org.apache.flink.runtime.rest.handler.legacy.backpressure

Class StackTraceSampleCoordinator

java.lang.Object

org.apache.flink.runtime.rest.handler.legacy.backpressure.StackTraceSampleCoordinator

public class StackTraceSampleCoordinator
extends Object

A coordinator for triggering and collecting stack traces of running tasks.

Constructor Summary

Constructors

Constructor and Description
StackTraceSampleCoordinator(Executor executor, long sampleTimeout) Creates a new coordinator for the job.

Method Summary

Modifier and Type	Method and Description
void	cancelStackTraceSample(int sampleId, Throwable cause) Cancels a pending sample.
void	collectStackTraces(int sampleId, ExecutionAttemptID executionId, List<StackTraceElement[]> stackTraces) Collects stack traces of a task.
void	shutDown() Shuts down the coordinator.
CompletableFuture<StackTraceSample>	triggerStackTraceSample(ExecutionVertex[] tasksToSample, int numSamples, org.apache.flink.api.common.time.Time delayBetweenSamples, int maxStackTraceDepth) Triggers a stack trace sample to all tasks.

Methods inherited from class java.lang.Object

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

Constructor Detail

StackTraceSampleCoordinator

public StackTraceSampleCoordinator(Executor executor,
                                   long sampleTimeout)

Creates a new coordinator for the job.

Parameters:

executor - to use to execute the futures

sampleTimeout - Time out after the expected sampling duration. This is added to the expected duration of a sample, which is determined by the number of samples and the delay between each sample.

Method Detail

triggerStackTraceSample

public CompletableFuture<StackTraceSample> triggerStackTraceSample(ExecutionVertex[] tasksToSample,
                                                                   int numSamples,
                                                                   org.apache.flink.api.common.time.Time delayBetweenSamples,
                                                                   int maxStackTraceDepth)

Triggers a stack trace sample to all tasks.

Parameters:

tasksToSample - Tasks to sample.

numSamples - Number of stack trace samples to collect.

delayBetweenSamples - Delay between consecutive samples.

maxStackTraceDepth - Maximum depth of the stack trace. 0 indicates no maximum and keeps the complete stack trace.

Returns:

A future of the completed stack trace sample

cancelStackTraceSample

public void cancelStackTraceSample(int sampleId,
                                   Throwable cause)

Cancels a pending sample.

Parameters:

sampleId - ID of the sample 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.

collectStackTraces

public void collectStackTraces(int sampleId,
                               ExecutionAttemptID executionId,
                               List<StackTraceElement[]> stackTraces)

Collects stack traces of a task.

Parameters:

sampleId - ID of the sample.

executionId - ID of the sampled task.

stackTraces - Stack traces of the sampled task.

Throws:

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