org.apache.flink.runtime.webmonitor.stats

Class TaskStatsRequestCoordinator.PendingStatsRequest<T,V>

java.lang.Object

org.apache.flink.runtime.webmonitor.stats.TaskStatsRequestCoordinator.PendingStatsRequest<T,V>

Type Parameters:

T - Type of the result collected from tasks.

V - Type of the result assembled and returned when all tasks where sampled.

Enclosing class:

TaskStatsRequestCoordinator<T,V>

@NotThreadSafe
protected abstract static class TaskStatsRequestCoordinator.PendingStatsRequest<T,V>
extends Object

A pending task stats request, which collects samples from individual tasks and completes the response future upon gathering all of of them.

Has to be accessed in lock scope.

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	isDiscarded
protected Set<Set<ExecutionAttemptID>>	pendingTasks All tasks what did not yet return a result.
protected int	requestId ID of the sampling request to this coordinator.
protected CompletableFuture<V>	resultFuture The future with the final result.
protected long	startTime The time when the request is created.
protected Map<org.apache.flink.shaded.guava32.com.google.common.collect.ImmutableSet<ExecutionAttemptID>,T>	statsResultByTaskGroup Results returned by individual tasks and stored by the tasks' ExecutionAttemptID.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PendingStatsRequest(int requestId, Collection<? extends Set<ExecutionAttemptID>> tasksToCollect) Creates new TaskStatsRequestCoordinator.PendingStatsRequest.

Method Summary

Modifier and Type	Method and Description
protected abstract V	assembleCompleteStats(long endTime) A method that is called when responses from all tasks were collected successfully.
protected void	checkDiscarded()
protected void	collectTaskStats(org.apache.flink.shaded.guava32.com.google.common.collect.ImmutableSet<ExecutionAttemptID> executionId, T taskStatsResult) Collects result from one of the tasks.
protected void	completePromiseAndDiscard()
protected void	discard(Throwable cause)
CompletableFuture<V>	getStatsFuture() A Future, which will either complete successfully if all of the samples from individual tasks are collected or exceptionally, if at least one of the task responses fails.
protected boolean	isComplete()

Methods inherited from class java.lang.Object

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

Field Detail

requestId

protected final int requestId

ID of the sampling request to this coordinator.

startTime

protected final long startTime

The time when the request is created.

pendingTasks

protected final Set<Set<ExecutionAttemptID>> pendingTasks

All tasks what did not yet return a result.

statsResultByTaskGroup

protected final Map<org.apache.flink.shaded.guava32.com.google.common.collect.ImmutableSet<ExecutionAttemptID>,T> statsResultByTaskGroup

Results returned by individual tasks and stored by the tasks' ExecutionAttemptID.

resultFuture

protected final CompletableFuture<V> resultFuture

The future with the final result.

isDiscarded

protected boolean isDiscarded

Constructor Detail

PendingStatsRequest

protected PendingStatsRequest(int requestId,
                              Collection<? extends Set<ExecutionAttemptID>> tasksToCollect)

Creates new TaskStatsRequestCoordinator.PendingStatsRequest.

Parameters:

requestId - ID of the request.

tasksToCollect - tasks from which the stats responses are expected.

Method Detail

isComplete

protected boolean isComplete()

discard

protected void discard(Throwable cause)

collectTaskStats

protected void collectTaskStats(org.apache.flink.shaded.guava32.com.google.common.collect.ImmutableSet<ExecutionAttemptID> executionId,
                                T taskStatsResult)

Collects result from one of the tasks.

Parameters:

executionId - ID of the Task.

taskStatsResult - Result of the stats sample from the Task.

checkDiscarded

protected void checkDiscarded()

completePromiseAndDiscard

protected void completePromiseAndDiscard()

getStatsFuture

public CompletableFuture<V> getStatsFuture()

A Future, which will either complete successfully if all of the samples from individual tasks are collected or exceptionally, if at least one of the task responses fails.

Returns:

A future with the result of collecting tasks statistics.

assembleCompleteStats

protected abstract V assembleCompleteStats(long endTime)

A method that is called when responses from all tasks were collected successfully. It is responsible for assembling the final result from the individual tasks' samples. Those samples can be accessed via the Map<ExecutionAttemptID, T> statsResultByTask variable.

Parameters:

endTime - The time when the final sample was collected.

Returns:

The final combined result, which will be returned as a future by the CompletableFuture<V> getStatsFuture method