解决 hive maPredue转换hivesql出错Error: Could not find or load main class org.apache.hadoop.mapreduce.v2.a

找到hadoop安装目录下$HADOOP_HOME/etc/mapred-site.xml,增加以下代码

<property>
  <name>yarn.app.mapreduce.am.env</name>
  <value>HADOOP_MAPRED_HOME=${HADOOP_HOME}</value>
</property>
<property>
  <name>mapreduce.map.env</name>
  <value>HADOOP_MAPRED_HOME=${HADOOP_HOME}</value>
</property>
<property>
  <name>mapreduce.reduce.env</name>
  <value>HADOOP_MAPRED_HOME=${HADOOP_HOME}</value>
</property>
不用重启即可解决