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@@ -310,7 +310,7 @@ document.write("Last Published: " + document.lastModified);
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<a href="#Example%3A+WordCount+v2.0">Example: WordCount v2.0</a>
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<ul class="minitoc">
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<li>
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-<a href="#Source+Code-N10DD5">Source Code</a>
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+<a href="#Source+Code-N10DF5">Source Code</a>
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</li>
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<li>
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<a href="#Sample+Runs">Sample Runs</a>
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@@ -1116,7 +1116,24 @@ document.write("Last Published: " + document.lastModified);
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<br>
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</p>
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-<a name="N104EC"></a><a name="Walk-through"></a>
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+<p> Applications can specify a comma separated list of paths which
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+ would be present in the current working directory of the task
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+ using the option <span class="codefrag">-files</span>. The <span class="codefrag">-libjars</span>
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|
|
+ option allows applications to add jars to the classpaths of the maps
|
|
|
+ and reduces. The <span class="codefrag">-archives</span> allows them to pass archives
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|
+ as arguments that are unzipped/unjarred and a link with name of the
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|
+ jar/zip are created in the current working directory of tasks. More
|
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|
+ details about the command line options are available at
|
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|
+ <a href="commands_manual.html">Commands manual</a>
|
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+</p>
|
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|
+<p>Running <span class="codefrag">wordcount</span> example with
|
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+ <span class="codefrag">-libjars</span> and <span class="codefrag">-files</span>:<br>
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+
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+<span class="codefrag"> hadoop jar hadoop-examples.jar wordcount -files cachefile.txt
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+ -libjars mylib.jar input output </span>
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+
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+</p>
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+<a name="N1050C"></a><a name="Walk-through"></a>
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<h3 class="h4">Walk-through</h3>
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|
|
<p>The <span class="codefrag">WordCount</span> application is quite straight-forward.</p>
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<p>The <span class="codefrag">Mapper</span> implementation (lines 14-26), via the
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@@ -1226,7 +1243,7 @@ document.write("Last Published: " + document.lastModified);
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</div>
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-<a name="N105A3"></a><a name="Map%2FReduce+-+User+Interfaces"></a>
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+<a name="N105C3"></a><a name="Map%2FReduce+-+User+Interfaces"></a>
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<h2 class="h3">Map/Reduce - User Interfaces</h2>
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<div class="section">
|
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<p>This section provides a reasonable amount of detail on every user-facing
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@@ -1245,12 +1262,12 @@ document.write("Last Published: " + document.lastModified);
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<p>Finally, we will wrap up by discussing some useful features of the
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framework such as the <span class="codefrag">DistributedCache</span>,
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<span class="codefrag">IsolationRunner</span> etc.</p>
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-<a name="N105DC"></a><a name="Payload"></a>
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+<a name="N105FC"></a><a name="Payload"></a>
|
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<h3 class="h4">Payload</h3>
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<p>Applications typically implement the <span class="codefrag">Mapper</span> and
|
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|
<span class="codefrag">Reducer</span> interfaces to provide the <span class="codefrag">map</span> and
|
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<span class="codefrag">reduce</span> methods. These form the core of the job.</p>
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-<a name="N105F1"></a><a name="Mapper"></a>
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+<a name="N10611"></a><a name="Mapper"></a>
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<h4>Mapper</h4>
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<p>
|
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<a href="api/org/apache/hadoop/mapred/Mapper.html">
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@@ -1306,7 +1323,7 @@ document.write("Last Published: " + document.lastModified);
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<a href="api/org/apache/hadoop/io/compress/CompressionCodec.html">
|
|
|
CompressionCodec</a> to be used via the <span class="codefrag">JobConf</span>.
|
|
|
</p>
|
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|
-<a name="N10667"></a><a name="How+Many+Maps%3F"></a>
|
|
|
+<a name="N10687"></a><a name="How+Many+Maps%3F"></a>
|
|
|
<h5>How Many Maps?</h5>
|
|
|
<p>The number of maps is usually driven by the total size of the
|
|
|
inputs, that is, the total number of blocks of the input files.</p>
|
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@@ -1319,7 +1336,7 @@ document.write("Last Published: " + document.lastModified);
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<a href="api/org/apache/hadoop/mapred/JobConf.html#setNumMapTasks(int)">
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|
|
setNumMapTasks(int)</a> (which only provides a hint to the framework)
|
|
|
is used to set it even higher.</p>
|
|
|
-<a name="N1067F"></a><a name="Reducer"></a>
|
|
|
+<a name="N1069F"></a><a name="Reducer"></a>
|
|
|
<h4>Reducer</h4>
|
|
|
<p>
|
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|
<a href="api/org/apache/hadoop/mapred/Reducer.html">
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@@ -1342,18 +1359,18 @@ document.write("Last Published: " + document.lastModified);
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<p>
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|
<span class="codefrag">Reducer</span> has 3 primary phases: shuffle, sort and reduce.
