配置nginx + keepalived双主模式（双机互为主备）
前言
此前已经写过一篇使用keepalived实现nginx的高可用，这种方式有一台机器一直作backup使用，有50%的资源被浪费。
- 使用keepalived来实现nginx的高可用
下面来配置nginx+keepalived的双主机双机热备，这种配置下有两个Virtual IP，两个机器互为主备，最后我们把域名DNS服务器解析至两个Virtual IP即可。
环境介绍
两台服务器
Server1：192.168.30.61
Server2：192.168.30.62
要设置的两个虚拟IP
Virtual IP1：192.168.30.51
Virtual IP2：192.168.30.52
将DNS域名解析至两个虚拟IP： 192.168.30.51、192.168.30.52
网络扑拓图
配置第一台服务器
第一台服务器ip为192.168.30.61
vi /etc/keepalived/keepalived.conf配置内容如下：
global_defs
{
notification_email
{
[email protected]
}
notification_email_from 123456@qq.com
smtp_server 127.0.0.1
stmp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script Monitor_Nginx {
script "/usr/local/keepalived/scripts/monitor_nginx.sh"
interval 2
weight 2
}
# 虚拟IP1, 本机作为Master
vrrp_instance VI_1 {
state MASTER
interface enp0s3
virtual_router_id 51
priority 100
advert_int 1
track_interface {
enp0s3
}
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.30.51
}i
track_script {
Monitor_Nginx
}
}
# 虚拟IP2, 本机作为Backup
vrrp_instance VI_2 {
state BACKUP
interface enp0s3
virtual_router_id 52
priority 100
advert_int 1
track_interface {
enp0s3
}
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.30.52
}
track_script {
Monitor_Nginx
}
}
配置第二台服务器
第二台服务器ip为192.168.30.62
vi /etc/keepalived/keepalived.conf配置内容如下：
global_defs
{
notification_email
{
[email protected]
}
notification_email_from 123456@qq.com
smtp_server 127.0.0.1
stmp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script Monitor_Nginx {
script "/usr/local/keepalived/scripts/monitor_nginx.sh"
interval 2
weight 2
}
# 虚拟IP1, 本机作为BACKUP
vrrp_instance VI_1 {
state BACKUP
interface enp0s3
virtual_router_id 51
priority 100
advert_int 1
track_interface {
enp0s3
}
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.30.51
}
track_script {
Monitor_Nginx
}
}
# 虚拟IP2, 本机作为Master
vrrp_instance VI_2 {
state MASTER
interface enp0s3
virtual_router_id 52
priority 100
advert_int 1
track_interface {
enp0s3
}
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.30.52
}
track_script {
Monitor_Nginx
}
}
监控脚本
和之前的监控脚本一样
# 监控nginx进程，若nginx主进程不存在则启动nginx
# 若5s后nginx进程还是不存在的话kill掉keepalived进程,防止nginx没运行该主机的keepalived还接管虚拟IP
#!/bin/bash
if [ "$(ps -ef | grep "nginx: master process"| grep -v grep )" == "" ]
then
/usr/local/nginx/sbin/nginx
sleep 5
if [ "$(ps -ef | grep "nginx: master process"| grep -v grep )" == "" ]
then
killall keepalived
fi
fi测试
修改nginx默认访问页nginx的默认页面
# nginx 默认访问页面
$NGINX_HOME/html/index.html修改server1的页，加入IP： 192.168.30.61
<html>
<head>
<title>Welcome to nginx!title>
<style>
body {
width: 35em;
margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif;
}
style>
head>
<body>
<h1>Welcome to nginx! 192.168.30.61 h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.orga>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.coma>.p>
<p><em>Thank you for using nginx.em>p>
body>
html>
server2同理
两个机器都启动keepalived和nginx
访问虚拟ip1
在浏览器输入192.168.30.51进入访问页面
访问虚拟ip2
在浏览器输入192.168.30.52进入访问页面
证明两个VIP都起效果了
Kill掉server2的keepalived
pkill keepalived- 访问ip2
证明了server1为server2的备机，server2 down掉后server1接管server1的nginx访问
Kill掉server1机器的keepalived，启动server2机器的keepalived
- 访问ip1
证明了server2为server1的备机，server1 down掉后server1接管server1的nginx访问
有关nginx和keepalived的安装可参考
- Linux下安装nginx
- 使用keepalived来实现nginx的高可用