[
https://issues.apache.org/jira/browse/HADOOP-3677?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12612340#action_12612340
]
Raghu Angadi commented on HADOOP-3677:
--------------------------------------
I think it is better to fix the problem than asking users to go through
different procedure for upgrade. There are users with vastly different
expertise and caution. What happens if they don't follow the procedure by
mistake?
Also this special work around needs to be followed in even in future when some
one is upgrading from 0.17 to 0.20.
> Problems with generation stamp upgrade
> --------------------------------------
>
> Key: HADOOP-3677
> URL: https://issues.apache.org/jira/browse/HADOOP-3677
> Project: Hadoop Core
> Issue Type: Bug
> Components: dfs
> Affects Versions: 0.18.0
> Reporter: Konstantin Shvachko
> Assignee: dhruba borthakur
> Priority: Blocker
> Fix For: 0.18.0
>
>
> # The generation stamp upgrade renames blocks' meta-files so that the name
> contains the block generation stamp as stated in HADOOP-2656.
> If a data-node has blocks that do not belong to any files and the name-node
> asks the data-node to remove those blocks
> during or before the upgrade started the data-node will remove the blocks but
> not the meta-files because their names
> are still in the old format which is not recognized by the new code. So we
> can end up with a number of garbage files which
> will be hard to recognize that they are unused and the system will never
> remove them automatically.
> I think this should be handled by the upgrade code in the end, but may be it
> will be right to fix HADOOP-3002 for the 0.18 release,
> which will avoid scheduling block removal when the name-node is in safe-mode.
> # I was not able to get the upgrade -force option to work. This option lets
> the name-node proceed with a distributed upgrade even if
> the data-nodes are not able to complete their local upgrades. Did we test
> this feature at all for the generation stamp upgrade?
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