|
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|
</p>
|
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|
-<a name="N106AF"></a><a name="Shuffle"></a>
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|
+<a name="N106CF"></a><a name="Shuffle"></a>
|
|
|
<h5>Shuffle</h5>
|
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|
<p>Input to the <span class="codefrag">Reducer</span> is the sorted output of the
|
|
|
mappers. In this phase the framework fetches the relevant partition
|
|
|
of the output of all the mappers, via HTTP.</p>
|
|
|
-<a name="N106BC"></a><a name="Sort"></a>
|
|
|
+<a name="N106DC"></a><a name="Sort"></a>
|
|
|
<h5>Sort</h5>
|
|
|
<p>The framework groups <span class="codefrag">Reducer</span> inputs by keys (since
|
|
|
different mappers may have output the same key) in this stage.</p>
|
|
|
<p>The shuffle and sort phases occur simultaneously; while
|
|
|
map-outputs are being fetched they are merged.</p>
|
|
|
-<a name="N106CB"></a><a name="Secondary+Sort"></a>
|
|
|
+<a name="N106EB"></a><a name="Secondary+Sort"></a>
|
|
|
<h5>Secondary Sort</h5>
|
|
|
<p>If equivalence rules for grouping the intermediate keys are
|
|
|
required to be different from those for grouping keys before
|
|
|
@@ -1364,7 +1381,7 @@ document.write("Last Published: " + document.lastModified);
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|
JobConf.setOutputKeyComparatorClass(Class)</a> can be used to
|
|
|
control how intermediate keys are grouped, these can be used in
|
|
|
conjunction to simulate <em>secondary sort on values</em>.</p>
|
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|
-<a name="N106E4"></a><a name="Reduce"></a>
|
|
|
+<a name="N10704"></a><a name="Reduce"></a>
|
|
|
<h5>Reduce</h5>
|
|
|
<p>In this phase the
|
|
|
<a href="api/org/apache/hadoop/mapred/Reducer.html#reduce(K2, java.util.Iterator, org.apache.hadoop.mapred.OutputCollector, org.apache.hadoop.mapred.Reporter)">
|
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|
@@ -1380,7 +1397,7 @@ document.write("Last Published: " + document.lastModified);
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|
progress, set application-level status messages and update
|
|
|
<span class="codefrag">Counters</span>, or just indicate that they are alive.</p>
|
|
|
<p>The output of the <span class="codefrag">Reducer</span> is <em>not sorted</em>.</p>
|
|
|
-<a name="N10712"></a><a name="How+Many+Reduces%3F"></a>
|
|
|
+<a name="N10732"></a><a name="How+Many+Reduces%3F"></a>
|
|
|
<h5>How Many Reduces?</h5>
|
|
|
<p>The right number of reduces seems to be <span class="codefrag">0.95</span> or
|
|
|
<span class="codefrag">1.75</span> multiplied by (<<em>no. of nodes</em>> *
|
|
|
@@ -1395,7 +1412,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<p>The scaling factors above are slightly less than whole numbers to
|
|
|
reserve a few reduce slots in the framework for speculative-tasks and
|
|
|
failed tasks.</p>
|
|
|
-<a name="N10737"></a><a name="Reducer+NONE"></a>
|
|
|
+<a name="N10757"></a><a name="Reducer+NONE"></a>
|
|
|
<h5>Reducer NONE</h5>
|
|
|
<p>It is legal to set the number of reduce-tasks to <em>zero</em> if
|
|
|
no reduction is desired.</p>
|
|
|
@@ -1405,7 +1422,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
setOutputPath(Path)</a>. The framework does not sort the
|
|
|
map-outputs before writing them out to the <span class="codefrag">FileSystem</span>.
