hadoop 5台机器集群环境搭建

怼烎@ 2022-02-02 23:29 1541阅读 0赞

##  ##

## 一、准备 ##

5台机器上搭建hadoop集群环境

5台机器主机名与IP分别为

<table style="width:500px;"> 
 <tbody> 
  <tr> 
   <td>主机名</td> 
   <td>IP</td> 
  </tr> 
  <tr> 
   <td>nn1.hadoop</td> 
   <td>192.168.109.151</td> 
  </tr> 
  <tr> 
   <td>nn2.hadoop</td> 
   <td>192.168.109.152</td> 
  </tr> 
  <tr> 
   <td>s1.hadoop</td> 
   <td>192.168.109.153</td> 
  </tr> 
  <tr> 
   <td>s2.hadoop</td> 
   <td>192.168.109.154</td> 
  </tr> 
  <tr> 
   <td>s3.hadoop</td> 
   <td>192.168.109.155</td> 
  </tr> 
 </tbody> 
</table>

搭建思路：

1.利用VMware先搭建一台linux centos7最小安装版虚拟机

2.配置好单台虚拟机，利用VMware的克隆技术，克隆其他四台虚拟机

3.更改每台虚拟机的静态Ip及主机名称

4.生成每台虚拟机的SSH公钥，统一远程复制到同一台虚拟机上

5.将生成的公钥authorized\_keys远程复制到每台机器，实现集群的5台机器互相免密登录

## 二、配置单台机器 ##

### 1.配置静态IP ###

修改步骤 :

**1.1 执行ip add 命令 下面的ens33才是真实IP**

[root@localhost ~]# ip add 
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        inet 127.0.0.1/8 scope host lo
           valid_lft forever preferred_lft forever
        inet6 ::1/128 scope host 
           valid_lft forever preferred_lft forever
    2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
        link/ether 00:0c:29:e8:76:84 brd ff:ff:ff:ff:ff:ff
        inet 192.168.109.145/24 brd 192.168.109.255 scope global noprefixroute dynamic ens33
           valid_lft 1188sec preferred_lft 1188sec
        inet6 fe80::2839:870b:b85b:c218/64 scope link noprefixroute 
           valid_lft forever preferred_lft forever

**1.2 修改ens33这个网卡的配置**

[root@localhost ~]# cd /etc/sysconfig/network-scripts/
    [root@localhost network-scripts]# vi ifcfg-ens33

原来的内容是这样的 :

TYPE="Ethernet"
    PROXY_METHOD="none"
    BROWSER_ONLY="no"
    BOOTPROTO="dhcp"
    DEFROUTE="yes"
    IPV4_FAILURE_FATAL="no"
    IPV6INIT="yes"
    IPV6_AUTOCONF="yes"
    IPV6_DEFROUTE="yes"
    IPV6_FAILURE_FATAL="no"
    IPV6_ADDR_GEN_MODE="stable-privacy"
    NAME="ens33"
    UUID="45741c09-63f3-44ad-b4f9-6bcdd2e5d4f0"
    DEVICE="ens33"
    ONBOOT="yes"

修改如下 :

TYPE="Ethernet"
    PROXY_METHOD="none"
    BROWSER_ONLY="no"
    BOOTPROTO="static"     #修改为static
    IPADDR="192.168.109.151" #IP
    NETMASK="255.255.255.0" #子网掩码
    GATEWAY="192.168.109.2" #网关
    DNS="192.168.109.2"    #DNS
    DEFROUTE="yes"
    IPV4_FAILURE_FATAL="no"
    IPV6INIT="yes"
    IPV6_AUTOCONF="yes"
    IPV6_DEFROUTE="yes"
    IPV6_FAILURE_FATAL="no"
    IPV6_ADDR_GEN_MODE="stable-privacy"
    NAME="ens33"
    UUID="45741c09-63f3-44ad-b4f9-6bcdd2e5d4f0"
    DEVICE="ens33"
    ONBOOT="yes"

**1.3 停止 networkManager 服务 这样才能上网**

[root@localhost network-scripts]# systemctl stop NetworkManager.service

**1.4 关闭自动启动**

[root@localhost network-scripts]# systemctl disable NetworkManager.service
    Removed symlink /etc/systemd/system/multi-user.target.wants/NetworkManager.service.
    Removed symlink /etc/systemd/system/dbus-org.freedesktop.NetworkManager.service.
    Removed symlink /etc/systemd/system/dbus-org.freedesktop.nm-dispatcher.service.

