[
https://issues.apache.org/jira/browse/MAPREDUCE-2047?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13000050#comment-13000050
]
Hadoop QA commented on MAPREDUCE-2047:
--------------------------------------
-1 overall. Here are the results of testing the latest attachment
http://issues.apache.org/jira/secure/attachment/12457218/2047.3.patch
against trunk revision 1074251.
+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 passed core unit tests.
-1 contrib tests. The patch failed contrib unit tests.
+1 system test framework. The patch passed system test framework compile.
Test results:
https://hudson.apache.org/hudson/job/PreCommit-MAPREDUCE-Build/68//testReport/
Findbugs warnings:
https://hudson.apache.org/hudson/job/PreCommit-MAPREDUCE-Build/68//artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Console output:
https://hudson.apache.org/hudson/job/PreCommit-MAPREDUCE-Build/68//console
This message is automatically generated.
> reduce overhead of findSpeculativeTask
> --------------------------------------
>
> Key: MAPREDUCE-2047
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-2047
> Project: Hadoop Map/Reduce
> Issue Type: Improvement
> Components: jobtracker
> Environment: hadoop-20 with HADOOP-2141
> Reporter: Joydeep Sen Sarma
> Assignee: Joydeep Sen Sarma
> Attachments: 2047.3.patch, mapreduce-2047.1.patch,
> mapreduce-2047.2.patch
>
>
> We are bottlenecked (in the JT) on the jobtracker lock and calls to
> findSpeculativeTask frequently show up as one of the top routines (by time)
> called holding this lock.
> this routine calls canBeSpeculated() and hasRunOnMachine() for each task in a
> candidate job. Both these routines are reasonably expensive when invoked
> repeatedly for thousands of tasks. The top candidates for speculation from a
> job only need to be refreshed periodically (and not once every heartbeat) -
> and we can can avoid most of these invocations this way.
--
This message is automatically generated by JIRA.
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
