实验目的：
通过Keepalive来构建Mysql的高可用。Mysql已做主从，当一台Mysql宕机的时候不影响对Mysql的调用。
实验环境：
两台Mysql服务器(基于LAMP且已做主从)，两台Mysql服务器都通过Apache发布Discuz论坛(discuz调用的是主mysql地址)。
身份 主机名 IP地址
主Mysql master 192.168.1.3
从Myslq slave 192.168.1.4
LAMP平台请参见
Mysql主从参见
实验步骤：
一、在主mysql上安装配置keepalive
[root@master ~]# bash keepalive_install.sh
“脚本”内容如下：
[root@master ~]# cat keepalive_install.sh#!/bin/bashyum -y install kernel-devel openssl-devel popt-devel &&wgethttp://www.keepalived.org/software/keepalived-1.1.15.tar.gz &&tar -zxf keepalived-1.1.15.tar.gz &&cd keepalived-1.1.15 &&./configure--with-kernel-dir=/usr/src/kernels/2.6.32-431.el6.x86_64/ &&make && make install &&DIR=/usr/local/cp $DIR/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/ &&cp $DIR/etc/sysconfig/keepalived /etc/sysconfig/&& mkdir -p /etc/keepalived &&cp $DIR/sbin/keepalived/usr/sbin/&&cp/usr/local/etc/keepalived/keepalived.conf /etc/keepalived/ &&/etc/init.d/keepalived restartif [ $? -eq 0 ];then echo -e '\e[32mInstall Keepalive Successfully!\e[0m'else echo -e '\e[31mInstall Keepalive Failure!\e[0m'fi
加载ip_vs的内核模块
[root@master ~]# modprobe ip_vs[root@master~]# modprobe ip_vs_wrr[root@master~]# modprobe ip_vs_rr
修改keepalived.conf配置文件如下：
[root@master ~]# vim /etc/keepalived/keepalived.conf[root@master ~]# cat/etc/keepalived/keepalived.conf
! Configuration File for keepalived global_defs { notification_email { 654001593@qq.com } notification_email_from root@localhost.com smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL} vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.77 }} virtual_server 192.168.1.77 3306 { delay_loop 6 lb_algo wrr lb_kind DR persistence_timeout 50 protocol TCP real_server 192.168.1.3 3306 { weight 1 notify_down/data/sh/ keepalive_stop.sh TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3 connect_port 3306 } }} [root@master ~]# mkdir -p /data/sh[root@master ~]# vim/data/sh/keepalive_stop.sh[root@master ~]# chmod +x /data/sh/keepalive_stop.sh[root@master ~]# /etc/init.d/keepalivedreloadReloading keepalived: [ OK ][root@master ~]# cat/data/sh/keepalive_stop.sh#!/bin/bash/etc/init.d/keepalived stop[root@master ~]#
二、在从mysql上安装配置keepalive
[root@slave ~]# bash keepalive_install.sh
“脚本”内容如下，同master上执行的脚本一致(非严格意义上的脚本，安装命令放一起而已)。
[root@slave ~]# cat keepalive_install.sh#!/bin/bashyum -y install kernel-developenssl-devel popt-devel &&wget http://www.keepalived.org/software/keepalived-1.1.15.tar.gz&&tar -zxf keepalived-1.1.15.tar.gz &&cd keepalived-1.1.15 &&./configure--with-kernel-dir=/usr/src/kernels/2.6.32-431.el6.x86_64/ &&make && make install &&DIR=/usr/local/cp $DIR/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/ &&cp $DIR/etc/sysconfig/keepalived/etc/sysconfig/ && mkdir -p /etc/keepalived &&cp $DIR/sbin/keepalived/usr/sbin/&&cp/usr/local/etc/keepalived/keepalived.conf /etc/keepalived/ &&/etc/init.d/keepalived restartif [ $? -eq 0 ];then echo -e '\e[32mInstall Keepalive Successfully!\e[0m'else echo -e '\e[31mInstall Keepalive Failure!\e[0m'fi[root@slave ~]#
加载ip_vs的内核模块
[root@master ~]# modprobe ip_vs[root@master ~]# modprobe ip_vs_wrr[root@master ~]# modprobe ip_vs_rr
修改keepalived.conf配置文件如下
[root@slave ~]# vim/etc/keepalived/keepalived.conf[root@slave ~]# cat/etc/keepalived/keepalived.conf
! Configuration File for keepalived global_defs { notification_email { 654001593@qq.com } notification_email_from root@localhost.com smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id LVS_DEVEL} vrrp_instance VI_1 { state BACKUP !此处同master不一样 interface eth0 virtual_router_id 51 priority 90 !优先级比master上低 advert_int 1 authentication{ auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.77 }} virtual_server 192.168.1.77 3306 { delay_loop 6 lb_algo wrr lb_kind DR nat_mask 255.255.255.0 persistence_timeout 50 protocol TCP real_server 192.168.1.4 3306 { !Slave上的IP weight 1 notify_down/data/sh/keepalive_stop.sh TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3 connect_port 3306 } }} [root@slave ~]#root@slave ~]# mkdir -p /data/sh[root@slave ~]# vim/data/sh/keepalive_stop.sh[root@slave ~]# chmod +x/data/sh/keepalive_stop.sh[root@slave ~]# /etc/init.d/keepalivedreloadReloading keepalived: [ OK ][root@slave ~]# cat/data/sh/keepalive_stop.sh#!/bin/bash/etc/init.d/keepalived stop[root@slave ~]#
三、修改Discuz论坛数据库连接IP为VIP
直接访问master上的192.168.1.3论坛是可以访问的，且直接访问slave上的192.168.1.4论坛也是可以访问的，现在我们直接访问VIP(虚拟IP) 192.168.1.77依旧可以访问论坛。
这个时候因为discuz调用的是master上的数据库IP，所以我们应该让其调用VIP 192.168.1.77,这样才能保证在主挂的时候自动切换到从上。
在master上
[root@master ~]#sed -i 's/192.168.1.3/192.168.1.77/'/usr/local/apache/htdocs/config/config_global.php[root@master ~]#/usr/local/apache/bin/apachectl restart
在slave上
[root@slave ~]#sed -i 's/192.168.1.3/192.168.1.77/'/usr/local/apache/htdocs/config/config_global.php[root@slave ~]#/usr/local/apache/bin/apachectl restart
四、测试
上边两个图很明显可以看出此时VIP在master上。
手动模拟master上的mysql关闭
VIP自动漂到slave上
论坛依旧可以访问