不停mysql服务添加从库
存储引擎：Innodb
MySQL主从是基于binlog日志，所以在安装好数据库后就要开启binlog。这样好处是，一方面可以用binlog恢复数据库，另一方面可以为主从做准备。
原有主库配置参数如下：
# vi my.cnf server-id = 1 #id要唯一 log-bin = mysql-bin #开启binlog日志 auto-increment-increment = 1 #在Ubuntu系统中MySQL5.5以后已经默认是1 auto-increment-offset = 1 slave-skip-errors = all #跳过主从复制出现的错误
主库创建同步账号
mysql> grant all privileges on *.* to 'sync'@'%' IDENTIFIED BY 'sync';
从库配置MySQL
# vi my.cnf server-id = 3 #这个设置3 log-bin = mysql-bin #开启binlog日志 auto-increment-increment = 1 #这两个参数在Ubuntu系统中MySQL5.5以后都已经默认是1 auto-increment-offset = 1 slave-skip-errors = all #跳过主从复制出现的错误
xtrabackup方式（推荐）
在上面配置基础上做实验，先删除掉从库配置：
mysql> stop slave; #停止同步 mysql> reset slave; #清除从连接信息 mysql> show slave status\G; #再查看从状态，可以看到IO和SQL线程都为NO mysql> drop database weibo; #删除weibo库
此时，从库现在和新装的一样，继续前进！
1. 主库使用xtrabackup备份
wget https://www.percona.com/downloads/XtraBackup/Percona-XtraBackup-2.4.4/binary/redhat/7/x86_64/percona-xtrabackup-24-2.4.4-1.el7.x86_64.rpm
yum localinstall percona-xtrabackup-24-2.4.4-1.el7.x86_64.rpm -y
yum -y install perl-Digest-MD5
# innobackupex --user=root --password=123 ./
生成一个以时间为命名的备份目录：2015-07-01_16-49-43
# ll 2015-07-01_16-49-43/ total 18480 drwxr-xr-x 5 root root 4096 Jul 1 16:49 ./ drwx------ 4 root root 4096 Jul 1 16:49 ../ -rw-r--r-- 1 root root 188 Jul 1 16:49 backup-my.cnf -rw-r----- 1 root root 18874368 Jul 1 16:49 ibdata1 drwxr-xr-x 2 root root 4096 Jul 1 16:49 mysql/ drwxr-xr-x 2 root root 4096 Jul 1 16:49 performance_schema/ drwxr-xr-x 2 root root 12288 Jul 1 16:49 weibo/ -rw-r--r-- 1 root root 21 Jul 1 16:49 xtrabackup_binlog_info -rw-r----- 1 root root 89 Jul 1 16:49 xtrabackup_checkpoints -rw-r--r-- 1 root root 563 Jul 1 16:49 xtrabackup_info -rw-r----- 1 root root 2560 Jul 1 16:49 xtrabackup_logfile
2. 把备份目录拷贝到从库上
# scp -r 2015-07-01_16-49-43 root@192.168.18.214:/home/root
3. 从库上把MySQL服务停掉，删除datadir目录，将备份目录重命名为datadir目录
wget https://www.percona.com/downloads/XtraBackup/Percona-XtraBackup-2.4.4/binary/redhat/7/x86_64/percona-xtrabackup-24-2.4.4-1.el7.x86_64.rpm
yum localinstall percona-xtrabackup-24-2.4.4-1.el7.x86_64.rpm -y
innobackupex --defaults-file=/etc/my.cnf --apply-log /root/2021-08-25_15-15-26
innobackupex --defaults-file=/etc/my.cnf --copy-back /root/2021-08-25_15-15-26
# sudo chown mysql.mysql -R /var/lib/mysql # sudo /etc/init.d/mysql start # ps -ef |grep mysql #查看已经正常启动 mysql 8832 1 0 16:55 ? 00:00:00 /usr/sbin/mysqld
4. 在主库创建test_tb2表，模拟数据库新增数据
mysql> create table test_tb2(id int,name varchar(30));
5. 从备份目录中xtrabackup_info文件获取到binlog和pos位置
# cat /var/lib/mysql/xtrabackup_info uuid = 201af9db-1fce-11e5-96b0-525400e4239d name = tool_name = innobackupex tool_command = --user=root --password=... ./ tool_version = 1.5.1-xtrabackup ibbackup_version = xtrabackup version 2.2.11 based on MySQL server 5.6.24 Linux (x86_64) (revision id: ) server_version = 5.5.43-0ubuntu0.12.04.1-log start_time = 2015-07-01 16:49:43 end_time = 2015-07-01 16:49:46 lock_time = 1 binlog_pos = filename 'mysql-bin.000001', position 429 #这个位置 innodb_from_lsn = 0 innodb_to_lsn = 1598188 partial = N incremental = N format = file compact = N compressed = N
6. 从库设置从这个日志点同步，并启动
mysql> change master to master_host='192.168.18.212',master_user='sync',master_password='sync',master_log_file='mysql-bin.000001',master_log_pos=429 FOR CHANNEL 'Master_database_name'; mysql> start slave;
mysql> show slave status\G; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.18.212 Master_User: sync Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000001 Read_Master_Log_Pos: 539 Relay_Log_File: mysqld-relay-bin.000002 Relay_Log_Pos: 363 Relay_Master_Log_File: mysql-bin.000001 Slave_IO_Running: Yes Slave_SQL_Running: Yes ......
可以看到IO和SQL线程均为YES，说明主从配置成功。
9. 从库查看weibo库里面的表
mysql> show tables; +---------------------------+ | Tables_in_weibo | +---------------------------+ | test_tb | | test_tb2 |
发现刚才模拟创建的test_tb2表已经同步过来。
关闭slave 同步
stop slave;
reset slave all;
show slave status\G
reset slave for channel 'channel_name';
stop slave for channel 'channel_name';
更多Xtrabackup使用查看博文：http://lizhenliang.blog.51cto.com/7876557/1612800
