优先顺序:
1)share目录下默认的配置文件(最低)
2)etc目录下配置文件(其次)
3)命令执行(最高)
执行案例之前必须启动6个进程哦!

案例:删除uber模式启动
#bin/hadoop jar share/hadoop/mapreduce/hadoop-mapredude-examples-2.7.6.jar wordcount -D mapreduce.job.ubertask.enable=false /words /test01
执行后查看:
在启动时候查看:
(1)NameNode/SecondNameNode
http://hadoop.apache.org/docs/r2.7.6/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml
dfs.namenode.secondary.https-address 这两个配置一个就OK!
hdfs-site.xml文件
<!--浏览器访问的端口-->
<property>
<name>dfs.namenode.secondary.http-address</name>
<value>hlx:50090</value>
</property>
<!--namenode web UI 端口-->
<property>
<name>dfs.namenode.http-address</name>
<value>hlx:50070</value>
</property>
(2)DataNode/NodeManager在slaves修改
(3)JobHistoryServer
http://hadoop.apache.org/docs/r2.7.6/hadoop-mapreduce-client/hadoop-mapreduce-client-core/mapred-default.xml
mapred-site.xml文件
<!-- jobhistory web端口 -->
<property>
<name>mapreduce.jobhistory.webapp.address</name>
<value>hlx:19888</value>
</property>
<!-- jobhistory与yarn通信的端口 -->
<property>
<name>mapreduce.jobhistory.address</name>
<value>hlx:10020</value>
</property>
(4)ResourceManager
http://hadoop.apache.org/docs/r2.7.6/hadoop-yarn/hadoop-yarn-common/yarn-default.xml
yarn-site.xml文件
<!--yarn的主机 -->
<property>
<name>yarn.resourcemanager.hostname</name>
<value>hlx</value>
</property>
<!--yarn的web端口 -->
<property>
<name>yarn.resourcemanager.webapp.address</name>
<value>hlx:8088</value>
</property>
<!--yarn的通信端口 -->
<property>
<name>yarn.resourcemanager.address</name>
<value>hlx:8032</value>
</property>
(5)webapplication如何启动 (代理进程,防止攻击,系统防火墙)
#sbin/yarn-daemon.sh start proxyserver
#jps
#ls logs/
#more logs/yarn-root-proxyserver-hadoop.log
按Enter查看,有个错误!
http://hadoop.apache.org/docs/r2.7.6/hadoop-yarn/hadoop-yarn-common/yarn-default.xml查找
yarn-site.xml文件
<!--yarn的代理端口 8888:是自己定义 -->
<property>
<name>yarn.web-proxy.address</name>
<value>hlx:8888</value>
</property>
最后查看:(1)先停止dfs 再重新启动dfs
(2)先停止yarn 再重新启动yarn
(3)先停止jobhistory 再重新启动jobhistory
再依次启动查看,现在所有的都在主机hlx 中

(4) #sbin/yarn-daemon.sh start proxyserver