**1.5 编辑/etc/resolv.conf 文件**

[root@localhost network-scripts]# vi /etc/resolv.conf
    # Generated by NetworkManager
    search localdomain
    nameserver 192.168.109.2 #如没有，需要手动添加 设置为网关

**1.6 重启网络服务**

[root@localhost network-scripts]# systemctl restart network.service

**1.7 查看网卡配置**

[root@localhost network-scripts]# ip add
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        inet 127.0.0.1/8 scope host lo
           valid_lft forever preferred_lft forever
        inet6 ::1/128 scope host 
           valid_lft forever preferred_lft forever
    2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
        link/ether 00:0c:29:e8:76:84 brd ff:ff:ff:ff:ff:ff
        inet 192.168.109.151/24 brd 192.168.109.255 scope global ens33 #修改之后
           valid_lft forever preferred_lft forever
        inet6 fe80::20c:29ff:fee8:7684/64 scope link 
           valid_lft forever preferred_lft forever

**1.8 验证是否可以正常上网**

[root@localhost network-scripts]# ping www.baidu.com
    PING www.a.shifen.com (119.75.217.109) 56(84) bytes of data.
    64 bytes from 119.75.217.109 (119.75.217.109): icmp_seq=1 ttl=128 time=5.59 ms
    64 bytes from 119.75.217.109 (119.75.217.109): icmp_seq=2 ttl=128 time=7.22 ms
    64 bytes from 119.75.217.109 (119.75.217.109): icmp_seq=3 ttl=128 time=5.44 ms

### 2.修改主机名 ###

[root@localhost ~]# hostnamectl set-hostname nn1.hadoop
    [root@localhost ~]# hostname
    nn1.hadoop
    [root@localhost ~]# reboot    #重启

配置hosts IP与主机名映射文件

[root@nn1 ~]# vi /etc/hosts
    127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
    ::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
    # 添加如下信息
    192.168.109.151 nn1.hadoop
    192.168.109.152 nn2.hadoop
    192.168.109.153 s1.hadoop
    192.168.109.154 s2.hadoop
    192.168.109.155 s3.hadoop

### 3.关闭防火墙 ###

[root@nn1 ~]# systemctl stop firewalld.service 
    [root@nn1 ~]# systemctl disable firewalld.service

### 4.关闭SELinux ###

SELinux(Security-Enhanced Linux) 是[美国国家安全局][Link 1]（NSA）对于[强制访问控制][Link 2]的实现，是 Linux历史上最杰出的新安全子系统。

**4.1 查看关闭状态：**

[root@nn1 ~]# /usr/sbin/sestatus -v
    SELinux status:                 enabled
    SELinuxfs mount:                /sys/fs/selinux
    SELinux root directory:         /etc/selinux
    Loaded policy name:             targeted
    Current mode:                   enforcing
    Mode from config file:          enforcing
    Policy MLS status:              enabled
    Policy deny_unknown status:     allowed
    Max kernel policy version:      31

**4.2 关闭方法：**

[root@nn1 ~]# vim /etc/selinux/config

**4.3 把文件里的SELINUX设置为disabled**

# This file controls the state of SELinux on the system.
    # SELINUX= can take one of these three values:
    #     enforcing - SELinux security policy is enforced.
    #     permissive - SELinux prints warnings instead of enforcing.
    #     disabled - No SELinux policy is loaded.
    # SELINUX=enforcing
    SELINUX=disable
    # SELINUXTYPE= can take one of three two values:
    #     targeted - Targeted processes are protected,
    #     minimum - Modification of targeted policy. Only selected processes are protected. 
    #     mls - Multi Level Security protection.
    SELINUXTYPE=targeted

