在Hadoop系统中运行WordCount案例失败解决方法

报错提示:

mapreduce.shuffle set in yarn.nodemanager.aux-services is invalid

请在yarn-site.xml中添加

<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>

重启相应服务即可解决