org.apache.flink.runtime.executiongraph.failover

Class FailoverStrategy

java.lang.Object

org.apache.flink.runtime.executiongraph.failover.FailoverStrategy

Direct Known Subclasses:

NoOpFailoverStrategy, RestartAllStrategy

public abstract class FailoverStrategy
extends Object

A FailoverStrategy describes how the job computation recovers from task failures.

Failover strategies implement recovery logic for failures of tasks. The execution graph still implements "global failure / recovery" (which restarts all tasks) as a fallback plan or safety net in cases where it deems that the state of the graph may have become inconsistent.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	FailoverStrategy.Factory This factory is a necessary indirection when creating the FailoverStrategy to that we can have both the FailoverStrategy final in the ExecutionGraph, and the ExecutionGraph final in the FailOverStrategy.

Constructor Summary

Constructors

Constructor and Description
FailoverStrategy()

Method Summary

Modifier and Type	Method and Description
abstract String	getStrategyName() Gets the name of the failover strategy, for logging purposes.
abstract void	notifyNewVertices(List<ExecutionJobVertex> newJobVerticesTopological) Called whenever new vertices are added to the ExecutionGraph.
abstract void	onTaskFailure(Execution taskExecution, Throwable cause) Called by the execution graph when a task failure occurs.
void	registerMetrics(MetricGroup metricGroup) Tells the FailoverStrategy to register its metrics.

Methods inherited from class java.lang.Object

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

Constructor Detail

FailoverStrategy

public FailoverStrategy()

Method Detail

onTaskFailure

public abstract void onTaskFailure(Execution taskExecution,
                                   Throwable cause)

Called by the execution graph when a task failure occurs.

Parameters:

taskExecution - The execution attempt of the failed task.

cause - The exception that caused the task failure.

notifyNewVertices

public abstract void notifyNewVertices(List<ExecutionJobVertex> newJobVerticesTopological)

Called whenever new vertices are added to the ExecutionGraph.

Parameters:

newJobVerticesTopological - The newly added vertices, in topological order.

getStrategyName

public abstract String getStrategyName()

Gets the name of the failover strategy, for logging purposes.

registerMetrics

public void registerMetrics(MetricGroup metricGroup)

Tells the FailoverStrategy to register its metrics.

The default implementation does nothing

Parameters:

metricGroup - The metric group to register the metrics at