運維工作中難免會發生一些誤操作，當數據庫表被誤操作刪除需要緊急恢復，或者沒有備份時，Percona Data Recovery Tool for InnoDB這個工具也已提供一些便捷的恢復。
當然這個工具也有相當的限制：
1、只對innodb表有效
2、一旦發生誤操作，需要儘快停止對事故表的寫入，將idb文件拷貝出來
3、數據不一定總是能恢復，比如被重新寫入的情況等
原理簡述：
InnoDB的數據都是索引的方式組織的，而且所有的數據都是存儲在16KB的數據塊中。恢復的過程分幾步，分解所有數據文件爲單個16KB大小的頁面，根據每個頁面的標記的數據起點開始嘗試匹配，如果與給定表定義的size合適，認爲匹配成功，則輸出記錄。
操作步驟：
一、安裝編譯：
tar xvf percona-data-recovery-tool-for-innodb-0.5.tar.gz
...
[root@zabbix percona]# cd percona-data-recovery-tool-for-innodb-0.5
[root@zabbix percona-data-recovery-tool-for-innodb-0.5]# cd mysql-source/
[root@zabbix mysql-source]# ./configure
checking build system type... x86_64-unknown-linux-gnu
checking host system type... x86_64-unknown-linux-gnu
...
[root@zabbix percona-data-recovery-tool-for-innodb-0.5]# make
...
二、實驗數據：
mysql> create table luna (id int,name varchar(10),sex varchar(2),logtime date);
Query OK, 0 rows affected (0.10 sec)
mysql> insert into luna values(1,'kuja','m','1986-01-19');
Query OK, 1 row affected (0.00 sec)
mysql> insert into luna values(2,'ben','m','1986-01-19');
Query OK, 1 row affected (0.00 sec)
mysql> insert into luna values(3,'lulu','m','1986-01-19');
Query OK, 1 row affected (0.00 sec)
mysql> select * from luna;
+------+------+------+------------+
| id | name | sex | logtime |
+------+------+------+------------+
| 1 | kuja | m | 1986-01-19 |
| 2 | ben | m | 1986-01-19 |
| 3 | lulu | m | 1986-01-19 |
+------+------+------+------------+
3 rows in set (0.00 sec)
mysql> delete from luna;
Query OK, 3 rows affected (0.00 sec)
三、備份出要恢復表的idb文件並解析：
[root@zabbix percona-data-recovery-tool-for-innodb-0.5]# cp /usr/local/mysql/data/test/luna.ibd /app/qipai_data/kuja/percona/percona-data-recovery-tool-for-innodb-0.5
[root@zabbix percona-data-recovery-tool-for-innodb-0.5]# ./page_parser -5 -f luna.ibd
Opening file: luna.ibd:
64768 ID of device containing file
12419559 inode number
33184 protection
1 number of hard links
0 user ID of owner
0 group ID of owner
0 device ID (if special file)
98304 total size, in bytes
4096 blocksize for filesystem I/O
200 number of blocks allocated
1397468556 time of last access
1397468556 time of last modification
1397468590 time of last status change
98304 Size to process in bytes
104857600 Disk cache size in bytes
生成目錄：
drwxr-xr-x 3 root root 4096 Apr 14 17:43 pages-1397468622
四、生成表定義：
[root@zabbix percona-data-recovery-tool-for-innodb-0.5]# ./create_defs.pl --user=kuja --password=kuja --host=192.168.13.21 --db=test --table=luna >include/table_defs.h
[root@zabbix percona-data-recovery-tool-for-innodb-0.5]# make
gcc -DHAVE_OFFSET64_T -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE=1 -D_LARGEFILE_SOURCE=1 -Wall -O3 -g -I include -I mysql-source/include -I mysql-source/innobase/include -c tables_dict.c -o lib/tables_dict.o
gcc -DHAVE_OFFSET64_T -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE=1 -D_LARGEFILE_SOURCE=1 -Wall -O3 -g -I include -I mysql-source/include -I mysql-source/innobase/include -c print_data.c -o lib/print_data.o
gcc -DHAVE_OFFSET64_T -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE=1 -D_LARGEFILE_SOURCE=1 -Wall -O3 -g -I include -I mysql-source/include -I mysql-source/innobase/include -c check_data.c -o lib/check_data.o
gcc -DHAVE_OFFSET64_T -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE=1 -D_LARGEFILE_SOURCE=1 -Wall -O3 -g -I include -I mysql-source/include -I mysql-source/innobase/include -o constraints_parser constraints_parser.c lib/tables_dict.o lib/print_data.o lib/check_data.o lib/libut.a lib/libmystrings.a
