#!/bin/bash ###判断如果上次检查的脚本还没执行完，则退出此次执行 if [ `ps -ef|grep -w "$0"|grep -v "grep"|wc -l` -gt 2 ];then exit 0 fi mysql_con='mysql -uroot -p123456' error_log="/etc/keepalived/logs/check_mysql.err" ###定义一个简单判断mysql是否可用的函数 function excute_query { ${mysql_con} -e "select 1;" 2>> ${error_log} } ###定义无法执行查询，且mysql服务异常时的处理函数 function service_error { echo -e "`date "+%F %H:%M:%S"` -----mysql service error，now stop keepalived-----" >> ${error_log} service keepalived stop &>> ${error_log} echo "DB1 keepalived 已停止"|mail -s "DB1 keepalived 已停止,请及时处理！" slowtech@126.com 2>> ${error_log} echo -e "\n---------------------------------------------------------\n" >> ${error_log} } ###定义无法执行查询,但mysql服务正常的处理函数 function query_error { echo -e "`date "+%F %H:%M:%S"` -----query error, but mysql service ok, retry after 30s-----" >> ${error_log} sleep 30 excute_query if [ $? -ne 0 ];then echo -e "`date "+%F %H:%M:%S"` -----still can't execute query-----" >> ${error_log} ###对DB1设置read_only属性 echo -e "`date "+%F %H:%M:%S"` -----set read_only = 1 on DB1-----" >> ${error_log} mysql_con -e "set global read_only = 1;" 2>> ${error_log} ###kill掉当前客户端连接 echo -e "`date "+%F %H:%M:%S"` -----kill current client thread-----" >> ${error_log} rm -f /tmp/kill.sql &>/dev/null ###这里其实是一个批量kill线程的小技巧 mysql_con -e 'select concat("kill ",id,";") from information_schema.PROCESSLIST where command="Query" or command="Execute" into outfile "/tmp/kill.sql";' mysql_con -e "source /tmp/kill.sql" sleep 2 ###给kill一个执行和缓冲时间 ###关闭本机keepalived echo -e "`date "+%F %H:%M:%S"` -----stop keepalived-----" >> ${error_log} service keepalived stop &>> ${error_log} echo "DB1 keepalived 已停止"|mail -s "DB1 keepalived 已停止,请及时处理！" slowtech@126.com 2>> ${error_log} echo -e "\n---------------------------------------------------------\n" >> ${error_log} else echo -e "`date "+%F %H:%M:%S"` -----query ok after 30s-----" >> ${error_log} echo -e "\n---------------------------------------------------------\n" >> ${error_log} fi } ###检查开始: 执行查询 excute_query if [ $? -ne 0 ];then service mysqld status &>/dev/null if [ $? -ne 0 ];then service_error else query_error fi fi