MySQL 高可用：mysql+Lvs+Keepalived 负载均衡及故障转移

系统信息：
mysql主库	192.168.1.152	CentOS 5.6	mysql 5.6.22 
mysql从库	192.168.1.153	CentOS 5.6	mysql 5.6.22 
VIP			192.168.1.150

mysql 主主同步都设置 auto-increment-offset，auto-increment-increment ，以避免自增列冲突。
参考： MySQL 高可用：主主复制（双主复制）

LVS 下载：
http://www.linuxvirtualserver.org/software/
http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz


Keepalived 下载：
http://www.keepalived.org/software/

http://www.keepalived.org/software/keepalived-1.2.19.tar.gz

yum -y install gcc gcc-c++ gcc-g77 ncurses-devel bison libaio-devel
cmake libnl* libpopt* popt-static openssl-devel  

# LVS 安装配置：（yum -y install ipvsadm）

cd /usr/local/src
wget http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz
tar zxvf ipvsadm-1.24.tar.gz
cd ipvsadm-1.24
ln -s /usr/src/kernels/2.6.18-402.el5-i686/ /usr/src/linux  #找自己的目录看看/usr/src/kernels
make && make install

# Keepalived 安装配置

cd /usr/local/src
wget http://www.keepalived.org/software/keepalived-1.2.19.tar.gz
tar zxvf keepalived-1.2.19.tar.gz
cd keepalived-1.2.19
./configure --prefix=/usr/local/keepalived --disable-fwmark
make && make install

cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/

mkdir -p /etc/keepalived/
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/   

#编辑或者新建（主备除两地方，其他一样.备库改为 ：state BACKUP ，priority 50）

vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {				#全局标识模块
   notification_email {		#定义邮件通知
     [email protected]			#目标邮箱
   }
   notification_email_from [email protected]	#发送邮箱
   smtp_server 127.0.0.1	#发送邮箱的smtp服务器
   smtp_connect_timeout 30	#smtp服务器连接超时时间
   router_id LVS_DEVEL
}

vrrp_instance VI_1 {
    state MASTER			#本实例启动状态：MASTER/BACKUP
    interface eth0			#监控的网络接口
    virtual_router_id 51	#vrrp实例（同一个组主备服务器设置一样）
    priority 100			#优先级高的为master，不能超过255。（BACKUP可设置为50）
    advert_int 1			#均衡器检测间隔1秒（服务器设置都一样）
    authentication {		#验证类型及密码（服务器设置都一样）
        auth_type PASS		#认证方式，PASS或AH
        auth_pass 123456	#认证密码
    }
    virtual_ipaddress {		#虚拟ip地址virtual_ipaddress,可以定义多个
        192.168.1.150
    }
}

virtual_server 192.168.1.150 3306 {	#定义虚拟服务器，与上面的virtual_server一样
    delay_loop 6			#健康检查时间间隔，6秒
    lb_algo rr				#负载均衡调度算法：rr|wrr|lc|wlc|sh|dh|lblc
    lb_kind NAT				#负载均衡转发规则：NAT|DR|TUN
    nat_mask 255.255.255.0
    persistence_timeout 50	#回话保持时间50秒，动态服务建议开启
    protocol TCP			#转发协议protocol，一般有tcp和udp两种

	#后端真实服务器，有几台就设置几个
    real_server 192.168.1.152 3306 {
        weight 1			#权重越大负载分越大，0表示失效
        SSL_GET {			#健康检查方式：HTTP_GET|SSL_GET|TCP_CHECK|SMTP_CHECK|MISC_CHECK
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
    real_server 192.168.1.153 3306 {
        weight 1
        SSL_GET {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        }
    }
}

#启动 keepalived 服务
/etc/rc.d/init.d/keepalived start

#添加到rc.local自启动中
echo "/etc/rc.d/init.d/keepalived start" >> /etc/rc.local

#152服务器IP
[root@centos152 keepalived]# ip a
1: lo:  mtu 16436 qdisc noqueue 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
2: eth0:  mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:0c:29:3b:c4:a5 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.152/24 brd 192.168.1.255 scope global eth0
    inet 192.168.1.150/32 scope global eth0

#现在在第三台mysql服务器中连接VIP测试

#ping VIP 正常
ping 192.168.1.150

#连接到 VIP 正常
mysql -umysqlproxy -pmysqlproxy -h192.168.1.150 --port3306

#到 mysql 服务器 152 和 153 查看进程，查看用户 mysqlproxy 连接到哪台服务器
mysql> show processlist;

#停止 mysqlproxy 所在的服务器keepalived 服务
/etc/rc.d/init.d/keepalived stop

此时在150 连接的mysql切换到另一台服务器的mysql数据库了。


/etc/rc.d/init.d/keepalived start

末尾有些测试还没有规范，仅供参考。

更多参考：

MySQL 高可用：主主复制（双主复制）

ipvsadm 安装配置

mysql高可用探究(二)Lvs+Keepalived+Mysql单点写入主主同步高可用方案

Lvs+keepalived+mysql 双主

keepalived配置主从备份

Linux下Keepalived 安装与配置

CentOS 5.9下安装配置keepalived

keepalived.conf内容说明