org.apache.kafka.clients.admin.NewPartitions Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.kafka.clients.admin;
import org.apache.kafka.common.annotation.InterfaceStability;
import java.util.List;
import java.util.Map;
/**
* Describes new partitions for a particular topic in a call to {@link Admin#createPartitions(Map)}.
*
* The API of this class is evolving, see {@link Admin} for details.
*/
@InterfaceStability.Evolving
public class NewPartitions {
private int totalCount;
private List> newAssignments;
private NewPartitions(int totalCount, List> newAssignments) {
this.totalCount = totalCount;
this.newAssignments = newAssignments;
}
/**
* Increase the partition count for a topic to the given {@code totalCount}.
* The assignment of new replicas to brokers will be decided by the broker.
*
* @param totalCount The total number of partitions after the operation succeeds.
*/
public static NewPartitions increaseTo(int totalCount) {
return new NewPartitions(totalCount, null);
}
/**
* Increase the partition count for a topic to the given {@code totalCount}
* assigning the new partitions according to the given {@code newAssignments}.
* The length of the given {@code newAssignments} should equal {@code totalCount - oldCount}, since
* the assignment of existing partitions are not changed.
* Each inner list of {@code newAssignments} should have a length equal to
* the topic's replication factor.
* The first broker id in each inner list is the "preferred replica".
*
* For example, suppose a topic currently has a replication factor of 2, and
* has 3 partitions. The number of partitions can be increased to 6 using a
* {@code NewPartition} constructed like this:
*
*
* NewPartitions.increaseTo(6, asList(asList(1, 2),
* asList(2, 3),
* asList(3, 1)))
*
* In this example partition 3's preferred leader will be broker 1, partition 4's preferred leader will be
* broker 2 and partition 5's preferred leader will be broker 3.
*
* @param totalCount The total number of partitions after the operation succeeds.
* @param newAssignments The replica assignments for the new partitions.
*/
public static NewPartitions increaseTo(int totalCount, List> newAssignments) {
return new NewPartitions(totalCount, newAssignments);
}
/**
* The total number of partitions after the operation succeeds.
*/
public int totalCount() {
return totalCount;
}
/**
* The replica assignments for the new partitions, or null if the assignment will be done by the controller.
*/
public List> assignments() {
return newAssignments;
}
@Override
public String toString() {
return "(totalCount=" + totalCount() + ", newAssignments=" + assignments() + ")";
}
}