CentOS下編寫shell腳本來監控MySQL主從復制的教程

目的：定時監控MySQL主從數據庫是否同步，如果不同步，記錄故障時間，並執行命令使主從恢復同步狀態

1、創建腳本文件

vi /home/crontab/check_mysql_slave.sh  #編輯，添加下面代碼

#!/bin/sh

# check_mysql_slave status

ip=eth0 #網卡名稱

mysql_binfile=/usr/local/mysql/bin/mysql

mysql_user=root #MySQL數據庫賬號

mysql_pass=123456 #密碼

mysql_sockfile=/tmp/mysql.sock

datetime=`date +"%Y-%m-%d/%H:%M:%S"`  #獲取當前時間

mysql_slave_logfile=/home/logs/check_mysql_slave.log  #日志文件路徑，必須提前創建好

slave_ip=`ifconfig $ip|grep "inet addr" | awk -F[:" "]+ '{print $4}'`

status=$($mysql_binfile -u$mysql_user -p$mysql_pass -S $mysql_sockfile -e "show slave status\G" | grep -i "running")

Slave_IO_Running=`echo $status | grep Slave_IO_Running | awk ' {print $2}'`

Slave_SQL_Running=`echo $status | grep Slave_SQL_Running | awk '{print $2}'`

if [ "$Slave_IO_Running" = "Yes" -a "$Slave_SQL_Running" = "Yes" ]

then echo "Slave is Running!"

else

echo " $datetime $slave_ip Slave is not running!" >> $mysql_slave_logfile

$mysql_binfile -u$mysql_user -p$mysql_pass -S $mysql_sockfile -e "SLAVE STOP;"

$mysql_binfile -u$mysql_user -p$mysql_pass -S $mysql_sockfile -e "SET GLOBAL SQL_SLAVE_SKIP_COUNTER=1;"

$mysql_binfile -u$mysql_user -p$mysql_pass -S $mysql_sockfile -e "SLAVE START;"

$mysql_binfile -u$mysql_user -p$mysql_pass -S $mysql_sockfile -e "EXIT"

fi

:wq! #保存退出

chmod +x /home/crontab/check_mysql_slave.sh #添加腳本執行權限

2、添加任務計劃，修改/etc/crontab

vi /etc/crontab #在最後一行添加

*/10 * * * * root /home/crontab/check_mysql_slave.sh #表示每10分鐘執行一次

:wq! #保存退出

3、重新啟動crond使設置生效

/etc/rc.d/init.d/crond restart  #yum install -y vixie-cron安裝計劃任務，某些系統上可能沒有預裝

chkconfig crond on #設為開機啟動

service crond start #啟動

可以根據日志文件/home/logs/check_mysql_slave.log查看MySQL主從同步狀態

PS：接下來這個腳本增加了“當發現同步出現無法同步的時候”會自動提取主庫的file號，以及pos,進行同步主庫，腳本內容如下：
 

#!/bin/sh
#set -x
#file is slave_repl.sh
#Author by Kevin
#date is 2011-11-13

mstool="/usr/local/mysql-3307/bin/mysql -h 192.168.1.106 -uroot -pw!zl7POg27 -P 3307"
sltool="/usr/local/mysql-3307/bin/mysql -h 192.168.1.107 -uroot -pw!zl7POg27 -P 3307"
declare -a slave_stat
slave_stat=($($sltool -e "show slave status\G"|grep Running |awk '{print $2}'))
if [ "${slave_stat[0]}" = "Yes" -a "${slave_stat[1]}" = "Yes" ]
   then
   echo "OK slave is running"
   exit 0
else
   echo "Critical slave is error"
   echo
   echo "*********************************************************"
   echo "Now Starting replication with Master Mysql!"
    file=`$mstool -e "show master status\G"|grep "File"|awk '{print $2}'` 
    pos=`$mstool -e "show master status\G"|grep "Pos"|awk '{print $2}'` 
    $sltool -e "slave stop;change master to master_host='192.168.1.106',master_port=3307,master_user='repl',master_password='w!zl7POg27',master_log_file='$file',master_log_pos=$pos;slave start;"
    sleep 3
    $sltool -e "show slave status\G;"|grep Running
  echo
  echo "Now Replication is Finished!"
  echo
  echo "**********************************************************"
    exit 2
fi

# ./slave_stop3307.sh 
*******************************
Now stop Slave Replication!
      Slave_IO_Running: No
     Slave_SQL_Running: No
*******************************
# ./slave_repl3307.sh 
Critical slave is error
*********************************************************
Now Starting replication with Master Mysql!
      Slave_IO_Running: Yes
     Slave_SQL_Running: Yes
Now Replication is Finished!
**********************************************************