[
https://issues.apache.org/jira/browse/KAFKA-6584?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16376591#comment-16376591
]
Manikumar commented on KAFKA-6584:
----------------------------------
Thanks for details. looks like this is the root cause for existing issues like
KAFKA-4277, KAFKA-5971
> Session expiration concurrent with ZooKeeper leadership failover may lead to
> broker registration failure
> --------------------------------------------------------------------------------------------------------
>
> Key: KAFKA-6584
> URL: https://issues.apache.org/jira/browse/KAFKA-6584
> Project: Kafka
> Issue Type: Bug
> Affects Versions: 1.0.0
> Reporter: Chris Thunes
> Priority: Major
>
> It seems that an edge case exists which can lead to sessions "un-expiring"
> during a ZooKeeper leadership failover. Additional details can be found in
> ZOOKEEPER-2985.
> This leads to a NODEXISTS error when attempting to re-create the ephemeral
> brokers/ids/\{id} node in ZkUtils.registerBrokerInZk. We experienced this
> issue on each node within a 3-node Kafka cluster running 1.0.0. All three
> nodes continued running (producers and consumers appeared unaffected), but
> none of the nodes were considered online and partition leadership could be
> not re-assigned.
> I took a quick look at trunk and I believe the issue is still present, but
> has moved into KafkaZkClient.checkedEphemeralCreate which will [raise an
> error|https://github.com/apache/kafka/blob/90e0bbe/core/src/main/scala/kafka/zk/KafkaZkClient.scala#L1512]
> when it finds that the broker/ids/\{id} node exists, but belongs to the old
> (believed expired) session.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
