[ 
https://issues.apache.org/jira/browse/HADOOP-15297?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16395271#comment-16395271
 ] 

Steve Loughran commented on HADOOP-15297:
-----------------------------------------

+Attached the final patch which went in; s/skipcrccheck/skipcrc and rebased to 
trunk to address some conflict in aws/index.md

> Make S3A etag => checksum feature optional
> ------------------------------------------
>
>                 Key: HADOOP-15297
>                 URL: https://issues.apache.org/jira/browse/HADOOP-15297
>             Project: Hadoop Common
>          Issue Type: Sub-task
>          Components: fs/s3
>    Affects Versions: 3.1.0
>            Reporter: Steve Loughran
>            Assignee: Steve Loughran
>            Priority: Blocker
>             Fix For: 3.1.0
>
>         Attachments: HADOOP-15297-001.patchh, HADOOP-15297-002.patch, 
> HADOOP-15297-002.patch, HADOOP-15297-003.patch
>
>
> HADOOP-15273 shows how distcp doesn't handle non-HDFS filesystems with 
> checksums.
> Exposing Etags as checksums, HADOOP-13282, breaks workflows which back up to 
> s3a.
> Rather than revert  I want to make it an option, off by default. Once we are 
> happy with distcp in future, we can turn it on.
> Why an option? Because it lines up for a successor to distcp which saves src 
> and dest checksums to a file and can then verify whether or not files have 
> really changed. Currently distcp relies on dest checksum algorithm being the 
> same as the src for incremental updates, but if either of the stores don't 
> serve checksums, silently downgrades to not checking. 



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

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

Reply via email to