### 5.添加hadoop用户并添加到whell 群组 ###

**5.1 添加hadoop用户**

[root@nn1 ~]# useradd hadoop
    [root@nn1 ~]# passwd hadoop
    Changing password for user hadoop.
    New password:               #密码：123456
    BAD PASSWORD: The password is shorter than 8 characters
    Retype new password:        #密码：123456
    passwd: all authentication tokens updated successfully.
    [root@nn1 ~]#

**5.2 添加hadoop用户到wheel 用户组里面，使hadoop拥有root的权限**

[root@nn1 ~]# gpasswd -a hadoop wheel
    正在将用户“hadoop”加入到“wheel”组中
    [root@nn1 ~]# cat /etc/group | grep wheel
    wheel:x:10:hadoop

**5.3 禁止非 whell 组用户切换到root，配置wheel组成员免密切换root**

[root@nn1 ~]# vim /etc/pam.d/su

**5.3.1 找到如下两行，解除注释**  
\#auth           sufficient      pam\_wheel.so trust use\_uid    免密切换到root  
\#auth           required        pam\_wheel.so use\_uid           只允许wheel组里面的允许su 切换

#%PAM-1.0
    auth            sufficient      pam_rootok.so
    # Uncomment the following line to implicitly trust users in the "wheel" group.
    #auth           sufficient      pam_wheel.so trust use_uid
    auth            sufficient      pam_wheel.so trust use_uid
    # Uncomment the following line to require a user to be in the "wheel" group.
    #auth           required        pam_wheel.so use_uid
    auth            required        pam_wheel.so use_uid
    auth            substack        system-auth
    auth            include         postlogin
    account         sufficient      pam_succeed_if.so uid = 0 use_uid quiet
    account         include         system-auth
    password        include         system-auth
    session         include         system-auth
    session         include         postlogin
    session         optional        pam_xauth.so

**5.3.2 修改/etc/login.defs文件**

只有wheel组可以su 到root

[root@nn1 ~]# cp /etc/login.defs  /etc/login_defs.bak     #先备份一下
    [root@nn1 ~]# echo "SU_WHEEL_ONLY yes" >> /etc/login.defs  #在文件尾部追加
    [root@nn1 ~]# tail /etc/login.defs #从文件尾部查看
    UMASK           077
    
    # This enables userdel to remove user groups if no members exist.
    #
    USERGROUPS_ENAB yes
    
    # Use SHA512 to encrypt password.
    ENCRYPT_METHOD SHA512 
    
    SU_WHEEL_ONLY yes
    [root@nn1 ~]#

**5.3.3 验证免密切换用户**

[root@nn1 ~]# su - hadoop
    上一次登录：三 5月  8 14:16:26 CST 2019pts/0 上
    [hadoop@nn1 ~]$ su - root
    上一次登录：三 5月  8 14:15:30 CST 2019pts/0 上
    最后一次失败的登录：三 5月  8 14:16:35 CST 2019pts/0 上
    最有一次成功登录后有 1 次失败的登录尝试。
    [root@nn1 ~]#

### 6.配置阿里云yum源 ###

**6.1.准备文件**：链接：https://pan.baidu.com/s/16fgL0dY-QVk6PnNL1GyglA     提取码：wivt

**6.2.首先安装linux与windows文件互传工具 lrzsz**

[root@nn1 ~]# yum install -y lrzsz

**6.3.执行rz命令，选择之前下载好的的 Centos-7.repo文件 **

覆盖原来的CentOS-Base.repo

[root@nn1 ~]# cd /usr
    [root@nn1 usr]# rz
    .......
    [root@nn1 usr]# cp Centos-7.repo /etc/yum.repos.d/ 
    [root@nn1 usr]# cd /etc/yum.repos.d/ 
    [root@nn1 yum.repos.d]# mv CentOS-Base.repo CentOS-Base.repo.bak 
    [root@nn1 yum.repos.d]# mv Centos-7.repo CentOS-Base.repo

