keepalived 安装

yum 安装模式

   yum install keepalived -y

主节点配置

[root@sjyd4 keepalived-1.2.2]# more /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
   notification_email {
    
   }
   notification_email_from
   smtp_server smtp.ytxt.com
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}

vrrp_script Monitor_Nginx {
 script "/home/app/bin/monitor_nginx"
 interval 2
 weight 2
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 101
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }

 track_script {
 Monitor_Nginx
}
    virtual_ipaddress {
        192.168.10.75
    }
}

从节点需要改 state BACKUP 和priority就可以

state MASTER #//负载均衡器的角色
interface eth0 #//承载VIP地址的物理接口
virtual_router_id 1 #//虚拟路由器的ID号，每个热备组保持相同
priority 101 #//竞选优先级，数字越大优先级越高
advert_int 1 #//通告间隔秒数（心跳频率）
authentication { #//本VRRP组的认证信息

 virtual_ipaddress {    #//热备所针对的虚拟地址（VIP），可以有多行
192.168.10.75

使用命令 ip addr 可以查看vip地址起来了

 

创建lvsrs 脚本，放到/etc/init.d/下

#!/bin/bash
# 配置虚拟IP，取消arp应答
VIP=211.147.11.8
. /etc/rc.d/init.d/functions
case "$1" in
start)
       ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP up
       /sbin/route add -host $VIP dev lo:0
       echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
       echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
       echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
       echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
       sysctl -p >/dev/null 2>&1
       echo "RealServer Start OK"
       ;;
stop)
       ifconfig lo:0 down
       route del $VIP >/dev/null 2>&1
       echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore
       echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce
       echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
       echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
       echo "RealServer Stoped"
       ;;
*)
       echo "Usage: $0 {start|stop}"
       exit 1
esac
exit 0

virtual_router_id 取值在0-255之间，用来区分多个instance的VRRP组播。
同一网段中virtual_router_id的值不能重复，否则会出错
可以用这条命令来查看该网络中所存在的vrid：tcpdump -nn -i any net 224.0.0.0/8