利用Keepalived构建高可用的MySQL

公司大牛让用keepalived构建高可用的MySQL，在网上看到一篇很完整的文章，于是乎照着前辈的足迹，加上自己补充。如上述均正确配置

前言：公司大牛让用keepalived构建高可用的MySQL，在网上看到一篇很完整的文章，于是乎照着前辈的足迹，加上自己补充。

环境拓扑如下：

MySQL-VIP：192.168.1.150
MySQL-master1：192.168.1.151
MySQL-master2：192.168.1.152

OS版本：RedHat 5.4
MySQL版本：5.0.77
Keepalived版本：1.1.20

一、MySQL master-master的安装及配置
1、安装mysql
#yum install mysql-server -y \\为了节省时间，这里两台server都直接yum装，希望你配好了yum源。

2、修改配置文件
On server1：
#vim /etc/my.cnf
[mysqld]
server-id = 10
log-bin = mysql-bin
replicate-do-db = ccledb
auto-increment-increment = 2
auto-increment-offset = 1
On server2 ：
#vim /etc/my.cnf
[mysqld]
server-id = 20
log-bin = mysql-bin
replicate-do-db = ccledb
auto-increment-increment = 2
auto-increment-offset = 2
3、建立授权用户
On server1：
mysql> grant replication client,replication slave on *.* to cclo1@’192.168.1.%’ identified by ‘123456’;

On server2：
mysql> grant replication client,replication slave on *.* to cclo2@’192.168.1.%’ identified by ‘123456’；

4、指定主服务器
On server1
mysql> show master status;
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| MySQL-bin.000003 | 374 | | |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
mysql> change master to master_host='192.168.1.152',master_user='cclo2',master_password='123456',master_log_file='mysql-bin.000003',master_log_pos=374;
Query OK, 0 rows affected (0.05 sec)

On server2
mysql> show master status;
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| MySQL-bin.000003 | 374 | | |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
mysql> change master to master_host='192.168.1.151',master_user='cclo1',master_password='123456',master_log_file='mysql-bin.000003',master_log_pos=374;
Query OK, 0 rows affected (0.05 sec)

5、开启主主服务
mysql> start slave; \\两台server分别执行
MySQL> show slave status\G \\查看主主状态
Slave_IO_Running: Yes
Slave_SQL_Running: Yes \\如果此2项都为yes，master-master配置即成功

如上述均正确配置，现在在任何一台MySQL上更新数据都会同步到另一台MySQL。

二、keepalived安装及配置

1、192.168.1.151服务器上keepalived安装及配置

安装keepalived

#tar zxvf keepalived-1.1.20.tar.gz
#cd keepalived-1.1.20
#./configure --prefix=/usr/local/keepalived --with-kernel-dir=/usr/src/kernels/2.6.18-164.el5-i686
\\此处一定确保你的linux中有/usr/src/kernels/2.6.18-164.el5-i686这个目录，如果没有请安装kernel- devel包，建议最好是下载和你的linux系统内核版本相同的devel包安装（一般安装镜像有），此处直接#yum install -y kernel-devel
#make && make install

配置keepalived
此处需新建一个配置文件，默认情况下keepalived启动时会去/etc/keepalived目录下找配置文件

#mkdir /etc/keepalived
#vim /etc/keepalived/keepalived.conf \\配置文件内容如下：
! Configuration File for keepalived
global_defs {
notification_email {
[e-mail]
}
notification_email_from [e-mail]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id MySQL-ha
}

vrrp_instance VI_1 {
state BACKUP #两台配置此处均是BACKUP
interface eth0
virtual_router_id 51
priority 100 #优先级，另一台改为90
advert_int 1
nopreempt #不主动抢占资源，只在优先级高的机器上设置即可，优先级低的机器不设置
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.150
}
}

virtual_server 192.168.1.150 3306 {
delay_loop 2 #每个2秒检查一次real_server状态
lb_algo wrr #LVS算法
lb_kind DR #LVS模式
persistence_timeout 60 #会话保持时间
protocol TCP
real_server 192.168.1.151 3306 {
weight 3
notify_down /usr/local/my/my.sh #检测到服务down后执行的脚本
TCP_CHECK {
connect_timeout 10 #连接超时时间
nb_get_retry 3 #重连次数
delay_before_retry 3 #重连间隔时间
connect_port 3306 #健康检查端口
}
}

编写检测服务down后所要执行的脚本:
#vim /usr/local/my/my.sh
#!/bin/sh
pkill keepalived
#chmod +x /usr/local/my/my.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

启动keepalived:
#/usr/local/keepalived/sbin/keepalived –D
#ps -aux | grep keepalived

测试
找一台局域网PC，然后去ping MySQL的VIP，这时候MySQL的VIP是可以ping的通的
停止MySQL服务，#ps -aux | grep keepalived 看keepalived健康检查程序是否会触发我们编写的脚本