Author: acmurthy
Date: Thu Jan 10 12:09:01 2008
New Revision: 610910
URL: http://svn.apache.org/viewvc?rev=610910&view=rev
Log:
HADOOP-2131. Allow finer-grained control over speculative-execution. Now users
can set it for maps and reduces independently. Contributed by Amareshwari Sri
Ramadasu.
Modified:
lucene/hadoop/trunk/CHANGES.txt
lucene/hadoop/trunk/conf/hadoop-default.xml
lucene/hadoop/trunk/docs/hadoop-default.html
lucene/hadoop/trunk/docs/mapred_tutorial.html
lucene/hadoop/trunk/docs/mapred_tutorial.pdf
lucene/hadoop/trunk/src/contrib/streaming/src/java/org/apache/hadoop/streaming/StreamJob.java
lucene/hadoop/trunk/src/docs/src/documentation/content/xdocs/mapred_tutorial.xml
lucene/hadoop/trunk/src/docs/src/documentation/content/xdocs/site.xml
lucene/hadoop/trunk/src/java/org/apache/hadoop/mapred/JobConf.java
lucene/hadoop/trunk/src/java/org/apache/hadoop/mapred/TaskInProgress.java
Modified: lucene/hadoop/trunk/CHANGES.txt
URL:
http://svn.apache.org/viewvc/lucene/hadoop/trunk/CHANGES.txt?rev=610910&r1=610909&r2=610910&view=diff
==============================================================================
--- lucene/hadoop/trunk/CHANGES.txt (original)
+++ lucene/hadoop/trunk/CHANGES.txt Thu Jan 10 12:09:01 2008
@@ -191,6 +191,15 @@
HADOOP-2406. Add a benchmark for measuring read/write performance through
the InputFormat interface, particularly with compression. (cdouglas)
+ HADOOP-2131. Allow finer-grained control over speculative-execution. Now
+ users can set it for maps and reduces independently.
+ Configuration changes to hadoop-default.xml:
+ deprecated mapred.speculative.execution
+ add mapred.map.tasks.speculative.execution
+ add mapred.reduce.tasks.speculative.execution
+ (Amareshwari Sri Ramadasu via acmurthy)
+
+
OPTIMIZATIONS
HADOOP-1898. Release the lock protecting the last time of the last stack
Modified: lucene/hadoop/trunk/conf/hadoop-default.xml
URL:
http://svn.apache.org/viewvc/lucene/hadoop/trunk/conf/hadoop-default.xml?rev=610910&r1=610909&r2=610910&view=diff
==============================================================================
--- lucene/hadoop/trunk/conf/hadoop-default.xml (original)
+++ lucene/hadoop/trunk/conf/hadoop-default.xml Thu Jan 10 12:09:01 2008
@@ -678,9 +678,16 @@
</property>
<property>
- <name>mapred.speculative.execution</name>
+ <name>mapred.map.tasks.speculative.execution</name>
<value>true</value>
- <description>If true, then multiple instances of some map and reduce tasks
+ <description>If true, then multiple instances of some map tasks
+ may be executed in parallel.</description>
+</property>
+
+<property>
+ <name>mapred.reduce.tasks.speculative.execution</name>
+ <value>true</value>
+ <description>If true, then multiple instances of some reduce tasks
may be executed in parallel.</description>
</property>
Modified: lucene/hadoop/trunk/docs/hadoop-default.html
URL:
http://svn.apache.org/viewvc/lucene/hadoop/trunk/docs/hadoop-default.html?rev=610910&r1=610909&r2=610910&view=diff
==============================================================================
--- lucene/hadoop/trunk/docs/hadoop-default.html (original)
+++ lucene/hadoop/trunk/docs/hadoop-default.html Thu Jan 10 12:09:01 2008
@@ -163,7 +163,7 @@
directories, for redundancy. </td>
</tr>
<tr>
-<td><a name="dfs.permissions">dfs.permissions</a></td><td>false</td><td>
+<td><a name="dfs.permissions">dfs.permissions</a></td><td>true</td><td>
If "true", enable permission checking in HDFS.
If "false", permission checking is turned off,
but all other behavior is unchanged.
@@ -261,6 +261,12 @@
excluded.</td>
</tr>
<tr>
+<td><a name="dfs.max.objects">dfs.max.objects</a></td><td>0</td><td>The
maximum number of files, directories and blocks
+ dfs supports. A value of zero indicates no limit to the number
+ of objects that dfs supports.
