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
以上摘自官方文檔對Xtrabackup的描述。
Xtrabackup是Percona公司的開源mysql熱備軟件,軟件自身支持完全備份和增量備份,功能強大,使用簡單,且備份結束會自動檢查備份的可用性。對於InnoDB和XtraDB可以實現無阻塞的備份。
Xtrabackup會在備份目錄下自動生成以當前日期和時間爲名的目錄,目錄下包含當前備份所有數據文件和豐富的當前備份時的狀態信息。
實例演示:
xtrabackup的安裝,安裝包可從官網下載http://www.percona.com/software/percona-xtrabackup,官方提供了二進制和源碼包,根據自己需要下載
/* 下載官方的rpm包安裝,xtrabackup要依賴perl-DBD-mysql包,不想手動解決依賴關係可以yum localinstall安裝 */ [root@console ~]# yum localinstall --nogpgcheck percona-xtrabackup-2.1.4-656.rhel6.x86_64.rpm -y /* xtrabackup安裝後生成的文件不多 */ [root@console ~]# rpm -ql percona-xtrabackup /usr/bin/innobackupex /* 備份時用的命令,會根據mysql版本自動調用xtrabackup_{55,56} */ /usr/bin/innobackupex-1.5.1 /usr/bin/xbcrypt /* 提供備份過程加密支持 */ /usr/bin/xbstream /* 支持流式備份 */ /usr/bin/xtrabackup /usr/bin/xtrabackup_55 / * 這個和下面那個纔是備份過程實際調用的備份程序 */ /usr/bin/xtrabackup_56 /usr/share/doc/percona-xtrabackup-2.1.4 /usr/share/doc/percona-xtrabackup-2.1.4/COPYING /* 文檔只有一個軟件授權文件,沒有man文檔,不過--help給出的幫助信息也比較豐富 */
備份過程:
/* 在庫db1中準備一張表tb1,做效果比較用 */ 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) /* 創建一個用於備份的最小權限的用戶 */ 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)
現在先做一次完全備份:
/* 全備只需指定用於備份的用戶名、密碼和備份路徑即可,最後出現innobackupex: completed OK! 則代表備份成功 */ [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! /* 看一下備份都生成了哪些文件,除了數據庫文件外還多了一些文件,注意由於我用root登陸系統,備份後的文件屬主屬組都是root,恢復後要改爲運行mysqld進程的用戶,不然mysql起不來 */ [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 /* 備份命令用到的配置選項信息 */ 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 /* 記錄備份過程實際用的備份程序 */ -rw-r--r--. 1 root root 24 Jul 31 09:27 xtrabackup_binlog_info /* 記錄備份時的二進制日誌文件和當前的位置 */ -rw-r-----. 1 root root 89 Jul 31 09:27 xtrabackup_checkpoints /* 記錄備份類型、 狀態(是否prepared)、是否壓縮、備份的LSN(Log Sequence Number日誌序列號)範圍等信息 */ -rw-r-----. 1 root root 2560 Jul 31 09:27 xtrabackup_logfile /* xtrabackup自己的日誌文件,新版本中不直接可見 */ [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
全備完成後,對數據庫做一些修改後再做一次增備:
/* 第一次增量備份,--incremental 備份類型爲增量, --incremental-basedir 指定這次增備是相對哪一個備份做的增量,這裏是相對全備 */ [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,做第二次增備 */ 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 相對第一次增量的增量 */ [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! /* 第二次增備完成後,再做一些數據修改操作,以模擬實際生產環境數據庫突然崩潰場景 */ MariaDB [db1]> INSERT INTO tb1 (Name,Gender) VALUES ('Kangshifu Guamian','O'); Query OK, 1 row affected (0.04 sec) /* 將二進制日誌備份出來一份,生產環境中二進制日誌切記不要和數據文件放在一起, 最好不要在同一分區甚至同一物理磁盤, 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/ /* 人工讓數據庫徹底崩盤 */ [root@node1 innobackup]# service mysqld stop Shutting down MySQL.. [ OK ] [root@node1 innobackup]# rm -rf /mydata/data/*
恢復:
xtrabackup的恢復比較特殊,恢復前要先執行prepare過程,prepare主要完成把已提交的事務數據同步到數據文件,未完成的事務則回滾,這是對於只有一個完全備份來說。當還需要結合其他的增備時,則在些過程只需要將已提交的事務同步,未提交的事務則不用回滾,因爲在本次備份時未提交的事務可能會在下一備份中已經提交,以避免這種無謂的勞動。
/* 注意 backup_type 和 to_lsn的變化 */ [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全備,--apply-log 指定要prepare, --redo-only 只處理已提交事務,未提交的事務則不回滾 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 增備1, --incremental-dir 增備的路徑 */ [root@node1 innobackup]# innobackupex --apply-log --redo-only /innobackup/2014-07-31_09-27-36/ --incremental-dir /innobackup/2014-07-31_11-51-19/ /* 再來看full backup 的 to_lsn 已經 --> 增備1 的 to_lsn了,此時增量1也就退出舞臺了 */ [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 增備2,增量1已經prepare上去了,所以基準還是全備,--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/ /* 完事後再瞅一眼,全備的 to_lsn 已經 --> 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,恢復的預準備工作已完成,兩個增備也完成了歷史使命,恢復只要用全備的一個就可以了:
/* 恢復過程灰常簡單,恢復過程也不需要啓動mysql, 但是備份過程是一定要啓動mysql的,因爲要以備份用戶身份連到Mysql上的嘛 */ [root@node1 innobackup]# innobackupex --copy-back /innobackup/2014-07-31_09-27-36/ /* 現在還不能啓動mysql, 對了,屬主屬組還沒改 */ [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/* /* 現在就可以啓動了 。。 */ [root@node1 innobackup]# service mysqld start Starting MySQL..... [ OK ] /* 正常啓動,數據都在 */ 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)
再加上最後的二進制日誌恢復,整個恢復過程就全搞顛了
[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) /* 二進制日誌恢復,kangshifu guamian finnaly O 出鍋了 */
To be continued ...