org.apache.kafka.streams.processor.PartitionGrouper Maven / Gradle / Ivy
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package org.apache.kafka.streams.processor;
import org.apache.kafka.common.Cluster;
import org.apache.kafka.common.TopicPartition;
import java.util.Map;
import java.util.Set;
/**
* A partition grouper that generates partition groups given the list of topic-partitions.
*
* This grouper also acts as the stream task creation function along with partition distribution
* such that each generated partition group is assigned with a distinct {@link TaskId};
* the created task ids will then be assigned to Kafka Streams instances that host the stream
* processing application.
*
* @deprecated since 2.4 release; will be removed in 3.0.0 via KAFKA-7785
*/
@Deprecated
public interface PartitionGrouper {
/**
* Returns a map of task ids to groups of partitions. A partition group forms a task, thus, partitions that are
* expected to be processed together must be in the same group.
*
* Note that the grouping of partitions need to be sticky such that for a given partition, its assigned
* task should always be the same regardless of the input parameters to this function. This is to ensure task's
* local state stores remain valid through workload rebalances among Kafka Streams instances.
*
* The default partition grouper implements this interface by assigning all partitions across different topics with the same
* partition id into the same task. See {@link DefaultPartitionGrouper} for more information.
*
* @param topicGroups The map from the topic group id to topics
* @param metadata Metadata of the consuming cluster
* @return a map of task ids to groups of partitions
*/
Map> partitionGroups(Map> topicGroups, Cluster metadata);
}