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https://issues.apache.org/jira/browse/HBASE-9272?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Lars Hofhansl updated HBASE-9272:
---------------------------------

    Fix Version/s:     (was: 0.94.14)
                       (was: 0.96.1)
                       (was: 0.98.0)

I'm not happy with this, yet.
Unscheduling for now.

> A parallel, unordered scanner
> -----------------------------
>
>                 Key: HBASE-9272
>                 URL: https://issues.apache.org/jira/browse/HBASE-9272
>             Project: HBase
>          Issue Type: New Feature
>            Reporter: Lars Hofhansl
>            Assignee: Lars Hofhansl
>            Priority: Minor
>         Attachments: 9272-0.94-v2.txt, 9272-0.94-v3.txt, 9272-0.94-v4.txt, 
> 9272-0.94.txt, 9272-trunk-v2.txt, 9272-trunk-v3.txt, 9272-trunk-v3.txt, 
> 9272-trunk-v4.txt, 9272-trunk.txt, ParallelClientScanner.java, 
> ParallelClientScanner.java
>
>
> The contract of ClientScanner is to return rows in sort order. That limits 
> the order in which region can be scanned.
> I propose a simple ParallelScanner that does not have this requirement and 
> queries regions in parallel, return whatever gets returned first.
> This is generally useful for scans that filter a lot of data on the server, 
> or in cases where the client can very quickly react to the returned data.
> I have a simple prototype (doesn't do error handling right, and might be a 
> bit heavy on the synchronization side - it used a BlockingQueue to hand data 
> between the client using the scanner and the threads doing the scanning, it 
> also could potentially starve some scanners long enugh to time out at the 
> server).
> On the plus side, it's only a 130 lines of code. :)



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