CENTOS6中用Keepalived实现MySQL双机热备份(1/2)
这里介绍如何配合前者实现Keepalived双机热备
系统环境：CentOS 6.3 x64
MySQL版本：mysql-5.6.10
Keepalived版本：keepalived-1.2.7
MySQL-VIP：192.168.7.253
MySQL-master1：192.168.7.201
MySQL-master2：192.168.7.249
首先关闭iptables和SELINUX
# service iptables stop
# setenforce 0
# vi /etc/sysconfig/selinux
---------------
SELINUX=disabled
---------------
注: 若线上需要开启iptables,需加一条规则使keepalived的vrrp通行
# iptables -A INPUT -p vrrp -j ACCEPT
1.在MySQL-master1：192.168.7.201服务器上keepalived安装及配置
编译安装，实际以本机kernel版本为准
# wget http://www.keepalived.org/software/keepalived-1.2.7.tar.gz
# tar zxvf keepalived-1.2.7.tar.gz
# cd keepalived-1.2.7
# ./configure --prefix=/usr/local/keepalived --with-kernel-dir=/usr/src/kernels/2.6.32-
279.el6.x86_64
# make && make install
设置keepalived开机启动脚本
# 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 keepalived on
新建一个配置文件，默认keepalived启动会去/etc/keepalived目录下寻找配置文件
# mkdir /etc/keepalived
# vi /etc/keepalived/keepalived.conf
------------------
global_defs {
notification_email {
lzyangel@126.com
}
#当主、备份设备发生改变时，通过邮件通知
notification_email_from lzyangel@126.com
smtp_server stmp.126.com
smtp_connect_timeout 30
router_id MySQL-ha
}
vrrp_instance VI_1{
# 在初始化状态下定义为主设备
state BACKUP
# 注意网卡接口
interface eth0
virtual_router_id 51
# 优先级，另一台改为90
priority 100
advert_int 1
# 不主动抢占资源
nopreempt
authentication {
# 认证方式，可以是PASS或AH两种认证方式
auth_type PASS
# 认证密码
auth_pass 1111
}
virtual_ipaddress {
# 虚拟IP地址，随着state的变化而增加删除
192.168.7.253
}
}
virtual_server 192.168.7.253 3306 {
# 每个2秒检查一次real_server状态
delay_loop 2
# LVS算法
lb_algo wrr
# LVS模式
lb_kind DR
# 会话保持时间
persistence_timeout 60
protocol TCP
real_server 192.168.7.201 3306 {
# 权重
weight 3
# 检测到服务down后执行的脚本
notify_down /etc/rc.d/keepalived.sh
TCP_CHECK {
# 连接超时时间
connect_timeout 10
# 重连次数
nb_get_retry 3
# 重连间隔时间
delay_before_retry 3
# 健康检查端口
connect_port 3306
}
}
}
----------------------
编写检测服务down后所要执行的脚本
# vi /etc/rc.d/keepalived.sh
-------------
#!/bin/sh
/etc/init.d/keepalived stop
-------------
# chmod +x /etc/rc.d/keepalived.sh
注：此脚本是上面配置文件notify_down选项所用到的，keepalived使用notify_down选项来检查
real_server的服务状态。
当发现real_server服务故障时，便触发此脚本.
我们可以看到，脚本就一个命令:
通过pkill keepalived强制杀死keepalived进程，从而实现了MySQL故障自动转移.
另外，我们不用担心两个MySQL会同时提供数据更新操作，因为每台MySQL上的keepalived的配置里面只
有本机MySQL的IP+VIP，而不是两台MySQL的IP+VIP.
