org.apache.flink.streaming.runtime.operators

Class TimestampsAndWatermarksOperator<T>

java.lang.Object

org.apache.flink.streaming.api.operators.AbstractStreamOperator<T>

org.apache.flink.streaming.runtime.operators.TimestampsAndWatermarksOperator<T>

Type Parameters:

T - The type of the input elements

All Implemented Interfaces:

Serializable, ProcessingTimeService.ProcessingTimeCallback, CheckpointListener, Input<T>, KeyContext, KeyContextHandler, OneInputStreamOperator<T,T>, SetupableStreamOperator<T>, StreamOperator<T>, StreamOperatorStateHandler.CheckpointedStreamOperator

public class TimestampsAndWatermarksOperator<T>
extends AbstractStreamOperator<T>
implements OneInputStreamOperator<T,T>, ProcessingTimeService.ProcessingTimeCallback

A stream operator that may do one or both of the following: extract timestamps from events and generate watermarks.

These two responsibilities run in the same operator rather than in two different ones, because the implementation of the timestamp assigner and the watermark generator is frequently in the same class (and should be run in the same instance), even though the separate interfaces support the use of different classes.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TimestampsAndWatermarksOperator.WatermarkEmitter Implementation of the WatermarkEmitter, based on the components that are available inside a stream operator.

Field Summary

Fields inherited from class org.apache.flink.streaming.api.operators.AbstractStreamOperator

chainingStrategy, config, latencyStats, LOG, metrics, output, processingTimeService

Constructor Summary

Constructors

Constructor and Description
TimestampsAndWatermarksOperator(WatermarkStrategy<T> watermarkStrategy, boolean emitProgressiveWatermarks)

Method Summary

Modifier and Type	Method and Description
void	finish() This method is called at the end of data processing.
void	onProcessingTime(long timestamp) This method is invoked with the time which the callback register for.
void	open() This method is called immediately before any elements are processed, it should contain the operator's initialization logic, e.g. state initialization.
void	processElement(StreamRecord<T> element) Processes one element that arrived on this input of the MultipleInputStreamOperator.
void	processWatermark(Watermark mark) Override the base implementation to completely ignore watermarks propagated from upstream, except for the "end of time" watermark.
void	processWatermarkStatus(WatermarkStatus watermarkStatus) Override the base implementation to completely ignore statuses propagated from upstream.

Methods inherited from class org.apache.flink.streaming.api.operators.AbstractStreamOperator

close, getChainingStrategy, getContainingTask, getCurrentKey, getExecutionConfig, getInternalTimerService, getKeyedStateBackend, getKeyedStateStore, getMetricGroup, getOperatorConfig, getOperatorID, getOperatorName, getOperatorStateBackend, getOrCreateKeyedState, getPartitionedState, getPartitionedState, getProcessingTimeService, getRuntimeContext, getTimeServiceManager, getUserCodeClassloader, hasKeyContext1, hasKeyContext2, initializeState, initializeState, isUsingCustomRawKeyedState, notifyCheckpointAborted, notifyCheckpointComplete, prepareSnapshotPreBarrier, processLatencyMarker, processLatencyMarker1, processLatencyMarker2, processWatermark1, processWatermark2, processWatermarkStatus1, processWatermarkStatus2, reportOrForwardLatencyMarker, setChainingStrategy, setCurrentKey, setKeyContextElement1, setKeyContextElement2, setProcessingTimeService, setup, snapshotState, snapshotState

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.streaming.api.operators.OneInputStreamOperator

setKeyContextElement

Methods inherited from interface org.apache.flink.streaming.api.operators.StreamOperator

close, getMetricGroup, getOperatorID, initializeState, prepareSnapshotPreBarrier, setKeyContextElement1, setKeyContextElement2, snapshotState

Methods inherited from interface org.apache.flink.api.common.state.CheckpointListener

notifyCheckpointAborted, notifyCheckpointComplete

Methods inherited from interface org.apache.flink.streaming.api.operators.KeyContext

getCurrentKey, setCurrentKey

Methods inherited from interface org.apache.flink.streaming.api.operators.Input

processLatencyMarker

Methods inherited from interface org.apache.flink.streaming.api.operators.KeyContextHandler

hasKeyContext

Constructor Detail

TimestampsAndWatermarksOperator

public TimestampsAndWatermarksOperator(WatermarkStrategy<T> watermarkStrategy,
                                       boolean emitProgressiveWatermarks)

Method Detail

open

public void open()
          throws Exception

Description copied from class: AbstractStreamOperator

This method is called immediately before any elements are processed, it should contain the operator's initialization logic, e.g. state initialization.

The default implementation does nothing.

Specified by:

open in interface StreamOperator<T>

Overrides:

open in class AbstractStreamOperator<T>

Throws:

Exception - An exception in this method causes the operator to fail.

processElement

public void processElement(StreamRecord<T> element)
                    throws Exception

Description copied from interface: Input

Processes one element that arrived on this input of the MultipleInputStreamOperator. This method is guaranteed to not be called concurrently with other methods of the operator.

Specified by:

processElement in interface Input<T>

Throws:

Exception

onProcessingTime

public void onProcessingTime(long timestamp)
                      throws Exception

Description copied from interface: ProcessingTimeService.ProcessingTimeCallback

This method is invoked with the time which the callback register for.

Specified by:

onProcessingTime in interface ProcessingTimeService.ProcessingTimeCallback

Parameters:

timestamp - The time this callback was registered for.

Throws:

Exception

processWatermark

public void processWatermark(Watermark mark)
                      throws Exception

Override the base implementation to completely ignore watermarks propagated from upstream, except for the "end of time" watermark.

Specified by:

processWatermark in interface Input<T>

Overrides:

processWatermark in class AbstractStreamOperator<T>

Throws:

Exception

See Also:

Watermark

processWatermarkStatus

public void processWatermarkStatus(WatermarkStatus watermarkStatus)
                            throws Exception

Override the base implementation to completely ignore statuses propagated from upstream.

Specified by:

processWatermarkStatus in interface Input<T>

Overrides:

processWatermarkStatus in class AbstractStreamOperator<T>

Throws:

Exception

See Also:

WatermarkStatus

finish

public void finish()
            throws Exception

Description copied from interface: StreamOperator

This method is called at the end of data processing.

The method is expected to flush all remaining buffered data. Exceptions during this flushing of buffered data should be propagated, in order to cause the operation to be recognized as failed, because the last data items are not processed properly.

After this method is called, no more records can be produced for the downstream operators.

WARNING: It is not safe to use this method to commit any transactions or other side effects! You can use this method to flush any buffered data that can later on be committed e.g. in a CheckpointListener.notifyCheckpointComplete(long).

NOTE:This method does not need to close any resources. You should release external resources in the StreamOperator.close() method.

Specified by:

finish in interface StreamOperator<T>

Overrides:

finish in class AbstractStreamOperator<T>

Throws:

Exception - An exception in this method causes the operator to fail.