org.apache.flink.api.common.eventtime

Class BoundedOutOfOrdernessWatermarks<T>

java.lang.Object

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

All Implemented Interfaces:

WatermarkGenerator<T>

Direct Known Subclasses:

AscendingTimestampsWatermarks

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

A WatermarkGenerator for situations where records are out of order, but you can place an upper bound on how far the events are out of order. An out-of-order bound B means that once an event with timestamp T was encountered, no events older than T - B will follow any more.

The watermarks are generated periodically. The delay introduced by this watermark strategy is the periodic interval length, plus the out-of-orderness bound.

Constructor Summary

Constructors

Constructor and Description
BoundedOutOfOrdernessWatermarks(Duration maxOutOfOrderness) Creates a new watermark generator with the given out-of-orderness bound.

Method Summary

Modifier and Type	Method and 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

BoundedOutOfOrdernessWatermarks

public BoundedOutOfOrdernessWatermarks(Duration maxOutOfOrderness)

Creates a new watermark generator with the given out-of-orderness bound.

Parameters:

maxOutOfOrderness - The bound for the out-of-orderness of the event timestamps.

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>