AsyncExecutionController (Flink : Runtime 1.20.1 API)

java.lang.Object
- org.apache.flink.runtime.asyncprocessing.AsyncExecutionController<K>

Type Parameters:

K - the type of the key

All Implemented Interfaces:

StateRequestHandler
```
public class AsyncExecutionController<K>
extends Object
implements StateRequestHandler
```
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).

Constructor Summary

Constructors
Constructor and 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)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`RecordContext<K>`	`buildContext(Object record, K key)` Build a new context based on record and key.
`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.
`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.
`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)

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.

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()

Class AsyncExecutionController<K>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

AsyncExecutionController

Method Detail

buildContext

setCurrentContext

handleRequest

triggerIfNeeded

syncPointRequestWithCallback

drainInflightRecords

processNonRecord

getStateExecutor

getInFlightRecordNum