id - the TaskId of the task we are asking about

Returns:

the task's maximum reasonable runtime, or MAX_VALUE if we don't have enough information to rule out any runtime, however long.

estimatedRuntime

public long estimatedRuntime(TaskAttemptId id)

Description copied from interface: TaskRuntimeEstimator

Estimate a task attempt's total runtime. Includes the time already elapsed.

Specified by:

estimatedRuntime in interface TaskRuntimeEstimator

Parameters:

id - the TaskAttemptId of the attempt we are asking about

Returns:

our best estimate of the attempt's runtime, or -1 if we don't have enough information yet to produce an estimate.

estimatedNewAttemptRuntime

public long estimatedNewAttemptRuntime(TaskId id)

Description copied from interface: TaskRuntimeEstimator

Estimates how long a new attempt on this task will take if we start one now

Specified by:

estimatedNewAttemptRuntime in interface TaskRuntimeEstimator

Parameters:

id - the TaskId of the task we are asking about

Returns:

our best estimate of a new attempt's runtime, or -1 if we don't have enough information yet to produce an estimate.

runtimeEstimateVariance

public long runtimeEstimateVariance(TaskAttemptId id)

Description copied from interface: TaskRuntimeEstimator

Computes the width of the error band of our estimate of the task runtime as returned by TaskRuntimeEstimator.estimatedRuntime(TaskAttemptId)

Specified by:

runtimeEstimateVariance in interface TaskRuntimeEstimator

Parameters:

id - the TaskAttemptId of the attempt we are asking about

Returns:

our best estimate of the attempt's runtime, or -1 if we don't have enough information yet to produce an estimate.