定期驗證MYSQL主從數據一致性在某些時候是一項很值得做的事情，google還提供了MYSQL補丁來自動實現該功能。但某些時候我們能夠定期檢查到複製的狀態也足夠了，目前在網上自動檢查mysql主從複製狀態的方法比較少，所以自已寫了一個腳本,該腳本實現功能：
1.通過mysql命令判斷mysql從服務器三個主要的複製狀態值是否正常，檢測到有問題後，根據設定時間間隔值，再重複檢測兩遍，其中Seconds_Behind_Master值因爲不能準確地描述複製延遲，所以在3600秒以下都判斷爲正常。
2.檢測到有問題後記錄日誌併發送郵件通知狀態值內容，問題持續則根據設定時間間隔值再發郵件通知，恢復正常也郵件通知。另外，無論正常與否，每天都發送一次郵件通知，由計劃任務和時間相關的變量值決定。
該腳本可以監控主從複製狀態，如果要驗證主從MYSQL數據一致性，可以研究下google提供的MYSQL補丁。
#/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<[email protected]' mailtoadd='user1<[email protected]>' #mailccadd='user2<[email protected]>' 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