title: Adding a new partition Kafka 0.8.1.1
body: <p>For a particular topic we want to have one partition per broker. The idea is that to scale we keep on adding brokers. However, when I test out how new partitions are added it does not work in the way I would expect. For example, I have three brokers: 2064029428, 2064029280, 2064028458. I create a new topic:</p>
  
  <pre><code>/opt/kafka/bin/kafka-topics.sh --create --zookeeper zk.net:2181/stream --topic test --partitions 2 --replication-factor 1
  
  /opt/kafka/bin/kafka-topics.sh --describe --zookeeper zk.net:2181/stream --topic test
  Topic:test  PartitionCount:2    ReplicationFactor:1 Configs:
  Topic: test Partition: 0    Leader: 2064029428  Replicas: 2064029428    Isr: 2064029428
  Topic: test Partition: 1    Leader: 2064028458  Replicas: 2064028458    Isr: 2064028458
  </code></pre>
  
  <p>I then alter the topic to add another partition.</p>
  
  <pre><code>/opt/kafka/bin/kafka-topics.sh --alter --zookeeper zk.net:2181/stream --topic test --partitions 3
  
  /opt/kafka/bin/kafka-topics.sh --describe --zookeeper zk.net:2181/stream --topic test
  Topic:test  PartitionCount:3    ReplicationFactor:1 Configs:
  Topic: test Partition: 0    Leader: 2064029428  Replicas: 2064029428    Isr: 2064029428
  Topic: test Partition: 1    Leader: 2064028458  Replicas: 2064028458    Isr: 2064028458
  Topic: test Partition: 2    Leader: 2064029428  Replicas: 2064029428    Isr: 2064029428
  </code></pre>
  
  <p>I would have expected the new partition to have been created on broker 2064029280 since it does not currently have a partition. Instead I get two partitions on the same broker 2064029428. Is this expected? Is there a way to control where the new partition is added? I tried the <code>--replica-assignment</code> option, which works when creating the topic, but doesn't not work when altering the topic.</p>