双机热备 keepalived

朴灿烈づ我的快乐病毒、 2022-01-13 02:35 353阅读 0赞

负载均衡，负责分发任务的 是单节点

那么如果这个单节点挂掉了，我们后面不管多少服务器，都将不能使用。

Keepalived 程序，是抢占IP用的。

抢占到IP的就是主服务，没有抢到的就是备用。

备用的就一直等待时机，当主服务器挂掉，备用就会抢占这个IP。

这个就是双机热备。

安装keepalived

# ubuntu
    apt-get update
    apt-get install keepalived
    
    # centos7
    # 下载地址 https://www.keepalived.org/download.html
    tar -zxvf keepalived-2.0.16.tar.gz
    cd keepalived-2.0.16
    ./configure --prefix=/usr/local/keepalived
    make && make install
    
    # 若出现警告 不支持IPV6字样，运行下面命令后./configure
    yum -y install libnl libnl-devel

修改配置文件

vim /usr/local/keepalived/etc/keepalived/keepalived.conf

vrrp_instance VI_1 {
        state MASTER                               # keepalived的身份，MASTER、slave
        interface eth0                             # 定义的虚拟IP保存在哪个网卡里
        virtual_router_id 51                       # 取id  0-255
        priority 100                               # 权重，越高越优先
        advert_int 1                               # 心跳检测的时间间隔 秒
        authentication {                           # 心跳检测对外开放的账号
            auth_type PASS
            auth_pass 1111
        }
        virtual_ipaddress {                        # 绑定抢占的虚拟IP
            192.168.200.16
            192.168.200.17
            192.168.200.18
        }
    }

宿主机

vrrp_instance VI_1 {
        state MASTER
        interface ens33
        virtual_router_id 51
        priority 100
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass 1111
        }
        virtual_ipaddress {
           	192.168.99.150
        }
    }
    
    
    virtual_server 192.168.99.150 8888 {
        delay_loop 3
        lb_algo rr 
        lb_kind NAT
        persistence_timeout 50
        protocol TCP
    
        real_server 172.18.0.201 8888 {
            weight 1
        }
    }
    
    
    virtual_server 192.168.99.150 3306 {
        delay_loop 3
        lb_algo rr 
        lb_kind NAT
        persistence_timeout 50
        protocol TCP
    
        real_server 172.18.0.201 3306 {
            weight 1
        }
    }

docker容器内

vrrp_instance  VI_1 {
        state  MASTER
        interface  eth0
        virtual_router_id  51
        priority  100
        advert_int  1
        authentication {
            auth_type  PASS
            auth_pass  123456
        }
        virtual_ipaddress {
            172.18.0.201
        }
    }

将 keepalived 注册为系统服务，  
这儿复制三个文件到指定的系统启动文件夹即可，  
源文件的目录 keepalived-1.4.2/keepalived/etc/init.d 的两个个快捷启动文件和 keepalived 安装目录下的 /usr/local/keepalived 目录下一个配置文件需要复制

cp /root/keepalived-2.0.16/keepalived/etc/init.d/keepalived /etc/init.d/
    cp /root/keepalived-2.0.16/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
    cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/