MySQL学习笔记-Keepalived VIP配置使用

如果我们使用的MHA时，app1.cnf 中的master_ip_failover_script和master_ip_online_change_script两项没有配，即没有使用MHA的VIP方式，可使用keepalived来设置VIP。

本例中keepalived的master端和backup端ip：

master：10.1.5.8

backup：10.1.5.9



MHA配置见：/article/3635640.html

1. 安装keepalived

linux6自带keepalived，yum installkeepalived安装，配置样本是vi /etc/keepalived/keepalived.conf

linux5需下载安装，如下：

下载：http://www.keepalived.org/download.html

# tar zxvf keepalived-1.2.19.tar.gz

# cd keepalived-1.2.19

# ./configure --prefix=/usr/local/keepalived --with-kernel-dir=/usr/src/kernels/2.6.39-300.26.1.el5uek

如遇到configure: error: No SO_MARK declaration in headers，则用./configure --prefix=/usr/local/keepalived --disable-fwmark

# make

# make install

# cp /usr/local/keepalived/sbin/keepalived /usr/sbin/

# cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/

# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/

2. 配置keepalived

# mkdir /etc/keepalived



master配置：

# cat/etc/keepalived/keepalived.conf
! Configuration File forkeepalived

global_defs {
notification_email {
licz@umessage.com.cn
94097432@qq.com
lichangzai@163.com
}
notification_email_fromroot@localhost.localdomain
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}

vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 100
nopreempt
advert_int 1
authentication {
auth_type PASS
auth_pass 1234
}
virtual_ipaddress {
10.1.5.21/24
}
}




backup配置：

# cat /etc/keepalived/keepalived.conf
! Configuration File forkeepalived

global_defs {
notification_email {
licz@umessage.com.cn
94097432@qq.com
lichangzai@163.com
}
notification_email_fromroot@localhost.localdomain
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}

vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1234
}
virtual_ipaddress {
10.1.5.21/24
}
}

3.用脚本实现定时检查MySQL实例是否存活

安装keepalieved的节点，定时检查MySQL实例是否存活，宕掉时自动杀掉keepalived进程，从而实现VIP转移到backup节点。

# crontab -l

* * * * * /data/mysqldata/scripts/check_keepalived.sh > /dev/null 2>&1 &


# cat /data/mysqldata/scripts/check_keepalived.sh
#/bin/bash
source /root/.bash_profile
# source /data/mysqldata/scripts/mysql_env.ini
MYSQL_CMD=/usr/local/mysql/bin/mysql
CHECK_TIME=3 #check 3 times
MYSQL_OK=1 #MYSQL_OK values to 1 when mysql servicework,else values to 0

function check_mysql_health (){
$MYSQL_CMD -uroot -p123456 -S /var/lib/mysql/mysql.sock -e "show status;" > /dev/null 2>&1
if [ $? = 0 ]
then
MYSQL_OK=1
/etc/init.d/keepalived start
else
MYSQL_OK=0
fi
return $MYSQL_OK
}

while [ $CHECK_TIME -ne 0 ]
do
let "CHECK_TIME -=1"
check_mysql_health
if [ $MYSQL_OK = 1 ]
then
CHECK_TIME=0
exit 0
fi
if [ $MYSQL_OK -eq 0 ] && [$CHECK_TIME -eq 0 ]
then
/etc/init.d/keepalived stop
echo "mysql 3306实例宕掉，keepalived已关闭" |mutt -s "master keepalived已关闭"94097532@qq.com
exit 1
fi
sleep 1
done