**6.4 依次执行yum源更新命令 **

[root@nn1~]# yum clean all   #清空国外源的
    [root@nn1~]# yum makecache   #缓存阿里云的
    [root@nn1~]# yum update -y   #从阿里云更新

**6.5 安装常用软件**

[root@nn1~]# yum install -y openssh-server vim gcc gcc-c++ glibc-headers bzip2-devel lzo-devel curl wget openssh-clients zlib-devel autoconf automake cmake libtool openssl-devel fuse-devel snappy-devel telnet unzip zip net-tools.x86_64 firewalld systemd ntp psmisc

openssh：SSH协议        --依赖-->  openssl：加密软件

curl ：利用URL语法在命令行方式下工作的开源文件传输工具

wget ：下载工具

zlib、snappy-devel、unzip、zip：压缩工具

autoconf、automake、cmake、fuse-devel：源代码编译相关

libtool：动态库

如果安装失败，可以尝试用 yum -reinstall 覆盖安装

[root@nn1~]# yum reinstall -y openssh-server vim gcc gcc-c++ glibc-headers bzip2-devel lzo-devel curl wget openssh-clients zlib-devel autoconf automake cmake libtool openssl-devel fuse-devel snappy-devel telnet unzip zip net-tools.x86_64 firewalld systemd ntp

### 7.安装jdk8 ###

**7.1 准备文件**：链接：https://pan.baidu.com/s/1z6WaVzdb-RoW5G6gf87sFQ  提取码：1xof

**7.2 利用rz执行上传**

[root@nn1~]# cd /usr/tmp
    [root@nn1 tmp]# rz

**7.3.rpm 安装**

[root@nn1 tmp]# rpm -ivh jdk-8u144-linux-x64.rpm
    准备中...                          ################################# [100%]
    正在升级/安装...
       1:jdk1.8.0_144-2000:1.8.0_144-fcs  ################################# [100%]
    Unpacking JAR files...
            tools.jar...
            plugin.jar...
    .............

**7.4 配置jdk环境变量**

[root@localhost tmp]# vim /etc/profile

在文件尾部添加如下配置

#在文件尾部添加如下配置
    export JAVA_HOME=/usr/java/jdk1.8.0_144
    export JRE_HOME=$JAVA_HOME/jre
    export PATH=$PATH:$JAVA_HOME/bin
    export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

**7.5.使配置文件生效**，查看jdk是否安装成功 java -version

[root@nn1 ~]# source /etc/profile
    [root@nn1 ~]# java -version 
    java version "1.8.0_144"
    Java(TM) SE Runtime Environment (build 1.8.0_144-b01)
    Java HotSpot(TM) 64-Bit Server VM (build 25.144-b01, mixed mode)
    [root@nn1 ~]#

### 8.设置整点同步时间 定时任务 ###

crontab -l  \# 表示列出所有的定时任务  
crontab -r  \# 表示删除用户的定时任务，当执行此命令后，所有用户下面的定时任务会被删除  
crontab -e 创建一个定时任务

[root@nn1 ~]# crontab -e

添加定时任务  整点执行 ntpdate time1.aliyun.com 命令，校对时间

0 * * * *  /usr/sbin/ntpdate time1.aliyun.com >> /tmp/autontpdate 2>&1

## 三、克隆4台机器 ##

执行完上面的命令，一个基础的linux系统就配置好了。然后把这个nn1.hadoop虚拟机导出，再根据这个导出的虚拟机创建4个linux系统。

其中：nn2.hadoop： 从节点

s1.hadoop、s2.hadoop、s3.hadoop：三个工作节点

### 1.配置nn2 ,s1,s2,s3的主机名与静态IP ###

以nn2主机的配置为例，其他主机配置步骤相同：

\*\*\*配置其他主机ip地址时，首先把nn1主机关闭，打开一台配置一台，避免ip冲突。

[root@nn1 ~]# hostnamectl set-hostname nn2.hadoop 
    [root@nn1 ~]# hostname
    nn2.hadoop
    [root@nn1 ~]# vim /etc/sysconfig/network-scripts/ifcfg-ens33

