keepalived的高可用部署

keepalived的高可用部署

keepalived的高可用部署
三台主机为例：
  master：192.128.232.128
  slave01：192.128.232.129
  slave02：192.128.232.130

1. 环境配置：
host1：192.128.232.128
host1：192.128.232.129
host1：192.128.232.130
VIP: 192.128.232.131
1. *** 作步骤
1. 三台主机都安装keepalived

~]# yum -y install keepalived

2. 监控业务脚本进行判断，迁移vip，
###本测试以nginx服务的80端口作为测试触发判断
[root@localhost ~]# cat /etc/keepalived/check_port.sh 
#!/bin/bash
#使用方法：
#在keepalived的配置文件中
#vrrp_script check_port {#创建一个vrrp_script脚本,检查配置
#    script "/etc/keepalived/check_port.sh 28089" #配置监听的端口
#    interval 2 #检查脚本的频率,单位（秒）
#}
CHK_PORT=$1
if [ -n "$CHK_PORT" ];then
         PORT_PROCESS=`ss -lnt|awk -F':' '{print $2}'|awk '{print $1}'|grep "^$CHK_PORT$"|wc -l`
        echo $PORT_PROCESS
        if [ $PORT_PROCESS -eq 0 ];then
                echo "Port $CHK_PORT Is Not Used,End."
                systemctl stop keepalived 
        fi
else
        echo "Check Port Cant Be Empty!"
fi

3.keepalived配置文件
a. 主机192.128.232.128的配置
[root@localhost keepalived]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
   router_id 192.128.232.128
}
vrrp_script chk_nginx {
    script "/etc/keepalived/check_port.sh 28089"
    interval 2
    weight -20
}
vrrp_instance VI_1 {
    state BACKUP    #全部节点设置BACKUP,以优先级高暂时为master。
    interface eth0      #对应主机的网卡名称
    virtual_router_id 251   #id号要一致
    priority 100
    advert_int 1
    nopreempt     #当优先级高的主机宕机后，再次恢复时，不会抢夺vip，防止业务频繁切换。
    unicast_peer {        #写上其他安装keepalived主机的ip
        192.128.232.129       
        192.128.232.130
    }
    authentication {
        auth_type PASS
        auth_pass 11111111
    }
    track_script {
         chk_nginx
    }
    virtual_ipaddress {
        192.128.232.131/24
    }
}

b. 主机192.128.232.129的配置
[root@localhost keepalived]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
   router_id 192.128.232.129
}
vrrp_script chk_nginx {
    script "/etc/keepalived/check_port.sh 28089"
    interval 2
    weight -20
}
vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 251
    priority 95
    advert_int 1
    nopreempt
    unicast_peer {
        192.128.232.128
        192.128.232.130
    }
    authentication {
        auth_type PASS
        auth_pass 11111111
    }
    track_script {
         chk_nginx
    }
    virtual_ipaddress {
        192.128.232.131/24
    }
}

c. 主机192.128.232.130的配置
[root@localhost keepalived]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
   router_id 192.128.232.130
}
vrrp_script chk_nginx {
    script "/etc/keepalived/check_port.sh 28089"
    interval 2
    weight -20
}
vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 251
    priority 85
    advert_int 1
    nopreempt
    unicast_peer {
        192.128.232.128
        192.128.232.129
    }
    authentication {
        auth_type PASS
        auth_pass 11111111
    }
    track_script {
         chk_nginx
    }
    virtual_ipaddress {
        192.128.232.131/24
    }
}

4.启动三台主机的nginx，以及keepalived服务，启动主机顺序是128，129，130。
[root@localhost ~]# systemctl start keepalived
[root@localhost ~]# systemctl enable keepalived

5.vip漂移测试过程。
a.vip在128主机上

b.128主机停止nginx，vip会迁移到129，因为129的优先级比130要高。

d. 验证128主机nginx跟keepalived服务都正常，是否会抢夺vip。