shell脚本监控mysql主从状态

此脚本首先判断mysql服务器是否运行，如果正常，继续判断主从，否则发邮件告警,只发一次。
判断主从状态是判断io和sql线程是否都为yes，如果不是则发邮件通知，只发一次。

#!/bin/bash
#define mysql variable
mysql_user="root"
mysql_pass="123456"
email_addr="[e-mail]"

mysql_status=`netstat -nl | awk 'nr>2{if ($4 ~ /.*:3306/) {print "yes";exit 0}}'`
if [ "$mysql_status" == "yes" ];then
        slave_status=`mysql -u${mysql_user} -p${mysql_pass} -e"show slave status\g" | grep "running" | awk '{if ($2 != "yes") {print "no";exit 1}}'`
        if [ "$slave_status" == "no" ];then
                echo "slave is not working!"
                [ ! -f "/tmp/slave" ] && echo "slave is not working!" | mail -s "warn!mysql slave is not working" ${email_addr}
                touch /tmp/slave
        else
                echo "slave is working."
                [ -f "/tmp/slave" ] && rm -f /tmp/slave
        fi
        [ -f "/tmp/mysql_down" ] && rm -f /tmp/mysql_down
else
        [ ! -f "/tmp/mysql_down" ] && echo "mysql server is down!" | mail -s "warn!mysql server is down!" ${email_addr}
        touch /tmp/mysql_down
fi