[
https://issues.apache.org/jira/browse/HADOOP-13786?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15644187#comment-15644187
]
Steve Loughran commented on HADOOP-13786:
-----------------------------------------
One thing to consider: an atomic PUT-no-overwrite can be used for speculative
commits of a single file; I'm not so confident that it can be used for any task
writing more than one file: it's no longer a single atomic commit at the end of
the task. There's also the little detail which the output committer code in
mapred.Task assumes that work is not-committed until the final communication
with the AM; we'll need to make sure that cleanup always takes place. Maybe the
> add output committer which uses s3guard for consistent O(1) commits to S3
> -------------------------------------------------------------------------
>
> Key: HADOOP-13786
> URL: https://issues.apache.org/jira/browse/HADOOP-13786
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs/s3
> Affects Versions: 3.0.0-alpha2
> Reporter: Steve Loughran
> Assignee: Steve Loughran
>
> A goal of this code is "support O(1) commits to S3 repositories in the
> presence of failures". Implement it, including whatever is needed to
> demonstrate the correctness of the algorithm. (that is, assuming that s3guard
> provides a consistent view of the presence/absence of blobs, show that we can
> commit directly).
> I consider ourselves free to expose the blobstore-ness of the s3 output
> streams (ie. not visible until the close()), if we need to use that to allow
> us to abort commit operations.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
