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https://issues.apache.org/jira/browse/MAILBOX-209?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14352063#comment-14352063
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Eric Charles commented on MAILBOX-209:
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Can you rebase on latest trunk (uploaded patch does not apply here)? Thx.
> A data race is possible with Cassandra modseq generation
> --------------------------------------------------------
>
> Key: MAILBOX-209
> URL: https://issues.apache.org/jira/browse/MAILBOX-209
> Project: James Mailbox
> Issue Type: Bug
> Reporter: Tellier Benoit
> Attachments: fix_cassandra_modseq_provider.patch
>
>
> The Cassandra mailbox implementation proceed as follow to increase the modseq
> :
> - a first call to Cassandra to increase the modseq value for a given mailbox
> - a second call allow us to retrieve the current value.
> Note that you can not do it in a single call...
> In a distributed environment, imagine that :
> - for a mailbox the current modseq is n
> - server A increments modseq. Modseq is n+1
> - server B increments modseq. Modseq is n+2
> - server A and B then retrieve the modseq value and have a duplicated modseq
> : they for instance both can assign n+2 value to a different message.
> The problem can be solved using conditionnal updates with lightweight
> transactions.
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