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https://issues.apache.org/jira/browse/CRUNCH-660?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16743122#comment-16743122
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Andrew Olson commented on CRUNCH-660:
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On a side note, even DistCp can be pretty severely afflicted by
https://issues.apache.org/jira/browse/HADOOP-15281 (it writes to a temp file
then does a costly S3 rename, but that extra work is parallelized across all of
the map tasks).
> FileTargetImpl uses Distcp vs FileUtils.copy
> --------------------------------------------
>
> Key: CRUNCH-660
> URL: https://issues.apache.org/jira/browse/CRUNCH-660
> Project: Crunch
> Issue Type: Improvement
> Components: Core
> Reporter: Micah Whitacre
> Assignee: Josh Wills
> Priority: Major
>
> So for handling multiple runtimes I'm not sure there is a way to solve this
> but documenting as a JIRA regardless.
> If you are running in a multi-cluster environment where you might want to
> read data from one cluster and then write the output on another cluster (e.g.
> generating HFiles to be loaded into a separate HBase cluster), the
> performance of moving files is noticeable. Specifically due to the fact that
> the moving of the files happens in the launcher/driver process versus as part
> of the node execution it seems.[1]
> An efficient option would be to kick off a DistCp instead but that would tie
> the target directly to a runtime which is not a great approach.
> [1] -
> https://github.com/apache/crunch/blob/5609b014378d3460a55ce25522f0c00659872807/crunch-core/src/main/java/org/apache/crunch/io/impl/FileTargetImpl.java#L157
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