Reputation: 21
I'm new to using Hadoop, and I want to execute Hadoop syntax using WordCount to count words. However, why is it that when I try to display the output, it doesn't appear? I would appreciate an explanation and assistance
yarn-site.xml settings:
<configuration>
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property>
<property>
<name>yarn.nodemanager.aux-services.mapreduce.shuffle.class</name>
<value>org.apache.hadoop.mapred.ShuffleHandler</value>
</property>
</configuration>
mapred-site.xml settings:
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
</configuration>
note : i'm use hadoop version 3.2.4
Upvotes: 0
Views: 85
Reputation: 191884
You have an error there - /tmp
is not a valid Windows path, and your /tmp/hadoop-<username>
value is not a valid Shell command. You need to override hadoop.tmp.dir
in core-site.xml
to a valid Windows path like file://c:/tmp_hadoop
I'd suggest using WSL2, not CMD. Hadoop is not really designed to run on Windows.
The execution of Mapreduce runs outside of your terminal session, in multiple YARN containers. There is a driver (your terminal) and executors (where job output is stored).
You can open link in your logs - The url to track the job
or For more detailed output...
to find the real issue
If you want WordCount in less code, with faster output, and more interactive session, then use Spark. https://spark.apache.org/docs/latest/quick-start.html#more-on-dataset-operations
Upvotes: 0