Percona XtraBackup is the world’s only open-source, free MySQL hot backup software that performs non-blocking backups for InnoDB and XtraDB databases. With Percona XtraBackup, you can achieve the following benefits:
Backups that complete quickly and reliably
Uninterrupted transaction processing during backups
Savings on disk space and network bandwidth
Automatic backup verification
Higher uptime due to faster restore time
以上摘自官方文档对Xtrabackup的描述。
Xtrabackup是Percona公司的开源mysql热备软件，软件自身支持完全备份和增量备份，功能强大，使用简单，且备份结束会自动检查备份的可用性。对于InnoDB和XtraDB可以实现无阻塞的备份。
Xtrabackup会在备份目录下自动生成以当前日期和时间为名的目录，目录下包含当前备份所有数据文件和丰富的当前备份时的状态信息。
实例演示：
xtrabackup的安装，安装包可从官网下载http://www.percona.com/software/percona-xtrabackup，官方提供了二进制和源码包，根据自己需要下载
/* 下载官方的rpm包安装，xtrabackup要依赖perl-DBD-mysql包，不想手动解决依赖关系可以yum localinstall安装 */
[root@console ~]# yum localinstall --nogpgcheck percona-xtrabackup-2.1.4-656.rhel6.x86_64.rpm -y
/* xtrabackup安装后生成的文件不多 */
[root@console ~]# rpm -ql percona-xtrabackup
/usr/bin/innobackupex /* 备份时用的命令,会根据mysql版本自动调用xtrabackup_{55,56} */
/usr/bin/innobackupex-1.5.1
/usr/bin/xbcrypt /* 提供备份过程加密支持 */
/usr/bin/xbstream /* 支持流式备份 */
/usr/bin/xtrabackup
/usr/bin/xtrabackup_55 / * 这个和下面那个才是备份过程实际调用的备份程序 */
/usr/bin/xtrabackup_56
/usr/share/doc/percona-xtrabackup-2.1.4
/usr/share/doc/percona-xtrabackup-2.1.4/COPYING /* 文档只有一个软件授权文件，没有man文档，不过--help给出的帮助信息也比较丰富 */
备份过程：
/* 在库db1中准备一张表tb1，做效果比较用 */ MariaDB [(none)]> CREATE DATABASE db1; Query OK, 1 row affected (0.00 sec) MariaDB [(none)]> USE db1 Database changed MariaDB [db1]> CREATE TABLE `tb1` ( `id` int(11) NOT NULL AUTO_INCREMENT, `Name` varchar(30) NOT NULL, `Gender` enum(‘F‘,‘M‘,‘O‘) NOT NULL, PRIMARY KEY (`id`) ); Query OK, 0 rows affected (0.22 sec) MariaDB [db1]> DESC tb1; +--------+-------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +--------+-------------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | Name | varchar(30) | NO | | NULL | | | Gender | enum(‘F‘,‘M‘,‘O‘) | NO | | NULL | | +--------+-------------------+------+-----+---------+----------------+ 3 rows in set (0.00 sec) MariaDB [db1]> INSERT INTO tb1 (Name,Gender) VALUES (‘Tom‘,‘M‘),(‘Jerry‘,‘F‘); Query OK, 2 rows affected (0.05 sec) Records: 2 Duplicates: 0 Warnings: 0 MariaDB [db1]> SELECT * FROM tb1; +----+-------+--------+ | id | Name | Gender | +----+-------+--------+ | 1 | Tom | M | | 2 | Jerry | F | +----+-------+--------+ 2 rows in set (0.00 sec) /* 创建一个用于备份的最小权限的用户 */ MariaDB [(none)]> CREATE USER ‘bakuser‘@‘localhost‘ IDENTIFIED BY ‘backupass‘; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> REVOKE ALL PRIVILEGES,GRANT OPTION FROM ‘bakuser‘@‘localhost‘; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> GRANT RELOAD,LOCK TABLES,REPLICATION CLIENT ON *.* TO ‘bakuser‘@‘localhost‘; Query OK, 0 rows affected (0.00 sec)