|
|
|
</p>
|
|
|
-<a name="N10752"></a><a name="Partitioner"></a>
|
|
|
+<a name="N10772"></a><a name="Partitioner"></a>
|
|
|
<h4>Partitioner</h4>
|
|
|
<p>
|
|
|
<a href="api/org/apache/hadoop/mapred/Partitioner.html">
|
|
|
@@ -1419,7 +1436,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<p>
|
|
|
<a href="api/org/apache/hadoop/mapred/lib/HashPartitioner.html">
|
|
|
HashPartitioner</a> is the default <span class="codefrag">Partitioner</span>.</p>
|
|
|
-<a name="N10771"></a><a name="Reporter"></a>
|
|
|
+<a name="N10791"></a><a name="Reporter"></a>
|
|
|
<h4>Reporter</h4>
|
|
|
<p>
|
|
|
<a href="api/org/apache/hadoop/mapred/Reporter.html">
|
|
|
@@ -1438,7 +1455,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
</p>
|
|
|
<p>Applications can also update <span class="codefrag">Counters</span> using the
|
|
|
<span class="codefrag">Reporter</span>.</p>
|
|
|
-<a name="N1079B"></a><a name="OutputCollector"></a>
|
|
|
+<a name="N107BB"></a><a name="OutputCollector"></a>
|
|
|
<h4>OutputCollector</h4>
|
|
|
<p>
|
|
|
<a href="api/org/apache/hadoop/mapred/OutputCollector.html">
|
|
|
@@ -1449,7 +1466,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<p>Hadoop Map/Reduce comes bundled with a
|
|
|
<a href="api/org/apache/hadoop/mapred/lib/package-summary.html">
|
|
|
library</a> of generally useful mappers, reducers, and partitioners.</p>
|
|
|
-<a name="N107B6"></a><a name="Job+Configuration"></a>
|
|
|
+<a name="N107D6"></a><a name="Job+Configuration"></a>
|
|
|
<h3 class="h4">Job Configuration</h3>
|
|
|
<p>
|
|
|
<a href="api/org/apache/hadoop/mapred/JobConf.html">
|
|
|
@@ -1507,7 +1524,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<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="N10848"></a><a name="Task+Execution+%26+Environment"></a>
|
|
|
+<a name="N10868"></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.
|
|
|
@@ -1739,7 +1756,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<a href="native_libraries.html#Loading+native+libraries+through+DistributedCache">
|
|
|
native_libraries.html</a>
|
|
|
</p>
|
|
|
-<a name="N109E8"></a><a name="Job+Submission+and+Monitoring"></a>
|
|
|
+<a name="N10A08"></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">
|
|
|
@@ -1800,7 +1817,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<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="N10A48"></a><a name="Job+Control"></a>
|
|
|
+<a name="N10A68"></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
|
|
|
@@ -1836,7 +1853,7 @@ document.write("Last Published: " + document.lastModified);
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|
|
</li>
|
|
|
|
|
|
</ul>
|
|
|
-<a name="N10A72"></a><a name="Job+Input"></a>
|
|
|
+<a name="N10A92"></a><a name="Job+Input"></a>
|
|
|
<h3 class="h4">Job Input</h3>
|
|
|
<p>
|
|
|
<a href="api/org/apache/hadoop/mapred/InputFormat.html">
|
|
|
@@ -1884,7 +1901,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
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="N10ADC"></a><a name="InputSplit"></a>
|
|
|
+<a name="N10AFC"></a><a name="InputSplit"></a>
|
|
|
<h4>InputSplit</h4>
|
|
|
<p>
|
|
|
<a href="api/org/apache/hadoop/mapred/InputSplit.html">
|
|
|
@@ -1898,7 +1915,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
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="N10B01"></a><a name="RecordReader"></a>
|
|
|
+<a name="N10B21"></a><a name="RecordReader"></a>
|
|
|
<h4>RecordReader</h4>
|
|
|
<p>
|
|
|
<a href="api/org/apache/hadoop/mapred/RecordReader.html">
|
|
|
@@ -1910,7 +1927,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
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="N10B24"></a><a name="Job+Output"></a>
|
|
|
+<a name="N10B44"></a><a name="Job+Output"></a>
|
|
|
<h3 class="h4">Job Output</h3>
|
|
|
<p>
|
|
|
<a href="api/org/apache/hadoop/mapred/OutputFormat.html">
|
|
|
@@ -1935,7 +1952,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<p>
|
|
|
<span class="codefrag">TextOutputFormat</span> is the default
|
|
|
<span class="codefrag">OutputFormat</span>.</p>
|
|
|
-<a name="N10B4D"></a><a name="Task+Side-Effect+Files"></a>
|
|
|
+<a name="N10B6D"></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>
|
|
|
@@ -1974,7 +1991,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<p>The entire discussion holds true for maps of jobs with
|
|
|
reducer=NONE (i.e. 0 reduces) since output of the map, in that case,
|
|
|
goes directly to HDFS.</p>
|
|
|
-<a name="N10B95"></a><a name="RecordWriter"></a>
|
|
|
+<a name="N10BB5"></a><a name="RecordWriter"></a>
|
|
|
<h4>RecordWriter</h4>
|
|
|
<p>
|
|
|
<a href="api/org/apache/hadoop/mapred/RecordWriter.html">
|
|
|
@@ -1982,9 +1999,9 @@ document.write("Last Published: " + document.lastModified);
