keepalived+nginx高可用之双机热备_nginx keepalived mysql 双机热备-优快云博客

通过访问keepalived虚拟ip实现nginx双机热备，防止服务器单点故障

架构图

CentOS 7 + keepalived1.2.18 + nginx1.16.0
在这里插入图片描述
nginx安装
 keepalived官网安装文档

keepalived安装

点击下载官网安装文件
这里使用的版本是1.2.18 点击下载
首先安装keepalived需要的依赖

yum install curl gcc openssl-devel libnl3-devel net-snmp-devel

解压压缩文件

tar -zxvf keepalived-1.2.18.tar.gz

创建安装目录

mkdir /usr/local/keepalived

指定路径安装

cd keepalived-1.2.18

./configure --prefix=/usr/local/keepalived

安装

make && make install

keepalived的默认路径安装（默认是/usr/local），安装完成之后，复制默认配置文件到默认路径

mkdir /etc/keepalived

cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/
cp /usr/local/keepalived/etc/init.d/keepalived /etc/init.d/
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
ln -s /usr/local/sbin/keepalived /usr/sbin/
ln -s /usr/local/keepalived/sbin/keepalived /sbin/

设置keepalived开机启动

chkconfig keepalived on

添加主机IP映射文本最后一行添加127.0.0.1 keep201

vi /etc/hosts

配置主节点

vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id keep201
}

vrrp_script chk_nginx {
     script "/etc/keepalived/nginx_check.sh"
    interval 2
    weight -20
}

vrrp_instance VI_1 {
    state MASTER
    interface ens32
    virtual_router_id 200
    mcast_src_ip 192.168.241.201
    priority 100
    nopreempt
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        chk_nginx
    }
    virtual_ipaddress {
        192.168.241.200
    }
}

创建nginx检测脚本（nginx_check.sh）

vi /etc/keepalived/nginx_check.sh

添加如下内容

#!/bin/bash
CHECK_NGINX=`ps -C nginx -no-header | wc -1`
if [ $ CHECK_NGINX -eq 0 ];then
	/usr/local/nginx/sbin/nginx
	sleep 2
	if [ `ps -C nginx –no-header |wc -1` -eq 0];then
		service keepalived stop
	fi
fi

启动keepalived

service keepalived start

备机安装与主机类似

配置备节点

! Configuration File for keepalived

global_defs {
   router_id keep202
}

vrrp_script chk_nginx {
     script "/etc/keepalived/nginx_check.sh"
    interval 2     
    weight -20
}

vrrp_instance VI_1 {
    state MASTER
    interface ens32
    virtual_router_id 200
    mcast_src_ip 192.168.241.202
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        chk_nginx
    } 
    virtual_ipaddress {
        192.168.241.200
    }
}

配置说明，详细配置请查看官方文档

! Configuration File for keepalived

global_defs {
   router_id keep201
}

vrrp_script chk_nginx {
     script "/etc/keepalived/nginx_check.sh"	#检测nginx状态的脚本路径
    interval 2									#检测时间间隔，单位为秒
    weight -20									#条件成力，权重-20，根据配置priority对应的值
}

vrrp_instance VI_1 {				#VI_1为虚拟路由的标识符
    state MASTER					#主节点为MASTER，对应的备份节点为BACKUP
    interface ens32					#虚拟IP的网络接口，与本机IP地址所在的网络接口相同
    virtual_router_id 200			#虚拟路由的ID号，两个节点必须一致，相同的VRID为一个组，它将决定多播的MAC地址
    mcast_src_ip 192.168.241.201	#本机IP地址
    priority 100					#节点优先级，值f范围0-254，MASTER要比BACKUP高
    nopreempt
    advert_int 1					#组播信息发送间隔，两个节点必须一致，单位为秒
    authentication {				#设置验证信息，两个节点必须一致
        auth_type PASS
        auth_pass 1111			
    }
    track_script {					#将track_script块加入instance配置块
        chk_nginx     				#执行nginx监控的服务
    }
    virtual_ipaddress {				#虚拟IP池，可多个，两个节点设置必须一样
        192.168.241.200				#虚拟IP
    }
}