org.apache.flink.runtime.webmonitor.stats

Class TaskStatsRequestCoordinator<T,V>

java.lang.Object

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

Type Parameters:

T - Type of the statistics to be gathered.

V - Type of the combined response.

Direct Known Subclasses:

ThreadInfoRequestCoordinator

public class TaskStatsRequestCoordinator<T,V>
extends Object

Encapsulates the common functionality for requesting statistics from tasks and combining their responses.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	TaskStatsRequestCoordinator.PendingStatsRequest<T,V> A pending task stats request, which collects samples from individual tasks and completes the response future upon gathering all of of them.

Field Summary

Fields

Modifier and Type	Field and Description
protected Executor	executor Executor used to run the futures.
protected boolean	isShutDown Flag indicating whether the coordinator is still running.
protected Object	lock
protected org.slf4j.Logger	log
protected static int	NUM_GHOST_SAMPLE_IDS
protected Map<Integer,TaskStatsRequestCoordinator.PendingStatsRequest<T,V>>	pendingRequests In progress samples.
protected ArrayDeque<Integer>	recentPendingRequestIds A list of recent request IDs to identify late messages vs. invalid ones.
protected int	requestIdCounter Sample ID counter.
protected Duration	requestTimeout Request time out of the triggered tasks stats request.

Constructor Summary

Constructors

Constructor and Description
TaskStatsRequestCoordinator(Executor executor, Duration requestTimeout) Creates a new coordinator for the cluster.

Method Summary

Modifier and Type	Method and Description
int	getNumberOfPendingRequests()
void	handleFailedResponse(int requestId, Throwable cause) Handles the failed stats response by canceling the corresponding unfinished pending request.
void	handleSuccessfulResponse(int requestId, org.apache.flink.shaded.guava32.com.google.common.collect.ImmutableSet<ExecutionAttemptID> executionIds, T result) Handles the successfully returned tasks stats response by collecting the corresponding subtask samples.
void	shutDown() Shuts down the coordinator.

Methods inherited from class java.lang.Object

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

Field Detail

log

protected final org.slf4j.Logger log

NUM_GHOST_SAMPLE_IDS

protected static final int NUM_GHOST_SAMPLE_IDS

See Also:

Constant Field Values

lock

protected final Object lock

executor

protected final Executor executor

Executor used to run the futures.

requestTimeout

protected final Duration requestTimeout

Request time out of the triggered tasks stats request.

pendingRequests

protected final Map<Integer,TaskStatsRequestCoordinator.PendingStatsRequest<T,V>> pendingRequests

In progress samples.

recentPendingRequestIds

protected final ArrayDeque<Integer> recentPendingRequestIds

A list of recent request IDs to identify late messages vs. invalid ones.

requestIdCounter

protected int requestIdCounter

Sample ID counter.

isShutDown

protected boolean isShutDown

Flag indicating whether the coordinator is still running.

Constructor Detail

TaskStatsRequestCoordinator

public TaskStatsRequestCoordinator(Executor executor,
                                   Duration requestTimeout)

Creates a new coordinator for the cluster.

Parameters:

executor - Used to execute the futures.

requestTimeout - Request time out of the triggered tasks stats request.

Method Detail

handleFailedResponse

public void handleFailedResponse(int requestId,
                                 @Nullable
                                 Throwable cause)

Handles the failed stats response by canceling the corresponding unfinished pending request.

Parameters:

requestId - ID of the request to cancel.

cause - Cause of the cancelling (can be null).

shutDown

public void shutDown()

Shuts down the coordinator.

After shut down, no further operations are executed.

handleSuccessfulResponse

public void handleSuccessfulResponse(int requestId,
                                     org.apache.flink.shaded.guava32.com.google.common.collect.ImmutableSet<ExecutionAttemptID> executionIds,
                                     T result)

Handles the successfully returned tasks stats response by collecting the corresponding subtask samples.

Parameters:

requestId - ID of the request.

executionIds - ID of the sampled task.

result - Result of stats request returned by an individual task.

Throws:

IllegalStateException - If unknown request ID and not recently finished or cancelled sample.

getNumberOfPendingRequests

@VisibleForTesting
public int getNumberOfPendingRequests()