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https://issues.apache.org/jira/browse/KAFKA-8970?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16944806#comment-16944806
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Boyang Chen commented on KAFKA-8970:
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Thanks for the report Nishkam. I suspect your unusual way of initializing two
stream instances on the same physical host could be triggering this problem, as
natively we assume single reader-writer from stream JVM to state dir. If both
instances are reading from the same state dir, they probably overlap task
ownership during assignment which is also not a truly ideal scenario. I also
agree that using different state dir is a good temporary solution, but let's
see if the upgrade shall work first.
> StateDirectory creation fails with Exception
> --------------------------------------------
>
> Key: KAFKA-8970
> URL: https://issues.apache.org/jira/browse/KAFKA-8970
> Project: Kafka
> Issue Type: Bug
> Components: streams
> Reporter: Nishkam Ravi
> Priority: Major
>
> When two threads try to create KafkaStreams simultaneously, one of them
> succeeds while the other fails with the following exception:
> org.apache.kafka.streams.errors.StreamsException:
> org.apache.kafka.streams.errors.ProcessorStateException: base state directory
> [/tmp/kafka-streams] doesn't exist and couldn't be created
> Quick investigation suggests that this is because the code at/around:
> [https://github.com/apache/kafka/blob/trunk/streams/src/main/java/org/apache/kafka/streams/processor/internals/StateDirectory.java#L82]
> is not synchronized and can lead to race conditions.
> Specifying different values for state.dir can be a workaround for this issue
> but a bit cumbersome. Can we just make this synchronized?
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