+ </td>
+</tr>
+<tr>
<td><a
name="fs.s3.block.size">fs.s3.block.size</a></td><td>67108864</td><td>Block
size to use when writing files to S3.</td>
</tr>
<tr>
@@ -412,7 +418,11 @@
</td>
</tr>
<tr>
-<td><a
name="mapred.speculative.execution">mapred.speculative.execution</a></td><td>true</td><td>If
true, then multiple instances of some map and reduce tasks
+<td><a
name="mapred.map.tasks.speculative.execution">mapred.map.tasks.speculative.execution</a></td><td>true</td><td>If
true, then multiple instances of some map tasks
+ may be executed in parallel.</td>
+</tr>
+<tr>
+<td><a
name="mapred.reduce.tasks.speculative.execution">mapred.reduce.tasks.speculative.execution</a></td><td>true</td><td>If
true, then multiple instances of some reduce tasks
may be executed in parallel.</td>
</tr>
<tr>
Modified: lucene/hadoop/trunk/docs/mapred_tutorial.html
URL:
http://svn.apache.org/viewvc/lucene/hadoop/trunk/docs/mapred_tutorial.html?rev=610910&r1=610909&r2=610910&view=diff
==============================================================================
--- lucene/hadoop/trunk/docs/mapred_tutorial.html (original)
+++ lucene/hadoop/trunk/docs/mapred_tutorial.html Thu Jan 10 12:09:01 2008
@@ -277,7 +277,7 @@
<a href="#Example%3A+WordCount+v2.0">Example: WordCount v2.0</a>
<ul class="minitoc">
<li>
-<a href="#Source+Code-N10B98">Source Code</a>
+<a href="#Source+Code-N10B9C">Source Code</a>
</li>
<li>
<a href="#Sample+Runs">Sample Runs</a>
@@ -1453,7 +1453,7 @@
user-provided scripts
(<a
href="api/org/apache/hadoop/mapred/JobConf.html#setMapDebugScript(java.lang.String)">setMapDebugScript(String)</a>/<a
href="api/org/apache/hadoop/mapred/JobConf.html#setReduceDebugScript(java.lang.String)">setReduceDebugScript(String)</a>)
, whether job tasks can be executed in a <em>speculative</em> manner
- (<a
href="api/org/apache/hadoop/mapred/JobConf.html#setSpeculativeExecution(boolean)">setSpeculativeExecution(boolean)</a>)
+ (<a
href="api/org/apache/hadoop/mapred/JobConf.html#setMapSpeculativeExecution(boolean)">setMapSpeculativeExecution(boolean)</a>)/(<a
href="api/org/apache/hadoop/mapred/JobConf.html#setReduceSpeculativeExecution(boolean)">setReduceSpeculativeExecution(boolean)</a>)
, maximum number of attempts per task
(<a
href="api/org/apache/hadoop/mapred/JobConf.html#setMaxMapAttempts(int)">setMaxMapAttempts(int)</a>/<a
href="api/org/apache/hadoop/mapred/JobConf.html#setMaxReduceAttempts(int)">setMaxReduceAttempts(int)</a>)
, percentage of tasks failure which can be tolerated by the job
@@ -1463,7 +1463,7 @@
<a
href="api/org/apache/hadoop/conf/Configuration.html#set(java.lang.String,
java.lang.String)">set(String, String)</a>/<a
href="api/org/apache/hadoop/conf/Configuration.html#get(java.lang.String,
java.lang.String)">get(String, String)</a>
to set/get arbitrary parameters needed by applications. However, use
the
<span class="codefrag">DistributedCache</span> for large amounts of
(read-only) data.</p>
-<a name="N1082C"></a><a name="Task+Execution+%26+Environment"></a>
+<a name="N10830"></a><a name="Task+Execution+%26+Environment"></a>
<h3 class="h4">Task Execution & Environment</h3>
<p>The <span class="codefrag">TaskTracker</span> executes the <span
class="codefrag">Mapper</span>/
<span class="codefrag">Reducer</span> <em>task</em> as a child
process in a separate jvm.
