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https://issues.apache.org/jira/browse/HDFS-10178?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15224294#comment-15224294
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Kihwal Lee commented on HDFS-10178:
-----------------------------------
[~vinayrpet], sorry, I gave a confusing description of the problem. I was
mixing the meta file header and the non-payload protobuf fields. After a
connection is made and the command is parsed, a {{BlockReceiver}} is created
and {{createRbw()}} is called before getting to the packet. It creates a meta
file with header only. If this is used for transferring the block, the checksum
type is lost.
> Permanent write failures can happen if pipeline recoveries occur for the
> first packet
> -------------------------------------------------------------------------------------
>
> Key: HDFS-10178
> URL: https://issues.apache.org/jira/browse/HDFS-10178
> Project: Hadoop HDFS
> Issue Type: Bug
> Reporter: Kihwal Lee
> Assignee: Kihwal Lee
> Priority: Critical
> Attachments: HDFS-10178.patch, HDFS-10178.v2.patch,
> HDFS-10178.v3.patch, HDFS-10178.v4.patch
>
>
> We have observed that write fails permanently if the first packet doesn't go
> through properly and pipeline recovery happens. If the packet header is sent
> out, but the data portion of the packet does not reach one or more datanodes
> in time, the pipeline recovery will be done against the 0-byte partial block.
>
> If additional datanodes are added, the block is transferred to the new nodes.
> After the transfer, each node will have a meta file containing the header
> and 0-length data block file. The pipeline recovery seems to work correctly
> up to this point, but write fails when actual data packet is resent.
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