MySQL 高可用性之Keepalived+Mysql（双主热备）
环境描述：
OS：CentOS6.5_X64
MASTER：192.168.0.202
BACKUP：192.168.0.203
VIP：192.168.0.204
1. 配置两台 MySQL 主主同步
1.1 安装配置MySQL
[root@master ~]# yum install mysql-server mysql -y
[root@master ~]# service mysqld start
[root@master ~]# mysqladmin -u root password 123.com
#### 开启二进制日志，设置id
[root@master ~]# vi /etc/my.cnf
[mysqld]
server-id = 1 #backup这台设置2
log-bin = mysql-bin
binlog-ignore-db = mysql,information_schema #忽略写入binlog日志的库
auto-increment-increment = 2 #字段变化增量值
auto-increment-offset = 1 #初始字段ID为1
slave-skip-errors = all #忽略所有复制产生的错误
[root@master ~]# service mysqld restart
查看下log bin日志和pos值位置mysql> show master status;
1.2 配置 master
[root@ master ~]# mysql -u root -p123.com
mysql> GRANT REPLICATION SLAVE ON *.* TO 'replication'@'192.168.0.%' IDENTIFIED BY 'replication';
mysql> flush privileges;
mysql> change master to
-> master_host='192.168.0.203',
-> master_user='replication',
-> master_password='replication',
-> master_log_file='mysql-bin.000002',
-> master_log_pos=106; #对端状态显示的值
mysql> start slave; #启动同步
1.3 配置 backup
[root@backup ~]# mysql -u root -p123.com
mysql> GRANT REPLICATION SLAVE ON *.* TO 'replication'@'192.168.0.%' IDENTIFIED BY 'replication';
mysql> flush privileges;
mysql> change master to
-> master_host='192.168.0.202',
-> master_user='replication',
-> master_password='replication',
-> master_log_file='mysql-bin.000002',
-> master_log_pos=106;
mysql> start slave;
1.4 测试主主同步
主主同步配置完毕，查看同步状态mysql> show slave status\G; Slave_IO和Slave_SQL是YES说明主主同步成功。
在master插入数据测试下：
在backup查看是否同步成功：
可以看到已经成功同步过去，同样在backup插入到user表数据，一样同步过去，双主就做成功了。
2. 配置 keepalived 实现热备
2.1 安装 keepalived
[root@backup ~]# yum install -y pcre-devel openssl-devel popt-devel #安装依赖包
[root@master ~]# wget http://www.keepalived.org/software/keepalived-1.2.7.tar.gz
[root@master ~]# tar zxvf keepalived-1.2.7.tar.gz
[root@master ~]# cd keepalived-1.2.7
[root@master ~]#./configure --prefix=/usr/local/keepalived
make && make install
2.2 将keepalived配置成系统服务
[root@master ~]# cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/
[root@master ~]# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
[root@master ~]# mkdir /etc/keepalived/
[root@master ~]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
[root@master ~]# cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
[root@master ~]# vi /etc/keepalived/keepalived.conf
! Configuration File forkeepalived
global_defs {
notification_email {
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id MYSQL_HA #标识，双主相同
}
vrrp_instance VI_1 {
state BACKUP #两台都设置BACKUP
interface eth0
virtual_router_id 51 #主备相同
priority 100 #优先级，backup设置90
advert_int 1
nopreempt #不主动抢占资源，只在master这台优先级高的设置，backup不设置
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.0.204
}
}
virtual_server 192.168.0.204 3306 {
delay_loop 2
#lb_algo rr #LVS算法，用不到，我们就关闭了
#lb_kind DR #LVS模式，如果不关闭，备用服务器不能通过VIP连接主MySQL
persistence_timeout 50 #同一IP的连接60秒内被分配到同一台真实服务器
protocol TCP
real_server 192.168.0.202 3306 { #检测本地mysql，backup也要写检测本地mysql
weight 3
notify_down /usr/local/keepalived/mysql.sh #当mysq服down时，执行此脚本，杀死keepalived实现切换
TCP_CHECK {
connect_timeout 3 #连接超时
nb_get_retry 3 #重试次数
delay_before_retry 3 #重试间隔时间
}
}
[root@master ~]# vi /usr/local/keepalived/mysql.sh
#!/bin/bash
pkill keepalived
[root@master ~]# chmod +x /usr/local/keepalived/mysql.sh
[root@master ~]# /etc/init.d/keepalived start
- backup服务器只修改priority为90、nopreempt不设置、real_server设置本地IP。
2.3 MySQL授权root远程登录
授权两台Mysql服务器允许root远程登录，用于在其他服务器登陆测试！
mysql> grant all on *.* to'root'@'192.168.0.%' identified by '123.com';
mysql> flush privileges;
3. 测试高可用性
3.1 通过Mysql客户端通过VIP连接，看是否连接成功
3.2 停止master这台mysql服务，是否能正常切换过去，可通过ip addr命令来查看VIP在哪台服务器上。
3.3 通过查看/var/log/messges日志，看出主备切换过程。
3.4 master服务器故障恢复后，是否主动抢占资源，成为活动服务器。
- 测试把master上面的这台数据库停掉，keepalived的脚本会检测mysql断开自动会断开keepalived，此时VIP漂移到BACKUP，不影响客户端使用，重新启动mysql和keepalived发现VIP不会被抢占