集群启动/停止方式总结
1）各个模块分开启动/停止（配置ssh是前提）（1）整体启动/停止HDFSstart-dfs.sh/stop-dfs.sh（2）整体启动/停止YARNstart-yarn.sh/stop-yarn.sh2）各个服务组件逐一启动/停止（1）分别启动/停止HDFS组件hdfs --daemon start/stop namenode/datanode/secondarynamenode（2）分别启动/停止YARN组件yarn --daemon start/stop resourceman
