Package org.apache.flink.api.common.eventtime

Class WatermarksWithIdleness<T>

java.lang.Object

org.apache.flink.api.common.eventtime.WatermarksWithIdleness<T>

All Implemented Interfaces:

WatermarkGenerator<T>

@Public
public class WatermarksWithIdleness<T>
extends Object
implements WatermarkGenerator<T>

A WatermarkGenerator that adds idleness detection to another WatermarkGenerator. If no events come within a certain time (timeout duration) then this generator marks the stream as idle, until the next watermark is generated.

Constructor Summary

Constructors

Constructor	Description
WatermarksWithIdleness(WatermarkGenerator<T> watermarks, Duration idleTimeout)	Deprecated.
WatermarksWithIdleness(WatermarkGenerator<T> watermarks, Duration idleTimeout, RelativeClock clock)	Creates a new WatermarksWithIdleness generator to the given generator idleness detection with the given timeout.

Method Summary

Modifier and Type	Method	Description
void	onEvent(T event, long eventTimestamp, WatermarkOutput output)	Called for every event, allows the watermark generator to examine and remember the event timestamps, or to emit a watermark based on the event itself.
void	onPeriodicEmit(WatermarkOutput output)	Called periodically, and might emit a new watermark, or not.

Methods inherited from class java.lang.Object

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

Constructor Detail

WatermarksWithIdleness

@Deprecated
public WatermarksWithIdleness(WatermarkGenerator<T> watermarks,
                              Duration idleTimeout)

Deprecated.

This is not used anymore, but it's technically part of the Public API. Please use WatermarksWithIdleness(WatermarkGenerator, Duration, RelativeClock) instead.

WatermarksWithIdleness

public WatermarksWithIdleness(WatermarkGenerator<T> watermarks,
                              Duration idleTimeout,
                              RelativeClock clock)

Creates a new WatermarksWithIdleness generator to the given generator idleness detection with the given timeout.

Parameters:

watermarks - The original watermark generator.

idleTimeout - The timeout for the idleness detection.

clock - The clock that will be used to measure idleness period. It is expected that this clock will hide periods when this WatermarkGenerator has been blocked from making any progress despite availability of records on the input.

Method Detail

onEvent

public void onEvent(T event,
                    long eventTimestamp,
                    WatermarkOutput output)

Description copied from interface: WatermarkGenerator

Called for every event, allows the watermark generator to examine and remember the event timestamps, or to emit a watermark based on the event itself.

Specified by:

onEvent in interface WatermarkGenerator<T>

onPeriodicEmit

public void onPeriodicEmit(WatermarkOutput output)

Description copied from interface: WatermarkGenerator

Called periodically, and might emit a new watermark, or not.

The interval in which this method is called and Watermarks are generated depends on ExecutionConfig.getAutoWatermarkInterval().

Specified by:

onPeriodicEmit in interface WatermarkGenerator<T>