Andrew Wang created HDFS-4596:
---------------------------------
Summary: Shutting down namenode during checkpointing can lead to
md5sum error
Key: HDFS-4596
URL: https://issues.apache.org/jira/browse/HDFS-4596
Project: Hadoop HDFS
Issue Type: Bug
Components: namenode
Affects Versions: 3.0.0
Reporter: Andrew Wang
Assignee: Andrew Wang
Fix For: 2.0.4-alpha
This is a really rare error that can hit if a NN shutdown happens during the
checkpointing process.
Checkpointing and restarting nominally looks like this:
# FSImage is written to a tmp file and then renamed
# MD5 file is written to a tmp file and then renamed
# NN is killed and restarted
# NN scans storage directories and picks up the renamed image file
# NN validates that the image file matches its md5 file
If the NN is killed before step 2 completes, this is what happens:
# FSImage is written to a tmp file and then renamed
# NN is killed and restarted (no MD5 file!)
# NN scans storage directories and picks up the renamed image file
# Since there's no matching MD5 file, NN errors out with a checksum error
I think we can fix this by inverting the order of writing the image then md5,
or inverting the order of reading the image then md5.
--
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