@@ -1523,7 +1523,7 @@
loaded via <a
href="http://java.sun.com/j2se/1.5.0/docs/api/java/lang/System.html#loadLibrary(java.lang.String)">
System.loadLibrary</a> or <a
href="http://java.sun.com/j2se/1.5.0/docs/api/java/lang/System.html#load(java.lang.String)">
System.load</a>.</p>
-<a name="N108A1"></a><a name="Job+Submission+and+Monitoring"></a>
+<a name="N108A5"></a><a name="Job+Submission+and+Monitoring"></a>
<h3 class="h4">Job Submission and Monitoring</h3>
<p>
<a href="api/org/apache/hadoop/mapred/JobClient.html">
@@ -1559,7 +1559,7 @@
<p>Normally the user creates the application, describes various facets
of the job via <span class="codefrag">JobConf</span>, and then uses
the
<span class="codefrag">JobClient</span> to submit the job and monitor
its progress.</p>
-<a name="N108DF"></a><a name="Job+Control"></a>
+<a name="N108E3"></a><a name="Job+Control"></a>
<h4>Job Control</h4>
<p>Users may need to chain map-reduce jobs to accomplish complex
tasks which cannot be done via a single map-reduce job. This is
fairly
@@ -1595,7 +1595,7 @@
</li>
</ul>
-<a name="N10909"></a><a name="Job+Input"></a>
+<a name="N1090D"></a><a name="Job+Input"></a>
<h3 class="h4">Job Input</h3>
<p>
<a href="api/org/apache/hadoop/mapred/InputFormat.html">
@@ -1643,7 +1643,7 @@
appropriate <span class="codefrag">CompressionCodec</span>. However,
it must be noted that
compressed files with the above extensions cannot be <em>split</em>
and
each compressed file is processed in its entirety by a single
mapper.</p>
-<a name="N10973"></a><a name="InputSplit"></a>
+<a name="N10977"></a><a name="InputSplit"></a>
<h4>InputSplit</h4>
<p>
<a href="api/org/apache/hadoop/mapred/InputSplit.html">
@@ -1657,7 +1657,7 @@
FileSplit</a> is the default <span
class="codefrag">InputSplit</span>. It sets
<span class="codefrag">map.input.file</span> to the path of the
input file for the
logical split.</p>
-<a name="N10998"></a><a name="RecordReader"></a>
+<a name="N1099C"></a><a name="RecordReader"></a>
<h4>RecordReader</h4>
<p>
<a href="api/org/apache/hadoop/mapred/RecordReader.html">
@@ -1669,7 +1669,7 @@
for processing. <span class="codefrag">RecordReader</span> thus
assumes the
responsibility of processing record boundaries and presents the
tasks
with keys and values.</p>
-<a name="N109BB"></a><a name="Job+Output"></a>
+<a name="N109BF"></a><a name="Job+Output"></a>
<h3 class="h4">Job Output</h3>
<p>
<a href="api/org/apache/hadoop/mapred/OutputFormat.html">
@@ -1694,7 +1694,7 @@
<p>
<span class="codefrag">TextOutputFormat</span> is the default
<span class="codefrag">OutputFormat</span>.</p>
-<a name="N109E4"></a><a name="Task+Side-Effect+Files"></a>
+<a name="N109E8"></a><a name="Task+Side-Effect+Files"></a>
<h4>Task Side-Effect Files</h4>
<p>In some applications, component tasks need to create and/or write to
side-files, which differ from the actual job-output files.</p>
@@ -1720,7 +1720,7 @@
JobConf.getOutputPath()</a>, and the framework will promote them
similarly for succesful task-attempts, thus eliminating the need to
pick unique paths per task-attempt.</p>
-<a name="N10A19"></a><a name="RecordWriter"></a>
+<a name="N10A1D"></a><a name="RecordWriter"></a>
<h4>RecordWriter</h4>
<p>
<a href="api/org/apache/hadoop/mapred/RecordWriter.html">
@@ -1728,9 +1728,9 @@
pairs to an output file.</p>
<p>RecordWriter implementations write the job outputs to the
<span class="codefrag">FileSystem</span>.</p>
-<a name="N10A30"></a><a name="Other+Useful+Features"></a>
+<a name="N10A34"></a><a name="Other+Useful+Features"></a>
<h3 class="h4">Other Useful Features</h3>
-<a name="N10A36"></a><a name="Counters"></a>
+<a name="N10A3A"></a><a name="Counters"></a>
<h4>Counters</h4>
<p>
<span class="codefrag">Counters</span> represent global counters, defined
either by
@@ -1744,7 +1744,7 @@
Reporter.incrCounter(Enum, long)</a> in the <span
class="codefrag">map</span> and/or
<span class="codefrag">reduce</span> methods. These counters are
then globally
aggregated by the framework.</p>
-<a name="N10A61"></a><a name="DistributedCache"></a>
+<a name="N10A65"></a><a name="DistributedCache"></a>
<h4>DistributedCache</h4>
<p>
<a href="api/org/apache/hadoop/filecache/DistributedCache.html">
@@ -1777,7 +1777,7 @@
<a
href="api/org/apache/hadoop/filecache/DistributedCache.html#createSymlink(org.apache.hadoop.conf.Configuration)">
DistributedCache.createSymlink(Path, Configuration)</a> api. Files
have <em>execution permissions</em> set.</p>
-<a name="N10A9F"></a><a name="Tool"></a>
+<a name="N10AA3"></a><a name="Tool"></a>
<h4>Tool</h4>
<p>The <a href="api/org/apache/hadoop/util/Tool.html">Tool</a>
interface supports the handling of generic Hadoop command-line
options.
