MySQL备份与恢复之percona-xtrabackup实现增量备份及恢复

loinooo

一 文章回顾
在上一篇文章，我们讲到percona-xtrabackup软件的使用，这一篇文章我们讲解percona-xtrabackup实现增量备份及恢复。

二 增量备份示意图


三 percona-xtrabackup实现增量备份及恢复原理

首先，使用percona-xtrabackup工具对数据库进行全备，然后再每次数据库的数据更新后对数据进行增量备份，每次增量备份均在上一次备份的基础上。恢复时依次把每次增量备份的数据恢复到全备中，最后使用合并的数据进行数据恢复。

四 percona-xtrabackup实现增量备份及恢复

第一步，全备
[iyunv@serv01 databackup]# innobackupex --user=root --password=123456 /databackup/

第二步，查看数据
mysql> use larrydb;
Database changed
mysql> select * from class;
+------+-------+
| cid  | cname |
+------+-------+
|    1 | linux |
|    2 | dab   |
|    3 | Devel |
+------+-------+
3 rows in set (0.00 sec)

mysql> select * from stu;
+------+----------+------+
| sid  | sname    | cid  |
+------+----------+------+
|    1 | larry007 |    1 |
+------+----------+------+
1 row in set (0.00 sec)

第三步，更新数据
mysql> insert into stu values(2,'larry02',1);
Query OK, 1 row affected (0.00 sec)

mysql> select * from stu;
+------+----------+------+
| sid  | sname    | cid  |
+------+----------+------+
|    1 | larry007 |    1 |
|    2 | larry02  |    1 |
+------+----------+------+
2 rows in set (0.00 sec)

第四步，增量备份，进行了全备和第一次增量备份，所以有两个备份文件夹。我们每次增量备份都是针对上一次备份。
#--incremental：增量备份的文件夹
#--incremental-dir：针对哪个做增量备份
[iyunv@serv01 databackup]# innobackupex --user=root --password=123456 --incremental /databackup/ --incremental-dir /databackup/2013-09-10_22-12-50/

InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona Inc 2009-2012.  All Rights Reserved.
……
innobackupex: Backup created in directory '/databackup/2013-09-10_22-15-45'
innobackupex: MySQL binlog position: filename 'mysql-bin.000004', position 353
130910 22:16:04  innobackupex: completed OK!

[iyunv@serv01 databackup]# ll
total 8
drwxr-xr-x. 9 root root 4096 Sep 10 22:13 2013-09-10_22-12-50
drwxr-xr-x. 9 root root 4096 Sep 10 22:16 2013-09-10_22-15-45

第五步，再次插入数据
mysql> insert into stu values(3,'larry03',1);
Query OK, 1 row affected (0.00 sec)

mysql> select * from stu;
+------+----------+------+
| sid  | sname    | cid  |
+------+----------+------+
|    1 | larry007 |    1 |
|    2 | larry02  |    1 |
|    3 | larry03  |    1 |
+------+----------+------+
3 rows in set (0.00 sec)

第六步，再次增量备份
[iyunv@serv01 databackup]# ll
total 8
drwxr-xr-x. 9 root root 4096 Sep 10 22:13 2013-09-10_22-12-50
drwxr-xr-x. 9 root root 4096 Sep 10 22:16 2013-09-10_22-15-45
[iyunv@serv01 databackup]# innobackupex --user=root --password=123456 --incremental /databackup/ --incremental-dir /databackup/2013-09-10_22-15-45/

第七步，再次插入数据
mysql> insert into stu values(4,'larry04',1);
Query OK, 1 row affected (0.00 sec)

mysql> select * from stu;
+------+----------+------+
| sid  | sname    | cid  |
+------+----------+------+
|    1 | larry007 |    1 |
|    2 | larry02  |    1 |
|    3 | larry03  |    1 |
|    4 | larry04  |    1 |
+------+----------+------+
4 rows in set (0.00 sec)

第八步，再次增量备份。一次全备，三次增量备份，所以有四个备份文件夹
[iyunv@serv01 databackup]# innobackupex --user=root --password=123456 --incremental /databackup/ --incremental-dir /databackup/2013-09-10_22-19-21/


[iyunv@serv01 databackup]# ll
total 16
drwxr-xr-x. 9 root root 4096 Sep 10 22:13 2013-09-10_22-12-50
drwxr-xr-x. 9 root root 4096 Sep 10 22:16 2013-09-10_22-15-45
drwxr-xr-x. 9 root root 4096 Sep 10 22:19 2013-09-10_22-19-21
drwxr-xr-x. 9 root root 4096 Sep 10 22:22 2013-09-10_22-21-42

第九步，模拟数据丢失
mysql> drop database larrydb;
Query OK, 2 rows affected (0.02 sec)

第十步，对全部的数据进行检查。可以看到增量备份和全备的文件占用磁盘大小有很大的差别，显然全备占用磁盘空间多，增量备份占用磁盘空间少
[iyunv@serv01 databackup]# innobackupex --apply-log --redo-only /databackup/2013-09-10_22-12-50/

InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona Inc 2009-2012.  All Rights Reserved.
……
xtrabackup: starting shutdown with innodb_fast_shutdown = 1
130910 22:23:35  InnoDB: Starting shutdown...
130910 22:23:36  InnoDB: Shutdown completed; log sequence number 2098700
130910 22:23:36  innobackupex: completed OK!

