Package org.apache.flink.streaming.api.windowing.assigners

Enum WindowStagger

java.lang.Object

java.lang.Enum<WindowStagger>

org.apache.flink.streaming.api.windowing.assigners.WindowStagger

All Implemented Interfaces:

Serializable, Comparable<WindowStagger>

@PublicEvolving
public enum WindowStagger
extends Enum<WindowStagger>

A WindowStagger staggers offset in runtime for each window assignment.

Enum Constant Summary

Enum Constants

Enum Constant	Description
ALIGNED	Default mode, all panes fire at the same time across all partitions.
NATURAL	When the first event is received in the window operator, take the difference between the start of the window and current procesing time as the offset.
RANDOM	Stagger offset is sampled from uniform distribution U(0, WindowSize) when first event ingested in the partitioned operator.

Method Summary

Modifier and Type	Method	Description
abstract long	getStaggerOffset(long currentProcessingTime, long size)
static WindowStagger	valueOf(String name)	Returns the enum constant of this type with the specified name.
static WindowStagger[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

ALIGNED

public static final WindowStagger ALIGNED

Default mode, all panes fire at the same time across all partitions.

RANDOM

public static final WindowStagger RANDOM

Stagger offset is sampled from uniform distribution U(0, WindowSize) when first event ingested in the partitioned operator.

NATURAL

public static final WindowStagger NATURAL

When the first event is received in the window operator, take the difference between the start of the window and current procesing time as the offset. This way, windows are staggered based on when each parallel operator receives the first event.

Method Detail

values

public static WindowStagger[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (WindowStagger c : WindowStagger.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static WindowStagger valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

getStaggerOffset

public abstract long getStaggerOffset(long currentProcessingTime,
                                      long size)