[
https://issues.apache.org/jira/browse/HDFS-1103?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12935560#action_12935560
]
Thanh Do commented on HDFS-1103:
--------------------------------
"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)). "
Hairong, can you explain to me that why RBW B and RBW C's GS are bumped up.
Is that because of the lease recovery protocol?
But from my understanding, from Todd description, NN lease recovery is trigger
after Machine A report...
> 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.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
