[
https://issues.apache.org/jira/browse/HADOOP-3873?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12618539#action_12618539
]
Tsz Wo (Nicholas), SZE commented on HADOOP-3873:
------------------------------------------------
> In most cases, the total size to be copied can be determined up front, before
> the copying begins, no?
Yes, you are right that we can pre-compute lists of files being copied and
impose whatever constraints. The new option is to automate the
pre-computation. DistCp currently computes a list of files before copying. I
am planning to change the computation so that the list will satisfy the
file/size limit constraints.
> What might be better is a mechanism to stop a DistCp job. E.g., one could
> provide a "stop" file name. When this is non-null, copying will stop as soon
> as the named file exists. Might that meet the need here?
This is a good idea to stop DistCp job nicely. Let me see whether it could
solve the backup use case described above.
> DistCp should have an option for limiting the number of files/bytes being
> copied
> --------------------------------------------------------------------------------
>
> Key: HADOOP-3873
> URL: https://issues.apache.org/jira/browse/HADOOP-3873
> Project: Hadoop Core
> Issue Type: New Feature
> Components: tools/distcp
> Reporter: Tsz Wo (Nicholas), SZE
>
> A single DistCp command may potentially copies a huge number of files/bytes.
> In such case, DistCp will run a long time and there is no way stop it nicely.
> It would be good if DistCp have an option to limit the number of files/bytes
> being copied. Once the limit is reached, DistCp will terminate and return
> success. All files copied are guaranteed to be good and there is no
> partially copied file.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
