add example mysql-rollback
This commit is contained in:
danfengcao
parent
84d5a3be0a
commit
939b29269d
|
|
@ -85,6 +85,8 @@ DELETE FROM `test`.`test4` WHERE `data`='World' AND `id`=1 AND `data2`='Hello' L
|
|||
|
||||
#### **案例一 跑错SQL，需要紧急回滚**
|
||||
|
||||
详细描述可参见[example/mysql-rollback-your-data.md](./example/mysql-rollback-your-data.md)
|
||||
|
||||
**背景**：误删test库c表的数据，需要紧急回滚。
|
||||
|
||||
**步骤**：
|
||||
|
|
|
|||
|
|
@ -0,0 +1,134 @@
|
|||
MySQL误操作后如何快速回滚
|
||||
========================
|
||||
|
||||
基本上每个跟数据库打交道的程序员（当然也可能是你同事）都会碰一个问题，MySQL误操作后如何快速回滚？比如，delete一张表，忘加限制条件，整张表没了。假如这还是线上环境核心业务数据，那这事就闹大了。误操作后，能快速回滚数据是非常重要的。
|
||||
|
||||
binlog2sql快速回滚
|
||||
===
|
||||
首先，确认你的MySQL server开启了binlog，设置了以下参数:
|
||||
|
||||
[mysqld]
|
||||
server-id = 1
|
||||
log_bin = /var/log/mysql/mysql-bin.log
|
||||
max_binlog_size = 1000M
|
||||
binlog-format = row
|
||||
如果没有开启binlog，也没有预先生成回滚SQL，那真的无法快速回滚了。对存放重要业务数据的MySQL，强烈建议开启binlog。
|
||||
|
||||
随后，安装开源工具[binlog2sql](https://github.com/danfengcao/binlog2sql)。binlog2sql是一款简单易用的binlog解析工具，其中一个功能就是生成回滚SQL。
|
||||
|
||||
```
|
||||
git clone https://github.com/danfengcao/binlog2sql.git
|
||||
pip install -r requirements.txt
|
||||
```
|
||||
|
||||
然后，我们就可以生成回滚SQL了。
|
||||
|
||||
**背景**：误删了test库f表整张表的数据，需要紧急回滚。
|
||||
|
||||
```bash
|
||||
原有数据
|
||||
mysql> select * from f;
|
||||
+-----+-----+---------------------+
|
||||
| uid | did | updateTime |
|
||||
+-----+-----+---------------------+
|
||||
| 1 | 18 | 2016-12-06 12:28:18 |
|
||||
| 2 | 19 | 2016-12-06 12:55:56 |
|
||||
| 3 | 20 | 2016-12-07 14:00:58 |
|
||||
| 4 | 21 | 2016-12-07 14:01:00 |
|
||||
+-----+-----+---------------------+
|
||||
|
||||
误操作
|
||||
mysql> delete from f;
|
||||
Query OK, 4 rows affected (0.00 sec)
|
||||
|
||||
f表被清空
|
||||
mysql> select * from f;
|
||||
Empty set (0.00 sec)
|
||||
```
|
||||
|
||||
**回滚步骤**：
|
||||
|
||||
1. 登录mysql，查看目前的binlog文件
|
||||
|
||||
```bash
|
||||
mysql> show master logs;
|
||||
+------------------+-----------+
|
||||
| Log_name | File_size |
|
||||
+------------------+-----------+
|
||||
| mysql-bin.000001 | 12262268 |
|
||||
| mysql-bin.000002 | 132776 |
|
||||
+------------------+-----------+
|
||||
```
|
||||
|
||||
2. 最新的binlog文件是mysql-bin.000002，我们再定位误操作SQL的binlog位置
|
||||
|
||||
```bash
|
||||
$ python binlog2sql/binlog2sql.py -h127.0.0.1 -P3306 -uadmin -p'admin' -dtest -t f --start-file='mysql-bin.000002'
|
||||
|
||||
输出：
|
||||
DELETE FROM `test`.`f` WHERE `did`=18 AND `updateTime`='2016-12-06 12:28:18' AND `uid`=1 LIMIT 1; #start 4 end 314
|
||||
DELETE FROM `test`.`f` WHERE `did`=19 AND `updateTime`='2016-12-06 12:55:56' AND `uid`=2 LIMIT 1; #start 4 end 314
|
||||
