Hi Sven, You will see this exception during leader election. When the leader for a partition moves to another broker, there is a period during which the replicas would still connect to the original leader, at which point they will raise this exception. This should be a very short period, after which they will connect to and replicate from the new leader correctly.
This is not a fatal error, and you will see it if you are bouncing brokers (since all the leaders on that broker will have to move after the bounce). You may also see it if some brokers have connectivity issues: they may be considered dead, and their partitions would be moved elsewhere. Hope this helps, Apurva On Tue, Dec 6, 2016 at 10:06 AM, Sven Ludwig <s_lud...@gmx.de> wrote: > Hello, > > in our Kafka clusters we sometimes observe a specific ERROR log-statement, > and therefore we have doubts whether it is already running sable in our > configuration. This occurs every now and then, like two or three times in a > day. It is actually the predominant ERROR log-statement in our cluster. > Example: > > [2016-12-06 17:14:50,909] ERROR [ReplicaFetcherThread-0-3], Error for > partition [<topic_name>,<partition_number>] to broker > 3:org.apache.kafka.common.errors.NotLeaderForPartitionException: This > server is > not the leader for that topic-partition. (kafka.server. > ReplicaFetcherThread) > > We already asked Google, but we did not find sufficient answers to our > questions, therefore I am asking on the mailing list: > > 1. What are the possible reasons for this particular error? > > 2. What are the implications of it? > > 3. What can be done to prevent it? > > Best Regards, > Sven >
