-------------------
core-site.xml
-------------------
<configuration>
  <property>
    <name>fs.default.name</name>
    <value>hdfs://pi3cluster:9000</value>
  </property>
</configuration>

-------------------
hdfs-site.xml
-------------------
<configuration>
  <property>
    <name>dfs.datanode.data.dir</name>
    <value>file:///mnt/hdfs/datanode</value>
  </property>
  <property>
    <name>dfs.namenode.name.dir</name>
    <value>file:///mnt/hdfs/namenode</value>
  </property>
  <property>
</configuration> 

-------------------
mapred-site.xml
-------------------
<configuration>
  <property>
    <name>mapreduce.framework.name</name>
    <value>yarn</value>
  </property>
  <property>
    <name>yarn.app.mapreduce.am.resource.mb</name>
    <value>256</value>
  </property>
  <property>
    <name>mapreduce.map.memory.mb</name>
    <value>128</value>
  </property>
  <property>
    <name>mapreduce.reduce.memory.mb</name>
    <value>128</value>
  </property>
</configuration>

-------------------
yarn-site.xml
------------------- 
 <configuration>
  <property>
    <name>yarn.acl.enable</name>
    <value>0</value>
  </property>
  <property>
    <name>yarn.resourcemanager.hostname</name>
    <value>192.168.1.32</value>
  </property>
  <property>
    <name>yarn.nodemanager.aux-services</name>
    <value>mapreduce_shuffle</value>
  </property>
  <property>
    <name>yarn.nodemanager.auxservices.mapreduce.shuffle.class</name>
    <value>org.apache.hadoop.mapred.ShuffleHandler</value>
  </property>
  <property>
    <name>yarn.nodemanager.resource.memory-mb</name>
    <value>900</value>
  </property>
  <property>
    <name>yarn.scheduler.maximum-allocation-mb</name>
    <value>900</value>
  </property>
  <property>
    <name>yarn.scheduler.minimum-allocation-mb</name>
    <value>64</value>
  </property>
  <property>
    <name>yarn.nodemanager.vmem-check-enabled</name>
    <value>false</value>
  </property>
</configuration>