企業面試題1：（生產實戰案例）：監控MySQL主從同步是否異常，如果異常，則發送短信或者郵件給管理員。提示：如果沒主從同步環境,可以用下面文本放到文件裏讀取來模擬：
階段1：開發一個守護進程腳本每30秒實現檢測一次。
階段2：如果同步出現如下錯誤號（1158,1159,1008,1007,1062），則跳過錯誤。
階段3：請使用數組技術實現上述腳本（獲取主從判斷及錯誤號部分）
此題來自：http://oldboy.blog.51cto.com/2561410/1632876
解答參考1：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 | #!/bin/sh
#oldboy linux training
#2015-05-17
#說明：本腳本來自老男孩linux21期學員張耀開發！
# 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 $errorlog|mail -s "MySQL Slave is error" [email protected]
}
}
# Defined check slave Functions
function check_slave(){
MyResult=`$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
else
error_skip ${array[3]}
fi
}
# Defined main Functions
function main(){
while true
do
check_slave
sleep 60
done
}
main |
解答參考2：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 | #!/bin/sh
#oldboy linux
#2015-05-17
#說明：本腳本來自老男孩教育21期學員李新宇！
USER=root
PASSWORD=123456
PORT=3307
error=(1158 1159 1008 1007 1062)
MYSQLCMD="mysql -u$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 |
老男孩老師提示：企業實際場景，還可能根據主庫寫時間戳的方式更嚴格的判斷數據庫是否同步。
本文出自 “老男孩linux培訓” 博客，請務必保留此出處http://oldboy.blog.51cto.com/2561410/1652086