Call From s150/192.168.109.150 to 0.0.0.0:10020 failed on connection exception:
参考博客：点击打开链接
Hadoop连接本地数据库的时候报错
Exception in thread "main" java.io.IOException: java.net.ConnectException:
Call From s150/192.168.109.150 to 0.0.0.0:10020 failed on connection exception:
java.net.ConnectException: Connection refused; For more details see:
http://wiki.apache.org/hadoop/ConnectionRefused原因：historyservice没有启动
配置yarn-site.xml，添加历史服务器
然后在sbin目录下执行命令
mr-jobhistory-daemon.sh start historyserver