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https://issues.apache.org/jira/browse/HBASE-2856?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12981151#action_12981151
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stack commented on HBASE-2856:
------------------------------

How do the arrays of outstanding txs work?  How do you correlate a particular 
bit to a particular transaction?

I don't get how this would be different than read point since you can't return 
to client till all transactions before yours have completed, right?  Or does 
the bit array somehow expand our vocabulary beyond binary read point?

> TestAcidGuarantee broken on trunk 
> ----------------------------------
>
>                 Key: HBASE-2856
>                 URL: https://issues.apache.org/jira/browse/HBASE-2856
>             Project: HBase
>          Issue Type: Bug
>    Affects Versions: 0.89.20100621
>            Reporter: ryan rawson
>            Assignee: stack
>            Priority: Blocker
>             Fix For: 0.92.0
>
>         Attachments: 2856-v2.txt, 2856-v3.txt, acid.txt
>
>
> TestAcidGuarantee has a test whereby it attempts to read a number of columns 
> from a row, and every so often the first column of N is different, when it 
> should be the same.  This is a bug deep inside the scanner whereby the first 
> peek() of a row is done at time T then the rest of the read is done at T+1 
> after a flush, thus the memstoreTS data is lost, and previously 'uncommitted' 
> data becomes committed and flushed to disk.
> One possible solution is to introduce the memstoreTS (or similarly equivalent 
> value) to the HFile thus allowing us to preserve read consistency past 
> flushes.  Another solution involves fixing the scanners so that peek() is not 
> destructive (and thus might return different things at different times alas).

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