@@ -1817,7 +1817,7 @@
</span>
</p>
-<a name="N10AD1"></a><a name="IsolationRunner"></a>
+<a name="N10AD5"></a><a name="IsolationRunner"></a>
<h4>IsolationRunner</h4>
<p>
<a href="api/org/apache/hadoop/mapred/IsolationRunner.html">
@@ -1841,13 +1841,13 @@
<p>
<span class="codefrag">IsolationRunner</span> will run the failed task in a
single
jvm, which can be in the debugger, over precisely the same input.</p>
-<a name="N10B04"></a><a name="JobControl"></a>
+<a name="N10B08"></a><a name="JobControl"></a>
<h4>JobControl</h4>
<p>
<a href="api/org/apache/hadoop/mapred/jobcontrol/package-summary.html">
JobControl</a> is a utility which encapsulates a set of Map-Reduce
jobs
and their dependencies.</p>
-<a name="N10B11"></a><a name="Data+Compression"></a>
+<a name="N10B15"></a><a name="Data+Compression"></a>
<h4>Data Compression</h4>
<p>Hadoop Map-Reduce provides facilities for the application-writer to
specify compression for both intermediate map-outputs and the
@@ -1861,7 +1861,7 @@
codecs for reasons of both performance (zlib) and non-availability of
Java libraries (lzo). More details on their usage and availability
are
available <a href="native_libraries.html">here</a>.</p>
-<a name="N10B31"></a><a name="Intermediate+Outputs"></a>
+<a name="N10B35"></a><a name="Intermediate+Outputs"></a>
<h5>Intermediate Outputs</h5>
<p>Applications can control compression of intermediate map-outputs
via the
@@ -1882,7 +1882,7 @@
<a
href="api/org/apache/hadoop/mapred/JobConf.html#setMapOutputCompressionType(org.apache.hadoop.io.SequenceFile.CompressionType)">
JobConf.setMapOutputCompressionType(SequenceFile.CompressionType)</a>
api.</p>
-<a name="N10B5D"></a><a name="Job+Outputs"></a>
+<a name="N10B61"></a><a name="Job+Outputs"></a>
<h5>Job Outputs</h5>
<p>Applications can control compression of job-outputs via the
<a
href="api/org/apache/hadoop/mapred/OutputFormatBase.html#setCompressOutput(org.apache.hadoop.mapred.JobConf,%20boolean)">
@@ -1902,12 +1902,12 @@
</div>
-<a name="N10B8C"></a><a name="Example%3A+WordCount+v2.0"></a>
+<a name="N10B90"></a><a name="Example%3A+WordCount+v2.0"></a>
<h2 class="h3">Example: WordCount v2.0</h2>
<div class="section">
<p>Here is a more complete <span class="codefrag">WordCount</span> which uses
many of the
features provided by the Map-Reduce framework we discussed so far:</p>
-<a name="N10B98"></a><a name="Source+Code-N10B98"></a>
+<a name="N10B9C"></a><a name="Source+Code-N10B9C"></a>
<h3 class="h4">Source Code</h3>
<table class="ForrestTable" cellspacing="1" cellpadding="4">
@@ -3085,7 +3085,7 @@
</tr>
</table>
-<a name="N112CA"></a><a name="Sample+Runs"></a>
+<a name="N112CE"></a><a name="Sample+Runs"></a>
<h3 class="h4">Sample Runs</h3>
<p>Sample text-files as input:</p>
<p>
@@ -3250,7 +3250,7 @@
<br>
</p>
-<a name="N1139A"></a><a name="Salient+Points"></a>
+<a name="N1139E"></a><a name="Salient+Points"></a>
<h3 class="h4">Salient Points</h3>
<p>The second version of <span class="codefrag">WordCount</span> improves upon
the
previous one by using some features offered by the Map-Reduce
framework:
