手机与PC访问分离
环境
主机 | ip |
---|---|
Proxy | 10.0.0.6 |
web01 | 10.0.0.7 |
web02 | 10.0.0.8 |
配置web01访问页面为iphone页面
[root@web01 conf.d]# cat sj.conf
server {
listen 80;
server_name sj.oldboy.com;
location / {
root /sj;
index index.html;
}
}
[root@web01 conf.d]# mkdir /sj
[root@web01 conf.d]# echo "Iphone....." >/sj/index.html
[root@web01 conf.d]# systemctl restart nginx
配置web02为android访问页面
[root@web02 conf.d]# cat sj.conf
server {
listen 80;
server_name sj.oldboy.com;
location / {
root /sj;
index index.html;
}
}
[root@web02 conf.d]# mkdir /sj
[root@web02 conf.d]# echo "Android...." > /sj/index.html
[root@web02 conf.d]# systemctl restart nginx
通过负载均衡分流
[root@lb01 ~]# cd /etc/nginx/conf.d/
[root@lb01 conf.d]# cat sj_proxy.conf
upstream iphone {
server 172.16.1.7:80;
}
upstream android {
server 172.16.1.8:80;
}
server {
listen 80;
server_name sj.oldboy.com;
location / {
if ($http_user_agent ~* "iphone"){
proxy_pass http://iphone;
}
if ($http_user_agent ~* "android"){
proxy_pass http://android;
}
}
}
[root@lb01 conf.d]# systemctl restart nginx
访问测试
nginx+keepalive实现负载均衡高可用
环境
服务器系统 | 角色 | 外网IP | 内网IP |
---|---|---|---|
CentOS7.5 | keepalived-master | eth0:10.0.0.5 | eth1:172.16.1.5 |
CentOS7.5 | keepalived-slave | eth0:10.0.0.6 | eth1:172.16.1.6 |
在lb01和lb02分别安装keepalived
[root@lb01 ~]# yum install keepalived -y
[root@lb02 ~]# yum install keepalived -y
配置lb01-keepalive-master
[root@lb01 ~]# cat /etc/keepalived/keepalived.conf
global_defs {
router_id lb01
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 50
priority 150
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.0.3
}
}
配置lb02-keepalive-backup
[root@lb02 ~]# cat /etc/keepalived/keepalived.conf
global_defs {
router_id lb02
}
vrrp_instance VI_1 {
state BAKCUP
interface eth0
virtual_router_id 50
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.0.3
}
}
keepalived配置文件含义
列脑故障排查思路
当keepalive-backup服务器无法联系主服务器时会响应虚拟ip,此时两台服务器同时响应虚拟ip,导致ip无法连接的现象为列脑。
常见列脑故障原因
服务器网线松动等网络故障
服务器硬件故障发生损坏现象而崩溃
主备都开启firewalld防火墙
Nginx服务死掉等
解决思路
在备上编写检测脚本, 测试如果能ping通主并且备节点还有VIP的话则认为产生了列脑
1.编写脚本
[root@lb02 ~]# cat check_split_brain.sh
#!/bin/sh
lb01_vip=10.0.0.3
lb01_ip=10.0.0.5
while true;do
ping -c 2 -W 3 $lb01_ip &>/dev/null
if [ $? -eq 0 -a `ip add|grep "$lb01_vip"|wc -l` -eq 1 ];then
echo "ha is split brain.warning."
else
echo "ha is ok"
fi
sleep 5
done
2.执行脚本
通过screen命令在后台执行该脚本即可
如果Nginx宕机, 会导致用户请求失败, 但Keepalived并不会进行切换, 所以需要编写一个脚本检测Nginx的存活状态, 如果不存活则kill nginx和keepalived
[root@lb01 ~]# mkdir /server/scripts
[root@lb01 ~]# vim /server/scripts/check_web.sh
#!/bin/sh
#使用while死循环
while true;do
nginxpid=$(ps -C nginx --no-header|wc -l)
#1.判断Nginx是否存活,如果不存活则尝试启动Nginx
if [ $nginxpid -eq 0 ];then
systemctl start nginx
sleep 5
#2.5秒后再次获取一次Nginx状态
nginxpid=$(ps -C nginx --no-header|wc -l)
#3.再次进行判断, 如Nginx还不存活则停止Keepalived,让地址进行漂移,并退出脚本
if [ $nginxpid -eq 0 ];then
systemctl stop keepalived
exit 1
fi
fi
sleep 5
done
[root@lb01 ~]# chmod +x /server/scripts/check_web.sh
在keepalived配置文件中调用此脚本,lb01与lb02都需操作(并将脚本中的循环取消掉)
[root@lb02 ~]# cat /etc/keepalived/keepalived.conf
global_defs {
router_id lb02
}
vrrp_script check_web {
script "/server/scripts/check_web.sh"
interval 2
weight 50
}
vrrp_instance VI_1 {
state BAKCUP
interface eth0
virtual_router_id 50
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.0.0.3
}
}