Fine. I’m convinced. Double checked the patch and I was wrong about the config 
option. Thanks for the clarification. Patch looks like a nice workaround the 
problem. Approved.

Need another approval and it’s ready to go unless Damien wants to rebase it 
first.

Regards,
Andor


> On Aug 13, 2026, at 04:44, Dmitrii Duzhinskii <[email protected]> wrote:
> 
> Hi all,
> 
> A few clarifications on the patch:
> 
> 1. #1716 doesn't introduce a new config option. Making the limit 
> independently configurable was discussed, 
> and ztzg explained why it isn't needed. it simply tracks jute.maxbuffer:
> https://github.com/apache/zookeeper/pull/1716#issuecomment-866691807
> So there is nothing to deprecate later: when CloseSessionTxn goes away, the 
> check goes away with it. 
> The point of the patch is crash protection, not a new mechanism.
> 
> 2. What it does introduce is a new error code, which old clients won't 
> recognize. 
> That's a real trade-off, but the alternative is the whole cluster going down.
> An unknown error on the one misbehaving client is harmless in comparison.
> 
> 3. On the -1: @eolivelli seems to have stepped back from it in Aug 2024.
> "I think that we can resume this patch ... I don't have a better proposal at 
> the moment": 
> https://github.com/apache/zookeeper/pull/1716#issuecomment-2296414881
> 
> On process: the 2024 revival already turned into the non-fuzzy snapshot 
> discussion and then went quiet for lack of participants,
> while the production problem stayed. I'd suggest keeping this thread to the 
> blockers for merging the fix - a broader discussion will most likely end the 
> same way.
> 
> On ZOOKEEPER-4874 being small: technically perhaps, but conceptually it 
> reworks durability, 
> and I'd wait a few months after such a release before running it in 
> production anyway, so it can't be the near-term answer.
> 
> Andor, as for our numbers and use case: I'd rather not build the case on our 
> specifics. Sharing details would have to go through internal approval, and 
> that takes time. 
> What I can say: I run ZooKeeper for many products in a large company, two 
> independent products hit this issue, and there are other reports of it too. 
> We used to run an old internally patched version and recently moved to the 
> latest open-source release, wanting to stay with the community, and this is
> the first thing we hit. Let's focus on stopping the production crashes.
> 
> Dmitrii
> 
>> Hi all,
>> 
>> We've hit ZOOKEEPER-4306 (CloseSessionTxn exceeding jute.maxbuffer takes 
>> down the whole ensemble) twice in production, in two independent deployments 
>> — I've also left a comment on the JIRA.
>> 
>> PR #1716 has been open since 2021 and was rebased in Oct 2024 with a 
>> branch-3.9 backport (#2201), but both seem to have stalled since.
>> 
>> Is anything still blocking them? If the 2021 review comments are the 
>> remaining concern, we'd be glad to help address them
>> 
>> https://issues.apache.org/jira/browse/ZOOKEEPER-4306
>> https://github.com/apache/zookeeper/pull/1716
>> https://github.com/apache/zookeeper/pull/2201

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