在前面的文章中我們介紹了MySQL誤操作后數據恢復(update,delete忘加where條件),大概操作是通過sed命令把binlog中相關SQL誤操作給逆向回來，然后導入SQL文件來恢復錯誤操作，sed相關命令也比較復雜。如果沒有正則基礎的同學肯定搞不清楚在干嘛。今天無意中發現淘寶的大神（翻譯高性能mysql第三版的作者之一）開發了一個補丁，該補丁能夠模擬Oracle的閃回操作，這樣以來我們的MySQL也可以實現閃回咯。真是給力。注意：同樣binlog格式需要是ROW
項目主頁：http://mysql.taobao.org/index.php/Patch_source_code#Add_flashback_feature_for_mysqlbinlog
測試過程
1.給mysql打補丁，該補丁是針對mysql 5.5.18的版本，我測試的mysql 5.5.25版本也可以。（也可以使用我編譯好了的，64位平台下的，在文中最后會有下載地址）
wget http://mysql.taobao.org/images/0/0f/5.5.18_flashback.diff cd /usr/local/src/mysql-5.5.25a/ patch -p0 < /root/5.5.18_flashback.diff cmake -DCMAKE_INSTALL_PREFIX=/usr/local/mysql make && make install
2.檢查補丁是否應用成功，如果mysqlbinlog命令多了-B選項，那么就ok了。
[root@yayun-mysql-server ~]# mysqlbinlog --help | grep '\-B' -B, --flashback Flashback data to start_postition or start_datetime. [root@yayun-mysql-server ~]#
3.模擬誤操作（update忘記加where條件）
(root@yayun-mysql-server) [test]> select * from tb1; +------+--------+ | id | name | +------+--------+ | 1 | yayun | | 2 | atlas | | 3 | dyy | | 4 | nginx | | 5 | apache | +------+--------+ 5 rows in set (0.00 sec) (root@yayun-mysql-server) [test]> update tb1 set name='yayun'; Query OK, 4 rows affected (0.03 sec) Rows matched: 5 Changed: 4 Warnings: 0 (root@yayun-mysql-server) [test]> select * from tb1; +------+-------+ | id | name | +------+-------+ | 1 | yayun | | 2 | yayun | | 3 | yayun | | 4 | yayun | | 5 | yayun | +------+-------+ 5 rows in set (0.00 sec) (root@yayun-mysql-server) [test]>
4.開始恢復
（1）首先需要找出錯誤的操作語句以及position點。
(root@yayun-mysql-server) [test]> show master status; +------------------+----------+--------------+------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | +------------------+----------+--------------+------------------+ | mysql-bin.000023 | 364 | | | +------------------+----------+--------------+------------------+ 1 row in set (0.00 sec) (root@yayun-mysql-server) [test]>
可見現在正在使用的是mysql-bin.000023這個binlog
[root@yayun-mysql-server mysql]# mysqlbinlog -vv mysql-bin.000023 |egrep -i -C 20 'update|tb1' # Warning: this binlog is either in use or was not closed properly. BINLOG ' RgZoUw8BAAAAZwAAAGsAAAABAAQANS41LjI1YS1sb2cAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAEzgNAAgAEgAEBAQEEgAAVAAEGggAAAAICAgCAA== '/*!*/; # at 107 #140506 5:45:21 server id 1 end_log_pos 175 Query thread_id=3 exec_time=0 error_code=0 SET TIMESTAMP=1399326321/*!*/; SET @@session.pseudo_thread_id=3/*!*/; SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/; SET @@session.sql_mode=0/*!*/; SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/; /*!\C utf8 *//*!*/; SET @@session.character_set_client=33,@@session.collation_connection=33,@@session.collation_server=33/*!*/; SET @@session.lc_time_names=0/*!*/; SET @@session.collation_database=DEFAULT/*!*/; BEGIN /*!*/; # at 175 # at 220 #140506 5:45:21 server id 1 end_log_pos 220 Table_map: `test`.