[
https://issues.apache.org/jira/browse/HDFS-8118?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14660213#comment-14660213
]
Casey Brotherton commented on HDFS-8118:
----------------------------------------
Talked with Harsh about this offline.
Still working through a testcase. We have talked about a method for delaying
between the different checkpoints.
There are still difficulties, though , as the problem occurs when two different
users delete files, and there is a delay between checkpointing each user's
deletes.
However, TestTrash operates under the assumption that there is only one user
that is creating files, and removing them for the trash.
( For example, the shell is used to getCurrentTrashDirectory, and that will
only return one location. For a test, I will either need to
break Object Oriented walls, and create a path with users/d/.Trash/Current, or
create a test that doesn't really test for the issue. )
Still trying to work on this.
> Delay in checkpointing Trash can leave trash for 2 intervals before deleting
> ----------------------------------------------------------------------------
>
> Key: HDFS-8118
> URL: https://issues.apache.org/jira/browse/HDFS-8118
> Project: Hadoop HDFS
> Issue Type: Bug
> Reporter: Casey Brotherton
> Assignee: Casey Brotherton
> Priority: Trivial
> Attachments: HDFS-8118.patch
>
>
> When the fs.trash.checkpoint.interval and the fs.trash.interval are set
> non-zero and the same, it is possible for trash to be left for two intervals.
> The TrashPolicyDefault will use a floor and ceiling function to ensure that
> the Trash will be checkpointed every "interval" of minutes.
> Each user's trash is checkpointed individually. The time resolution of the
> checkpoint timestamp is to the second.
> If the seconds switch while one user is checkpointing, then the next user's
> timestamp will be later.
> This will cause the next user's checkpoint to not be deleted at the next
> interval.
> I have recreated this in a lab cluster
> I also have a suggestion for a patch that I can upload later tonight after
> testing it further.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
