环境描述:
Centos7 版本
Master1:192.168.10.1 安装mysql和keepalived
Master2: 192.168.10.2 安装mysql和keepalived
VIP:192.168.10.188
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。
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)(在这里可以使用yum安装keepalived。配置在有关Keepalived博文中详细介绍,这里略)
[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 192.168.10.1
virtual_router_id 51
priority 101
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.10.188
}
track_script {
chk_mysql_port
}
virtual_server 192.168.10.188 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 192.168.10.1 3306 {
weight 3 ##权重
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 3306
}
}
real_server 192.168.10.2 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 192.168.10.2
virtual_router_id 51
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.10.188
}
track_script {
chk_mysql_port
}
virtual_server 192.168.10.188 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 192.168.10.1 3306 {
weight 3 ##权重
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 3306
}
}
real_server 192.168.10.2 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
测试
mysql -h192.168.10.188 -uroot1 -proot1
show databases;
在147服务上看 ip addr 也可以看到vip漂移到了192.168.10.2服务器上
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