Package org.apache.kafka.clients.consumer.internals

Class AbstractStickyAssignor

java.lang.Object

org.apache.kafka.clients.consumer.internals.AbstractPartitionAssignor

org.apache.kafka.clients.consumer.internals.AbstractStickyAssignor

All Implemented Interfaces:

ConsumerPartitionAssignor

Direct Known Subclasses:

CooperativeStickyAssignor, StickyAssignor

public abstract class AbstractStickyAssignor
extends AbstractPartitionAssignor

Sticky assignment implementation used by StickyAssignor and CooperativeStickyAssignor. Sticky assignors are rack-aware. If racks are specified for consumers, we attempt to match consumer racks with partition replica racks on a best-effort basis, prioritizing balanced assignment over rack alignment. Previously owned partitions may be reassigned to improve rack locality. We use rack-aware assignment if both consumer and partition racks are available and some partitions have replicas only on a subset of racks.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	AbstractStickyAssignor.MemberData

Nested classes/interfaces inherited from class org.apache.kafka.clients.consumer.internals.AbstractPartitionAssignor

AbstractPartitionAssignor.MemberInfo

Nested classes/interfaces inherited from interface org.apache.kafka.clients.consumer.ConsumerPartitionAssignor

ConsumerPartitionAssignor.Assignment, ConsumerPartitionAssignor.GroupAssignment, ConsumerPartitionAssignor.GroupSubscription, ConsumerPartitionAssignor.RebalanceProtocol, ConsumerPartitionAssignor.Subscription

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_GENERATION
protected Map<org.apache.kafka.common.TopicPartition,String>	partitionsTransferringOwnership

Constructor Summary

Constructors

Constructor	Description
AbstractStickyAssignor()

Method Summary

Modifier and Type	Method	Description
Map<String,List<org.apache.kafka.common.TopicPartition>>	assign(Map<String,Integer> partitionsPerTopic, Map<String,ConsumerPartitionAssignor.Subscription> subscriptions)	Perform the group assignment given the partition counts and member subscriptions
Map<String,List<org.apache.kafka.common.TopicPartition>>	assignPartitions(Map<String,List<org.apache.kafka.common.PartitionInfo>> partitionsPerTopic, Map<String,ConsumerPartitionAssignor.Subscription> subscriptions)	Default implementation of assignPartitions() that does not include racks.
boolean	isSticky()
int	maxGeneration()
protected abstract AbstractStickyAssignor.MemberData	memberData(ConsumerPartitionAssignor.Subscription subscription)

Methods inherited from class org.apache.kafka.clients.consumer.internals.AbstractPartitionAssignor

assign, partitionInfosWithoutRacks, partitions, put, useRackAwareAssignment

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.kafka.clients.consumer.ConsumerPartitionAssignor

name, onAssignment, subscriptionUserData, supportedProtocols, version

Field Details

DEFAULT_GENERATION

public static final int DEFAULT_GENERATION

See Also:

• Constant Field Values

partitionsTransferringOwnership

protected Map<org.apache.kafka.common.TopicPartition,String> partitionsTransferringOwnership

Constructor Details

AbstractStickyAssignor

public AbstractStickyAssignor()

Method Details

memberData

protected abstract AbstractStickyAssignor.MemberData memberData(ConsumerPartitionAssignor.Subscription subscription)

assignPartitions

public Map<String,List<org.apache.kafka.common.TopicPartition>> assignPartitions(Map<String,List<org.apache.kafka.common.PartitionInfo>> partitionsPerTopic,
 Map<String,ConsumerPartitionAssignor.Subscription> subscriptions)

Description copied from class: AbstractPartitionAssignor

Default implementation of assignPartitions() that does not include racks. This is only included to avoid breaking any custom implementation that extends AbstractPartitionAssignor. Note that this class is internal, but to be safe, we are maintaining compatibility.

Overrides:

assignPartitions in class AbstractPartitionAssignor

assign

public Map<String,List<org.apache.kafka.common.TopicPartition>> assign(Map<String,Integer> partitionsPerTopic,
 Map<String,ConsumerPartitionAssignor.Subscription> subscriptions)

Description copied from class: AbstractPartitionAssignor

Perform the group assignment given the partition counts and member subscriptions

Specified by:

assign in class AbstractPartitionAssignor

Parameters:

partitionsPerTopic - The number of partitions for each subscribed topic. Topics not in metadata will be excluded from this map.

subscriptions - Map from the member id to their respective topic subscription

Returns:

Map from each member to the list of partitions assigned to them.

maxGeneration

public int maxGeneration()

isSticky

public boolean isSticky()