I installed the stable version of kafka (0.8.1 with 2.9.2 Scala) as per their website and am running it with a 3 node zookeeper ensemble (3.4.6). I tried to create a test topic but keep seeing that there is no leader assigned to the partition of the topic:
[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:**
I tried to write to the topic anyway using the console producer but ran into the LeaderNotAvailableException exception:
[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)
I should also state that this was working initially for a few days and then suddenly any topic that was created had this missing leader problem.
Kafka uses an external coordination framework (by default Zookeeper) to maintain configuration. It seems the configuration is now out-of-sync with the Kafka log data. In this case, I'd remove affected topic data and related Zookeeper data.
For Test Environment:
Kafka-server
and Zookeeper-server
/tmp/kafka-log
and /tmp/zookeeper
.Kafka-server
and Zookeeper-server
againNow you are able to work with the topic again.
For Production Environment:
As the Kafka topics are stored in different directories, you should remove particular directories. You should also remove /brokers/{broker_id}/topics/{broken_topic}
from Zookeeper by using a Zookeeper client.
Please read Kafka documentation carefully to make sure the configuration structure, before you do anything stupid. Kafka is rolling out a delete topic feature (KAFKA-330), so that the problem can be solved more easily.