- Hadoop端口：
50070 ======》namenode http port
50075 =======》datanode http port
50090 ========》2namenode http port
8020 ========》namenode rpc port
50010 ========》datanode rpc port
- hadoop 四大模块
common =======》普通模块
hdfs ========》namenode+datanode+secondarynamenode
mapred
yarn =========》resourcemanager + nodemanager
- 启动脚本
1》start-all.sh ===>启动所有进程
2》stop-all.sh =====>关闭所有进程
3》start-dfs.sh/stop-dfs.sh =====>启动/关闭hdfs节点
4》start-yarn.sh/stop-yarn.sh =====>启动/关闭yarn节点