BOOTPROTO="static"     #修改为static
    #IPADDR="192.168.109.151" #IP
    IPADDR="192.168.109.152" #将151 修改为 nn2对应的hosts配置的ip地址 152
    NETMASK="255.255.255.0" #子网掩码

配置IP后验证ping通信是否正常

[hadoop@nn2 ~]$ ping www.baidu.com
    PING www.baidu.com (182.61.200.7) 56(84) bytes of data.
    64 bytes from 182.61.200.7 (182.61.200.7): icmp_seq=1 ttl=128 time=4.25 ms
    64 bytes from 182.61.200.7 (182.61.200.7): icmp_seq=2 ttl=128 time=4.74 ms

## 四 SSH免密登录配置 ##

5台机器都切换到hadoop用户，配置hadoop用户之间的免密登录

**1.分别在nn1 nn2 s1 s2 s3 机器上执行ssh-keygen -t rsa命令 **

[hadoop@nn1 ~]$ ssh-keygen -t rsa
    Generating public/private rsa key pair.
    
    Enter file in which to save the key (/home/hadoop/.ssh/id_rsa): Created directory '/home/hadoop/.ssh'.
    Enter passphrase (empty for no passphrase): 
    Enter same passphrase again: 
    Your identification has been saved in /home/hadoop/.ssh/id_rsa.
    Your public key has been saved in /home/hadoop/.ssh/id_rsa.pub.
    The key fingerprint is:
    SHA256:PIM/73UWa/RV+8GbeMUsHPKVDoVE4OezVkFAZ1+UEY4 hadoop@s2.hadoop
    The key's randomart image is:
    +---[RSA 2048]----+
    |           .==oO*|
    |          .  .B.+|
    |           ..E.++|
    |       o    o++=+|
    |      . S    o**=|
    |       . o   .==B|
    |        o   .+=+o|
    |         o ..+.  |
    |         .o      |
    +----[SHA256]-----+
    [hadoop@nn1 ~]$

在home目录下生成：id\_rsa 私钥和 id\_rsa.pub 公钥

[hadoop@nn1 ~]$ cd .ssh
    [hadoop@nn1 .ssh]$ ll
    总用量 16
    -rw-------. 1 hadoop hadoop 1675 5月   8 15:07 id_rsa
    -rw-r--r--. 1 hadoop hadoop  398 5月   8 15:07 id_rsa.pub

**2.在nn1机器上 创建 all\_id 目录**

[hadoop@nn1 ~]$ mkdir all_id
    [hadoop@nn1 ~]$ ll
    total 0
    drwxrwxr-x. 2 hadoop hadoop 6 May  8 15:09 all_id

**3.通过nn1 nn2 s1 s2 s3 机器 分别执行scp 远程复制命令，将本机的id\_rsa.pub 发送到nn1 的id\_all目录下**

[hadoop@nn2 ~]$ scp .ssh/id_rsa.pub hadoop@nn1.hadoop:/home/hadoop/all_id/nn2_rsa_pub
    hadoop@nn1.hadoop's password: 
    id_rsa.pub                                                                                                    100%  398   185.1KB/s   00:00    
    [hadoop@nn2 ~]$

