使用KeepAlived搭建高可用的LVS_调度器以及实时监控后端服务器集群

]# tcpdump -i ens33 -nn host 224.1.101.33
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on ens33, link-type EN10MB (Ethernet), capture size 262144 bytes
10:24:41.802780 IP 192.168.60.129 > 224.1.101.33: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20
10:24:42.822797 IP 192.168.60.129 > 224.1.101.33: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20
10:24:43.842762 IP 192.168.60.129 > 224.1.101.33: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20

10:25:56.592852 IP 192.168.60.129 > 224.1.101.33: VRRPv2, Advertisement, vrid 51, prio 100, authtype simple, intvl 1s, length 20
10:25:56.885660 IP 192.168.60.129 > 224.1.101.33: VRRPv2, Advertisement, vrid 51, prio 0, authtype simple, intvl 1s, length 20
10:25:57.518427 IP 192.168.60.132 > 224.1.101.33: VRRPv2, Advertisement, vrid 51, prio 95, authtype simple, intvl 1s, length 20
10:25:58.522799 IP 192.168.60.132 > 224.1.101.33: VRRPv2, Advertisement, vrid 51, prio 95, authtype simple, intvl 1s, length 20
10:25:59.524474 IP 192.168.60.132 > 224.1.101.33: VRRPv2, Advertisement, vrid 51, prio 95, authtype simple, intvl 1s, length 20
10:26:00.527112 IP 192.168.60.132 > 224.1.101.33: VRRPv2, Advertisement, vrid 51, prio 95, authtype simple, intvl 1s, length 20

#!/bin/bash
#
contact='root@localhost'  
notify() {            
local mailsubject="$(hostname) to be $1, vip floating"
local mailbody="$(date +'%F %T'): vrrp transition, $(hostname) changed to be $1"
echo "$mailbody" | mail -s "$mailsubject" $contact
}
case $1 in
master)
notify master
;;
backup)
notify backup
;;
fault)
notify fault
;;
*)
echo "Usage: $(basename $0) {master|backup|fault}"
exit 1
;;
esac           

global_defs {
   notification_email {
    root@localhost
   }
   notification_email_from keepalived@localhost
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id node1
    vrrp_mcast_group4 224.1.101.33
}
 
vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 12345678
    }
    virtual_ipaddress {
        192.168.60.127/24 dev ens33 label ens33:0
    }
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}

#?/bin/bash
#用作RS主机上配置DR模式。
vip='192.168.60.127'
mask='255.255.255.255'
iface='lo:0'
case $1 in
start)
echo 1 >/proc/sys/net/ipv4/conf/all/arp_ignore
echo 1 >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo 2 >/proc/sys/net/ipv4/conf/all/arp_announce
echo 2 >/proc/sys/net/ipv4/conf/lo/arp_announce
ifconfig $iface $vip netmask $mask broadcast $vip up
route add -host $vip dev $iface
;;
stop)
    ifconfig $iface down
 
 
 
 
echo 0 >/proc/sys/net/ipv4/conf/all/arp_ignore
echo 0 >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo 0 >/proc/sys/net/ipv4/conf/all/arp_announce
echo 0 >/proc/sys/net/ipv4/conf/lo/arp_announce
;;
*)
    echo "Usage: $(basename $0) start|stop"
    exit 1
    ;;
esac

virtual_server 192.168.60.127 80 {
delay_loop 1
lb_algo wrr
lb_kind DR
protocol TCP
sorry_server 127.0.0.1 80
real_server 192.168.60.137 80 {
    weight 1
    HTTP_GET {
    url {
        path /index.html
        status_code 200
        }
    nb_get_retry 3
    delay_before_retry 2
    connect_timeout 3
}
}
real_server 192.168.60.138 80 {
    weight 1
    HTTP_GET {
    url {
        path /index.html
        status_code 200
        }
    nb_get_retry 3
    delay_before_retry 2
    connect_timeout 3
}
}
}

• 配置项的英文不能写错
• 大括号左侧要有空格隔开，如，HTTP_GET {
• 注意权重设置为0时，表示down掉此主机。

• 当RS1 down机后，调度器自动把RS1删除。同样当RS1上机，调度器自动加上RS1.
• 当调度器1 down机后，调度器2自动上线提供服务。

• 高可用LVS的调度器
• 可以动态监控调度器的状态，实现故障转移和修复。
• 当发现调度器出现状态改变时，可以调用脚本进行告警。如发送邮件。
• 大大简化ipvs规则的设置
• 自身可以生成ipvs规则。
• 动态监控后端RS的状态
• 可以动态监控后端RS主机的状态，实时更新ipvs规则。
• 还可以调用脚本进行告警。