现在先做一次完全备份：
/* 全备只需指定用于备份的用户名、密码和备份路径即可，最后出现innobackupex: completed OK! 则代表备份成功 */ [root@node1 ~]# innobackupex --user=bakuser --password=backupass /innobackup/ innobackupex: Backup created in directory ‘/innobackup/2014-07-31_09-27-36‘ innobackupex: MySQL binlog position: filename ‘mysql-bin.000001‘, position 1270 140731 09:27:39 innobackupex: Connection to database server closed 140731 09:27:40 innobackupex: completed OK! /* 看一下备份都生成了哪些文件,除了数据库文件外还多了一些文件，注意由于我用root登陆系统，备份后的文件属主属组都是root，恢复后要改为运行mysqld进程的用户，不然mysql起不来 */ [root@node1 ~]# cd /innobackup/2014-07-31_09-27-36/ [root@node1 2014-07-31_09-27-36]# ll total 18476 -rw-r--r--. 1 root root 260 Jul 31 09:27 backup-my.cnf /* 备份命令用到的配置选项信息 */ drwx------. 2 root root 4096 Jul 31 09:27 db1 drwx------. 2 root root 4096 Jul 31 09:27 hellodb -rw-r-----. 1 root root 18874368 Jul 31 09:27 ibdata1 drwx------. 2 root root 4096 Jul 31 09:27 mydb drwxr-xr-x. 2 root root 4096 Jul 31 09:27 mysql drwxr-xr-x. 2 root root 4096 Jul 31 09:27 performance_schema drwxr-xr-x. 2 root root 4096 Jul 31 09:27 test -rw-r--r--. 1 root root 13 Jul 31 09:27 xtrabackup_binary /* 记录备份过程实际用的备份程序 */ -rw-r--r--. 1 root root 24 Jul 31 09:27 xtrabackup_binlog_info /* 记录备份时的二进制日志文件和当前的位置 */ -rw-r-----. 1 root root 89 Jul 31 09:27 xtrabackup_checkpoints /* 记录备份类型、 状态（是否prepared)、是否压缩、备份的LSN(Log Serial Number日志序列号）范围等信息 */ -rw-r-----. 1 root root 2560 Jul 31 09:27 xtrabackup_logfile /* xtrabackup自己的日志文件，新版本中不直接可见 */ [root@node1 2014-07-31_09-27-36]# cat backup-my.cnf # This MySQL options file was generated by innobackupex. # The MySQL server [mysqld] innodb_data_file_path=ibdata1:10M:autoextend innodb_log_files_in_group=2 innodb_log_file_size=5242880 innodb_fast_checksum=0 innodb_page_size=16384 innodb_log_block_size=512 [root@node1 2014-07-31_09-27-36]# cat xtrabackup_binary xtrabackup_55[root@node1 2014-07-31_09-27-36]# [root@node1 2014-07-31_09-27-36]# cat xtrabackup_binlog_info mysql-bin.000001 1270 [root@node1 2014-07-31_09-27-36]# cat xtrabackup_checkpoints backup_type = full-backuped from_lsn = 0 to_lsn = 1660869 last_lsn = 1660869 compact = 0 [root@node1 2014-07-31_09-27-36]# file xtrabackup_logfile xtrabackup_logfile: data
全备完成后，对数据库做一些修改后再做一次增备：
/* 第一次增量备份,--incremental 备份类型为增量， --incremental-basedir 指定这次增备是相对哪一个备份做的增量,这里是相对全备 */ [root@node1 innobackup]# innobackupex --user=bakuser --password=backupass --incremental /innobackup/ --incremental-basedir=/innobackup/2014-07-31_09-27-36/ innobackupex: Backup created in directory ‘/innobackup/2014-07-31_11-51-19‘ innobackupex: MySQL binlog position: filename ‘mysql-bin.000001‘, position 1525 140731 11:51:48 innobackupex: Connection to database server closed 140731 11:51:48 innobackupex: completed OK! /* 做些修改，做第二次增备 */ MariaDB [db1]> DELETE FROM tb1 