<configuration>

  <property>

    <name>yarn.nodemanager.aux-services</name>

    <value></value>

    <description>默认值是“mapreduce.shuffle”，但如果在hadoop-2.2 中继续使用这个值，NodeManager 会启动失败改为“mapreduce_shuffle”。</description>

  </property>

  <property>

    <name>yarn.nodemanager.aux-services.mapreduce_shuffle.class</name>

    <value>org.apache.hadoop.mapred.ShuffleHandler</value>

    <description>为了能够运行MapReduce程序，需要让各个NodeManager在启动时加载shuffle server，shuffle server实际上是Jetty/Netty Server，Reduce Task通过该server从各个NodeManager上远程拷贝Map Task产生的中间结果。上面增加的两个配置均用于指定shuffle serve。如果YARN集群有多个节点，你还要配置yarn.resourcemanager.address等参数???</description>

  </property>

  <property>

    <name>yarn.log-aggregation-enable</name>

    <value>true</value>

    <description>是否启用日志聚集功能。</description>

  </property>

  <property>

    <description>List of directories to store localized files in.</description>

    <name>yarn.nodemanager.local-dirs</name>

    <value>file:///var/lib/hadoop-yarn/cache/${user.name}/nm-local-dir</value>

  </property>

  <property>

    <description>Where to store container logs.</description>

    <name>yarn.nodemanager.log-dirs</name>

    <value>file:///var/log/hadoop-yarn/containers</value>

  </property>

  <property>

    <description>Where to aggregate logs to.</description>

    <name>yarn.nodemanager.remote-app-log-dir</name>

    <value>hdfs://var/log/hadoop-yarn/apps</value>

  </property>