**4.将nn1 nn2 s1 s2 s3 机器的公钥分别追加到authorized\_keys 文件里**

[hadoop@nn1 ~]$ cd all_id
    [hadoop@nn1 all_id]$ cat nn1_rsa_pub > ~/.ssh/authorized_keys
    [hadoop@nn1 all_id]$ cat nn2_rsa_pub >> ~/.ssh/authorized_keys
    [hadoop@nn1 all_id]$ cat s1_rsa_pub >> ~/.ssh/authorized_keys
    [hadoop@nn1 all_id]$ cat s2_rsa_pub >> ~/.ssh/authorized_keys
    [hadoop@nn1 all_id]$ cat s3_rsa_pub >> ~/.ssh/authorized_keys
    [hadoop@nn1 all_id]$ cat ~/.ssh/authorized_keys 
    ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDKCSNDL6TPDU1dVkNe3ss0dPkl8/OV9pMsOGccTKgUQKb4iJFt3PdnFn9EO+YcKX0wQzDbZkG0TDSHpOhdpgnVPXYBUNv1A6YEnEH2xdJ2Nt5ZGzclRaWuesak+iPJiWF/9AWMhWjw/DCuxh9eDGz4F7iVsvlP557yFAQR6bJM0uESMSdkA/72SCrJT7H0PQ+scdSg6lAdb3ij5EMsjWcyY5kAm7wJMX53R0w2sg9kTgpq2a/HP6hp81N9zjvckGKBNCsy6SrsOguyO0tlo13VpdBqUaYRxBpeKW1YIxfHTBCtVD2ha4dm03PGqpd2as3rnHvl/HTkrFB099fzC0n5 hadoop@nn1.hadoop
    ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDHowws1HajWVCC8TOzVdIj1zdWgHLaJXVRzu0RyRsv6fS5xL0HMDzpwrdH6fzc7U32t/dyTa1uAi5a5gwXm6pydyKCrmlrECX2g4dm72ZiiBpFP3oETHePIlk09AImcFlV72tXDOFmmVH3QxwnM2JkmmQUO3hZkrDF/0TtHRKHEj4b1yntTZebPgTavPK4M0Tu2NXXXhW00kcwLYcI8VCwDYBcxMQ6KWBkkQg5G6aZfXT3uGyYCSdWaDM0YFOnv5GJpaD+Ha1PfwcLrRhtuKhOsS8VoSICg6Af1O8uBfQukEy281fT7rL08Ba/SztjAWGuZ9iDZTZjaY/P8cWczC7z hadoop@nn2.hadoop
    ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC6ti5YCzMssYilq0f6Mg6hVKkYxho1ldlOVQrOMYgccI4k//SkfXdBoWZQcUa2Vlj8L2HmP/u3JGbUF51ANXBirWzoBC+gQ4yiK4ErjiW82u//obwZ4lte3k7FeKHqcgw32P3G82sH12ftKAl/1ni7gJBT0FdYM70cd3Z4RLQRtfW+fr+1R+J8iSBunT8SFIFw6D+fhZAEmqT26p5Dy++KnMx5nrZfgrHCMuLUmSr9WRm4PkGBxrzObmVRbhnYR0/W+wyoFtlwBQg/r2x3dwap6/Akt0Twipt3z7N4rV/8XM86NO6YugB5fuUT/L4O3xUHUc9TCHdk0GUnBq1vU4wr hadoop@s1.hadoop
    ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDFJLVOb7KTrIZQrAP13AH7SPES4MNAY5JhGY8hdP3W1IF33rAvwgBMJNPGGDmv//pbEdhMnOS45+jXr92cDdSyKuhAjZA33QquBYapGNAznUQzim5NB1cd+IxD0m7CQQSz+jMRh917JpiHGV1ZmAj3tQ8mSaYYmSAIx5MabPGJgmTR0Rlml+wCSLnHECUPSyusQ9+KcdyN9WdQk9C9vSGaloUOj4lyjL5zYracuzemuAVk6uTLjQiy3nzk2lZM/7EzbP6I1bK4+wmFDoAHYU0gV6NIc2mH0KF4MIN32qSZA6CSEbEaaU+F3e3xADTNIMdm2T6J86aj2iFCF31FgrTP hadoop@s2.hadoop
    ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC5uizSo1VqwQIRxlvC2wAyDKCr1YSdHwA1eS2pCnn0gjrSPlglIe5qkKj9WyUKYkqJVFKdpkcTAsNsp/G9RRGSrZKAW8gY20kMq8ggBjyfb5JcOHao7wTqwY834EZUslM9J4eZUAqQWO5IdeUnncW+mNdAl+oVSpF51uQoe1kLVkGF0vQ3bfmtT+jFyptmEmumggSHuNadvdshG3w2crJZQB8KgM+5xiA8ydOPXYpeu/i3J+R7mqhQVlrU/IQGzSyXI99dbRzeUWmAVh1UfUhO17qY+PqC6SaGcfI/9Z5RgGsxBRByI0Lj5xgDUPF1kf4PF5kiBN+5CTC3x+31say3 hadoop@s3.hadoop

