org.apache.flink.runtime.io.network.partition

Class ResultPartition

java.lang.Object

org.apache.flink.runtime.io.network.partition.ResultPartition

All Implemented Interfaces:

AutoCloseable, AvailabilityProvider, ResultPartitionWriter

Direct Known Subclasses:

BufferWritingResultPartition, HsResultPartition, SortMergeResultPartition

public abstract class ResultPartition
extends Object
implements ResultPartitionWriter

A result partition for data produced by a single task.

This class is the runtime part of a logical IntermediateResultPartition. Essentially, a result partition is a collection of Buffer instances. The buffers are organized in one or more ResultSubpartition instances or in a joint structure which further partition the data depending on the number of consuming tasks and the data DistributionPattern.

Tasks, which consume a result partition have to request one of its subpartitions. The request happens either remotely (see RemoteInputChannel) or locally (see LocalInputChannel)

Life-cycle

The life-cycle of each result partition has three (possibly overlapping) phases:

1. Produce:
2. Consume:
3. Release:

Buffer management

State management

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.runtime.io.AvailabilityProvider

AvailabilityProvider.AvailabilityHelper

Field Summary

Fields

Modifier and Type	Field and Description
protected BufferCompressor	bufferCompressor Used to compress buffer to reduce IO.
protected BufferPool	bufferPool
protected static org.slf4j.Logger	LOG
protected Counter	numBuffersOut
protected Counter	numBytesOut
protected int	numSubpartitions
protected ResultPartitionID	partitionId
protected ResultPartitionManager	partitionManager
protected ResultPartitionType	partitionType Type of this partition.
protected ResultPartitionBytesCounter	resultPartitionBytes

Fields inherited from interface org.apache.flink.runtime.io.AvailabilityProvider

AVAILABLE

Constructor Summary

Constructors

Constructor and Description
ResultPartition(String owningTaskName, int partitionIndex, ResultPartitionID partitionId, ResultPartitionType partitionType, int numSubpartitions, int numTargetKeyGroups, ResultPartitionManager partitionManager, BufferCompressor bufferCompressor, SupplierWithException<BufferPool,IOException> bufferPoolFactory)

Method Summary

Modifier and Type	Method and Description
protected boolean	canBeCompressed(Buffer buffer) Whether the buffer can be compressed or not.
protected void	checkInProduceState()
void	close() Closes the partition writer which releases the allocated resource, for example the buffer pool.
void	fail(Throwable throwable) Fail the production of the partition.
void	finish() Finishes the result partition.
CompletableFuture<Void>	getAllDataProcessedFuture() Gets the future indicating whether all the records has been processed by the downstream tasks.
CompletableFuture<?>	getAvailableFuture()
BufferPool	getBufferPool()
Throwable	getFailureCause()
abstract int	getNumberOfQueuedBuffers() Returns the total number of queued buffers of all subpartitions.
abstract int	getNumberOfQueuedBuffers(int targetSubpartition) Returns the number of queued buffers of the given target subpartition.
int	getNumberOfSubpartitions()
int	getNumTargetKeyGroups()
String	getOwningTaskName()
ResultPartitionID	getPartitionId()
int	getPartitionIndex()
ResultPartitionManager	getPartitionManager()
ResultPartitionType	getPartitionType() Returns the type of this result partition.
abstract long	getSizeOfQueuedBuffersUnsafe() Returns the total size in bytes of queued buffers of all subpartitions.
boolean	isFinished()
boolean	isReleased() Whether this partition is released.
void	notifyEndOfData(StopMode mode) Notifies the downstream tasks that this ResultPartitionWriter have emitted all the user records.
void	onSubpartitionAllDataProcessed(int subpartition) The subpartition notifies that the corresponding downstream task have processed all the user records.
void	release()
void	release(Throwable cause) Releases the partition writer which releases the produced data and no reader can consume the partition any more.
protected abstract void	releaseInternal() Releases all produced data including both those stored in memory and persisted on disk.
void	setMaxOverdraftBuffersPerGate(int maxOverdraftBuffersPerGate) Sets the max overdraft buffer size of per gate.
void	setMetricGroup(TaskIOMetricGroup metrics) Sets the metric group for the ResultPartitionWriter.
void	setup() Registers a buffer pool with this result partition.
protected abstract void	setupInternal() Do the subclass's own setup operation.
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.runtime.io.network.api.writer.ResultPartitionWriter

abortCheckpoint, alignedBarrierTimeout, broadcastEvent, broadcastRecord, createSubpartitionView, emitRecord, flush, flushAll

Methods inherited from interface org.apache.flink.runtime.io.AvailabilityProvider

and, isApproximatelyAvailable, isAvailable, or

Field Detail

LOG

protected static final org.slf4j.Logger LOG

partitionId

protected final ResultPartitionID partitionId

partitionType

protected final ResultPartitionType partitionType

Type of this partition. Defines the concrete subpartition implementation to use.

partitionManager

protected final ResultPartitionManager partitionManager

numSubpartitions

protected final int numSubpartitions

bufferPool

protected BufferPool bufferPool

bufferCompressor

@Nullable
protected final BufferCompressor bufferCompressor

Used to compress buffer to reduce IO.

numBytesOut

protected Counter numBytesOut

numBuffersOut

protected Counter numBuffersOut

resultPartitionBytes

protected ResultPartitionBytesCounter resultPartitionBytes

Constructor Detail

ResultPartition

public ResultPartition(String owningTaskName,
                       int partitionIndex,
                       ResultPartitionID partitionId,
                       ResultPartitionType partitionType,
                       int numSubpartitions,
                       int numTargetKeyGroups,
                       ResultPartitionManager partitionManager,
                       @Nullable
                       BufferCompressor bufferCompressor,
                       SupplierWithException<BufferPool,IOException> bufferPoolFactory)

Method Detail

setup

public void setup()
           throws IOException

Registers a buffer pool with this result partition.

