MySQL主从复制与lvs+keepalived单点写入读负载均衡高可用实验【转】

一、环境
Master（主机A）：192.168.1.1
Slave（主机B） ：192.168.1.2  
W-VIP（写入）  ：192.168.1.3 
R-VIP（读取）  ：192.168.1.4 
Client（测试） ：192.168.1.100

操作系统版本：CentOS release 6.4
MySQL数据库版本：5.6.14
keepalived版本：1.2.7
LVS版本：1.26

所有环境均为虚拟机

二、设计思路

1. 服务器A和B，通过mysql的slave进程同步数据。
2. 通过keepalived启用两个虚IP：W-VIP/R-VIP，一个负责写入，一个负责读取，实现读写分离。
3. A和B都存在时，W-VIP下将请求转发至主机A，R-VIP将请求转发给A和B，实现负载均衡。
4. 当主机A异常时，B接管服务，W-VIP/R-VIP此时漂到了主机B上，此时这两个虚IP下都是主机B，实现高可用
5. 当主机B异常时，R-VIP会将B踢出，其他不变

三、架构图

四、软件安装
主从两个主机都要装以下软件：
1. MySQL的安装（略）
2. keepalived安装
yum install keepalived
2. LVS安装
yum install ipvsadm

五、配置
1. 配置MySQL的主从复制（略）
2. 配置keepalived
Master上的配置
vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
     router_id MySQL-ha
}

vrrp_instance VI_1 {
     state BACKUP
     interface eth1
     virtual_router_id 90
     priority 100
     advert_int 1
     notify_master "/usr/local/mysql/bin/remove_slave.sh"
     nopreempt
     authentication {
     auth_type PASS
     auth_pass 1111
     }
     virtual_ipaddress {
     192.168.1.3 label eth1:1
     192.168.1.4 label eth1:2
     }
}

virtual_server 192.168.1.3 6603 {
     delay_loop 2
     lb_algo wrr
     lb_kind DR
     persistence_timeout 60
     protocol TCP
     real_server 192.168.1.1 6603 {
     weight 3
     notify_down /usr/local/mysql/bin/mysql.sh
     TCP_CHECK {
     connect_timeout 10
     nb_get_retry 3
     delay_before_retry 3
     connect_port 6603
     }
     }
}

virtual_server 192.168.1.4 6603 {
     delay_loop 2
     lb_algo wrr
     lb_kind DR
     persistence_timeout 60
     protocol TCP
     real_server 192.168.1.1 6603 {
     weight 1
     notify_down /usr/local/mysql/bin/mysql.sh
     TCP_CHECK {
     connect_timeout 10
     nb_get_retry 3
     delay_before_retry 3
     connect_port 6603
     }
     }
     real_server 192.168.1.2 6603 {
     weight 3
     TCP_CHECK {
     connect_timeout 10
     nb_get_retry 3
     delay_before_retry 3
     connect_port 6603
     }
     }
}

keepalived配置成服务并开机启动

cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
chkconfig --add keepalived
chkconfig --level 345 keepalived on

vi /usr/local/mysql/bin/remove_slave.sh

#!/bin/bash
user=u1
password=12345
log=/usr/local/mysql/log/remove_slave.log
echo "`date`" >> $log
/usr/local/mysql/bin/mysql -u$user -p$password -e "set global read_only=OFF;reset master;stop slave;change master to master_host='localhost';" >> $log
/bin/sed -i 's#read-only##read-only#' /etc/my.cnf

vi /usr/local/mysql/bin/mysql.sh

#!/bin/bash
/etc/init.d/keepalived stop

Slave上的配置
vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
     router_id MySQL-ha
}

vrrp_instance VI_1 {
     state BACKUP
     interface eth1
     virtual_router_id 90
     priority 99
     advert_int 1
     notify_master "/usr/local/mysql/bin/remove_slave.sh"
     authentication {
     auth_type PASS
     auth_pass 1111
     }
     virtual_ipaddress {
     192.168.1.3 label eth1:1
     192.168.1.4 label eth1:2
     }
}

virtual_server 192.168.1.3 6603 {
     delay_loop 2
     lb_algo wrr
     lb_kind DR
     persistence_timeout 60
     protocol TCP
     real_server 192.168.1.2 6603 {
     weight 3
     notify_down /usr/local/mysql/bin/mysql.sh
     TCP_CHECK {
     connect_timeout 10
     nb_get_retry 3
     delay_before_retry 3
     connect_port 6603
     }
     }
}

virtual_server 192.168.1.4 6603 {
     delay_loop 2
     lb_algo wrr
     lb_kind DR
     persistence_timeout 60
     protocol TCP
     real_server 192.168.1.2 6603 {
     weight 3
     notify_down /usr/local/mysql/bin/mysql.sh
     TCP_CHECK {
     connect_timeout 10
     nb_get_retry 3
     delay_before_retry 3
     connect_port 6603
     }
     }
}

