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https://issues.apache.org/jira/browse/ZOOKEEPER-1485?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15367709#comment-15367709
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Flavio Junqueira commented on ZOOKEEPER-1485:
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bq. Alternatively, we could add another counter in client code that records how
many times a wrap happen. This effectively make the real xid (xid + INT_MAX *
counter) not repeatable on client side. The counter could be sneaked into the
OpCode field (as we don't use all the bits so far) of the request header so the
times to wrap has a paper trail on server side as well.
If we are to do this, then perhaps we should just make the zxid a 64-bit
integer and deal with the backward compatibility problem.
> client xid overflow is not handled
> ----------------------------------
>
> Key: ZOOKEEPER-1485
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-1485
> Project: ZooKeeper
> Issue Type: Bug
> Components: c client, java client
> Affects Versions: 3.4.3, 3.3.5
> Reporter: Michi Mutsuzaki
> Assignee: Martin Kuchta
> Attachments: ZOOKEEPER-1485.patch
>
>
> Both Java and C clients use signed 32-bit int as XIDs. XIDs are assumed to be
> non-negative, and zookeeper uses some negative values as special XIDs (e.g.
> -2 for ping, -4 for auth). However, neither Java nor C client ensures the
> XIDs it generates are non-negative, and the server doesn't reject negative
> XIDs.
> Pat had some suggestions on how to fix this:
> - (bin-compat) Expire the session when the client sends a negative XID.
> - (bin-incompat) In addition to expiring the session, use 64-bit int for XID
> so that overflow will practically never happen.
> --Michi
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