Core-site.xml – It contain configuration setting for Hadoop core such as I/O settings that are common to HDFS & MapReduce. It use Hostname and port .The most commonly used port is 9000.
[php]<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://localhost:9000</value>
</property>
</configuration>[/php]
hdfs-site.xml – This file contains the configuration setting for HDFS daemons. hdfs-site.xml also specify default block replication and permission checking on HDFS.
[php]<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
</configuration>[/php]
mapred-site.xml – In this file, we specify a framework name for MapReduce. we can specify by setting the mapreduce.framework.name.
[php]<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
</configuration>[/php]
yarn-site.xml – This file provide configuration setting for NodeManager and ResourceManager.
[php]<configuration>
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property>
<property>
<name>yarn.nodemanager.env-whitelist</name> <value>
JAVA_HOME,HADOOP_COMMON_HOME,HADOOP_HDFS_HOME,HADOOP_CONF_DIR,CLASSPATH_PREPEND_DISTCACHE,HADOOP_YARN_HOME,HADOOP_MAPRED_HOME</value> </property>
</configuration>[/php]
