CentOS下编写shell脚本来监控MySQL主从复制的教程

目的：定时监控MySQL主从数据库是否同步，如果不同步，记录故障时间，并执行命令使主从恢复同步状态
1、创建脚本文件

vi /home/crontab/check_mysql_slave.sh#编辑，添加下面代码

#！/bin/sh# check_mysql_slave statusip=eth0 #网卡名称mysql_binfile=/usr/local/mysql/bin/mysqlmysql_user=root #MySQL数据库账号mysql_pass=123456 #密码mysql_sockfile=/tmp/mysql.sockdatetime=`date +"%Y-%m-%d/%H:%M:%S"`#获取当前时间mysql_slave_logfile=/home/logs/check_mysql_slave.log#日志文件路径，必须提前创建好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 statusG" | 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！"elseecho " $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 #添加脚本执行权限

2、添加任务计划，修改/etc/crontab

vi /etc/crontab #在最后一行添加*/10 * * * * root /home/crontab/check_mysql_slave.sh #表示每10分钟执行一次:wq！ #保存退出

3、重新启动crond使设置生效

/etc/rc.d/init.d/crond restart#yum install -y vixie-cron安装计划任务，某些系统上可能没有预装chkconfig crond on #设为开机启动service crond start #启动

可以根据日志文件/home/logs/check_mysql_slave.log查看MySQL主从同步状态
PS：接下来这个脚本增加了“当发现同步出现无法同步的时候”会自动提取主库的file号，以及pos,进行同步主库，脚本内容如下：

#！/bin/sh#set -x#file is slave_repl.sh#Author by Kevin#date is 2011-11-13mstool="/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_statslave_stat=（$（$sltool -e "show slave statusG"|grep Running |awk "{print $2}"））if [ "${slave_stat[0]}" = "Yes" -a "${slave_stat[1]}" = "Yes" ] then echo "OK slave is running" exit 0else echo "Critical slave is error" echo echo "*********************************************************" echo "Now Starting replication with Master Mysql！"file=`$mstool -e "show master statusG"|grep "File"|awk "{print $2}"` pos=`$mstool -e "show master statusG"|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 statusG;"|grep Runningechoecho "Now Replication is Finished！"echoecho "**********************************************************"exit 2fi

运行后效果，如下：

# ./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: YesNow Replication is Finished！**********************************************************