hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Dave Revell (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-6358) Bulkloading from remote filesystem is problematic
Date Fri, 03 Aug 2012 20:49:02 GMT

    [ https://issues.apache.org/jira/browse/HBASE-6358?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13428368#comment-13428368
] 

Dave Revell commented on HBASE-6358:
------------------------------------

@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.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message