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HBase >> mail # user >> independent scans to same region processed serially

James Taylor 2013-02-09, 01:49
Marcos Ortiz 2013-02-09, 03:18
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Re: independent scans to same region processed serially
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]>
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 Taylor 2013-02-09, 05:52
lars hofhansl 2013-02-09, 17:02
James Taylor 2013-02-09, 17:28
lars hofhansl 2013-02-09, 19:04
James Taylor 2013-02-10, 08:30
ramkrishna vasudevan 2013-02-09, 10:48
lars hofhansl 2013-02-09, 16:49