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https://issues.apache.org/jira/browse/HDFS-10178?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Kihwal Lee updated HDFS-10178:
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Description:
We have observed that write fails permanently if the first packet doesn't go
through properly and pipeline recovery happens. If the write op creates a
pipeline, but the actual data 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.
was:
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.
> 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 write op creates a
> pipeline, but the actual data 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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