org.apache.flink.streaming.api.datastream

Class IterativeStream<T>

java.lang.Object

org.apache.flink.streaming.api.datastream.DataStream<T>

org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator<T>

org.apache.flink.streaming.api.datastream.IterativeStream<T>

Type Parameters:

T - Type of the elements in this Stream

@PublicEvolving
public class IterativeStream<T>
extends SingleOutputStreamOperator<T>

The iterative data stream represents the start of an iteration in a DataStream.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	IterativeStream.ConnectedIterativeStreams<I,F> The IterativeStream.ConnectedIterativeStreams represent a start of an iterative part of a streaming program, where the original input of the iteration and the feedback of the iteration are connected as in a ConnectedStreams.

Field Summary

Fields inherited from class org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator

nonParallel

Fields inherited from class org.apache.flink.streaming.api.datastream.DataStream

environment, transformation

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	IterativeStream(DataStream<T> dataStream, long maxWaitTime)

Method Summary

Methods

Modifier and Type	Method and Description
DataStream<T>	closeWith(DataStream<T> feedbackStream) Closes the iteration.
<F> IterativeStream.ConnectedIterativeStreams<T,F>	withFeedbackType(Class<F> feedbackTypeClass) Changes the feedback type of the iteration and allows the user to apply co-transformations on the input and feedback stream, as in a ConnectedStreams.
<F> IterativeStream.ConnectedIterativeStreams<T,F>	withFeedbackType(String feedbackTypeString) Changes the feedback type of the iteration and allows the user to apply co-transformations on the input and feedback stream, as in a ConnectedStreams.
<F> IterativeStream.ConnectedIterativeStreams<T,F>	withFeedbackType(TypeInformation<F> feedbackType) Changes the feedback type of the iteration and allows the user to apply co-transformations on the input and feedback stream, as in a ConnectedStreams.

Methods inherited from class org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator

disableChaining, forceNonParallel, getName, name, returns, returns, returns, returns, setBufferTimeout, setConnectionType, setMaxParallelism, setParallelism, setUidHash, slotSharingGroup, startNewChain, uid

Methods inherited from class org.apache.flink.streaming.api.datastream.DataStream

addSink, assignTimestamps, assignTimestampsAndWatermarks, assignTimestampsAndWatermarks, broadcast, clean, coGroup, connect, countWindowAll, countWindowAll, filter, flatMap, forward, getExecutionConfig, getExecutionEnvironment, getId, getParallelism, getTransformation, getType, global, iterate, iterate, join, keyBy, keyBy, keyBy, map, partitionCustom, partitionCustom, partitionCustom, print, printToErr, project, rebalance, rescale, shuffle, split, timeWindowAll, timeWindowAll, transform, union, windowAll, writeAsCsv, writeAsCsv, writeAsCsv, writeAsText, writeAsText, writeToSocket, writeUsingOutputFormat

Methods inherited from class java.lang.Object

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

Constructor Detail

IterativeStream

protected IterativeStream(DataStream<T> dataStream,
               long maxWaitTime)

Method Detail

closeWith

public DataStream<T> closeWith(DataStream<T> feedbackStream)

Closes the iteration. This method defines the end of the iterative program part that will be fed back to the start of the iteration.

A common usage pattern for streaming iterations is to use output splitting to send a part of the closing data stream to the head. Refer to DataStream.split(org.apache.flink.streaming.api.collector.selector.OutputSelector) for more information.

Parameters:

feedbackStream - DataStream that will be used as input to the iteration head.

Returns:

The feedback stream.

withFeedbackType

public <F> IterativeStream.ConnectedIterativeStreams<T,F> withFeedbackType(String feedbackTypeString)

Changes the feedback type of the iteration and allows the user to apply co-transformations on the input and feedback stream, as in a ConnectedStreams.

For type safety the user needs to define the feedback type

Parameters:

feedbackTypeString - String describing the type information of the feedback stream.

Returns:

A IterativeStream.ConnectedIterativeStreams.

withFeedbackType

public <F> IterativeStream.ConnectedIterativeStreams<T,F> withFeedbackType(Class<F> feedbackTypeClass)

Changes the feedback type of the iteration and allows the user to apply co-transformations on the input and feedback stream, as in a ConnectedStreams.

For type safety the user needs to define the feedback type

Parameters:

feedbackTypeClass - Class of the elements in the feedback stream.

Returns:

A IterativeStream.ConnectedIterativeStreams.

withFeedbackType

public <F> IterativeStream.ConnectedIterativeStreams<T,F> withFeedbackType(TypeInformation<F> feedbackType)

Changes the feedback type of the iteration and allows the user to apply co-transformations on the input and feedback stream, as in a ConnectedStreams.

For type safety the user needs to define the feedback type

Parameters:

feedbackType - The type information of the feedback stream.

Returns:

A IterativeStream.ConnectedIterativeStreams.