There is one pool for each result partition, which is shared by all its sub partitions.

The pool is registered with the partition *after* it as been constructed in order to conform to the life-cycle of task registrations in the TaskExecutor.

Specified by:

setup in interface ResultPartitionWriter

Throws:

IOException

setupInternal

protected abstract void setupInternal()
                               throws IOException

Do the subclass's own setup operation.

Throws:

IOException

getOwningTaskName

public String getOwningTaskName()

getPartitionId

public ResultPartitionID getPartitionId()

Specified by:

getPartitionId in interface ResultPartitionWriter

getPartitionIndex

public int getPartitionIndex()

getNumberOfSubpartitions

public int getNumberOfSubpartitions()

Specified by:

getNumberOfSubpartitions in interface ResultPartitionWriter

getBufferPool

public BufferPool getBufferPool()

getNumberOfQueuedBuffers

public abstract int getNumberOfQueuedBuffers()

Returns the total number of queued buffers of all subpartitions.

getSizeOfQueuedBuffersUnsafe

public abstract long getSizeOfQueuedBuffersUnsafe()

Returns the total size in bytes of queued buffers of all subpartitions.

getNumberOfQueuedBuffers

public abstract int getNumberOfQueuedBuffers(int targetSubpartition)

Returns the number of queued buffers of the given target subpartition.

setMaxOverdraftBuffersPerGate

public void setMaxOverdraftBuffersPerGate(int maxOverdraftBuffersPerGate)

Description copied from interface: ResultPartitionWriter

Sets the max overdraft buffer size of per gate.

Specified by:

setMaxOverdraftBuffersPerGate in interface ResultPartitionWriter

getPartitionType

public ResultPartitionType getPartitionType()

Returns the type of this result partition.

Returns:

result partition type

notifyEndOfData

public void notifyEndOfData(StopMode mode)
                     throws IOException

Description copied from interface: ResultPartitionWriter

Notifies the downstream tasks that this ResultPartitionWriter have emitted all the user records.

Specified by:

notifyEndOfData in interface ResultPartitionWriter

Parameters:

mode - tells if we should flush all records or not (it is false in case of stop-with-savepoint (--no-drain))

Throws:

IOException

getAllDataProcessedFuture

public CompletableFuture<Void> getAllDataProcessedFuture()

Description copied from interface: ResultPartitionWriter

Gets the future indicating whether all the records has been processed by the downstream tasks.

Specified by:

getAllDataProcessedFuture in interface ResultPartitionWriter

onSubpartitionAllDataProcessed

public void onSubpartitionAllDataProcessed(int subpartition)

The subpartition notifies that the corresponding downstream task have processed all the user records.

Parameters:

subpartition - The index of the subpartition sending the notification.

See Also:

EndOfData

finish

public void finish()
            throws IOException

Finishes the result partition.

After this operation, it is not possible to add further data to the result partition.

For BLOCKING results, this will trigger the deployment of consuming tasks.

Specified by:

finish in interface ResultPartitionWriter

Throws:

IOException

isFinished

public boolean isFinished()

Specified by:

isFinished in interface ResultPartitionWriter

release

public void release()

release

public void release(Throwable cause)

Description copied from interface: ResultPartitionWriter

Releases the partition writer which releases the produced data and no reader can consume the partition any more.

Specified by:

release in interface ResultPartitionWriter

releaseInternal

protected abstract void releaseInternal()

Releases all produced data including both those stored in memory and persisted on disk.

close

public void close()

Description copied from interface: ResultPartitionWriter

Closes the partition writer which releases the allocated resource, for example the buffer pool.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface ResultPartitionWriter

fail

public void fail(@Nullable
                 Throwable throwable)

Description copied from interface: ResultPartitionWriter

Fail the production of the partition.

This method propagates non-null failure causes to consumers on a best-effort basis. This call also leads to the release of all resources associated with the partition. Closing of the partition is still needed afterwards if it has not been done before.

Specified by:

fail in interface ResultPartitionWriter

Parameters:

throwable - failure cause

getFailureCause

public Throwable getFailureCause()

getNumTargetKeyGroups

public int getNumTargetKeyGroups()

Specified by:

getNumTargetKeyGroups in interface ResultPartitionWriter

setMetricGroup

public void setMetricGroup(TaskIOMetricGroup metrics)

Description copied from interface: ResultPartitionWriter

Sets the metric group for the ResultPartitionWriter.

Specified by:

setMetricGroup in interface ResultPartitionWriter

isReleased

public boolean isReleased()

Whether this partition is released.

A partition is released when each subpartition is either consumed and communication is closed by consumer or failed. A partition is also released if task is cancelled.

Specified by:

isReleased in interface ResultPartitionWriter

getAvailableFuture

public CompletableFuture<?> getAvailableFuture()

Specified by:

getAvailableFuture in interface AvailabilityProvider

Returns:

a future that is completed if the respective provider is available.

toString

public String toString()

Overrides:

toString in class Object

checkInProduceState

protected void checkInProduceState()
                            throws IllegalStateException

Throws:

IllegalStateException

getPartitionManager

@VisibleForTesting
public ResultPartitionManager getPartitionManager()

canBeCompressed

protected boolean canBeCompressed(Buffer buffer)

Whether the buffer can be compressed or not. Note that event is not compressed because it is usually small and the size can become even larger after compression.