目的：
1.监控mysql服务器的状态
2.当发现mysql down机就自动重启mysql服务
3.重启mysql不成功，发邮件给管理员警告mysql down机
#vi /usr/local/sbin/sbin/check_mysql.sh
#!/bin/sh
cat << EOF
+--------------------------------------------------------------------------+
| === Welcome to LinuxTone=== |
|-------------------------http://www.linuxtone.org------------------------ |
+-------------------------------By:hamgua----------------------------------+
EOF
PORT=`netstat -na|grep "LISTEN"|grep "3306"|awk -F[:" "]+ '{print $5}'`
MYSQLIP=`ifconfig eth0|awk '/inet/{print $2}'|cut -c 6-`
while [ `whoami` == "root" ]
do
if [ "$PORT" == "3306" ];then
echo "mysql is running......"
else
echo "restart mysql"
/etc/init.d/mysqld restart
if [ "$PORT" == "3306" ];then
echo "mysql restart successful......"
else
echo "mysql restart failure......"
echo "server: $MYSQLIP mysql is down,please try to restart mysql!" > /var/log/mymsg
mail -s "warn!server: $MYSQLIP mysql is down" hamgua@gmail.com < /var/log/mymsg
fi
fi
break
done
赋予check_mysql.sh可执行的权限
#chmod u+x /usr/local/sbin/check_mysql.sh
加入crontab，让系统五分钟检测一次mysql状态
#crontab -l
…………
*/5 * * * * /usr/local/sbin/check_mysql.sh > /dev/null 2>&1