WHERE Name=‘Tom‘; Query OK, 1 row affected (0.09 sec) MariaDB [db1]> UPDATE tb1 SET Gender=‘F‘ WHERE Name=‘Dongfang Bubai‘; Query OK, 1 row affected (0.02 sec) Rows matched: 1 Changed: 1 Warnings: 0 MariaDB [db1]> SELECT * FROM tb1; +----+----------------+--------+ | id | Name | Gender | +----+----------------+--------+ | 2 | Jerry | F | | 3 | Bob | M | | 4 | Dongfang Bubai | F | +----+----------------+--------+ 3 rows in set (0.00 sec) /* incremental-basedir 相对第一次增量的增量 */ [root@node1 innobackup]# innobackupex --user=bakuser --password=backupass --incremental /innobackup/ --incremental-basedir=/innobackup/2014-07-31_11-51-19/ innobackupex: Backup created in directory ‘/innobackup/2014-07-31_11-59-29‘ innobackupex: MySQL binlog position: filename ‘mysql-bin.000001‘, position 1922 140731 11:59:33 innobackupex: Connection to database server closed 140731 11:59:33 innobackupex: completed OK! /* 第二次增备完成后，再做一些数据修改操作，以模拟实际生产环境数据库突然崩溃场景 */ MariaDB [db1]> INSERT INTO tb1 (Name,Gender) VALUES (‘Kangshifu Guamian‘,‘O‘); Query OK, 1 row affected (0.04 sec) /* 将二进制日志备份出来一份，生产环境中二进制日志切记不要和数据文件放在一起， 最好不要在同一分区甚至同一物理磁盘, 以免一旦玉石俱焚，悔之晚矣 */ [root@node1 innobackup]# mysql -e ‘SHOW MASTER STATUS;‘ +------------------+----------+--------------+------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | +------------------+----------+--------------+------------------+ | mysql-bin.000001 | 2168 | | | +------------------+----------+--------------+------------------+ [root@node1 innobackup]# cp /mydata/data/ aria_log.00000001 hellodb/ ib_logfile1 mysql-bin.000001 node1.bob.org.pid aria_log_control ibdata1 mydb/ mysql-bin.index performance_schema/ db1/ ib_logfile0 mysql/ node1.bob.org.err test/ [root@node1 innobackup]# cp /mydata/data/mysql-bin.000001 /innobackup/ /* 人工让数据库彻底崩盘 */ [root@node1 innobackup]# service mysqld stop Shutting down MySQL.. [ OK ] [root@node1 innobackup]# rm -rf /mydata/data/*
恢复：
xtrabackup的恢复比较特殊，恢复前要先执行prepare过程，prepare主要完成把已提交的事务数据同步到数据文件，未完成的事务则回滚，这是对于只有一个完全备份来说。当还需要结合其他的增备时，则在些过程只需要将已提交的事务同步，未提交的事务则不用回滚，因为在本次备份时未提交的事务可能会在下一备份中已经提交，以避免这种无谓的劳动。
/* 注意 backup_type 和 to_lsn的变化 */ [root@node1 innobackup]# cat 2014-07-31_09-27-36/xtrabackup_checkpoints backup_type = full-backuped from_lsn = 0 to_lsn = 1660869 last_lsn = 1660869 compact = 0 /* Prepare全备,--apply-log 指定要prepare, --redo-only 只处理已事务 backup_type由full-backuped --> full-prepared */ [root@node1 innobackup]# innobackupex --apply-log --redo-only /innobackup/2014-07-31_09-27-36/ ... 