Mailing-List: contact issues-help@hbase.apache.org; run by ezmlm
Precedence: bulk
Date: Fri, 30 Sep 2011 05:02:46 +0000 (UTC)
From: "jiraposter@reviews.apache.org (Commented) (JIRA)" <jira@apache.org>
To: issues@hbase.apache.org
Message-ID: 
 <1629551905.10468.1317358966763.JavaMail.tomcat@hel.zones.apache.org>
In-Reply-To: 
 <1217369738.13437.1317058406739.JavaMail.tomcat@hel.zones.apache.org>
Subject: [jira] [Commented] (HBASE-4487) The increment operation can release
 the rowlock before sync-ing the Hlog
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/HBASE-4487?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13117885#comment-13117885 ] 

jiraposter@reviews.apache.org commented on HBASE-4487:
------------------------------------------------------


-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/2116/#review2206
-----------------------------------------------------------


/src/main/java/org/apache/hadoop/hbase/regionserver/wal/HLog.java
<https://reviews.apache.org/r/2116/#comment5140>

    Am not sure.  Just to clarify
    Is this check not needed here then?


- ramkrishna


On 2011-09-29 19:27:36, Dhruba Borthakur wrote:
bq.  
bq.  -----------------------------------------------------------
bq.  This is an automatically generated e-mail. To reply, visit:
bq.  https://reviews.apache.org/r/2116/
bq.  -----------------------------------------------------------
bq.  
bq.  (Updated 2011-09-29 19:27:36)
bq.  
bq.  
bq.  Review request for hbase and Ted Yu.
bq.  
bq.  
bq.  Summary
bq.  -------
bq.  
bq.  The increment operation releases the rowlock before doing the sync to the HLog. This improves performance of increments on hot rows. Introduced method HLog.appendNoSync() that returns a txid. The increment method then release the rowlock and invokes HLog.sync(txid). The HLog.sync(txid) returns only if all the transactions upto the one identified by that txid has been successfully sycned to HDFS.
bq.  
bq.  There is a single test TestIncrement that creates a 100 threads and ensures that all the concurrent increments match the final expected result. There is a benchmark TestHLogBench that measures the performance of the appendNoSync call.
bq.  
bq.  
bq.  This addresses bug HBASE-4487.
bq.      https://issues.apache.org/jira/browse/HBASE-4487
bq.  
bq.  
bq.  Diffs
bq.  -----
bq.  
bq.    /src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java 1177401 
bq.    /src/main/java/org/apache/hadoop/hbase/regionserver/wal/HLog.java 1177401 
bq.    /src/test/java/org/apache/hadoop/hbase/regionserver/TestIncrement.java PRE-CREATION 
bq.    /src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestHLogBench.java PRE-CREATION 
bq.    /src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestWALActionsListener.java 1177401 
bq.    /src/test/java/org/apache/hadoop/hbase/replication/regionserver/TestReplicationSourceManager.java 1177401 
bq.  
bq.  Diff: https://reviews.apache.org/r/2116/diff
bq.  
bq.  
bq.  Testing
bq.  -------
bq.  
bq.  All unit tests pass now (expect TestDistributedLogSplitting, TestRollingRestart, TestHTablePool), but I am seeing the same test to fail on trunk, so these failures do not seem to be related to this patch.
bq.  
bq.  
bq.  Thanks,
bq.  
bq.  Dhruba
bq.  
bq.


> The increment operation can release the rowlock before sync-ing the Hlog
> ------------------------------------------------------------------------
>
>                 Key: HBASE-4487
>                 URL: https://issues.apache.org/jira/browse/HBASE-4487
>             Project: HBase
>          Issue Type: Improvement
>            Reporter: dhruba borthakur
>            Assignee: dhruba borthakur
>         Attachments: appendNoSync4.txt, appendNoSync5.txt, appendNoSync6.txt
>
>
> This allows for better throughput when there are hot rows.I have seen this change make a single row update improve from 400 increments/sec/server to 4000 increments/sec/server.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira