[ 
https://issues.apache.org/jira/browse/HDFS-13143?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16362872#comment-16362872
 ] 

Shashikant Banerjee commented on HDFS-13143:
--------------------------------------------

Patch v2 addresses the findBug warning.

> SnapshotDiff - snapshotDiffReport might be inconsistent if the snapshotDiff 
> calculation happens between a snapshot and the current tree
> ---------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: HDFS-13143
>                 URL: https://issues.apache.org/jira/browse/HDFS-13143
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>            Reporter: Shashikant Banerjee
>            Assignee: Shashikant Banerjee
>            Priority: Major
>         Attachments: HDFS-13143.001.patch, HDFS-13143.002.patch
>
>
> HDFS-12594 introduced an iterative approach for computing snapshotDiffs over 
> multiple rpc calls. The iterative approach depends upon the startPath (path 
> of the directory with respect to the snapshottable root) and the size of the 
> createdList (0 in case the startPath refers a file) to exactly determine form 
> where in each iteration the calculation has to start.
>  
> In case of the diff computation between a snapshot and current tree(if any of 
> the snapshot names specified in the getSnapshotDiffReport call is null or 
> empty), the last SnapshotDiff associated with directory/file might change 
> owing to changes in the current tree in between the rpc calls in the absence 
> of a global fsn lock. This might result in consistencies in the 
> snapshotDiffReport.
> In case the snapshotDiffReport computation needs to be done between the 
> current tree and a snapshot, we should fall back to non-iterative approach to 
> compute snapshotDiff.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org

Reply via email to