前文已经讲述了Nginx双机热备-主从模式,本文主要讲述主主模式的配置。
即前端使用两台负载均衡服务器，互为主备，且都处于活动状态，同时各自绑定一个公网虚拟IP，提供负载均衡服务；当其中一台发生故障时，另一台接管发生故障服务器的公网虚拟IP（这时由非故障机器一台负担所有的请求）。这种方案，经济实惠，非常适合于当前架构环境。
keepalived不支持跨网段ip地址
keepalived采用arp广播模式，无法跨网段。也就是10.11.7.235与10.128.2.106这种ip地址是无法通的,必须是在同一个子网内.
环境准备
操作系统：centos7.6
master机器(master-node)：10.11.7.231 vip：10.11.7.235
slave机器(slave-node)：10.11.7.232 vip: 10.11.7.236
slave机器(slave-node)：10.11.7.233 vip: 10.11.7.237
主主模式需要三个负载均衡的VIP:10.11.7.235 10.11.7.236 10.11.7.237
添加检测脚本
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|
[root@master-node ~]
VIP=$1
GATEWAY=$2
/sbin/arping -I em1 -c 5 -s $VIP $GATEWAY &>/dev/null
[root@master-node ~]
|
keepalived配置
在主从模式的基础上修改，可参考主从模式
master-node节点的keepalived配置,并重启keepalived服务
master负载机上的keepalived配置：（注意，这里是双主配置，MASTER-BACKUP和BACKUP-MASTER;如果是多主，比如三主，就是MATER-BACKUP-BACKUP（101-99-99）、BACKUP-MASTER-BACKUP（99-101-97）和BACKUP-BACKUP-MASTER（97-97-101））
注意：配置中的虚拟路由标识virtual_router_id在MASTER和BACKUP处配置不能一样（但在主从模式下配置是一样的）
同一个virtual_router_id下 priority需设置不一样
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| [root@master-node ~]
! Configuration File for keepalived
global_defs {
router_id master-node
}
vrrp_script chk_http_port {
script "/etc/keepalived/check_nginx.sh"
interval 2
weight -5
fall 2
rise 1
}
vrrp_instance VI_1 {
state MASTER
interface ens192
virtual_router_id 51
priority 101
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
10.11.7.235/24
}
notify_master "/etc/keepalived/clean_arp.sh 10.11.7.235 10.11.7.2"
}
vrrp_instance VI_2 {
state BACKUP
interface ens192
virtual_router_id 52
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
10.11.7.236/24
}
notify_master "/etc/keepalived/clean_arp.sh 10.11.7.236 10.11.7.2"
}
vrrp_instance VI_3 {
state BACKUP
interface ens192
virtual_router_id 53
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
10.11.7.237/24
}
notify_master "/etc/keepalived/clean_arp.sh 10.11.7.237 10.11.7.2"
}
|
slave-node节点的keepalived配置 backup-master-backup,并重启keepalived服务
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| ! Configuration File for keepalived
global_defs {
router_id slave-node
}
vrrp_script chk_http_port {
script "/etc/keepalived/check_nginx.sh"
interval 2
weight -5
fall 2
rise 1
}
vrrp_instance VI_1 {
state BACKUP
interface ens192
virtual_router_id 51
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.11.7.235/24
}
track_script {
chk_http_port
}
notify_master "/etc/keepalived/clean_arp.sh 10.11.7.235 10.11.7.2"
}
vrrp_instance VI_2 {
state MASTER
interface ens192
virtual_router_id 52
priority 101
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
10.11.7.236/24
}
notify_master "/etc/keepalived/clean_arp.sh 10.11.7.236 10.11.7.2"
}
vrrp_instance VI_3 {
state BACKUP
interface ens192
virtual_router_id 53
priority 97
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
10.11.7.237/24
}
notify_master "/etc/keepalived/clean_arp.sh 10.11.7.237 10.11.7.2"
}
|
slave-node节点的keepalived配置 backup-backup-master,并重启keepalived服务
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| ! Configuration File for keepalived
global_defs {
router_id slave-node
}
vrrp_script chk_http_port {
script "/etc/keepalived/check_nginx.sh"
interval 2
weight -5
fall 2
rise 1
}
vrrp_instance VI_1 {
state BACKUP
interface ens192
virtual_router_id 51
priority 97
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.11.7.235/24
}
track_script {
chk_http_port
}
notify_master "/etc/keepalived/clean_arp.sh 10.11.7.235 10.11.7.2"
}
vrrp_instance VI_2 {
state BACKUP
interface ens192
virtual_router_id 52
priority 97
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
10.11.7.236/24
}
notify_master "/etc/keepalived/clean_arp.sh 10.11.7.236 10.11.7.2"
}
vrrp_instance VI_3 {
state MASTER
interface ens192
virtual_router_id 53
priority 101
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
10.11.7.237/24
}
notify_master "/etc/keepalived/clean_arp.sh 10.11.7.237 10.11.7.2"
}
|
VIP漂移验证
关闭两台负载机其中一台的keepalived服务，那么它的VIP就会自动漂移到另一台机器上。
关闭两台机器的nginx，会自动重启（前提是keepalived服务要启动）！对网站域名的访问丝毫不受影响。
