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Posted to common-commits@hadoop.apache.org by sz...@apache.org on 2009/03/21 02:16:25 UTC
svn commit: r756859 - in /hadoop/core/branches/branch-0.20: CHANGES.txt
src/mapred/mapred-default.xml
Author: szetszwo
Date: Sat Mar 21 01:16:24 2009
New Revision: 756859
URL: http://svn.apache.org/viewvc?rev=756859&view=rev
Log:
HADOOP-5519. Remove claims from mapred-default.xml that prime numbers of tasks are helpful. (Owen O'Malley via szetszwo)
Modified:
hadoop/core/branches/branch-0.20/CHANGES.txt
hadoop/core/branches/branch-0.20/src/mapred/mapred-default.xml
Modified: hadoop/core/branches/branch-0.20/CHANGES.txt
URL: http://svn.apache.org/viewvc/hadoop/core/branches/branch-0.20/CHANGES.txt?rev=756859&r1=756858&r2=756859&view=diff
==============================================================================
--- hadoop/core/branches/branch-0.20/CHANGES.txt (original)
+++ hadoop/core/branches/branch-0.20/CHANGES.txt Sat Mar 21 01:16:24 2009
@@ -788,6 +788,9 @@
HADOOP-5520. Fix a typo in disk quota help message. (Ravi Phulari
via szetszwo)
+ HADOOP-5519. Remove claims from mapred-default.xml that prime numbers
+ of tasks are helpful. (Owen O'Malley via szetszwo)
+
Release 0.19.2 - Unreleased
BUG FIXES
Modified: hadoop/core/branches/branch-0.20/src/mapred/mapred-default.xml
URL: http://svn.apache.org/viewvc/hadoop/core/branches/branch-0.20/src/mapred/mapred-default.xml?rev=756859&r1=756858&r2=756859&view=diff
==============================================================================
--- hadoop/core/branches/branch-0.20/src/mapred/mapred-default.xml (original)
+++ hadoop/core/branches/branch-0.20/src/mapred/mapred-default.xml Sat Mar 21 01:16:24 2009
@@ -323,8 +323,7 @@
<property>
<name>mapred.map.tasks</name>
<value>2</value>
- <description>The default number of map tasks per job. Typically set
- to a prime several times greater than number of available hosts.
+ <description>The default number of map tasks per job.
Ignored when mapred.job.tracker is "local".
</description>
</property>
@@ -332,9 +331,10 @@
<property>
<name>mapred.reduce.tasks</name>
<value>1</value>
- <description>The default number of reduce tasks per job. Typically set
- to a prime close to the number of available hosts. Ignored when
- mapred.job.tracker is "local".
+ <description>The default number of reduce tasks per job. Typically set to 99%
+ of the cluster's reduce capacity, so that if a node fails the reduces can
+ still be executed in a single wave.
+ Ignored when mapred.job.tracker is "local".
</description>
</property>