高可用负载均衡服务器实现（keepalived+haproxy）

准备

两台Centos服务器，分别为118、119

一个未被使用的ip地址，180

配置 haproxy 安装haproxy

yum -y install haproxy

编辑 haproxy.service 文件

vi /usr/lib/systemd/system/haproxy.service

在 ExecStart 前添加 ExecStartPre

ExecStartPre=/usr/bin/mkdir -p /run/haproxy

配置 haproxy.cfg 文件

global
        log /dev/log    local0
        log /dev/log    local1 notice
        chroot /var/lib/haproxy
        stats socket /run/haproxy/admin.sock mode 660 level admin
        stats timeout 30s
        user haproxy
        group haproxy
        daemon
        nbproc 1

defaults
        log     global
        timeout connect 5000
        timeout client  50000
        timeout server  50000

listen frontend
        bind 0.0.0.0:80
        mode tcp
        option tcplog
        balance source
        server s1 [ip地址]  check inter 10000 fall 2 rise 2 weight 1
        server s2 [ip地址]  check inter 10000 fall 2 rise 2 weight 1

	配置 keepalived	

安装keepalived

yum -y install keepalived
yum -y install psmisc

编辑 keepalived.conf 文件，两台服务器会分配两个角色：master、backup，分别需要不同的配置。

vi /etc/keepalived/keepalived.conf

//master 118
global_defs {
    router_id 192.168.22.118
}

vrrp_script check-haproxy {
    script "killall -0 haproxy"
    interval 5
    weight -30
}

vrrp_instance VI-lb {
    state MASTER
    priority 120
    dont_track_primary
    interface ens160
    virtual_router_id 52
    advert_int 3
    track_script {
        check-haproxy
    }
    virtual_ipaddress {
        192.168.22.180
    }
}

//backup
global_defs {
    router_id 192.168.22.119
}

vrrp_instance VI-lb {
    state BACKUP
    priority 110
    dont_track_primary
    interface ens160
    virtual_router_id 52
    advert_int 3
    virtual_ipaddress {
        192.168.22.180
    }
}

重启 重新加载 haproxy.service

systemctl daemon-reload

设置 haproxy和keepalived 开机自启并重新启动

systemctl enable haproxy && systemctl restart haproxy
systemctl enable keepalived && systemctl restart keepalived