Ambari2.6.2 和HDP2.6.5搭建Hadoop集群-03_CentOS7.5 集群环境配置

1.安装JDK

1.1、卸载系统自带OPEN-JDK（所有节点）

执行以下命令查看系统中有哪些OpenJk相关包：

rpm -qa | grep java

其中有如下包必须卸载

rpm -e --nodeps java-1.5.0-gcj-1.5.0.0-29.1.el6.x86_64
rpm -e --nodeps java-1.6.0-openjdk-1.6.0.0-1.66.1.13.0.el6.x86_64
rpm -e --nodeps java-1.6.0-openjdk-devel-1.6.0.0-1.66.1.13.0.el6.x86_64

1.2.下载安装 jdk-8u121-linux-x64.rpm

安装jdk

chmod +x jdk-8u121-linux-x86.rpm
rpm -ivh jkd-8u121-linux-86.rpm

1.3.配置环境变量

[root@iZbp1barmvtqfdn6lceoyxZ tmp]# vi /etc/profile

追加配置：

export JAVA_HOME=/usr/java/jdk1.8.0_121
export JRE_HOME=$JAVA_HOME/jre
export PATH=$JAVA_HOME/bin:$PATH

保存配置文件source /etc/profile激活配置,不然重开机后可能没有成功修改配置文件

2.修改swappiness配置文件

执行命令cat /proc/sys/vm/swappiness 一般情况下都是60
vi /etc/sysctl.conf 添加 vm.swappiness=0 保存退出；重启后再查看就回是0
操作这个是为了最后一步安装检查集群节点时出现警告
具体原理请看http://blog.csdn.net/wulantian/article/details/36184943

3.关闭防火墙（所有节点）

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centos7之前
临时关闭：service iptables stop
永久关闭：chkconfig iptables off
查看关闭状况：service iptables status

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centos从7开始默认用的是firewalld，这个是基于iptables的，虽然有iptables的核心，但是iptables的服务是没安装的。所以你只要停止firewalld服务即可：

sudo systemctl stop firewalld.service && sudo systemctl disable firewalld.service

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4.关闭SELINUX关、配置umask值

vi /etc/selinux/config

setenforce 0 （临时生效）修改 SELINUX=disabled （重启后永久生效）
查看SELINUX状态
若SELinux status 为disabled 即为关闭

echo umask 0022 >> /etc/profile

source /etc/profile

5.修改主机名称

vi /etc/hostname

6.修改域名映射

vi /etc/hosts

添加以下信息：
192.168.12.191 Master1.Hadoop node1
192.168.12.192 Master2.Hadoop node2
192.168.12.193 Slave1.Hadoop node3
192.168.12.194 Slave2.Hadoop node4
192.168.12.195 Slave3.Hadoop node5

重启网络服务生效:

service network restart

7.SSH无密码登陆

7.1 生成公钥和私钥 (每台机器)

输入命令：(一路回车)

ssh-keygen -t rsa

7.2 执行ssh-copy-id（每台机器）

ssh-copy-id -i ~/.ssh/id_rsa.pub root@node1
ssh-copy-id -i ~/.ssh/id_rsa.pub root@node2
ssh-copy-id -i ~/.ssh/id_rsa.pub root@node3
ssh-copy-id -i ~/.ssh/id_rsa.pub root@node4
ssh-copy-id -i ~/.ssh/id_rsa.pub root@node5

• ssh-copy-id将pub值写入远程机器的~/.ssh/authorized_key中

8.NTP时间服务设置

按照此文章配置NTP即可

Server端补充添加国内可用NTP服务

server ntp1.aliyun.com iburst minpoll 4 maxpoll 10
restrict ntp1.aliyun.com nomodify notrap nopeer noquery
server ntp1.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
restrict ntp1.cloud.aliyuncs.com nomodify notrap nopeer noquery
server ntp10.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
restrict ntp10.cloud.aliyuncs.com nomodify notrap nopeer noquery
server ntp11.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
restrict ntp11.cloud.aliyuncs.com nomodify notrap nopeer noquery
server ntp12.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
restrict ntp12.cloud.aliyuncs.com nomodify notrap nopeer noquery
server ntp2.aliyun.com iburst minpoll 4 maxpoll 10
restrict ntp2.aliyun.com nomodify notrap nopeer noquery
server ntp2.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
restrict ntp2.cloud.aliyuncs.com nomodify notrap nopeer noquery
server ntp3.aliyun.com iburst minpoll 4 maxpoll 10
restrict ntp3.aliyun.com nomodify notrap nopeer noquery
server ntp3.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
restrict ntp3.cloud.aliyuncs.com nomodify notrap nopeer noquery
server ntp4.aliyun.com iburst minpoll 4 maxpoll 10
restrict ntp4.aliyun.com nomodify notrap nopeer noquery
server ntp4.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
restrict ntp4.cloud.aliyuncs.com nomodify notrap nopeer noquery
server ntp5.aliyun.com iburst minpoll 4 maxpoll 10
restrict ntp5.aliyun.com nomodify notrap nopeer noquery
server ntp5.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
restrict ntp5.cloud.aliyuncs.com nomodify notrap nopeer noquery
server ntp6.aliyun.com iburst minpoll 4 maxpoll 10
restrict ntp6.aliyun.com nomodify notrap nopeer noquery
server ntp6.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
restrict ntp6.cloud.aliyuncs.com nomodify notrap nopeer noquery
server ntp7.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
restrict ntp7.cloud.aliyuncs.com nomodify notrap nopeer noquery
server ntp8.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
restrict ntp8.cloud.aliyuncs.com nomodify notrap nopeer noquery
server ntp9.cloud.aliyuncs.com iburst minpoll 4 maxpoll 10
restrict ntp9.cloud.aliyuncs.com nomodify notrap nopeer noquery