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https://issues.apache.org/jira/browse/KAFKA-17499?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17881721#comment-17881721
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Matthias J. Sax commented on KAFKA-17499:
-----------------------------------------
Thanks for the follow up. Two comments:
* There should also be a memory leak in 3.7 if you don't close the iterator –
I am not sure right now, why you only see it in 3.8 – closing iterators is (and
always was) the user's responsibility; thus, I don't think there is any
regression bug in 3.8
* Why do you think the commit you linked would be the root cause of the change
in behavior? Looking into the commit, I could not spot any remove `close()`
calls or newly added try-with-resource statement that would have close an
iterator in 3.7
Not sure what the next step for this ticket should be? I tend to say, we should
close it as "not a problem", but I am also confused (there might actually be a
bug in 3.7 for which KS incorrectly closes an iterator...) and curious about
the details.
> Memory leak when using ReadOnlyKeyValueStore `all()` method
> -----------------------------------------------------------
>
> Key: KAFKA-17499
> URL: https://issues.apache.org/jira/browse/KAFKA-17499
> Project: Kafka
> Issue Type: Bug
> Components: streams
> Affects Versions: 3.8.0
> Reporter: James Cook
> Assignee: Bill Bejeck
> Priority: Major
> Attachments: Screenshot 2024-09-09 at 08.31.57.png, Screenshot
> 2024-09-09 at 08.32.16.png, Screenshot 2024-09-09 at 08.32.25.png, Screenshot
> 2024-09-09 at 08.35.07.png
>
>
> There is a memory leak when using the `.all()` method of
> ReadOnlyKeyValueStore (specifically MeteredTimestampedKeyValueStore).
> I have recreated the problem in a small app here:
> [https://github.com/jamescookie/kafka-stream-memory-leak]
> When I run the test method using 3.8.0, I get this memory footprint:
> !Screenshot 2024-09-09 at 08.31.57.png!
> In a little over 90 seconds the number of `java.util.TreeMap$Entry` grows to
> over 10 million:
> !Screenshot 2024-09-09 at 08.32.16.png!
> !Screenshot 2024-09-09 at 08.32.25.png!
>
> When running against 3.7.1, this does not happen:
> !Screenshot 2024-09-09 at 08.35.07.png!
>
> The workaround (and correct way of coding) is to wrap a try-with-resources
> statement around the `store.all()`.
> I think this has been caused by this
> [commit|https://github.com/apache/kafka/pull/15219/files] to fix KAFKA-15770
>
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