[iyunv@serv01 databackup]# du -sh ./*
22M ./2013-09-10_22-12-50
1.5M  ./2013-09-10_22-15-45
1.5M  ./2013-09-10_22-19-21
1.5M  ./2013-09-10_22-21-42

第十一步，对第一次做的增量备份数据进行合并到全备份中去
[iyunv@serv01 databackup]# innobackupex --apply-log --redo-only --incremental /databackup/2013-09-10_22-12-50/ --incremental-dir=/databackup/2013-09-10_22-15-45/

InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona Inc 2009-2012.  All Rights Reserved.
……
innobackupex: Copying '/databackup/2013-09-10_22-15-45/hello/db.opt' to '/databackup/2013-09-10_22-12-50/hello/db.opt'
130910 22:32:26  innobackupex: completed OK!

第十二步，对第二次做的增量备份数据进行合并到全备份中去
[iyunv@serv01 databackup]# innobackupex --apply-log --redo-only --incremental /databackup/2013-09-10_22-12-50/ --incremental-dir=/databackup/2013-09-10_22-19-21/

第十三步，对第三次做的增量备份数据进行合并到全备份中去
[iyunv@serv01 databackup]# innobackupex --apply-log --redo-only --incremental /databackup/2013-09-10_22-12-50/ --incremental-dir=/databackup/2013-09-10_22-21-42/

第十四步，恢复时需要停掉MySQL，所以我们停掉MySQL
[iyunv@serv01 databackup]# /etc/init.d/mysqld stop
ERROR! MySQL server PID file could not be found!
[iyunv@serv01 databackup]# pkill -9 mysql

第十五步，恢复数据。注意这里指定的文件夹是2013-09-10_22-12-50
[iyunv@serv01 databackup]# innobackupex --copy-back /databackup/2013-09-10_22-12-50/

InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona Inc 2009-2012.  All Rights Reserved.

This software is published under
the GNU GENERAL PUBLIC LICENSE Version 2, June 1991.

IMPORTANT: Please check that the copy-back run completes successfully.
           At the end of a successful copy-back run innobackupex
           prints "completed OK!".

Original data directory is not empty! at /usr/bin/innobackupex line 571.

#报以上错需要删除数据目录下的东西
[iyunv@serv01 data]# pwd
/usr/local/mysql/data
[iyunv@serv01 data]# ls
game     ib_logfile0  mysql             mysql-bin.000003  performance_schema   test
hello    ib_logfile1  mysql-bin.000001  mysql-bin.000004  serv01.host.com.err  xtrabackup_binlog_pos_innodb
ibdata1  mnt          mysql-bin.000002  mysql-bin.index   serv01.host.com.pid

[iyunv@serv01 data]# rm -rf  *

#再次恢复数据，并更改数据库数据目录的拥有者和所属组
[iyunv@serv01 databackup]# innobackupex --copy-back /databackup/2013-09-10_22-12-50/

[iyunv@serv01 data]# ll
total 18464
drwxr-xr-x. 2 root root     4096 Sep 10 22:37 game
drwxr-xr-x. 2 root root     4096 Sep 10 22:37 hello
-rw-r-----. 1 root root 18874368 Sep 10 22:33 ibdata1
drwxr-xr-x. 2 root root     4096 Sep 10 22:37 larrydb
drwxr-xr-x. 2 root root     4096 Sep 10 22:37 mnt
drwxr-xr-x. 2 root root     4096 Sep 10 22:37 mysql
drwxr-xr-x. 2 root root     4096 Sep 10 22:37 performance_schema
drwxr-xr-x. 2 root root     4096 Sep 10 22:37 test
-rw-r--r--. 1 root root       24 Sep 10 22:37 xtrabackup_binlog_pos_innodb

[iyunv@serv01 data]# chown mysql.mysql /usr/local/mysql/data/ -R

第十六步，启动服务
[iyunv@serv01 data]# /etc/init.d/mysqld start
Starting MySQL.. SUCCESS!

第十七步，登录数据库，然后查看数据
[iyunv@serv01 data]# mysql -uroot -p123456
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| game               |
| hello              |
| larrydb            |
| mnt                |
| mysql              |
| performance_schema |
| test               |
+--------------------+
8 rows in set (0.00 sec)

mysql> select * from larrydb.class;
+------+-------+
| cid  | cname |
+------+-------+
|    1 | linux |
|    2 | dab   |
|    3 | Devel |
+------+-------+
3 rows in set (0.00 sec)

mysql> select * from larrydb.stu;
+------+----------+------+
| sid  | sname    | cid  |
+------+----------+------+
|    1 | larry007 |    1 |
|    2 | larry02  |    1 |
|    3 | larry03  |    1 |
|    4 | larry04  |    1 |
+------+----------+------+
4 rows in set (0.00 sec)

蓝晶灵

﹏回忆像一杯苦咖啡加多少糖还是苦的。