org.apache.beam.sdk.transforms.splittabledofn

Class WatermarkEstimators.WallTime

java.lang.Object

org.apache.beam.sdk.transforms.splittabledofn.WatermarkEstimators.WallTime

All Implemented Interfaces:

WatermarkEstimator<Instant>

Enclosing class:

WatermarkEstimators

public static class WatermarkEstimators.WallTime
extends java.lang.Object
implements WatermarkEstimator<Instant>

A watermark estimator that tracks wall time.

Note that this watermark estimator expects wall times of all machines performing the processing to be close to each other. Any machine with a wall clock that is far in the past may cause the pipeline to perform poorly while a watermark far in the future may cause records to be marked as late.

Constructor Summary

Constructors

Constructor and Description
WallTime(Instant watermark)

Method Summary

Modifier and Type	Method and Description
Instant	currentWatermark() Return estimated output watermark.
Instant	getState() Get current state of the WatermarkEstimator instance, which can be used to recreate the WatermarkEstimator when processing the restriction.

Methods inherited from class java.lang.Object

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

Constructor Detail

WallTime

public WallTime(Instant watermark)

Method Detail

currentWatermark

public Instant currentWatermark()

Description copied from interface: WatermarkEstimator

Return estimated output watermark. This method must return monotonically increasing watermarks across instances that are constructed from prior state.

Specified by:

currentWatermark in interface WatermarkEstimator<Instant>

getState

public Instant getState()

Description copied from interface: WatermarkEstimator

Get current state of the WatermarkEstimator instance, which can be used to recreate the WatermarkEstimator when processing the restriction. See DoFn.NewWatermarkEstimator for additional details.

The internal state of the estimator must not be mutated by this method.

The state returned must not be mutated.

Specified by:

getState in interface WatermarkEstimator<Instant>