centos7下 Mysql+Keepalived 双主热备高可用图文配置详解

环境描述:

Centos7 版本
Master1:192.168.1.146        安装mysql和keepalived
Master2: 192.168.1.147        安装mysql和keepalived
VIP:192.168.1.188

要实现主主同步,可以先实现主从同步,即master1->master2的主从同步,然后master2->master1的主从同步.
这样,双方就完成了主主同步。
 
注意下面几点:
1)要保证同步服务期间之间的网络联通。即能相互 ping 通,能使用对方授权信息连接到对方数据库(防火墙开放3306端口)。
2)关闭selinux。
3)同步前,双方数据库中需要同步的数据要保持一致。这样,同步环境实现后,再次更新的数据就会如期同步了。

这里略过。

配置Mysql+Keepalived故障转移的高可用环境   

1)安装keepalived并将其配置成系统服务。master1和master2两台机器上同样进行如下操作:

[root@master1 ~] # yum install -y openssl-devel popt-devel
[root@master1 ~] # cd /usr/local/src/
[root@master1 src] # wget http://www.keepalived.org/software/keepalived-1.3.5.tar.gz
[root@master1 src] # tar -zvxf keepalived-1.3.5.tar.gz
[root@master1 src] # cd keepalived-1.3.5
[root@master1 keepalived-1.3.5] # ./configure --prefix=/usr/local/keepalived
[root@master1 keepalived-1.3.5] # make && make install
     
[root@master1 keepalived-1.3.5] # cp /usr/local/src/keepalived-1.3.5/keepalived/etc/init.d/keepalived /etc/rc.d/init.d/
[root@master1 keepalived-1.3.5] # cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
[root@master1 keepalived-1.3.5] # mkdir /etc/keepalived/
[root@master1 keepalived-1.3.5] # cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
[root@master1 keepalived-1.3.5] # cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
[root@master1 keepalived-1.3.5] # echo "/etc/init.d/keepalived start" >> /etc/rc.local
     
2)master1机器上的keepalived.conf配置。(下面配置中没有使用lvs的负载均衡功能,所以不需要配置虚拟服务器virtual server)
[root@master1 ~] # cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak
[root@master1 ~] # vim /etc/keepalived/keepalived.conf       #清空默认内容,直接采用下面配置:
! Configuration File for keepalived
       
global_defs {
router_id MASTER-HA
}
       
vrrp_script chk_mysql_port {
    script "/etc/keepalived/chk_mysql.sh"
    interval 2            
    weight -5                 
    fall 2                 
    rise 1               
}
       
vrrp_instance VI_1 {
    state MASTER
    interface ens33    
    mcast_src_ip 192.168.1.146
    virtual_router_id 51    
    priority 101          
    advert_int 1         
    authentication {   
        auth_type PASS 
        auth_pass 1111     
    }
    virtual_ipaddress {    
        192.168.1.188
    }
      
track_script {               
   chk_mysql_port             
}
virtual_server 192.168.1.188 3306 {
    delay_loop 6               
    lb_algo wrr             
    lb_kind DR                 
    #nat_mask 255.255.255.0
    persistence_timeout 50     
    protocol TCP              
    
    ## Real Server设置,3306就是连接端口
    real_server 192.168.1.146 3306 {
        weight 3  ##权重
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
    real_server 192.168.1.147 3306 {
        weight 3
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
}
}

master2机器上的keepalived配置。master2机器上的keepalived.conf文件只修改priority为90、nopreempt不设置、real_server设置本地IP。

