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https://issues.apache.org/jira/browse/HBASE-6358?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13428368#comment-13428368
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Dave Revell commented on HBASE-6358:
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@Todd, that idea seems fine to me overall.
If we just did the slow copy in LoadIncrementalHFiles as I suggested earlier,
users would still have the option of doing distcp before calling
LoadIncrementalHFiles if they need performance. This has the benefits of
# not breaking the current use case of non-local bulk loading when size or
speed requirements are modest
# not requiring a new DistributedLoadIncrementalHFiles utility
This scheme would not give locality though, so users with serious performance
requirements might not be satisfied.
> Bulkloading from remote filesystem is problematic
> -------------------------------------------------
>
> Key: HBASE-6358
> URL: https://issues.apache.org/jira/browse/HBASE-6358
> Project: HBase
> Issue Type: Bug
> Components: regionserver
> Affects Versions: 0.94.0
> Reporter: Dave Revell
> Assignee: Dave Revell
> Attachments: 6358-suggestion.txt, HBASE-6358-trunk-v1.diff,
> HBASE-6358-trunk-v2.diff, HBASE-6358-trunk-v3.diff
>
>
> Bulk loading hfiles that don't live on the same filesystem as HBase can cause
> problems for subtle reasons.
> In Store.bulkLoadHFile(), the regionserver will copy the source hfile to its
> own filesystem if it's not already there. Since this can take a long time for
> large hfiles, it's likely that the client will timeout and retry. When the
> client retries repeatedly, there may be several bulkload operations in flight
> for the same hfile, causing lots of unnecessary IO and tying up handler
> threads. This can seriously impact performance. In my case, the cluster
> became unusable and the regionservers had to be kill -9'ed.
> Possible solutions:
> # Require that hfiles already be on the same filesystem as HBase in order
> for bulkloading to succeed. The copy could be handled by
> LoadIncrementalHFiles before the regionserver is called.
> # Others? I'm not familiar with Hadoop IPC so there may be tricks to extend
> the timeout or something else.
> I'm willing to write a patch but I'd appreciate recommendations on how to
> proceed.
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