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https://issues.apache.org/jira/browse/CASSANDRA-3934?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Sylvain Lebresne updated CASSANDRA-3934:
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Attachment: 3934.txt
Patch is against 1.0. The patch:
* don't retry if we have enough columns to satisfy the initial query
* keep the original count intact even if we do multiple retries.
* optimize the number of columns asked by a retry based on the ratio of number
of column got/total asked on the initial query.
> Short read protection is broken
> -------------------------------
>
> Key: CASSANDRA-3934
> URL: https://issues.apache.org/jira/browse/CASSANDRA-3934
> Project: Cassandra
> Issue Type: Bug
> Affects Versions: 1.0.2
> Reporter: Sylvain Lebresne
> Assignee: Sylvain Lebresne
> Priority: Minor
> Fix For: 1.0.8, 1.1.0
>
> Attachments: 3934.txt
>
>
> When a read needs to do more than one retry (due to short reads), the
> originalCount is not preserved by the retry leading to returning more than
> the requested number of columns.
> Moreover, when a retried read checks whether more retry is needed, it doesn't
> compare the number of live column retrieved against the original number of
> columns requested by the user, but against the number of columns requested
> during the retry, making it much more likely to actually do one more retry.
> This catch by the two tests 'short_read_test' and 'short_read_reversed_test'
> at https://github.com/riptano/cassandra-dtest/blob/master/consistency_test.py
> that are failing intermittently.
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