|
|
|
pairs to an output file.</p>
|
|
|
<p>RecordWriter implementations write the job outputs to the
|
|
|
<span class="codefrag">FileSystem</span>.</p>
|
|
|
-<a name="N10BAC"></a><a name="Other+Useful+Features"></a>
|
|
|
+<a name="N10BCC"></a><a name="Other+Useful+Features"></a>
|
|
|
<h3 class="h4">Other Useful Features</h3>
|
|
|
-<a name="N10BB2"></a><a name="Counters"></a>
|
|
|
+<a name="N10BD2"></a><a name="Counters"></a>
|
|
|
<h4>Counters</h4>
|
|
|
<p>
|
|
|
<span class="codefrag">Counters</span> represent global counters, defined either by
|
|
|
@@ -2001,7 +2018,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
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="N10BE1"></a><a name="DistributedCache"></a>
|
|
|
+<a name="N10C01"></a><a name="DistributedCache"></a>
|
|
|
<h4>DistributedCache</h4>
|
|
|
<p>
|
|
|
<a href="api/org/apache/hadoop/filecache/DistributedCache.html">
|
|
|
@@ -2072,7 +2089,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<span class="codefrag">mapred.job.classpath.{files|archives}</span>. Similarly the
|
|
|
cached files that are symlinked into the working directory of the
|
|
|
task can be used to distribute native libraries and load them.</p>
|
|
|
-<a name="N10C64"></a><a name="Tool"></a>
|
|
|
+<a name="N10C84"></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.
|
|
|
@@ -2112,7 +2129,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
</span>
|
|
|
|
|
|
</p>
|
|
|
-<a name="N10C96"></a><a name="IsolationRunner"></a>
|
|
|
+<a name="N10CB6"></a><a name="IsolationRunner"></a>
|
|
|
<h4>IsolationRunner</h4>
|
|
|
<p>
|
|
|
<a href="api/org/apache/hadoop/mapred/IsolationRunner.html">
|
|
|
@@ -2136,7 +2153,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<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="N10CC9"></a><a name="Profiling"></a>
|
|
|
+<a name="N10CE9"></a><a name="Profiling"></a>
|
|
|
<h4>Profiling</h4>
|
|
|
<p>Profiling is a utility to get a representative (2 or 3) sample
|
|
|
of built-in java profiler for a sample of maps and reduces. </p>
|
|
|
@@ -2169,7 +2186,7 @@ document.write("Last Published: " + document.lastModified);
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<span class="codefrag">-agentlib:hprof=cpu=samples,heap=sites,force=n,thread=y,verbose=n,file=%s</span>
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</p>
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-<a name="N10CFD"></a><a name="Debugging"></a>
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+<a name="N10D1D"></a><a name="Debugging"></a>
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<h4>Debugging</h4>
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<p>Map/Reduce framework provides a facility to run user-provided
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scripts for debugging. When map/reduce task fails, user can run
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@@ -2180,14 +2197,14 @@ document.write("Last Published: " + document.lastModified);
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<p> In the following sections we discuss how to submit debug script
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along with the job. For submitting debug script, first it has to
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distributed. Then the script has to supplied in Configuration. </p>
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-<a name="N10D09"></a><a name="How+to+distribute+script+file%3A"></a>
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+<a name="N10D29"></a><a name="How+to+distribute+script+file%3A"></a>
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<h5> How to distribute script file: </h5>
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<p>
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The user has to use
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<a href="mapred_tutorial.html#DistributedCache">DistributedCache</a>
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mechanism to <em>distribute</em> and <em>symlink</em> the
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debug script file.</p>
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-<a name="N10D1D"></a><a name="How+to+submit+script%3A"></a>
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+<a name="N10D3D"></a><a name="How+to+submit+script%3A"></a>
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<h5> How to submit script: </h5>
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<p> A quick way to submit debug script is to set values for the
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properties "mapred.map.task.debug.script" and
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@@ -2211,17 +2228,17 @@ document.write("Last Published: " + document.lastModified);
