使用Kafka 0.8.1和Zookeeper 3.4.6时遇到LeaderNotAvailableException

Question

[kafka_2.9.2-0.8.1]$ ./bin/kafka-topics.sh --zookeeper <zookeeper_ensemble> --describe --topic test-1
Topic:test-1    PartitionCount:1    ReplicationFactor:3 Configs:
    Topic: test-1   Partition: 0    **Leader: none**    Replicas: 0,1,2 **Isr:** 

我试图使用控制台生成器写入主题,但遇到LeaderNotAvailableException异常：

[kafka_2.9.2-0.8.1]$ ./kafka-console-producer.sh --broker-list <broker_list> --topic test-1

hello world

[2014-04-22 11:58:48,297] WARN Error while fetching metadata [{TopicMetadata for topic test-1 -> 
No partition metadata for topic test-1 due to kafka.common.LeaderNotAvailableException}] for topic [test-1]: class kafka.common.LeaderNotAvailableException  (kafka.producer.BrokerPartitionInfo)

[2014-04-22 11:58:48,321] WARN Error while fetching metadata [{TopicMetadata for topic test-1 -> 
No partition metadata for topic test-1 due to kafka.common.LeaderNotAvailableException}] for topic [test-1]: class kafka.common.LeaderNotAvailableException  (kafka.producer.BrokerPartitionInfo)

[2014-04-22 11:58:48,322] ERROR Failed to collate messages by topic, partition due to: Failed to fetch topic metadata for topic: test-1 (kafka.producer.async.DefaultEventHandler)

[2014-04-22 11:58:48,445] WARN Error while fetching metadata [{TopicMetadata for topic test-1 -> 
No partition metadata for topic test-1 due to kafka.common.LeaderNotAvailableException}] for topic [test-1]: class kafka.common.LeaderNotAvailableException  (kafka.producer.BrokerPartitionInfo)

[2014-04-22 11:58:48,467] WARN Error while fetching metadata [{TopicMetadata for topic test-1 -> 
No partition metadata for topic test-1 due to kafka.common.LeaderNotAvailableException}] for topic [test-1]: class kafka.common.LeaderNotAvailableException  (kafka.producer.BrokerPartitionInfo)

[2014-04-22 11:58:48,467] ERROR Failed to collate messages by topic, partition due to: Failed to fetch topic metadata for topic: test-1 (kafka.producer.async.DefaultEventHandler)

[2014-04-22 11:58:48,590] WARN Error while fetching metadata [{TopicMetadata for topic test-1 -> 
No partition metadata for topic test-1 due to kafka.common.LeaderNotAvailableException}] for topic [test-1]: class kafka.common.LeaderNotAvailableException  (kafka.producer.BrokerPartitionInfo)

[2014-04-22 11:58:48,612] WARN Error while fetching metadata [{TopicMetadata for topic test-1 -> 
No partition metadata for topic test-1 due to kafka.common.LeaderNotAvailableException}] for topic [test-1]: class kafka.common.LeaderNotAvailableException  (kafka.producer.BrokerPartitionInfo)

[2014-04-22 11:58:48,612] ERROR Failed to collate messages by topic, partition due to: Failed to fetch topic metadata for topic: test-1 (kafka.producer.async.DefaultEventHandler)

[2014-04-22 11:58:48,731] WARN Error while fetching metadata [{TopicMetadata for topic test-1 -> 
No partition metadata for topic test-1 due to kafka.common.LeaderNotAvailableException}] for topic [test-1]: class kafka.common.LeaderNotAvailableException  (kafka.producer.BrokerPartitionInfo)

[2014-04-22 11:58:48,753] WARN Error while fetching metadata [{TopicMetadata for topic test-1 -> 
No partition metadata for topic test-1 due to kafka.common.LeaderNotAvailableException}] for topic [test-1]: class kafka.common.LeaderNotAvailableException  (kafka.producer.BrokerPartitionInfo)

[2014-04-22 11:58:48,754] ERROR Failed to collate messages by topic, partition due to: Failed to fetch topic metadata for topic: test-1 (kafka.producer.async.DefaultEventHandler)

[2014-04-22 11:58:48,876] WARN Error while fetching metadata [{TopicMetadata for topic test-1 -> 
No partition metadata for topic test-1 due to kafka.common.LeaderNotAvailableException}] for topic [test-1]: class kafka.common.LeaderNotAvailableException  (kafka.producer.BrokerPartitionInfo)

[2014-04-22 11:58:48,877] ERROR Failed to send requests for topics test-1 with correlation ids in [0,8] (kafka.producer.async.DefaultEventHandler)

[2014-04-22 11:58:48,878] ERROR Error in handling batch of 1 events (kafka.producer.async.ProducerSendThread)
kafka.common.FailedToSendMessageException: Failed to send messages after 3 tries.
    at kafka.producer.async.DefaultEventHandler.handle(DefaultEventHandler.scala:90)
    at kafka.producer.async.ProducerSendThread.tryToHandle(ProducerSendThread.scala:104)
    at kafka.producer.async.ProducerSendThread$$anonfun$processEvents$3.apply(ProducerSendThread.scala:87)
    at kafka.producer.async.ProducerSendThread$$anonfun$processEvents$3.apply(ProducerSendThread.scala:67)
    at scala.collection.immutable.Stream.foreach(Stream.scala:547)
    at kafka.producer.async.ProducerSendThread.processEvents(ProducerSendThread.scala:66)
    at kafka.producer.async.ProducerSendThread.run(ProducerSendThread.scala:44)

我还应该指出，这在最初的几天内是有效的，然后突然间，任何一个被创建的主题都有这个缺少领导者的问题。

Answer 1

Kafka使用外部协调框架（默认为Zookeeper）来维护配置。现在的配置似乎与Kafka日志数据不同步。在这种情况下，我会删除受影响的主题数据和相关的Zookeeper数据。

对于测试环境：

1. 停止kafka-server和zookeeper-server
2. 删除这两个服务的数据目录，默认情况下，它们是/tmp/kafka-log和/tmp/zookeeper。
3. 再次启动kafka-server和zookeeper-server
4. 创建新主题

现在你可以再一次使用这个主题了。

对于生产环境：

由于Kafaka主题存储在不同的目录中，您应该删除特定的目录。还应该使用Zookeeper客户端从Zookeeper中删除/brokers/{broker_id}/topics/{broken_topic}。