咱们目前所用到的在Mysql master不停机状况下做同步操作的支流工具都是 XtraBackup 包含阿里云、腾讯都是采纳此工具来备份解压。
MySQL主从同步原理：
MySQL主从同步是在MySQL主从复制(Master-Slave Replication)根底上实现的，通过设置在Master MySQL上的binlog(使其处于关上状态)，Slave MySQL上通过一个I/O线程从Master MySQL上读取binlog，而后传输到Slave MySQL的中继日志中，而后Slave MySQL的SQL线程从中继日志中读取中继日志，而后利用到Slave MySQL的数据库中。
XtraBackup备份原理：
innobackupex在后盾线程一直追踪InnoDB的日志文件，而后复制InnoDB的数据文件。数据文件复制实现之后，日志的复制线程也会完结。这样就失去了不在同一时间点的数据正本和开始备份当前的事务日志。实现下面的步骤之后，就能够应用InnoDB解体复原代码执行事务日志（redo log），以达到数据的一致性。
备份过程
1 ) backup，备份阶段，追踪事务日志和复制数据文件（物理备份）。
2 ) preparing，重放事务日志，使所有的数据处于同一个工夫点，达到一致性状态。
XtraBackup的长处：
1）备份速度快，物理备份牢靠
2）备份过程不会打断正在执行的事务（无需锁表）
3）可能基于压缩等性能节约磁盘空间和流量
4）主动备份校验
5）还原速度快
6）能够流传将备份传输到另外一台机器上
7）在不减少服务器负载的状况备份数据
xtrabackup装置
[root@localhost opt]# yum -y install perl perl-devel libaio libaio-devel perl-Time-HiRes perl-DBD-MySQL libev-devel rsync perl-Digest-MD5
Centos 6
[root@localhost opt]# wget https://www.percona.com/downl...
[root@localhost opt]# yum --enablerepo=epel localinstall percona-xtrabackup-2.3.2-1.el6.x86_64.rpm -y
Centos 7
[root@localhost opt]# wget https://downloads.percona.com...
[root@localhost opt]# rpm -ivh percona-xtrabackup-24-2.4.22-1.el7.x86_64.rpm -y
[root@localhost opt]# whereis innobackupex
innobackupex: /usr/bin/innobackupex /usr/share/man/man1/innobackupex.1.gz
备份数据库
[root@localhost opt]# innobackupex --defaults-file=/etc/my.cnf --user=账户 --password=明码 --socket=/home/mysql/mysql.sock /home/BackupData/"
复原数据库
注： 核查mysql的版本尽量保障数据库版本一致性。
slave机器上操作
[root@localhost opt]#mkdir 20210831_00[root@localhost opt]#ll 20210831_00.tar.gz -rw-r--r-- 1 root root 508147921 Aug 31 08:53 20210831_00.tar.gz[root@localhost opt]#tar -zxf 20210831_00.tar.gz -C ./20210831_00/[root@localhost opt]# ls -l ./20210831_00-rw-rw---- 1 root root 484 Aug 31 00:23 backup-my.cnf-rw-rw---- 1 root root 104857600 Aug 31 00:06 ibdata1drwxr-xr-x 2 root root 4096 Aug 31 14:25 mysqldrwxr-xr-x 2 root root 4096 Aug 31 14:25 performance_schema-rw-rw---- 1 root root 75 Aug 31 00:23 xtrabackup_binlog_info-rw-rw---- 1 root root 147 Aug 31 00:23 xtrabackup_checkpoints-rw-rw---- 1 root root 641 Aug 31 00:23 xtrabackup_info-rw-rw---- 1 root root 2747392 Aug 31 00:23 xtrabackup_logfile在Mysql的数据库配置文件中，指定的数据寄存目录创立对应文件夹
如：配置文件配置的 datadir = /home/mysql
[root@localhost home]# mkdir /home/mysql复原日志文件
[root@localhost home]# innobackupex --defaults-file=/etc/my.cnf --user=root --password=123123 --apply-log /opt/20210831_00InnoDB: Renaming log file ./ib_logfile101 to ./ib_logfile0InnoDB: New log files created, LSN=62456861898InnoDB: Highest supported file format is Barracuda.InnoDB: Log scan progressed past the checkpoint lsn 62456862220InnoDB: Doing recovery: scanned up to log sequence number 62456862229 (0%)InnoDB: Database was not shutdown normally!InnoDB: Starting crash recovery.InnoDB: xtrabackup: Last MySQL binlog file position 338527434, file name mysql-bin.000153InnoDB: Removed temporary tablespace data file: "ibtmp1"InnoDB: Creating shared tablespace for temporary tablesInnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...InnoDB: File './ibtmp1' size is now 12 MB.InnoDB: 96 redo rollback segment(s) found. 1 redo rollback segment(s) are active.InnoDB: 32 non-redo rollback segment(s) are active.InnoDB: page_cleaner: 1000ms intended loop took 15111ms. The settings might not be optimal. (flushed=0 and evicted=0, during the time.)InnoDB: 5.7.32 started; log sequence number 62456862229xtrabackup: starting shutdown with innodb_fast_shutdown = 1InnoDB: FTS optimize thread exiting.InnoDB: Starting shutdown...InnoDB: Shutdown completed; log sequence number 62456862248210831 14:37:52 completed OK!呈现 completed OK!才示意胜利解压实现
复原数据文件
[root@localhost home]# innobackupex --defaults-file=/etc/my.cnf --user=root --password=mopon123 --copy-back /opt/20210831_00210831 14:55:39 [01] ...done210831 14:55:39 [01] Copying ./xtrabackup_master_key_id to /home/mysql/xtrabackup_master_key_id210831 14:55:39 [01] ...done210831 14:55:39 [01] Copying ./ibtmp1 to /home/mysql/ibtmp1210831 14:55:39 [01] ...done210831 14:55:39 completed OK!completed OK! 后果为此提醒示意复原正确！！！
[root@localhost home]# chown -R mysql. mysql/[root@localhost home]# /etc/init.d/mysqld startStarting MySQL (Percona Server)............ SUCCESS!开始同步主库
[root@localhost home]#cat /opt/20210831_00/xtrabackup_binlog_infomysql-bin.000153 338527434 526b9441-6616-11eb-8737-005056b05ba7:1-77041081[root@localhost home]#mysql -uroot -p123456MySQL [(none)]> change master to master_host='192.168.0.1',master_user='slave',master_password='slave',master_log_file='mysql-bin.000153', master_log_pos=338527434;Query OK, 0 rows affected, 2 warnings (0.78 sec)MySQL [(none)]> start slave;MySQL [(none)]> show slave status\G;..................... Slave_IO_Running: Yes Slave_SQL_Running: Yes............................到此为止数据库在Mstar不停机状态下同步实现！