[ 
https://issues.apache.org/jira/browse/HBASE-13378?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14582744#comment-14582744
 ] 

Lars Hofhansl commented on HBASE-13378:
---------------------------------------

Follow the Money... Or {{HRegion.getSmallestReadPoint()}} :)

> RegionScannerImpl synchronized for READ_UNCOMMITTED Isolation Levels
> --------------------------------------------------------------------
>
>                 Key: HBASE-13378
>                 URL: https://issues.apache.org/jira/browse/HBASE-13378
>             Project: HBase
>          Issue Type: New Feature
>            Reporter: John Leach
>            Assignee: John Leach
>            Priority: Minor
>         Attachments: HBASE-13378.patch, HBASE-13378.txt
>
>   Original Estimate: 2h
>          Time Spent: 2h
>  Remaining Estimate: 0h
>
> This block of code below coupled with the close method could be changed so 
> that READ_UNCOMMITTED does not synchronize.  
> {CODE:JAVA}
>       // synchronize on scannerReadPoints so that nobody calculates
>       // getSmallestReadPoint, before scannerReadPoints is updated.
>       IsolationLevel isolationLevel = scan.getIsolationLevel();
>       synchronized(scannerReadPoints) {
>         this.readPt = getReadpoint(isolationLevel);
>         scannerReadPoints.put(this, this.readPt);
>       }
> {CODE}
> This hotspots for me under heavy get requests.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to