[
https://issues.apache.org/jira/browse/HBASE-9488?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13762844#comment-13762844
]
Nicolas Liochon commented on HBASE-9488:
----------------------------------------
Impressive patch.
Some comments:
- As Stack said, does it needs to be public? But it's strange,
AbstractClientScanner is public as well...
- The javadocs mentions ShortClientScanner.
- hbase.client.smallscanner.caching should be in hbase-default, it's an
important setting
- there seeems to be some duplication between ClientScanner & this class, may
be some stuff could be shared...
> Improve performance for small scan
> ----------------------------------
>
> Key: HBASE-9488
> URL: https://issues.apache.org/jira/browse/HBASE-9488
> Project: HBase
> Issue Type: Improvement
> Components: Client, Performance, Scanners
> Reporter: chunhui shen
> Assignee: chunhui shen
> Attachments: HBASE-9488-trunk.patch, HBASE-9488-trunkV2.patch, test
> results.jpg
>
>
> review board:
> https://reviews.apache.org/r/14059/
> Now, one scan operation would call 3 RPC at least:
> openScanner();
> next();
> closeScanner();
> I think we could reduce the RPC call to one for small scan to get better
> performance
> Also using pread is better than seek+read for small scan (For this point, see
> more on HBASE-7266)
> Implements such a small scan as the patch, and take the performance test as
> following:
> a.Environment：
> patched on 0.94 version
> one regionserver;
> one client with 50 concurrent threads;
> KV size:50/100;
> 100% LRU cache hit ratio;
> Random start row of scan
> b.Results:
> See the picture attachment
> *Usage:*
> Scan scan = new Scan(startRow,stopRow);
> scan.setSmall(true);
> ResultScanner scanner = table.getScanner(scan);
> Set the new 'small' attribute as true for scan, others are the same
>
--
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
