|NO.Z.00006|——————————|Deployment|——|Hadoop&Spark环境部署.v06|——|Hadoop.v06|集群启动|单节点启动|

一、启动HDFS集群

### --- 启动集群注意事项

~~~     # 注意：如果集群是第一次启动，需要在Namenode所在节点格式化NameNode，
~~~     # 非第一次不用执行格式化Namenode操作！！

二、单节点启动：格式化NameNode

### --- 单节点启动

~~~     # 所有节点执行
[root@hadoop01 ~]# cd /opt/yanqi/servers/hadoop-2.9.2/
[root@hadoop01 hadoop-2.9.2]# hadoop namenode -format

common.Storage: Storage directory /opt/yanqi/servers/hadoop-2.9.2/data/tmp/dfs/name has been successfully formatted.

~~~     # 注：输出这句内容说明格式化成功
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at hadoop01/192.168.1.121
************************************************************/

### --- 格式化命令执行效果：

~~~     格式化后创建的文件：/opt/yanqi/servers/hadoop-2.9.2/data/tmp/dfs/name/current

[root@hadoop01 hadoop-2.9.2]# ll /opt/yanqi/servers/hadoop-2.9.2/data/tmp/dfs/name/current
total 16
-rw-r--r-- 1 root root 323 Jun 20 12:41 fsimage_0000000000000000000

### --- 在Hadoop01上启动NameNode

[root@hadoop01 ~]# cd /opt/yanqi/servers/hadoop-2.9.2/sbin
[root@hadoop01 sbin]# hadoop-daemon.sh start namenode
starting namenode, logging to /opt/yanqi/servers/hadoop-2.9.2/logs/hadoop-root-namenode-hadoop01.out
[root@hadoop01 sbin]# jps
9939 Jps
9865 NameNode

二、单节点启动：启动DataNode

### --- 在所有节点分别启动DataNode

[root@hadoop01 ~]# hadoop-daemon.sh start datanode
[root@hadoop01 ~]# jps
9865 NameNode
9962 DataNode

[root@hadoop02 ~]# hadoop-daemon.sh start datanode
[root@hadoop02 ~]# jps
10421 DataNode

[root@hadoop03 ~]# hadoop-daemon.sh start datanode
[root@hadoop03 ~]# jps
10709 DataNode

三、查看HDFS集群的管理界面

### --- web端查看Hdfs界面
### --- 查看HDFS集群正常节点：

~~~     hdfs地址：http://hadoop01:50070/dfshealth.html#tab-overview

---

一、启动YARN集群：单节点启动：启动YARN集群

### --- YARN集群单节点启动

~~~     # 启动yarn集群的主节点hadoop01
[root@hadoop01 ~]# yarn-daemon.sh start resourcemanager
[root@hadoop01 ~]# jps
10112 ResourceManager

~~~     # 启动yarn集群的从节点hadoop01

[root@hadoop01 ~]# yarn-daemon.sh start nodemanager
[root@hadoop01 ~]# jps
10415 NodeManager

~~~     # 启动yarn集群的从节点hadoop02

[root@hadoop02 ~]# yarn-daemon.sh start nodemanager
[root@hadoop02 ~]# jps
10820 NodeManager

~~~     # 启动yarn集群的从节点hadoop03

[root@hadoop03 ~]# yarn-daemon.sh start nodemanager
[root@hadoop03 ~]# jps
10853 NodeManager

### --- 思考：Hadoop集群每次需要一个一个节点的启动，如果节点数增加到成千上万个怎么办？
### --- 停止集群服务 

~~~     # 停止hadoop01的服务
[root@hadoop01 ~]# jps
10112 ResourceManager
9865 NameNode
9962 DataNode
10415 NodeManager
 
[root@hadoop01 ~]# hadoop-daemon.sh stop namenode
[root@hadoop01 ~]# hadoop-daemon.sh stop datanode
[root@hadoop01 ~]# yarn-daemon.sh stop nodemanager
[root@hadoop01 ~]# yarn-daemon.sh stop resourcemanager

~~~     # 停止Hadoop02的服务

[root@hadoop02 ~]# jps
10820 NodeManager
10421 DataNode
 
[root@hadoop02 ~]# hadoop-daemon.sh stop datanode
[root@hadoop02 ~]# yarn-daemon.sh stop nodemanager

~~~     # 停止hadoop03的服务

[root@hadoop03 ~]# jps
10709 DataNode
10853 NodeManager
 
[root@hadoop03 ~]# hadoop-daemon.sh stop datanode
[root@hadoop03 ~]# yarn-daemon.sh stop nodemanager

---

一、集群群起

### --- 如果已经单节点方式启动了Hadoop,
~~~     可以先停止之前的启动的Namenode与Datanode进程,如果之前Namenode没有执行格式化，
~~~     这里需要执行格式化!!!!

