Package org.apache.flink.runtime.shuffle

Interface ShuffleMaster<T extends ShuffleDescriptor>

Type Parameters:

T - partition shuffle descriptor used for producer/consumer deployment and their data exchange.

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

NettyShuffleMaster

public interface ShuffleMaster<T extends ShuffleDescriptor>
extends AutoCloseable

Intermediate result partition registry to use in JobMaster.

Method Summary

Modifier and Type	Method	Description
default void	close()	Closes this shuffle master service which should release all resources.
default MemorySize	computeShuffleMemorySizeForTask(TaskInputsOutputsDescriptor taskInputsOutputsDescriptor)	Compute shuffle memory size for a task with the given TaskInputsOutputsDescriptor.
default CompletableFuture<Collection<PartitionWithMetrics>>	getPartitionWithMetrics(JobID jobId, Duration timeout, Set<ResultPartitionID> expectedPartitions)	Retrieves specified partitions and their metrics (identified by expectedPartitions), the metrics include sizes of sub-partitions in a result partition.
default void	notifyPartitionRecoveryStarted(JobID jobId)	Notifies that the recovery process of result partitions has started.
default void	registerJob(JobShuffleContext context)	Registers the target job together with the corresponding JobShuffleContext to this shuffle master.
CompletableFuture<T>	registerPartitionWithProducer(JobID jobID, PartitionDescriptor partitionDescriptor, ProducerDescriptor producerDescriptor)	Asynchronously register a partition and its producer with the shuffle service.
void	releasePartitionExternally(ShuffleDescriptor shuffleDescriptor)	Release any external resources occupied by the given partition.
default void	restoreState(List<ShuffleMasterSnapshot> snapshots)	Restores the state of the shuffle master from the provided snapshots.
default void	snapshotState(CompletableFuture<ShuffleMasterSnapshot> snapshotFuture, ShuffleMasterSnapshotContext context)	Triggers a snapshot of the shuffle master's state.
default void	start()	Starts this shuffle master as a service.
default boolean	supportsBatchSnapshot()	Whether the shuffle master supports taking snapshot in batch scenarios if BatchExecutionOptions.JOB_RECOVERY_ENABLED is true.
default void	unregisterJob(JobID jobID)	Unregisters the target job from this shuffle master, which means the corresponding job has reached a global termination state and all the allocated resources except for the cluster partitions can be cleared.

Method Detail

start

default void start()
            throws Exception

Starts this shuffle master as a service. One can do some initialization here, for example getting access and connecting to the external system.

Throws:

Exception

close

default void close()
            throws Exception

Closes this shuffle master service which should release all resources. A shuffle master will only be closed when the cluster is shut down.

Specified by:

close in interface AutoCloseable

Throws:

Exception

registerJob

default void registerJob(JobShuffleContext context)

Registers the target job together with the corresponding JobShuffleContext to this shuffle master. Through the shuffle context, one can obtain some basic information like job ID, job configuration. It enables ShuffleMaster to notify JobMaster about lost result partitions, so that JobMaster can identify and reproduce unavailable partitions earlier.

Parameters:

context - the corresponding shuffle context of the target job.

unregisterJob

default void unregisterJob(JobID jobID)

Unregisters the target job from this shuffle master, which means the corresponding job has reached a global termination state and all the allocated resources except for the cluster partitions can be cleared.

Parameters:

jobID - ID of the target job to be unregistered.

registerPartitionWithProducer

CompletableFuture<T> registerPartitionWithProducer(JobID jobID,
                                                   PartitionDescriptor partitionDescriptor,
                                                   ProducerDescriptor producerDescriptor)

Asynchronously register a partition and its producer with the shuffle service.

The returned shuffle descriptor is an internal handle which identifies the partition internally within the shuffle service. The descriptor should provide enough information to read from or write data to the partition.

Parameters:

jobID - job ID of the corresponding job which registered the partition

partitionDescriptor - general job graph information about the partition

producerDescriptor - general producer information (location, execution id, connection info)

Returns:

future with the partition shuffle descriptor used for producer/consumer deployment and their data exchange.

releasePartitionExternally

void releasePartitionExternally(ShuffleDescriptor shuffleDescriptor)

Release any external resources occupied by the given partition.

This call triggers release of any resources which are occupied by the given partition in the external systems outside of the producer executor. This is mostly relevant for the batch jobs and blocking result partitions. The producer local resources are managed by ShuffleDescriptor.storesLocalResourcesOn() and ShuffleEnvironment.releasePartitionsLocally(Collection).

Parameters:

shuffleDescriptor - shuffle descriptor of the result partition to release externally.

computeShuffleMemorySizeForTask

default MemorySize computeShuffleMemorySizeForTask(TaskInputsOutputsDescriptor taskInputsOutputsDescriptor)

Compute shuffle memory size for a task with the given TaskInputsOutputsDescriptor.

Parameters:

taskInputsOutputsDescriptor - describes task inputs and outputs information for shuffle memory calculation.

Returns:

shuffle memory size for a task with the given TaskInputsOutputsDescriptor.

getPartitionWithMetrics

default CompletableFuture<Collection<PartitionWithMetrics>> getPartitionWithMetrics(JobID jobId,
                                                                                    Duration timeout,
                                                                                    Set<ResultPartitionID> expectedPartitions)

Retrieves specified partitions and their metrics (identified by expectedPartitions), the metrics include sizes of sub-partitions in a result partition.

Parameters:

jobId - ID of the target job

timeout - The timeout used for retrieve the specified partitions.

expectedPartitions - The set of identifiers for the result partitions whose metrics are to be fetched.

Returns:

A future will contain a collection of the partitions with their metrics that could be retrieved from the expected partitions within the specified timeout period.

supportsBatchSnapshot

default boolean supportsBatchSnapshot()

Whether the shuffle master supports taking snapshot in batch scenarios if BatchExecutionOptions.JOB_RECOVERY_ENABLED is true. If it returns true, Flink will call snapshotState(java.util.concurrent.CompletableFuture<org.apache.flink.runtime.shuffle.ShuffleMasterSnapshot>, org.apache.flink.runtime.shuffle.ShuffleMasterSnapshotContext) to take snapshot, and call restoreState(java.util.List<org.apache.flink.runtime.shuffle.ShuffleMasterSnapshot>) to restore the state of shuffle master.

snapshotState

default void snapshotState(CompletableFuture<ShuffleMasterSnapshot> snapshotFuture,
                           ShuffleMasterSnapshotContext context)

Triggers a snapshot of the shuffle master's state.

restoreState

default void restoreState(List<ShuffleMasterSnapshot> snapshots)

Restores the state of the shuffle master from the provided snapshots.

notifyPartitionRecoveryStarted

default void notifyPartitionRecoveryStarted(JobID jobId)

Notifies that the recovery process of result partitions has started.

Parameters:

jobId - ID of the target job