[
https://issues.apache.org/jira/browse/HDFS-12294?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16129256#comment-16129256
]
Yongjun Zhang commented on HDFS-12294:
--------------------------------------
Hi [~chris.douglas],
I thought I udpated here, but seems I did not finish.
The requirement is, if a file has attribute X in fsimage, but external provider
overrides it to be Y, we want distcp to copy X instead of Y.
The external provider can both add and remove attributes, My worry is that
filtering by user name would be hacky and even not work, since the same user
can request external attributes when not running distcp. Even when running
distcp, possibly some calls may also need the external attribute, such as check
permission.
In addition, any other user is supposed to be able to run distcp too.
Do you agree?
Thanks.
> Let distcp to bypass external attribute provider when calling getFileStatus
> etc at source cluster
> -------------------------------------------------------------------------------------------------
>
> Key: HDFS-12294
> URL: https://issues.apache.org/jira/browse/HDFS-12294
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: hdfs
> Reporter: Yongjun Zhang
> Assignee: Yongjun Zhang
>
> This is an alternative solution for HDFS-12202, which proposed introducing a
> new set of API, with an additional boolean parameter bypassExtAttrProvider,
> so to let NN bypass external attribute provider when getFileStatus. The goal
> is to avoid distcp from copying attributes from one cluster's external
> attribute provider and save to another cluster's fsimage.
> The solution here is, instead of having an additional parameter, encode this
> parameter to the path itself, when calling getFileStatus (and some other
> calls), NN will parse the path, and figure out that whether external
> attribute provider need to be bypassed. The suggested encoding is to have a
> prefix to the path before calling getFileStatus, e.g. /ab/c becomes
> /.reserved/bypassExtAttr/a/b/c. NN will parse the path at the very beginning.
> Thanks much to [~andrew.wang] for this suggestion. The scope of change is
> smaller and we don't have to change the FileSystem APIs.
>
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
