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HBase, mail # user - independent scans to same region processed serially


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Re: independent scans to same region processed serially
Marcos Ortiz 2013-02-09, 03:18
Regards, James,
Hari Kumar, from Ericsson Labs, in Data && Knowledge blog talked about
these issues:
http://labs.ericsson.com/blog/hbase-performance-tuners

It would be nice to talk with him to convince him to share its knowledge
here in the list, or in the
next HBaseCon
On 02/08/2013 08:49 PM, James Taylor wrote:
> Wanted to check with folks and see if they've seen an issue around
> this before digging in deeper. I'm on 0.94.2. If I execute in parallel
> multiple scans to different parts of the same region, they appear to
> be processed serially. It's actually faster from the client side to
> execute a single serial scan than it is to execute multiple parallel
> scans to different segments of the region. I do have region observer
> coprocessors for the table I'm scanning, but my code is not doing any
> synchronization.
>
> Is there a known limitation in this area? Anyone else see anything
> similar?
>
>     James

--
Marcos Ortiz Valmaseda,
Product Manager && Data Scientist at UCI
Blog: http://marcosluis2186.posterous.com
Twitter: @marcosluis2186 <http://twitter.com/marcosluis2186>