How-to: enable fair scheduler in hadoop

Introduction and reference:
http://hadoop.apache.org/docs/r2.7.1/hadoop-yarn/hadoop-yarn-site/FairScheduler.html

Steps:

• Add following in yarn-site.xml:
          <property>
                  <name>yarn.resourcemanager.scheduler.class</name>
                  <value>org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler</value>
          </property>
          <property>
                  <name>yarn.resourcemanager.webapp.https.address.rm2</name>
                  <value>master02.dc.tj:8089</value>
          </property>
          <property>
                  <name>yarn.scheduler.fair.allocation.file</name>
                  <value>${HADOOP_HOME}/etc/hadoop/fair-scheduler.xml</value>
          </property>
          <property>
                  <name>yarn.scheduler.fair.user-as-default-queue</name>
                  <value>true</value>
          </property>
          <property>
                  <name>yarn.scheduler.fair.preemption</name>
                  <value>true</value>
          </property>
• Generate file ${HADOOP_HOME}/etc/hadoop/fair-scheduler.xml:
  <?xml version="1.0"?>
  <allocations>
  <!--Currently for jobs submitted with user hadoop(hadoop admin) -->
    <queue name="hadoop">
      <aclSubmitApps>hadoop</aclSubmitApps>
      <aclAdministerApps>hadoop</aclAdministerApps>
      <minResources>5000 mb,0vcores</minResources>
      <maxResources>90000 mb,0vcores</maxResources>
      <maxRunningApps>100</maxRunningApps>
      <maxAMShare>0.5</maxAMShare>
      <weight>10.0</weight>
    </queue>
  
  
  <!--Currently for jobs submitted with user chenfangfang -->
    <queue name="chenfangfang">
       <aclSubmitApps>chenfangfang</aclSubmitApps>
       <aclAdministerApps>hadoop,chenfangfang</aclAdministerApps>
       <minResources>5000 mb,0vcores</minResources>
       <maxResources>45000 mb,0vcores</maxResources>
       <maxRunningApps>30</maxRunningApps>
       <maxAMShare>0.5</maxAMShare>
       <weight>1.0</weight>
    </queue>
    <queueMaxAMShareDefault>0.5</queueMaxAMShareDefault>
  
    <!-- All other users besides hadoop and chenfangfang, will be included in clients queue -->
    <queue name="clients" type="parent">
      <aclSubmitApps>*</aclSubmitApps>
      <aclAdministerApps>hadoop</aclAdministerApps>
      <minResources>5000 mb,0vcores</minResources>
      <maxResources>45000 mb,0vcores</maxResources>
      <maxRunningApps>20</maxRunningApps>
      <maxAMShare>0.5</maxAMShare>
      <weight>1.0</weight>
    </queue>
              
    <queuePlacementPolicy>
      <!-- Firstly, use spacified queue name as submitted queue-->
      <rule name="specified" create="false" />
      <!-- Then, use submitter user name as submitted queue--> 
      <rule name="user" create="false" />
      <!-- Other jobs use clients queue as submitted queue--> 
      <rule name="default" queue="clients" />
    </queuePlacementPolicy>
  </allocations>