自动判断mysql主从复制状态并邮件通知

定期验证MYSQL主从数据一致性在某些时候是一项很值得做的事情，google还提供了MYSQL补丁来自动实现该功能。但某些时候我们能够定期检查到复制的状态也足够了，目前在网上自动检查mysql主从复制状态的方法比较少，所以自已写了一个脚本,该脚本实现功能：
1.通过mysql命令判断mysql从服务器三个主要的复制状态值是否正常，检测到有问题后，根据设定时间间隔值，再重复检测两遍，其中Seconds_Behind_Master值因为不能准确地描述复制延迟，所以在3600秒以下都判断为正常。
2.检测到有问题后记录日志并发送邮件通知状态值内容，问题持续则根据设定时间间隔值再发邮件通知，恢复正常也邮件通知。另外，无论正常与否，每天都发送一次邮件通知，由计划任务和时间相关的变量值决定。
该脚本可以监控主从复制状态，如果要验证主从MYSQL数据一致性，可以研究下google提供的MYSQL补丁。

#/bin/bash
#############################################
# author zhaoyanan
# date 2013/01/25   create
# update 2013/01/28  Adding duplicate detection
#
# Execution:
# touch /root/sh/mysql_slave_status.sh; chmod 700 /root/sh/mysql_slave_status.sh
# vi /etc/crontab
# 5,15,25,35,45,55 * * * * root /root/sh/mysql_slave_status.sh >> /root/sh/mysql_slave_status.log 2>&1
#############################################

######### set variables ############
tmpdir=/tmp

#mysqlhost="127.0.0.1"
#mysqlport="3306"
mysqlsocket="/opt/mysql/var/mysql.sock"
mysqlbinpath="/opt/mysql/bin"
mysqluser="root"
mysqlpw="pass"

servername="dbname"
mailfromadd='dbname<dbname@dbmon.domain.com'
mailtoadd='user1<user1@domain.com>'
#mailccadd='user2<user2@domain.com>'
repeat_alarm_time=12           # Repeat alarm time interval ( About *10 minute. value of 12, about two hours)
failure_interval=10            # Interval after a problem is detected, the unit: seconds ( < 25 seconds)
reporting_time=0855            # Must be notified of the time, even if normal.
current_time=$(date +%H%M)     # Current time

export LANG=C
export LC_ALL=C
export PATH="$mysqlbinpath":/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

###### do ####################################
echo ""
echo ""
echo "`date` Start monitoring."

#### function ####
function mailto() {
# mail
/usr/sbin/sendmail -t <<EOF
From: $mailfromadd
To: $mailtoadd
Cc: $mailccadd
Subject: $servername slave status ok!
----------------------------------
$servername slave status:
$slaveiostatus
$slavesqlstatus
$slavebehind
----------------------------------
EOF
}

function mailto2() {
# mail
/usr/sbin/sendmail -t <<EOF
From: $mailfromadd
To: $mailtoadd
Cc: $mailccadd
Subject: $servername slave status problems!
----------------------------------
$servername slave status:
$slaveiostatus
$lastioerror
$slavesqlstatus
$lastsqlerror
$slavebehind
----------------------------------
EOF
}

function mailto3() {
# mail
/usr/sbin/sendmail -t <<EOF
From: $mailfromadd
To: $mailtoadd
Cc: $mailccadd
Subject: $servername slave status problems! (too many times)
----------------------------------
$servername slave status:
$slaveiostatus
$lastioerror
$slavesqlstatus
$lastsqlerror
$slavebehind
----------------------------------
EOF
}

function mailto4() {
# mail
/usr/sbin/sendmail -t <<EOF
From: $mailfromadd
To: $mailtoadd
Cc: $mailccadd
Subject: $servername slave status return to normal from the question.
----------------------------------
$servername slave status:
$slaveiostatus
$slavesqlstatus
$slavebehind
----------------------------------
EOF
}