gcc -DHAVE_OFFSET64_T -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE=1 -D_LARGEFILE_SOURCE=1 -Wall -O3 -g -I include -I mysql-source/include -I mysql-source/innobase/include -static -lrt -o page_parser page_parser.c lib/tables_dict.o lib/libut.a
五、將數據導入sql文件
[root@zabbix percona-data-recovery-tool-for-innodb-0.5]# ./constraints_parser -5 -D -f pages-1397468622/FIL_PAGE_INDEX/0-13394/0-00000003.page > /tmp/111.sql
LOAD DATA INFILE '/app/qipai_data/kuja/percona/percona-data-recovery-tool-for-innodb-0.5/dumps/default/luna' REPLACE INTO TABLE `luna` FIELDS TERMINATED BY '\t' OPTIONALLY ENCLOSED BY '"' LINES STARTING BY 'luna\t' (id, name, sex, logtime);
[root@zabbix percona-data-recovery-tool-for-innodb-0.5]# more /tmp/111.sql
luna 1 "kuja" "m" "1986-01-19"
luna 2 "ben" "m" "1986-01-19"
luna 3 "lulu" "m" "1986-01-19"
至此得到數據恢復文本。
六、附加參數釋義：
[root@zabbix percona-data-recovery-tool-for-innodb-0.5]# ./constraints_parser -h
Error: Usage: ./constraints_parser -4|-5 [-dDV] -f <InnoDB page or dir> [-T N:M] [-b <extrenal pages directory>]
Where
-f <InnoDB page(s)> -- InnoDB page or directory with pages
-h -- Print this help
-d -- Process only those pages which potentially could have deleted records (default = NO)
-D -- Recover deleted rows only (default = NO)
-U -- Recover UNdeleted rows only (default = NO)
-V -- Verbode mode (lots of debug information)
-4 -- innodb_datafile is in REDUNDANT format
-5 -- innodb_datafile is in COMPACT format
-T -- retrieves only pages with index id = NM (N - high word, M - low word of id)
-b <dir> -- Directory where external pages can be found. Usually it is pages-XXX/FIL_PAGE_TYPE_BLOB/
七、實驗中的碰到的問題：
生成表定義時報錯
[root@zabbix percona-data-recovery-tool-for-innodb-0.5]# ./create_defs.pl --db test --table luna >include/table_defs.h
install_driver(mysql) failed: Can't locate DBD/mysql.pm in @INC (@INC contains: /usr/lib64/perl5/site_perl/5.8.8/x86_64-linux-thread-multi /usr/lib/perl5/site_perl/5.8.8 /usr/lib/perl5/site_perl /usr/lib64/perl5/vendor_perl/5.8.8/x86_64-linux-thread-multi /usr/lib/perl5/vendor_perl/5.8.8 /usr/lib/perl5/vendor_perl /usr/lib64/perl5/5.8.8/x86_64-linux-thread-multi /usr/lib/perl5/5.8.8 .) at (eval 3) line 3.
Perhaps the DBD::mysql perl module hasn't been fully installed,
or perhaps the capitalisation of 'mysql' isn't right.
Available drivers: DBM, ExampleP, File, Proxy, Sponge.
at ./create_defs.pl line 37
該問題的原因是沒有安裝perl-DBD-MySQL
安裝後解決：
[root@zabbix include]# yum install perl-DBD-MySQL
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* addons: centos.ustc.edu.cn
* base: centos.ustc.edu.cn
* extras: centos.ustc.edu.cn
* updates: centos.ustc.edu.cn
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package perl-DBD-MySQL.x86_64 0:3.0007-2.el5 set to be updated
--> Finished Dependency Resolution
Dependencies Resolved
=====================================================================================================================================================================
Package Arch Version Repository Size
=====================================================================================================================================================================
Installing:
perl-DBD-MySQL x86_64 3.0007-2.el5 base 148 k
Transaction Summary
=====================================================================================================================================================================
Install 1 Package(s)
Update 0 Package(s)
Remove 0 Package(s)
Total download size: 148 k
Is this ok [y/N]: y
Downloading Packages:
perl-DBD-MySQL-3.0007-2.el5.x86_64.rpm | 148 kB 00:00
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : perl-DBD-MySQL 1/1
Installed:
perl-DBD-MySQL.x86_64 0:3.0007-2.el5
Complete!