[
https://issues.apache.org/jira/browse/HDFS-2495?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13145931#comment-13145931
]
Hadoop QA commented on HDFS-2495:
---------------------------------
-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12502568/replicationMon.patch-1
against trunk revision .
+1 @author. The patch does not contain any @author tags.
+1 tests included. The patch appears to include 3 new or modified tests.
+1 javadoc. The javadoc tool did not generate any warning messages.
+1 javac. The applied patch does not increase the total number of javac
compiler warnings.
+1 findbugs. The patch does not introduce any new Findbugs (version 1.3.9)
warnings.
+1 release audit. The applied patch does not increase the total number of
release audit warnings.
-1 core tests. The patch failed these unit tests:
org.apache.hadoop.hdfs.TestFileAppend2
org.apache.hadoop.hdfs.TestBalancerBandwidth
+1 contrib tests. The patch passed contrib unit tests.
Test results:
https://builds.apache.org/job/PreCommit-HDFS-Build/1540//testReport/
Console output: https://builds.apache.org/job/PreCommit-HDFS-Build/1540//console
This message is automatically generated.
> Increase granularity of write operations in ReplicationMonitor thus reducing
> contention for write lock
> ------------------------------------------------------------------------------------------------------
>
> Key: HDFS-2495
> URL: https://issues.apache.org/jira/browse/HDFS-2495
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Components: name-node
> Reporter: Tomasz Nykiel
> Assignee: Tomasz Nykiel
> Attachments: replicationMon.patch, replicationMon.patch-1
>
>
> For processing blocks in ReplicationMonitor
> (BlockManager.computeReplicationWork), we first obtain a list of blocks to be
> replicated by calling chooseUnderReplicatedBlocks, and then for each block
> which was found, we call computeReplicationWorkForBlock. The latter processes
> a block in three stages, acquiring the writelock twice per call:
> 1. obtaining block related info (livenodes, srcnode, etc.) under lock
> 2. choosing target for replication
> 3. scheduling replication (under lock)
> We would like to change this behaviour and decrease contention for the write
> lock, by batching blocks and executing 1,2,3, for sets of blocks, rather than
> for each one separately. This would decrease the number of writeLock to 2,
> from 2*numberofblocks.
> Also, the info level logging can be pushed outside the writelock.
--
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