`tb1` mapped to number 35 #140506 5:45:21 server id 1 end_log_pos 337 Update_rows: table id 35 flags: STMT_END_F BINLOG ' cQZoUxMBAAAALQAAANwAAAAAACMAAAAAAAEABHRlc3QAA3RiMQACAw8CPAAD cQZoUxgBAAAAdQAAAFEBAAAAACMAAAAAAAEAAv///AIAAAAFYXRsYXP8AgAAAAV5YXl1bvwDAAAA A2R5efwDAAAABXlheXVu/AQAAAAFbmdpbnj8BAAAAAV5YXl1bvwFAAAABmFwYWNoZfwFAAAABXlh eXVu '/*!*/; ### UPDATE test.tb1 ### WHERE ### @1=2 /* INT meta=0 nullable=1 is_null=0 */ ### @2='atlas' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */ ### SET ### @1=2 /* INT meta=0 nullable=1 is_null=0 */ ### @2='yayun' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */ ### UPDATE test.tb1 ### WHERE ### @1=3 /* INT meta=0 nullable=1 is_null=0 */ ### @2='dyy' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */ ### SET ### @1=3 /* INT meta=0 nullable=1 is_null=0 */ ### @2='yayun' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */ ### UPDATE test.tb1 ### WHERE ### @1=4 /* INT meta=0 nullable=1 is_null=0 */ ### @2='nginx' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */ ### SET ### @1=4 /* INT meta=0 nullable=1 is_null=0 */ ### @2='yayun' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */ ### UPDATE test.tb1 ### WHERE ### @1=5 /* INT meta=0 nullable=1 is_null=0 */ ### @2='apache' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */ ### SET ### @1=5 /* INT meta=0 nullable=1 is_null=0 */ ### @2='yayun' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */ # at 337 #140506 5:45:21 server id 1 end_log_pos 364 Xid = 40 COMMIT/*!*/; DELIMITER ; # End of log file ROLLBACK /* added by mysqlbinlog */; /*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
開始的起點以107為准，因為107下面緊跟着BEGIN，結束的點以end_log_pos 337下一個點為准.
[root@yayun-mysql-server mysql]# mysqlbinlog -vv --start-position=337 mysql-bin.000023 /*!40019 SET @@session.max_insert_delayed_threads=0*/; /*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/; DELIMITER /*!*/; # at 4 #140506 5:44:38 server id 1 end_log_pos 107 Start: binlog v 4, server v 5.5.25a-log created 140506 5:44:38 # Warning: this binlog is either in use or was not closed properly. BINLOG ' RgZoUw8BAAAAZwAAAGsAAAABAAQANS41LjI1YS1sb2cAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAEzgNAAgAEgAEBAQEEgAAVAAEGggAAAAICAgCAA== '/*!*/; # at 337 #140506 5:45:21 server id 1 end_log_pos 364 Xid = 40 COMMIT/*!*/; DELIMITER ; # End of log file ROLLBACK /* added by mysqlbinlog */; /*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/; [root@yayun-mysql-server mysql]#
上面藍色字體顯示的很清楚了，那么結束的點就是364，因為下面緊跟着COMMIT。現在我們已經找到了日志開始起點為107，結束點為364，下面開始恢復。
[root@yayun-mysql-server mysql]# mysqlbinlog -B -vv --start-position=107 --stop-position=364 mysql-bin.000023 | mysql [root@yayun-mysql-server mysql]#
檢查是否恢復成功：
(root@yayun-mysql-server) [test]> select * from tb1; +------+--------+ | id | name | +------+--------+ | 1 | yayun | | 2 | atlas | | 3 | dyy | | 4 | nginx | | 5 | apache | +------+--------+ 5 rows in set (0.00 sec) (root@yayun-mysql-server) [test]>
可見數據已經成功恢復。其實原理和我們前面通過sed操作binlog進行恢復是一樣的。只是這個更簡單。對於delete忘記添加where條件，恢復方法是一樣的。這里不再重復。
總結:
binlog格式非常重要，無論是數據恢復還是主從復制，ROW格式都非常的給力。當然也有缺點，復制會占用過多帶寬，消耗大量磁盤空間。
已經應用補丁的mysqlbinlog下載地址（64位平台，直接替換原來的即可）