企业面试题1:(生产实战案例):监控MySQL主从同步是否异常,如果异常,则发送短信或者邮件给管理员。提示:如果没主从同步环境,可以用下面文本放到文件里读取来模拟:
阶段1:开发一个守护进程脚本每30秒实现检测一次。
阶段2:如果同步出现如下错误号(1158,1159,1008,1007,1062),则跳过错误。
阶段3:请使用数组技术实现上述脚本(获取主从判断及错误号部分)
此题来自:http://oldboy.blog.51cto.com/2561410/1632876
解答参考1:
#!/bin/sh #oldboy linux training #2015-05-17 #说明:本脚本来自老男孩linux21期学员张耀开发! # Source function library. . /etc/init.d/functions # Defined variables MysqlUser=root MysqlPass=oldboy123 MysqlPort=3307 Mysqlsock=/data/$MysqlPort/mysql.sock ErrorNo=(1158 1159 1008 1007 1062) errorlog=/tmp/error_skip.log MysqlCmd="/application/mysql/bin/mysql -u$MysqlUser -p$MysqlPass -S $Mysqlsock" # Judge mysql server is ok? [ -S $Mysqlsock ] ||{ echo "Maybe MySQL have someting wrong" exit 1 } # Defined skip error Functions function error_skip(){ local flag flag=0 for num in ${ErrorNo[@]} do if [ "$1" == "$num" ];then $MysqlCmd -e‘stop slave;set global sql_slave_skip_counter=1;start slave;‘ echo "$(date +%F_%R) $1" >>$errorlog else echo "$(date +%F_%R) $1" >>$errorlog ((flag++)) fi done [ "$flag" == "${#ErrorNo[@]}" ] &&{ action "MySQL Slave" /bin/false uniq $errorlog|mail -s "MySQL Slave is error" 12345678@qq.com } } # Defined check slave Functions function check_slave(){ MyResult=`$MysqlCmd -e‘show slave status\G‘|egrep ‘_Running|Behind_Master|SQL_Errno‘ |awk ‘{print $NF}‘` array=($MyResult) if [ "${array[0]}" == "Yes" -a "${array[1]}" == "Yes" -a "${array[2]}" == "0" ] then action "MySQL Slave" /bin/true||error_skip ${array[3]} fi } # Defined main Functions function main(){ while true do check_slave sleep 60 done } main
解答参考2:
#!/bin/sh #oldboy linux #2015-05-17 #说明:本脚本来自老男孩教育21期学员李新宇! USER=root PASSWORD=123456 PORT=3307 error=(1158 1159 1008 1007 1062) MYSQLCMD="mysql -u$USER -p$PASSWORD -S /data/$PORT/mysql.sock" is_run(){ [ `lsof -i:$PORT|wc -l` -lt 2 ]&&{ echo "mysql server is stopped" exit 1 } } status_array(){ status=($($MYSQLCMD -e "show slave status\G"|egrep "_Running|Last_Errno|Behind_Master"|awk ‘{print $NF}‘)) } status_error(){ for((i=0;i<${#error[*]};i++)) do if [ "$1" == "${error[$i]}" ] then $MYSQLCMD -e "stop slave;set global sql_slave_skip_counter=1;start slave;" else echo "MySQL slave is failed, errorno is $1" fi done } judge_slave(){ status_array if [ "${status[0]}" == "Yes" -a "${status[1]}" == "Yes" -a "${status[3]}" = "0" ] then echo "MySQL slave is ok" else status_error ${status[2]} fi } main(){ while true do is_run judge_slave sleep 60 done } main
老男孩老师提示:企业实际场景,还可能根据主库写时间戳的方式更严格的判断数据库是否同步。
本文出自 “老男孩linux运维” 博客,请务必保留此出处http://oldboy.blog.51cto.com/2561410/1652086
原文地址:http://oldboy.blog.51cto.com/2561410/1652086