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 status ip=eth0 #网卡名称 mysql_binfile=/usr/local/mysql/bin/mysql mysql_user=root #mysql数据库账号 mysql_pass=123456 #密码 mysql_sockfile=/tmp/mysql.sock datetime=`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 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 $mysql_sockfile -e "exit" fi
:wq! #保存退出 chmod +x /home/crontab/check_mysql_slave.sh #添加脚本执行权限
2、添加任务计划，修改/etc/crontab
vi /etc/crontab #在最后一行添加 */10 * * * * root /home/crontab/check_mysql_slave.sh #表示每10分钟执行一次 :wq! #保存退出
3、重新启动crond使设置生效
/etc/rc.d/init.d/crond restart #yum install -y vixie-cron安装计划任务，某些系统上可能没有预装 chkconfig crond on #设为开机启动 service crond start #启动
可以根据日志文件/home/logs/check_mysql_slave.log查看mysql主从同步状态
ps：接下来这个脚本增加了“当发现同步出现无法同步的时候”会自动提取主库的file号，以及pos,进行同步主库，脚本内容如下：
#!/bin/sh #set -x #file is slave_repl.sh #author by kevin #date is 2011-11-13 mstool="/usr/local/mysql-3307/bin/mysql -h 192.168.1.106 -uroot -pw!zl7pog27 -p 3307" sltool="/usr/local/mysql-3307/bin/mysql -h 192.168.1.107 -uroot -pw!zl7pog27 -p 3307" declare -a slave_stat slave_stat=($($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
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: yes now replication is finished! **********************************************************
以上就是centos下编写shell脚本来监控mysql主从复制的教程_mysql的内容。