Package org.apache.flink.runtime.asyncprocessing

Class AsyncExecutionController<K>

java.lang.Object

org.apache.flink.runtime.asyncprocessing.AsyncExecutionController<K>

Type Parameters:

K - the type of the key

All Implemented Interfaces:

Closeable, AutoCloseable, StateRequestHandler

public class AsyncExecutionController<K>
extends Object
implements StateRequestHandler, Closeable

The Async Execution Controller (AEC) receives processing requests from operators, and put them into execution according to some strategies.

It is responsible for:

Preserving the sequence of elements bearing the same key by delaying subsequent requests until the processing of preceding ones is finalized. Tracking the in-flight data(records) and blocking the input if too much data in flight (back-pressure). It invokes MailboxExecutor.yield() to pause current operations, allowing for the execution of callbacks (mails in Mailbox).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	AsyncExecutionController.SwitchContextListener<K>	A listener listens the key context switch.

Constructor Summary

Constructors

Constructor	Description
AsyncExecutionController(org.apache.flink.api.common.operators.MailboxExecutor mailboxExecutor, org.apache.flink.core.state.StateFutureImpl.AsyncFrameworkExceptionHandler exceptionHandler, StateExecutor stateExecutor, int maxParallelism, int batchSize, long bufferTimeout, int maxInFlightRecords, AsyncExecutionController.SwitchContextListener<K> switchContextListener)

Method Summary

Modifier and Type	Method	Description
RecordContext<K>	buildContext(Object record, K key)	Build a new context based on record and key.
void	close()
void	drainInflightRecords(int targetNum)	A helper function to drain in-flight records util inFlightRecordNum within the limit of given targetNum.
int	getInFlightRecordNum()
StateExecutor	getStateExecutor()
<IN,OUT> org.apache.flink.core.state.InternalStateFuture<OUT>	handleRequest(org.apache.flink.api.common.state.v2.State state, StateRequestType type, IN payload)	Submit a StateRequest to this AsyncExecutionController and trigger it if needed.
<IN,OUT> OUT	handleRequestSync(org.apache.flink.api.common.state.v2.State state, StateRequestType type, IN payload)	Submit a StateRequest to this StateRequestHandler, and wait for the response synchronously.
void	processNonRecord(org.apache.flink.util.function.ThrowingRunnable<? extends Exception> action)
void	setCurrentContext(RecordContext<K> switchingContext)	Each time before a code segment (callback) is about to run in mailbox (task thread), this method should be called to switch a context in AEC.
<N> void	setCurrentNamespaceForState(InternalPartitionedState<N> state, N namespace)	Set current namespace for a state.
void	syncPointRequestWithCallback(org.apache.flink.util.function.ThrowingRunnable<Exception> callback)	A helper to request a StateRequestType.SYNC_POINT and run a callback if it finishes (once the record is not blocked).
void	triggerIfNeeded(boolean force)	Trigger a batch of requests.

Methods inherited from class java.lang.Object

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

Constructor Detail

AsyncExecutionController

public AsyncExecutionController(org.apache.flink.api.common.operators.MailboxExecutor mailboxExecutor,
                                org.apache.flink.core.state.StateFutureImpl.AsyncFrameworkExceptionHandler exceptionHandler,
                                StateExecutor stateExecutor,
                                int maxParallelism,
                                int batchSize,
                                long bufferTimeout,
                                int maxInFlightRecords,
                                AsyncExecutionController.SwitchContextListener<K> switchContextListener)

Method Detail

buildContext

public RecordContext<K> buildContext(Object record,
                                     K key)

Build a new context based on record and key. Also wired with internal KeyAccountingUnit.

Parameters:

record - the given record.

key - the given key.

Returns:

the built record context.

setCurrentContext

public void setCurrentContext(RecordContext<K> switchingContext)

Each time before a code segment (callback) is about to run in mailbox (task thread), this method should be called to switch a context in AEC.

Parameters:

switchingContext - the context to switch.

handleRequest

public <IN,OUT> org.apache.flink.core.state.InternalStateFuture<OUT> handleRequest(@Nullable
                                                                                         org.apache.flink.api.common.state.v2.State state,
                                                                                         StateRequestType type,
                                                                                         @Nullable
                                                                                         IN payload)

Submit a StateRequest to this AsyncExecutionController and trigger it if needed.

Specified by:

handleRequest in interface StateRequestHandler

Parameters:

state - the state to request. Could be null if the type is StateRequestType.SYNC_POINT.

type - the type of this request.

payload - the payload input for this request.

Returns:

the state future.

handleRequestSync

public <IN,OUT> OUT handleRequestSync(org.apache.flink.api.common.state.v2.State state,
                                            StateRequestType type,
                                            @Nullable
                                            IN payload)

Description copied from interface: StateRequestHandler

Submit a StateRequest to this StateRequestHandler, and wait for the response synchronously.

Specified by:

handleRequestSync in interface StateRequestHandler

Parameters:

state - the state to request.

type - the type of this request.

payload - the payload input for this request.

Returns:

the state future.

setCurrentNamespaceForState

public <N> void setCurrentNamespaceForState(@Nonnull
                                            InternalPartitionedState<N> state,
                                            N namespace)

Description copied from interface: StateRequestHandler

Set current namespace for a state. See InternalPartitionedState.setCurrentNamespace(Object).

Specified by:

setCurrentNamespaceForState in interface StateRequestHandler

triggerIfNeeded

public void triggerIfNeeded(boolean force)

Trigger a batch of requests.

Parameters:

force - whether to trigger requests in force.

syncPointRequestWithCallback

public void syncPointRequestWithCallback(org.apache.flink.util.function.ThrowingRunnable<Exception> callback)

A helper to request a StateRequestType.SYNC_POINT and run a callback if it finishes (once the record is not blocked).

Parameters:

callback - the callback to run if it finishes (once the record is not blocked).

drainInflightRecords

public void drainInflightRecords(int targetNum)

A helper function to drain in-flight records util inFlightRecordNum within the limit of given targetNum.

Parameters:

targetNum - the target inFlightRecordNum to achieve.

processNonRecord

public void processNonRecord(org.apache.flink.util.function.ThrowingRunnable<? extends Exception> action)

getStateExecutor

@VisibleForTesting
public StateExecutor getStateExecutor()

getInFlightRecordNum

@VisibleForTesting
public int getInFlightRecordNum()

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException