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https://issues.apache.org/jira/browse/HDFS-1103?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12866018#action_12866018
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Todd Lipcon commented on HDFS-1103:
-----------------------------------

This is definitely the same issue -- I remember now that I opened this issue 
before when I had started forward-porting those same tests :)

I'm not 100% sure what the right recourse is - should we in fact always recover 
the longest valid replica for RWR/RUR cases, even if it means a lower 
replication count?

> Replica recovery doesn't distinguish between flushed-but-corrupted last chunk 
> and unflushed last chunk
> ------------------------------------------------------------------------------------------------------
>
>                 Key: HDFS-1103
>                 URL: https://issues.apache.org/jira/browse/HDFS-1103
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: data-node
>    Affects Versions: 0.21.0, 0.22.0
>            Reporter: Todd Lipcon
>            Priority: Blocker
>         Attachments: hdfs-1103-test.txt
>
>
> When the DN creates a replica under recovery, it calls validateIntegrity, 
> which truncates the last checksum chunk off of a replica if it is found to be 
> invalid. Then when the block recovery process happens, this shortened block 
> wins over a longer replica from another node where there was no corruption. 
> Thus, if just one of the DNs has an invalid last checksum chunk, data that 
> has been sync()ed to other datanodes can be lost.

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