keepalived配置成服务并开机启动

cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
chkconfig --add keepalived
chkconfig --level 345 keepalived on

vi /usr/local/mysql/bin/remove_slave.sh

#!/bin/bash
user=u1
password=12345
log=/usr/local/mysql/log/remove_slave.log
echo "`date`" >> $log
/usr/local/mysql/bin/mysql -u$user -p$password -e "set global read_only=OFF;reset master;stop slave;change master to master_host='localhost';" >> $log
/bin/sed -i 's#read-only##read-only#' /etc/my.cnf

vi /usr/local/mysql/bin/mysql.sh

#!/bin/bash
/etc/init.d/keepalived stop

3. 配置LVS
Master与Slave上的配置相同：
vi /usr/local/bin/lvs_real.sh

#!/bin/bash
# description: Config realserver lo and apply noarp

SNS_VIP=192.168.1.3
SNS_VIP2=192.168.1.4
source /etc/rc.d/init.d/functions
case "$1" in

start)
       ifconfig lo:0 $SNS_VIP netmask 255.255.255.255 broadcast $SNS_VIP
       ifconfig lo:1 $SNS_VIP2 netmask 255.255.255.255 broadcast $SNS_VIP2
       /sbin/route add -host $SNS_VIP dev lo:0
       /sbin/route add -host $SNS_VIP2 dev lo:1
       echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
       echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
       echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
       echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
       sysctl -p >/dev/null 2>&1
       echo "RealServer Start OK"
       ;;

stop)
       ifconfig lo:0 down
       ifconfig lo:1 down
       route del $SNS_VIP >/dev/null 2>&1
       route del $SNS_VIP2 >/dev/null 2>&1
       echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore
       echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce
       echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
       echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
       echo "RealServer Stoped"
       ;;

*)

       echo "Usage: $0 {start|stop}"
       exit 1
esac
exit 0

chmod 755 /usr/local/bin/lvs_real.sh
echo "/usr/local/bin/lvs_real.sh start" >> /etc/rc.local

五、Master和Slave的启动
1. 启动Master上的MySQL
service mysql start
2. 启动Slave上的MySQL
service mysql start
3. 启动Master上的realserver脚本
/usr/local/bin/lvs_real.sh start
4. 启动Slave上的realserver脚本
/usr/local/bin/lvs_real.sh start
5. 启动Master上的keepalived
service keepalived start
6. 启动Slave上的keepalived
service keepalived start


六、测试
1. 查看lvs能否进行负载均衡转发
在Master和Slave上分别执行：
ipvsadm -ln

2. 在Client上验证连通性：
ping 192.168.1.3
ping 192.168.1.4
mysql -u u1 -p12345 -P 6603 -h 192.168.1.3 -e "show variables like 'server_id'"
mysql -u u1 -p12345 -P 6603 -h 192.168.1.4 -e "show variables like 'server_id'"

3. 停掉Master上的MySQL，看写IP否自动切换到Slave，看读IP是否去掉了Master的MySQL
在Master和Slave上分别执行：
ipvsadm -ln
在Client上执行：
mysql -u u1 -p12345 -P 6603 -h 192.168.1.3 -e "show variables like 'server_id'"
mysql -u u1 -p12345 -P 6603 -h 192.168.1.4 -e "show variables like 'server_id'"

4. 停掉Master上的keepalived，看读写VIP是否会迁移到Slave上。
在Master和Slave上分别执行：
ipvsadm -ln
在Client上执行：
mysql -u u1 -p12345 -P 6603 -h 192.168.1.3 -e "show variables like 'server_id'"
mysql -u u1 -p12345 -P 6603 -h 192.168.1.4 -e "show variables like 'server_id'"

5. 停掉Slave上的MySQL，看读IP是否去掉了Slave的MySQL
在Master和Slave上分别执行：
ipvsadm -ln
在Client上执行：
mysql -u u1 -p12345 -P 6603 -h 192.168.1.3 -e "show variables like 'server_id'"
mysql -u u1 -p12345 -P 6603 -h 192.168.1.4 -e "show variables like 'server_id'"

6. 重启Master的系统，看看切换过程是否正常

七、参考
http://wenku.baidu.com/link?url=17K0UDApzfK18A8F5Of9wl0lmGx6AD_0PQ8GyVqmCsBMSz16xjt2JI88lPAeID2qECs7piUxkzQLyatTtDuEJxwZEy6joIBfBmT3vgTfdUS
http://blog.chinaunix.net/uid-23500957-id-3781918.html
http://blog.chinaunix.net/uid-23500957-id-3781919.html
http://blog.chinaunix.net/uid-20639775-id-3337471.html