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https://issues.apache.org/jira/browse/HDFS-125?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14068950#comment-14068950
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Allen Wittenauer edited comment on HDFS-125 at 7/21/14 6:12 PM:
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This feels like a special case of the problems mentioned in HDFS-366 and 
friends.


was (Author: aw):
This feels like a special case of the problems mentioned in HDFS-366 .

> Consistency of different replicas of the same block is not checked.
> -------------------------------------------------------------------
>
>                 Key: HDFS-125
>                 URL: https://issues.apache.org/jira/browse/HDFS-125
>             Project: Hadoop HDFS
>          Issue Type: Bug
>            Reporter: Konstantin Shvachko
>
> HDFS currently detects corrupted replicas by verifying that its contents 
> matches the checksum stored in the block meta-file. This is done 
> independently for each replica of the block on the data-node it belongs to. 
> But we do not check that the replicas are identical across data-nodes as long 
> as they have the same size.
> This is not common but can happen as a result of a software bug or an 
> operator mismanagement. And in this case different clients will read 
> different data from the same file.



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