! Configuration File for keepalived
       
global_defs {
router_id BACKUP-HA
}
       
vrrp_script chk_mysql_port {
    script "/etc/keepalived/chk_mysql.sh"
    interval 2            
    weight -5                 
    fall 2                 
    rise 1               
}
       
vrrp_instance VI_1 {
    state BACKUP
    interface ens33    
    mcast_src_ip 192.168.1.147
    virtual_router_id 51    
    priority 99          
    advert_int 1         
    authentication {   
        auth_type PASS 
        auth_pass 1111     
    }
    virtual_ipaddress {    
        192.168.1.188
    }
      
track_script {               
   chk_mysql_port             
}
virtual_server 192.168.1.188 3306 {
    delay_loop 6               #服务轮询的时间间隔
    lb_algo wrr                #加权轮询调度,LVS调度算法 rr|wrr|lc|wlc|lblc|sh|sh
    lb_kind DR                 #LVS集群模式 NAT|DR|TUN,其中DR模式要求负载均衡器网卡必须有一块与物理网卡在同一个网段
    #nat_mask 255.255.255.0
    persistence_timeout 50     #会话保持时间
    protocol TCP              #健康检查协议
    
    ## Real Server设置,3306就是连接端口
    real_server 192.168.1.146 3306 {
        weight 3  ##权重
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
    real_server 192.168.1.147 3306 {
        weight 3
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
}
}

编写切换脚本。KeepAlived做心跳检测,如果Master的MySQL服务挂了(3306端口挂了),那么它就会选择自杀。Slave的KeepAlived通过心跳检测发现这个情况,

就会将VIP的请求接管

[root@master1 ~]# vim /etc/keepalived/chk_mysql.sh

#!/bin/bash
counter=$( netstat   -na| grep   "LISTEN" | grep   "3306" | wc   -l)
if   [  "${counter}"   - eq   0 ];  then
     /etc/init .d /keepalived   stop
fi 

[root@master1 ~]# chmod 755 /etc/keepalived/chk_mysql.sh     

启动keepalived服务
[root@master1 ~] # /etc/init.d/keepalived start
正在启动 keepalived:                                      [确定]

在启动的时候有可能启动失败   打开 vim /lib/systemd/system/keepalived.service  在第7行

PIDFile=/usr/local/program/keepalived/var/run/keepalived.pid      ##发现这个目录不存在,无法写入keepalived.pid  

修改成 PIDFile=/var/run/keepalived.pid 
执行 systemctl daemon-reload    #重新载入 systemd,扫描新的或有变动的单元  
在运行就Ok了    /etc/init.d/keepalived start



ip addr 可以看到 vip在master上

三、测试 

最简单的测试

mysql -h192.168.1.188 -uroot1 -proot1

show databases;


在147服务上看 ip addr 也可以看到vip漂移到了147服务上


/******************/

上面那个脚本简单且粗暴,即脚本一旦监测到Master的mysql服务关闭,就立刻把keepalived服务关闭,不能实现vip转移,也就是当Master数据库恢复的是时候不能再切回来!

下面这个脚本可以实现 当监测到Master的mysql服务关闭后,就会将vip切换到Backup上 当Master的mysql服务恢复后,就会再次将VIP资源切回来

#!/bin/bash
MYSQL= /usr/local/mysql/bin/mysql
MYSQL_HOST=localhost
MYSQL_USER=root
MYSQL_PASSWORD=123456
CHECK_TIME=3
  
#mysql  is working MYSQL_OK is 1 , mysql down MYSQL_OK is 0
  
MYSQL_OK=1
  
function   check_mysql_helth (){
     $MYSQL -h $MYSQL_HOST -u $MYSQL_USER -p${MYSQL_PASSWORD} -e  "show status;"   > /dev/null   2>&1
     if   [ $? = 0 ] ; then
     MYSQL_OK=1
     else
     MYSQL_OK=0
     fi
     return   $MYSQL_OK
}
while   [ $CHECK_TIME - ne   0 ]
do
     let   "CHECK_TIME -= 1"
     check_mysql_helth
if   [ $MYSQL_OK = 1 ] ;  then
     CHECK_TIME=0
     exit   0
fi
if   [ $MYSQL_OK - eq   0 ] &&  [ $CHECK_TIME - eq   0 ]
then
     pkill keepalived
     exit   1
fi
sleep   1
done



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转载自blog.csdn.net/z13615480737/article/details/80856560