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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
lars hofhansl 2013-02-09, 02:51
Is your data all in the blockcache, otherwise you might have run into HBASE-7336 (https://issues.apache.org/jira/browse/HBASE-7336).Fixed 0.94.4.
I assume you have enough handlers, etc. (i.e. does the same happen if issue multiple scan request across different region of the same region server?)
-- Lars

________________________________
 From: James Taylor <[EMAIL PROTECTED]>
To: HBase User <[EMAIL PROTECTED]>
Sent: Friday, February 8, 2013 5:49 PM
Subject: independent scans to same region processed serially
 
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