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https://issues.apache.org/jira/browse/HDFS-1103?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12867381#action_12867381
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Hairong Kuang commented on HDFS-1103:
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I do not think that this is the case in 0.21 & the trunk. In our lease recovery
algorithm in 0.21, If there are 2 RBWs and 1 RWR, 1 RWR is excluded from the
lease recovery. In the scenario that you described, RBW B and RBW C's GS is
bumped and the length of recovered two replicas is truncated to MIN( len(B),
len(C)).
> 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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