[
https://issues.apache.org/jira/browse/HDFS-3875?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13508136#comment-13508136
]
Kihwal Lee commented on HDFS-3875:
----------------------------------
Whether it returns or throws an exception the result is not very different. The
packet responder will log the checksum error and initiate the shutdown. If an
exception is thrown, datanode ends up logging much more with multiple stack
traces. I thought clean termination of the writer (DataXceiver) thread is
acceptable, since it is a controlled shutdown with a purpose and expected
outcome, rather than a panic shutdown. If you think throwing exception makes
more sense, I will update the patch.
> Issue handling checksum errors in write pipeline
> ------------------------------------------------
>
> Key: HDFS-3875
> URL: https://issues.apache.org/jira/browse/HDFS-3875
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: datanode, hdfs-client
> Affects Versions: 2.0.2-alpha
> Reporter: Todd Lipcon
> Assignee: Kihwal Lee
> Priority: Blocker
> Attachments: hdfs-3875.branch-0.23.no.test.patch.txt,
> hdfs-3875.branch-0.23.with.test.patch.txt, hdfs-3875.trunk.no.test.patch.txt,
> hdfs-3875.trunk.no.test.patch.txt, hdfs-3875.trunk.with.test.patch.txt,
> hdfs-3875.trunk.with.test.patch.txt, hdfs-3875-wip.patch
>
>
> We saw this issue with one block in a large test cluster. The client is
> storing the data with replication level 2, and we saw the following:
> - the second node in the pipeline detects a checksum error on the data it
> received from the first node. We don't know if the client sent a bad
> checksum, or if it got corrupted between node 1 and node 2 in the pipeline.
> - this caused the second node to get kicked out of the pipeline, since it
> threw an exception. The pipeline started up again with only one replica (the
> first node in the pipeline)
> - this replica was later determined to be corrupt by the block scanner, and
> unrecoverable since it is the only replica
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