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<span class="codefrag">$script $stdout $stderr $syslog $jobconf $program </span>
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</p>
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-<a name="N10D3F"></a><a name="Default+Behavior%3A"></a>
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+<a name="N10D5F"></a><a name="Default+Behavior%3A"></a>
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<h5> Default Behavior: </h5>
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<p> For pipes, a default script is run to process core dumps under
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gdb, prints stack trace and gives info about running threads. </p>
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-<a name="N10D4A"></a><a name="JobControl"></a>
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+<a name="N10D6A"></a><a name="JobControl"></a>
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<h4>JobControl</h4>
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<p>
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|
<a href="api/org/apache/hadoop/mapred/jobcontrol/package-summary.html">
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JobControl</a> is a utility which encapsulates a set of Map/Reduce jobs
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|
and their dependencies.</p>
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-<a name="N10D57"></a><a name="Data+Compression"></a>
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+<a name="N10D77"></a><a name="Data+Compression"></a>
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<h4>Data Compression</h4>
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|
<p>Hadoop Map/Reduce provides facilities for the application-writer to
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|
specify compression for both intermediate map-outputs and the
|
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|
@@ -2235,7 +2252,7 @@ document.write("Last Published: " + document.lastModified);
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|
codecs for reasons of both performance (zlib) and non-availability of
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|
Java libraries (lzo). More details on their usage and availability are
|
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|
available <a href="native_libraries.html">here</a>.</p>
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-<a name="N10D77"></a><a name="Intermediate+Outputs"></a>
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|
+<a name="N10D97"></a><a name="Intermediate+Outputs"></a>
|
|
|
<h5>Intermediate Outputs</h5>
|
|
|
<p>Applications can control compression of intermediate map-outputs
|
|
|
via the
|
|
|
@@ -2244,7 +2261,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<span class="codefrag">CompressionCodec</span> to be used via the
|
|
|
<a href="api/org/apache/hadoop/mapred/JobConf.html#setMapOutputCompressorClass(java.lang.Class)">
|
|
|
JobConf.setMapOutputCompressorClass(Class)</a> api.</p>
|
|
|
-<a name="N10D8C"></a><a name="Job+Outputs"></a>
|
|
|
+<a name="N10DAC"></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/FileOutputFormat.html#setCompressOutput(org.apache.hadoop.mapred.JobConf,%20boolean)">
|
|
|
@@ -2264,7 +2281,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
</div>
|
|
|
|
|
|
|
|
|
-<a name="N10DBB"></a><a name="Example%3A+WordCount+v2.0"></a>
|
|
|
+<a name="N10DDB"></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
|
|
|
@@ -2274,7 +2291,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<a href="quickstart.html#SingleNodeSetup">pseudo-distributed</a> or
|
|
|
<a href="quickstart.html#Fully-Distributed+Operation">fully-distributed</a>
|
|
|
Hadoop installation.</p>
|
|
|
-<a name="N10DD5"></a><a name="Source+Code-N10DD5"></a>
|
|
|
+<a name="N10DF5"></a><a name="Source+Code-N10DF5"></a>
|
|
|
<h3 class="h4">Source Code</h3>
|
|
|
<table class="ForrestTable" cellspacing="1" cellpadding="4">
|
|
|
|
|
|
@@ -3484,7 +3501,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
</tr>
|
|
|
|
|
|
</table>
|
|
|
-<a name="N11537"></a><a name="Sample+Runs"></a>
|
|
|
+<a name="N11557"></a><a name="Sample+Runs"></a>
|
|
|
<h3 class="h4">Sample Runs</h3>
|
|
|
<p>Sample text-files as input:</p>
|
|
|
<p>
|
|
|
@@ -3652,7 +3669,7 @@ document.write("Last Published: " + document.lastModified);
|
|
|
<br>
|
|
|
|
|
|
</p>
|
|
|
-<a name="N1160B"></a><a name="Highlights"></a>
|
|
|
+<a name="N1162B"></a><a name="Highlights"></a>
|
|
|
<h3 class="h4">Highlights</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:
|
Doug Cutting