**5.将nn1的authorized\_keys 远程复制到 nn2 s1 s2 s3 的 .ssh 目录里**

[hadoop@nn1 .ssh]$ scp authorized_keys hadoop@s3.hadoop:~/.ssh/
    The authenticity of host 's3.hadoop (192.168.109.155)' can't be established.
    ECDSA key fingerprint is SHA256:9jCRb+TPi342pR2nLLpDmzmI/ulZQMTRFQAXVBKxwGk.
    ECDSA key fingerprint is MD5:0c:42:a6:0e:00:79:86:c4:8d:e5:a2:71:eb:30:2e:c0.
    Are you sure you want to continue connecting (yes/no)? yes
    Warning: Permanently added 's3.hadoop,192.168.109.155' (ECDSA) to the list of known hosts.
    hadoop@s3.hadoop's password: 
    authorized_keys

**6.修改文件及目录的权限**

分别修改nn1 nn2 s1 s2 s3  的***authorized\_keys的权限为600***

分别修改nn1 nn2 s1 s2 s3  的***home目录的权限为700***

分别修改nn1 nn2 s1 s2 s3  的***.ssh目录的权限为700***

[hadoop@nn1 .ssh]$chmod 600 authorized_keys 
    [hadoop@nn1 .ssh]$chmod 700 ~
    [hadoop@nn1 .ssh]$chmod 700 ~/.ssh

**7.SSH免密验证**

首次免密登录需要建立连接 输入yes即可。

[hadoop@nn2 ~]$ ssh s1.hadoop
    The authenticity of host 's1.hadoop (192.168.109.153)' can't be established.
    ECDSA key fingerprint is SHA256:9jCRb+TPi342pR2nLLpDmzmI/ulZQMTRFQAXVBKxwGk.
    ECDSA key fingerprint is MD5:0c:42:a6:0e:00:79:86:c4:8d:e5:a2:71:eb:30:2e:c0.
    Are you sure you want to continue connecting (yes/no)? yues
    Please type 'yes' or 'no': yes
    Warning: Permanently added 's1.hadoop,192.168.109.153' (ECDSA) to the list of known hosts.
    Last login: Wed May  8 15:28:52 2019 from s3.hadoop
    [hadoop@s1 ~]$ ssh s2.hadoop
    Last login: Wed May  8 15:30:56 2019 from s3.hadoop
    [hadoop@s2 ~]$ ssh s3.hadoop
    Last login: Wed May  8 15:34:55 2019 from nn2.hadoop
    [hadoop@s3 ~]$ ssh nn1.hadoop
    Last login: Wed May  8 15:35:08 2019 from s3.hadoop
    [hadoop@nn1 ~]$ ssh nn1.hadoop

[Link 1]: https://baike.baidu.com/item/%E7%BE%8E%E5%9B%BD%E5%9B%BD%E5%AE%B6%E5%AE%89%E5%85%A8%E5%B1%80/300052
[Link 2]: https://baike.baidu.com/item/%E5%BC%BA%E5%88%B6%E8%AE%BF%E9%97%AE%E6%8E%A7%E5%88%B6/3617989