mysql高可用衡搭建(Keepalived)

2.1 Keepalived介绍

Keepalived的作用是检测服务器的状态，如果有一台服务器宕机，或工作出现故障，Keepalived将检测到，并将有故障的服务器从系统中剔除，同时使用其它服务器代替该服务器的工作，当服务器工作 正常后Keepalived自动将服务器加入到服务器群中，这些工作全部自动完成，不需要人工干涉，需要人工做的只是修复故障的服务器。

192.168.8.110 (主)
192.168.8.111（从）

Keepalived安装

1. 安装Keepalived需要的扩展

[root@localhost keepalived]# yum install gcc gcc-c++ openssl openssl-devel
[root@localhost home]# wget -q https://www.keepalived.org/software/keepalived-1.2.18.tar.gz

1. 解压Keepalived并安装

[root@localhost home]# tar -zxvf keepalived-1.2.18.tar.gz
[root@localhost home]# cd keepalived-1.2.18
[root@localhost keepalived-1.2.18]# ./configure --prefix=/usr/local/keepalived
[root@localhost keepalived-1.2.18]# make && make install

1. 将 keepalived 安装成 Linux 系统服务

因为没有使用 keepalived 的默认路径安装（默认是/usr/local） ,安装完成之后，需要做一些工作 复制默认配置文件到默认路径

[root@localhost keepalived-1.2.18]# mkdir /etc/keepalived
[root@localhost keepalived-1.2.18]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/

复制 keepalived 服务脚本到默认的地址

[root@localhost keepalived-1.2.18]# cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/
[root@localhost keepalived-1.2.18]# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
[root@localhost keepalived-1.2.18]# ln -s /usr/local/keepalived/sbin/keepalived /usr/sbin/

设置 keepalived 服务开机启动

[root@localhost keepalived-1.2.18]# chkconfig keepalived on

3. mysql高可用搭建

3.1 Keepalived配置

keepalived主机配置

! Configuration File for keepalived
global_defs {
    router_id LVS_MASTER
}

vrrp_script chk_haproxy {
    script "/etc/keepalived/haproxy_check.sh" ## 检测 haproxy 状态的脚本路径
    interval 2 ## 检测时间间隔
    weight 2 ## 如果条件成立，权重+2
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 79
    priority 100
    advert_int 1
    nopreempt
    authentication {
        auth_type PASS
        auth_pass 1234
    }
    virtual_ipaddress {
        192.168.29.101
    }
    track_script {
        chk_haproxy
    }
}
# 写VIP virtual_server，只配置本地机器
virtual_server 192.168.8.101 3307 {# 定义虚拟服务器，地址与上面的virtual_ipaddress相同
    delay_loop 3 # 健康检查时间间隔，3秒
    lb_algo rr # 负载均衡调度算法：rr|wrr|lc|wlc|sh|dh|lblc
    lb_kind DR # 负载均衡转发规则：NAT|DR|TUN
    # persistence_timeout 5 # 会话保持时间5秒，动态服务建议开启
    protocol TCP # 转发协议protocol，一般有tcp和udp两种
    real_server 192.168.8.110 3307 {
        weight 1 # 权重越大负载分越大，0表示失效
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
}

Keepalived从机配置

! Configuration File for keepalived
global_defs {
    router_id LVS_MASTER
}

vrrp_script chk_haproxy {
    script "/etc/keepalived/haproxy_check.sh" ## 检测 haproxy 状态的脚本路径
    interval 2 ## 检测时间间隔
    weight 2 ## 如果条件成立，权重+2
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 79
    priority 90
    advert_int 1
    nopreempt
    authentication {
        auth_type PASS
        auth_pass 1234
    }
    virtual_ipaddress {
        192.168.8.101
    }
    track_script {
        chk_haproxy
    }
}
# 写VIP virtual_server，只配置本地机器
virtual_server 192.168.8.101 3307 {# 定义虚拟服务器，地址与上面的virtual_ipaddress相同
    delay_loop 3 # 健康检查时间间隔，3秒
    lb_algo rr # 负载均衡调度算法：rr|wrr|lc|wlc|sh|dh|lblc
    lb_kind DR # 负载均衡转发规则：NAT|DR|TUN
    # persistence_timeout 5 # 会话保持时间5秒，动态服务建议开启
    protocol TCP # 转发协议protocol，一般有tcp和udp两种
    real_server 192.168.8.111 3307 {
        weight 1 # 权重越大负载分越大，0表示失效
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
}

看网卡192.168.8.110(多了一块网卡) 192.168.8.110 （没有增加网卡）

测试192.168.8.110 （主停掉keepalived）
看192.168.8.111 的网卡会新增192.168.8.101 这就是漂移

本地测试(同样轮训)
D:\phpstudy_pro\Extensions\MySQL5.7.26\bin>mysql -h192.168.8.101 -uqiao -proot -P3307  -e "show variables like 'server_id'"
mysql: [Warning] Using a password on the command line interface can be insecure.
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id     | 3     |
+---------------+-------+

D:\phpstudy_pro\Extensions\MySQL5.7.26\bin>mysql -h192.168.8.101 -uqiao -proot -P3307  -e "show variables like 'server_id'"
mysql: [Warning] Using a password on the command line interface can be insecure.
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id     | 2     |
+---------------+-------+

D:\phpstudy_pro\Extensions\MySQL5.7.26\bin>

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