Nginx + Keepalived实现高可用

实验环境：

192.168.200.111   nginx主+tomcat

192.168.200.112   nginx备+tomcat

在111和112上安装tomcat的目的只是为了测试

也可以在其他两台服务器上安装tomcat

模式一：双机 主从模式

在111和112上首先安装tomcat

yum -y ipvsadm keepalived

源码安装nginx

安完启动服务（省略）

111和112的配置

 112的就修改state  BACKUP

vrrp_script chk_http_port {
script "/opt/chk_nginx.sh"
interval 2
weight -5
fall 2
rise 1
}

[root@localhost ~]# vim /opt/chk_nginx.sh

#!/bin/bash
counter=$(ps -C nginx --no-heading|wc -l)
echo "$counter"
if [ "${counter}" = "0" ]; then
/usr/local/nginx/sbin/nginx -c /usr/local/nginx/conf/nginx.conf
sleep 2
counter=$(ps -C nginx --no-heading|wc -l)
if [ "${counter}" = "0" ]; then
/etc/init.d/keepalived stop
fi
fi

chmod 755 /opt/chk_nginx.sh

sh /opt/chk_nginx.sh

vim /usr/local/nginx/conf/nginx.conf

如果是yum安装的nginx 步骤

vim /etc/nginx/conf.d/node1.conf

upstream web1 {
server 192.168.200.111:8080;
server 192.168.200.112:8080;
}
server {
listen 192.168.200.254:80;
server_name www.node.com;
index index.html index.htm;
location / {
proxy_set_header Host $host;
proxy_pass http://web1;
}
}

systemctl start keepalived

systemctl start nginx

killall  -1  nginx

测试：

ip  a

systemctl   stop  keepalived

来回测试

echo "111111" > /usr/local/tomcat8/webapps/ROOT/index.jsp （112可以是"22222"）

 二。双机 双主模式

111：

vrrp_instance VI_2 {
state BACKUP
interface ens32
virtual_router_id 52
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.200.253
}
track_script {
chk_http_port
}
}

112：

vrrp_instance VI_2 {
state MASTER
interface ens32
virtual_router_id 52
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.200.253
}
track_script {
chk_http_port
}
}

重启服务

ip  a 查看

Nginx + Keepalived实现高可用

原文：https://www.cnblogs.com/maoyanqing/p/11630678.html