function showstatus() {
mysql -S $mysqlsocket -u"$mysqluser" -p"$mysqlpw" -e "show slave status\G" > "$tmpdir"/"$servername"_status.txt
slaveiostatus=`cat "$tmpdir"/"$servername"_status.txt | grep "Slave_IO_Running" | sed 's/^[ \t]*//g'`
lastioerror=`cat "$tmpdir"/"$servername"_status.txt | grep "Last_IO_Error" | sed 's/^[ \t]*//g'`
slavesqlstatus=`cat "$tmpdir"/"$servername"_status.txt | grep "Slave_SQL_Running" | sed 's/^[ \t]*//g'`
lastsqlerror=`cat "$tmpdir"/"$servername"_status.txt | grep "Last_SQL_Error" | sed 's/^[ \t]*//g'`
slavebehind=`cat "$tmpdir"/"$servername"_status.txt | grep "Seconds_Behind_Master" | sed 's/^[ \t]*//g'`
slaveiovalue=`cat "$tmpdir"/"$servername"_status.txt | grep "Slave_IO_Running" | sed 's/^[ \t]*//g' | awk -F ': ' '{print $2}'`
slavesqlvalue=`cat "$tmpdir"/"$servername"_status.txt | grep "Slave_SQL_Running" | sed 's/^[ \t]*//g' | awk -F ': ' '{print $2}'`
slavebehindvalue=`echo "$slavebehind" | awk -F ': ' '{print $2}' | grep '[0-9]'`
}

### check ####
test -f "$tmpdir"/"$servername"_m_value || echo "0" > "$tmpdir"/"$servername"_m_value
test -f "$tmpdir"/"$servername"_n_value || echo "0" > "$tmpdir"/"$servername"_n_value
m=`cat "$tmpdir"/"$servername"_m_value`
n=`cat "$tmpdir"/"$servername"_n_value`

if   showstatus;sync;sleep 1
[ "$slaveiovalue" == "Yes" ] && [ "$slavesqlvalue" == "Yes" ] && [ "$slavebehindvalue" -le 3600 ];then
echo "`date` First detected, $servername slave status ok!"
m=0; echo $m > "$tmpdir"/"$servername"_m_value
elif sleep $failure_interval
showstatus;sync;sleep 1
[ "$slaveiovalue" == "Yes" ] && [ "$slavesqlvalue" == "Yes" ] && [ "$slavebehindvalue" -le 3600 ];then
echo "`date` Second detection, $servername slave status ok!"
m=0; echo $m > "$tmpdir"/"$servername"_m_value
elif sleep $failure_interval
showstatus;sync;sleep 1
[ "$slaveiovalue" == "Yes" ] && [ "$slavesqlvalue" == "Yes" ] && [ "$slavebehindvalue" -le 3600 ];then
echo "`date` Third detection, $servername slave status ok!"
m=0; echo $m > "$tmpdir"/"$servername"_m_value
else
echo "`date` After three detection, $servername slave problems!"
m=$(($m+1)); echo $m > "$tmpdir"/"$servername"_m_value
fi

#### log and mail ####
if   [ "$reporting_time" -eq "$current_time" ] && [ "$m" -eq 0 ] && [ "$n" -eq 0 ]; then
echo "mailto."
mailto
elif [ "$m" -eq 1 ] && [ "$n" -eq 0 ]; then
echo "`date` $servername slave status problems! mailto2."
echo "$servername slave status: "
echo "$slaveiostatus"
echo "$lastioerror"
echo "$slavesqlstatus"
echo "$lastsqlerror"
echo "$slavebehind"
mailto2
n=1; echo $n > "$tmpdir"/"$servername"_n_value
elif [ "$m" -eq "$repeat_alarm_time" ] && [ "$n" -eq 1 ]; then
mailto3
echo "`date` $servername slave status problems! too many times, mailto3."
m=0; echo $m > "$tmpdir"/"$servername"_m_value
elif [ "$m" -eq 0 ] && [ "$n" -eq 1 ]; then
mailto4
echo "$servername slave status return to normal from the question. mailto4."
n=0; echo $n > "$tmpdir"/"$servername"_n_value
elif [ "$m" -ne 0 ] && [ "$n" -eq 1 ]; then
echo "`date` $servername slave status problems! too many times, nomailto"
fi

原文：http://www.zhaoyanan.cn/mysql-slave-status-check.html

本文出自 “调兵虎符” 博客，谢绝转载！