企业面试题1: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。
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)发送邮件,否则跳过错误。
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)
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:
#!/bin/sh
. /etc/init.d/functions
# Defined variables
MysqlUser=root
MysqlPass=root
MysqlPort=
Mysqlsock=/var/mysql/mysql.sock /*在/etc/my.cnf中找到*/
ErrorNo=( )
errorlog=/tmp/error_skip.log
MysqlCmd="mysql-u$MysqlUser -p$MysqlPass -S $Mysqlsock"
# Judge mysql server is ok?
[ -S $Mysqlsock ] ||{ /*-S文件是否未0*/
echo "Maybe MySQL have sometingwrong"
exit
}
# Defined skip error Functions
function error_skip(){
local flag
flag=
for num in ${ErrorNo[@]}
do
if [ "$1" == "$num"];then
$MysqlCmd -e'stop slave;set globalsql_slave_skip_counter=1;start slave;'
echo "$(date +%F_%R) $1">>$errorlog
else
echo "$(date +%F_%R) $1">>$errorlog
((flag++))
fi
done
[ "$flag" =="${#ErrorNo[@]}" ] &&{
action "MySQL Slave"/bin/false
uniq $errorlog|mail -s "MySQLSlave is error" @qq.com
}
}
# Defined check slave Functions
function check_slave(){
MyResult=`$MysqlCmd -e'show slavestatus\G'|egrep '_Running|Behind_Master|SQL_Errno' |awk '{print $NF}'`
array=($MyResult)
if [ "${array[0]}" =="Yes" -a "${array[1]}" == "Yes" -a"${array[2]}" == "" ]
then
action "MySQL Slave"/bin/true
else
error_skip ${array[]}
fi
}
# Defined main Functions
function main(){
while true
do
check_slave
sleep
done
}
main
文件内容:
*************************** .row ***************************
Slave_IO_State:Waiting formaster to send event
Master_Host:10.0.0.179 #当前的mysql master服务器主机
Master_User: rep
Master_Port:
Connect_Retry:
Master_Log_File:mysql-bin.
Read_Master_Log_Pos:
Relay_Log_File:relay-bin.
Relay_Log_Pos:
Relay_Master_Log_File:mysql-bin.
Slave_IO_Running:Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB: mysql
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno:
Last_Error:
Skip_Counter:
Exec_Master_Log_Pos:
Relay_Log_Space:
Until_Condition:None
Until_Log_File:
Until_Log_Pos:
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: #和主库比同步延迟的秒数,这个参数很重要
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno:
Last_IO_Error:
Last_SQL_Errno:
Last_SQL_Error: