keepalived 的熱備可以看文檔：keepalived的配置使用
mysql 的主從 的文檔講解：mysql 主從複制
keepalived的雙主，就是主從的一種， 大家看一眼就懂了，為了省力， 下面的雙主配置我直接網上找了一篇，在下面，大家随便看下
keepalived的雙子多從的整體結構 如下圖：
1、配置兩台Mysql主主同步
[root@master ~]# yum install mysql-server mysql -y
[root@master ~]# service mysqld start
[root@master ~]# mysqladmin -u root password 123.com
[root@master ~]# vi /etc/my.cnf #開啟二進制日志，設定id
[mysqld]
server-id = 1 #backup這台設定2
log-bin = mysql-bin
binlog-ignore-db = mysql,information_schema #忽略寫入binlog日志的庫
auto-increment-increment = 2 #字段變化增量值
auto-increment-offset = 1 #初始字段ID為1
slave-skip-errors = all #忽略所有複制産生的錯誤
[root@master ~]# service mysqld restart
#先檢視下log bin日志和pos值位置
master配置如下：
[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; #對端狀态顯示的值
mysql> start slave; #啟動同步
backup配置如下：
[root@backup ~]# mysql -u root -p123.com
-> master_host='192.168.0.202',
-> master_log_pos=106;
mysql> start slave;
#主主同步配置完畢，檢視同步狀态Slave_IO和Slave_SQL是YES說明主主同步成功。
在master插入資料測試下：
在backup檢視是否同步成功：
可以看到已經成功同步過去，同樣在backup插入到user表資料，一樣同步過去，雙主就做成功了。
2、配置keepalived實作熱備
[root@backup ~]# yum install -y pcre-devel openssl-devel popt-devel #安裝依賴包
[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
#将keepalived配置成系統服務
[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 {
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id MYSQL_HA #辨別，雙主相同
vrrp_instance VI_1 {
state BACKUP #兩台都設定BACKUP
interface eth0
virtual_router_id 51 #主備相同
priority 100 #優先級，backup設定90
advert_int 1
nopreempt #不主動搶占資源，隻在master這台優先級高的設定，backup不設定
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，我們就關閉了
#lb_kind DR #LVS模式，如果不關閉，備用伺服器不能通過VIP連接配接主MySQL
persistence_timeout 50 #同一IP的連接配接60秒内被配置設定到同一台真實伺服器
protocol TCP
real_server 192.168.0.202 3306 { #檢測本地mysql，backup也要寫檢測本地mysql
weight 3
notify_down /usr/local/keepalived/mysql.sh #當mysq服down時，執行此腳本，殺死keepalived實作切換
TCP_CHECK {
connect_timeout 3 #連接配接逾時
nb_get_retry 3 #重試次數
delay_before_retry 3 #重試間隔時間
}
}
[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伺服器隻修改priority為90、nopreempt不設定、real_server設定本地IP。
#授權兩台Mysql伺服器允許root遠端登入，用于在其他伺服器登陸測試！
mysql> grant all on *.* to'root'@'192.168.0.%' identified by '123.com';
mysql> flush privileges;
3、測試高可用性
1、通過Mysql用戶端通過VIP連接配接，看是否連接配接成功。
2、停止master這台mysql服務，是否能正常切換過去，可通過ip addr指令來檢視VIP在哪台伺服器上。