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https://issues.apache.org/jira/browse/KAFKA-1120?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16331093#comment-16331093
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Jeff Widman edited comment on KAFKA-1120 at 1/18/18 7:58 PM:
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The issue description says "the broker will be in this weird state until it is
restarted."
Could this also be fixed by simply forcing a controller re-election through
removing the /controller znode? Since it will re-identify the leaders? In some
scenarios, it seems that might be a lighter-weight solution. I understand thisÂ
does not fix the root code cause, but just want to be sure I understand what
options I have if we hit this in an emergency situation.
was (Author: jeffwidman):
The issue description says "the broker will be in this weird state until it is
restarted."
Couldn't this also be fixed by simply forcing a controller re-election? Since
it will re-identiy the leaders?
> Controller could miss a broker state change
> --------------------------------------------
>
> Key: KAFKA-1120
> URL: https://issues.apache.org/jira/browse/KAFKA-1120
> Project: Kafka
> Issue Type: Sub-task
> Components: core
> Affects Versions: 0.8.1
> Reporter: Jun Rao
> Assignee: Mickael Maison
> Priority: Major
> Labels: reliability
> Fix For: 1.1.0
>
>
> When the controller is in the middle of processing a task (e.g., preferred
> leader election, broker change), it holds a controller lock. During this
> time, a broker could have de-registered and re-registered itself in ZK. After
> the controller finishes processing the current task, it will start processing
> the logic in the broker change listener. However, it will see no broker
> change and therefore won't do anything to the restarted broker. This broker
> will be in a weird state since the controller doesn't inform it to become the
> leader of any partition. Yet, the cached metadata in other brokers could
> still list that broker as the leader for some partitions. Client requests
> routed to that broker will then get a TopicOrPartitionNotExistException. This
> broker will continue to be in this bad state until it's restarted again.
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