~~~     # 不用执行
[root@hadoop01 ~]# hadoop namenode -format

### --- 启动HDFS

~~~     # 启动脚本
[root@hadoop01 ~]# start-dfs.sh 
Starting namenodes on [hadoop01]
hadoop01: starting namenode, logging to /opt/yanqi/servers/hadoop-2.9.2/logs/hadoop-root-namenode-hadoop01.out
hadoop02: starting datanode, logging to /opt/yanqi/servers/hadoop-2.9.2/logs/hadoop-root-datanode-hadoop02.out
hadoop03: starting datanode, logging to /opt/yanqi/servers/hadoop-2.9.2/logs/hadoop-root-datanode-hadoop03.out
hadoop01: starting datanode, logging to /opt/yanqi/servers/hadoop-2.9.2/logs/hadoop-root-datanode-hadoop01.out
Starting secondary namenodes [hadoop02]
hadoop02: starting secondarynamenode, logging to /opt/yanqi/servers/hadoop-2.9.2/logs/hadoop-root-secondarynamenode-hadoop02.out

~~~     # 查看启动的服务

[root@hadoop01 ~]# jps
10849 NameNode
10956 DataNode
 
[root@hadoop02 ~]# jps
11061 DataNode
11161 SecondaryNameNode

[root@hadoop03 ~]# jps
11091 DataNode

### --- 启动YARN

~~~     # 启动yarn服务
[root@hadoop01 ~]#  start-yarn.sh
starting yarn daemons
starting resourcemanager, logging to /opt/yanqi/servers/hadoop-2.9.2/logs/yarn-root-resourcemanager-hadoop01.out
hadoop02: starting nodemanager, logging to /opt/yanqi/servers/hadoop-2.9.2/logs/yarn-root-nodemanager-hadoop02.out
hadoop03: starting nodemanager, logging to /opt/yanqi/servers/hadoop-2.9.2/logs/yarn-root-nodemanager-hadoop03.out
hadoop01: starting nodemanager, logging to /opt/yanqi/servers/hadoop-2.9.2/logs/yarn-root-nodemanager-hadoop01.out

~~~     # 查看服务状态
~~~     注意：NameNode和ResourceManger不是在同一台机器，
~~~     不能在NameNode上启动 YARN，应该在ResouceManager所在的机器上启动YARN。

[root@hadoop01 ~]# jps
10849 NameNode
11350 NodeManager
10956 DataNode
11245 ResourceManager

[root@hadoop02 ~]# jps
11249 NodeManager
11061 DataNode
11161 SecondaryNameNode

[root@hadoop03 ~]# jps
11091 DataNode
11211 NodeManager

---

一、Hadoop集群启动停止命令汇总

### --- 各个服务组件逐一启动/停止

~~~     # 分别启动/停止HDFS组件
[root@hadoop01 sbin]#  hadoop-daemon.sh start / stop namenode / datanode / secondarynamenode
~~~     # 启动/停止YARN
[root@hadoop01 sbin]# yarn-daemon.sh start / stop resourcemanager / nodemanager

### --- 各个模块分开启动/停止（配置ssh是前提）常用

~~~     # 整体启动/停止HDFS
[root@hadoop01 sbin]# start-dfs.sh / stop-dfs.sh
~~~     # 整体启动/停止YARN
[root@hadoop01 sbin]# start-yarn.sh / stop-yarn.sh

---

 

 

 

 

 

 

 

 

 

---

Walter Savage Landor:strove with none,for none was worth my strife.Nature I loved and, next to Nature, Art:I warm'd both hands before the fire of life.It sinks, and I am ready to depart

                                                                                                                                                   ——W.S.Landor

---