140731 15:05:53 innobackupex: completed OK! [root@node1 innobackup]# cat 2014-07-31_09-27-36/xtrabackup_checkpoints backup_type = full-prepared from_lsn = 0 to_lsn = 1660869 last_lsn = 1660869 compact = 0 /* prepare 增备1， --incremental-dir 增备的路径 */ [root@node1 innobackup]# innobackupex --apply-log --redo-only /innobackup/2014-07-31_09-27-36/ --incremental-dir /innobackup/2014-07-31_11-51-19/ /* 再来看full backup 的 to_lsn 已经 --> 增备1 的 to_lsn了，此时增量1也就退出舞台了 */ [root@node1 innobackup]# cat 2014-07-31_11-51-19/xtrabackup_checkpoints backup_type = incremental from_lsn = 1660869 to_lsn = 1661993 last_lsn = 1661993 compact = 0 [root@node1 innobackup]# cat 2014-07-31_09-27-36/xtrabackup_checkpoints backup_type = full-prepared from_lsn = 0 to_lsn = 1661993 last_lsn = 1661993 compact = 0 /* prepare 增备2，增量1已经prepare上去了，所以基准还是全备，--incremental-dir 指向增量2 */ [root@node1 innobackup]# innobackupex --apply-log /innobackup/2014-07-31_09-27-36/ --incremental-dir=/innobackup/2014-07-31_11-59-29/ /* 完事后再瞅一眼，全备的 to_lsn 已经 --> 增量2 的了 */ [root@node1 innobackup]# cat 2014-07-31_09-27-36/xtrabackup_checkpoints backup_type = full-prepared from_lsn = 0 to_lsn = 1664255 last_lsn = 1664255 compact = 0 [root@node1 innobackup]# cat 2014-07-31_11-59-29/xtrabackup_checkpoints backup_type = incremental from_lsn = 1661993 to_lsn = 1664255 last_lsn = 1664255 compact = 0
至此，恢复的预准备工作已完成，两个增备也完成了历史使命，恢复只要用全备的一个就可以了：
/* 恢复过程灰常简单，恢复过程也不需要启动mysql, 但是备份过程是一定要启动mysql的，因为要以备份用户身份连到Mysql上的嘛 */ [root@node1 innobackup]# innobackupex --copy-back /innobackup/2014-07-31_09-27-36/ /* 现在还不能启动mysql, 对了，属主属组还没改 */ [root@node1 innobackup]# ll /mydata/data/ total 18456 drwxr-xr-x. 2 root root 4096 Jul 31 15:54 db1 drwxr-xr-x. 2 root root 4096 Jul 31 15:54 hellodb -rw-r--r--. 1 root root 18874368 Jul 31 15:54 ibdata1 drwxr-xr-x. 2 root root 4096 Jul 31 15:54 mydb drwxr-xr-x. 2 root root 4096 Jul 31 15:54 mysql drwxr-xr-x. 2 root root 4096 Jul 31 15:54 performance_schema drwxr-xr-x. 2 root root 4096 Jul 31 15:54 test [root@node1 innobackup]# chown -R mysql.mysql /mydata/data/* /* 现在就可以启动了 。。 */ [root@node1 innobackup]# service mysqld start Starting MySQL..... [ OK ] /* 正常启动，数据都在 */ MariaDB [db1]> SELECT * FROM tb1; +----+----------------+--------+ | id | Name | Gender | +----+----------------+--------+ | 2 | Jerry | F | | 3 | Bob | M | | 4 | Dongfang Bubai | F | +----+----------------+--------+ 3 rows in set (0.00 sec)
再加上最后的二进制日志恢复，整个恢复过程就全搞颠了
[root@node1 innobackup]# cat /innobackup/2014-07-31_11-59-29/xtrabackup_binlog_info mysql-bin.000001 1922 [root@node1 innobackup]# mysqlbinlog --start-position=1922 mysql-bin.000001 > 11.sql [root@node1 innobackup]# mysql < 11.sql MariaDB [(none)]> SELECT * FROM db1.tb1; +----+-------------------+--------+ | id | Name | Gender | +----+-------------------+--------+ | 2 | Jerry | F | | 3 | Bob | M | | 4 | Dongfang Bubai | F | | 5 | Kangshifu Guamian | O | +----+-------------------+--------+ 4 rows in set (0.01 sec) /* 二进制日志恢复，kangshifu guamian finnaly O 出锅了 */
To be continued ...
本文出自 “不懂IT的中医不是好IT” 博客，请务必保留此出处http://zhishen.blog.51cto.com/1612050/1533319