org.apache.kafka.streams.processor

Class DefaultPartitionGrouper

java.lang.Object

org.apache.kafka.streams.processor.DefaultPartitionGrouper

All Implemented Interfaces:

PartitionGrouper

public class DefaultPartitionGrouper
extends Object
implements PartitionGrouper

Default implementation of the PartitionGrouper interface that groups partitions by the partition id. Join operations requires that topics of the joining entities are copartitoned, i.e., being partitioned by the same key and having the same number of partitions. Copartitioning is ensured by having the same number of partitions on joined topics, and by using the serialization and Producer's default partitioner.

Constructor Summary

Constructors

Constructor and Description
DefaultPartitionGrouper()

Method Summary

Methods

Modifier and Type	Method and Description
protected int	maxNumPartitions(Cluster metadata, Set<String> topics)
Map<TaskId,Set<TopicPartition>>	partitionGroups(Map<Integer,Set<String>> topicGroups, Cluster metadata) Generate tasks with the assigned topic partitions.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultPartitionGrouper

public DefaultPartitionGrouper()

Method Detail

partitionGroups

public Map<TaskId,Set<TopicPartition>> partitionGroups(Map<Integer,Set<String>> topicGroups,
                                              Cluster metadata)

Generate tasks with the assigned topic partitions.

Specified by:

partitionGroups in interface PartitionGrouper

Parameters:

topicGroups - group of topics that need to be joined together

metadata - metadata of the consuming cluster

Returns:

The map from generated task ids to the assigned partitions

maxNumPartitions

protected int maxNumPartitions(Cluster metadata,
                   Set<String> topics)

Throws:

StreamsException - if no metadata can be received for a topic