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https://issues.apache.org/jira/browse/CASSANDRA-9669?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15112566#comment-15112566
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Benedict commented on CASSANDRA-9669:
-------------------------------------

I've already made the changes and am working on a merge (you assume correctly; 
it is in fact quite painful).

> If sstable flushes complete out of order, on restart we can fail to replay 
> necessary commit log records
> -------------------------------------------------------------------------------------------------------
>
>                 Key: CASSANDRA-9669
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-9669
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Local Write-Read Paths
>            Reporter: Benedict
>            Assignee: Benedict
>            Priority: Critical
>              Labels: correctness
>             Fix For: 2.2.x, 3.0.x, 3.x
>
>
> While {{postFlushExecutor}} ensures it never expires CL entries out-of-order, 
> on restart we simply take the maximum replay position of any sstable on disk, 
> and ignore anything prior. 
> It is quite possible for there to be two flushes triggered for a given table, 
> and for the second to finish first by virtue of containing a much smaller 
> quantity of live data (or perhaps the disk is just under less pressure). If 
> we crash before the first sstable has been written, then on restart the data 
> it would have represented will disappear, since we will not replay the CL 
> records.
> This looks to be a bug present since time immemorial, and also seems pretty 
> serious.



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