`假设新增一台slave5:172.16.0.8`
#### 准备工作
`a.所有机器添加主机名slave5的解析`
```bash
cat /etc/hosts
```
```bash
172.16.0.3 master
172.16.0.4 slave1
172.16.0.5 slave2
172.16.0.6 slave3
172.16.0.7 slave4
172.16.0.8 slave5
```
`b.master添加用户hadoop免密登陆`
```bash
su - hadoop
ssh-copy-id slave4
scp .bash_profile slave4:/opt/hadoop
```
 
#### 主节点slaves添加新机器信息
`master`
```bash
cat > etc/hadoop/slaves << EOF
master
slave1
slave2
slave3
slave4
slave5
EOF
```
 
#### 安装java和hadoop
`同上操作即可`
 
#### 拷贝hadoop配置到新增节点
```bash
su - hadoop
scp etc/hadoop/* slave5:/opt/hadoop/etc/hadoop/
scp sbin/* slave5:/opt/hadoop/sbin/
```
#### 启动节点
```bash
./sbin/hadoop-daemon.sh start datanode
./sbin/yarn-daemon.sh start nodemanager
```
#### 执行数据负载均衡
```bash
start-balancer.sh -threshold 1
```
