Arpit Agarwal created HDFS-6981: ----------------------------------- Summary: DN upgrade with layout version change should not use trash Key: HDFS-6981 URL: https://issues.apache.org/jira/browse/HDFS-6981 Project: Hadoop HDFS Issue Type: Bug Components: datanode Affects Versions: 3.0.0 Reporter: James Thomas
Post HDFS-6800, we can encounter the following scenario: # We start with DN software version -55 and initiate a rolling upgrade to version -56 # We delete some blocks, and they are moved to trash # We roll back to DN software version -55 using the -rollback flag – since we are running the old code (prior to this patch), we will restore the previous directory but will not delete the trash # We append to some of the blocks that were deleted in step 2 # We then restart a DN that contains blocks that were appended to – since the trash still exists, it will be restored at this point, the appended-to blocks will be overwritten, and we will lose the appended data So I think we need to avoid writing anything to the trash directory if we have a previous directory. Thanks to [~james.thomas] for reporting this. -- This message was sent by Atlassian JIRA (v6.3.4#6332)