[ 
https://issues.apache.org/jira/browse/HBASE-9272?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13745816#comment-13745816
 ] 

Lars Hofhansl commented on HBASE-9272:
--------------------------------------

Yeah, that was the one where I convinced Stack that we do not need this. :)
                
> A simple parallel, unordered scanner
> ------------------------------------
>
>                 Key: HBASE-9272
>                 URL: https://issues.apache.org/jira/browse/HBASE-9272
>             Project: HBase
>          Issue Type: New Feature
>            Reporter: Lars Hofhansl
>            Priority: Minor
>         Attachments: 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. :)

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to