DELETE FROM `test`.`f` WHERE `did`=20 AND `updateTime`='2016-12-07 14:00:58' AND `uid`=3 LIMIT 1; #start 4 end 314
|
||||
DELETE FROM `test`.`f` WHERE `did`=21 AND `updateTime`='2016-12-07 14:01:00' AND `uid`=4 LIMIT 1; #start 4 end 314
|
||||
```
|
||||
2. 生成回滚sql，并检查回滚sql是否正确
|
||||
|
||||
```bash
|
||||
$ python binlog2sql/binlog2sql.py -h127.0.0.1 -P3306 -uadmin -p'admin' -dtest -t f --start-file='mysql-bin.000002' --start-pos=4 --end-pos=314 -B
|
||||
|
||||
输出：
|
||||
INSERT INTO `test`.`f`(`did`, `updateTime`, `uid`) VALUES (21, '2016-12-07 14:01:00', 4); #start 4 end 314
|
||||
INSERT INTO `test`.`f`(`did`, `updateTime`, `uid`) VALUES (20, '2016-12-07 14:00:58', 3); #start 4 end 314
|
||||
INSERT INTO `test`.`f`(`did`, `updateTime`, `uid`) VALUES (19, '2016-12-06 12:55:56', 2); #start 4 end 314
|
||||
INSERT INTO `test`.`f`(`did`, `updateTime`, `uid`) VALUES (18, '2016-12-06 12:28:18', 1); #start 4 end 314
|
||||
```
|
||||
3. 确认回滚sql正确，执行回滚语句。登录mysql，数据回滚成功。
|
||||
|
||||
```bash
|
||||
$ python binlog2sql.py -h127.0.0.1 -P3306 -uadmin -p'admin' -dtest -t f --start-file='mysql-bin.000002' --start-pos=4 --end-pos=314 -B | mysql -h127.0.0.1 -P3306 -uadmin -p'admin'
|
||||
|
||||
mysql> select * from f;
|
||||
+-----+-----+---------------------+
|
||||
| uid | did | updateTime |
|
||||
+-----+-----+---------------------+
|
||||
| 1 | 18 | 2016-12-06 12:28:18 |
|
||||
| 2 | 19 | 2016-12-06 12:55:56 |
|
||||
| 3 | 20 | 2016-12-07 14:00:58 |
|
||||
| 4 | 21 | 2016-12-07 14:01:00 |
|
||||
+-----+-----+---------------------+
|
||||
|
||||
```
|
||||
|
||||
至此，不用再担心被炒鱿鱼了。
|
||||
|
||||
常见问题
|
||||
===
|
||||
* 有人会问，我DDL误操作了怎么快速回滚？比如drop了一张大表。
|
||||
|
||||
> 很难做到。因为即使在在row模式下，DDL操作也不会把每行数据的变化记录到binlog，所以DDL无法通过binlog回滚。实现DDL回滚，必须要在执行DDL前先备份老数据。确实有人通过修改mysql server源码实现了DDL的快速回滚，我找到阿里的xiaobin lin提交了一个patch。但据我所知，国内很少有互联网公司应用了这个特性。原因的话，我认为最主要还是懒的去折腾，没必要搞这个低频功能，次要原因是会增加一些额外存储。
|
||||
>
|
||||
所以，DDL误操作的话一般只能通过备份来恢复。如果公司连备份也不能用了，那真的建议去买张飞机票了。干啥？跑呗
|
||||
|
||||
* mysql除了[binlog2sql](https://github.com/danfengcao/binlog2sql)，是否还有其他回滚工具？
|
||||
|
||||
>当然有。阿里彭立勋对mysqlbinlog增加了flashback的特性，这应该是mysql最早有的flashback功能，彭解决的是DML的回滚，并说明了利用binlog进行DML闪回的设计思路。DDL回滚特性也是由阿里团队提出并实现的。这两个功能是有创新精神的，此后出现的闪回工具基本都是对上面两者的模仿。另外，去哪儿开源的Inception是一套MySQL自动化运维工具，这个就比较重了，支持DML回滚，还不是从binlog回滚的，是从备份回滚的，也支持DDL回滚表结构，数据是回滚不了滴~
|
||||
|
||||
本文如有任何错误，烦请告知。如有mysql回滚相关的优秀工具优秀文章遗漏，更烦请告知
|
||||
|
||||
我的邮箱 danfengcao.info@gmail.com
|
||||
|
||||
|
||||
参考资料
|
||||
==============
|
||||
[1] 彭立勋, [MySQL下实现闪回的设计思路](http://www.penglixun.com/tech/database/mysql_flashback_feature.html)
|
||||
|
||||
[2] Lixun Peng, [Provide the flashback feature by binlog](https://bugs.mysql.com/bug.php?id=65178)
|
||||
|
||||
[3] 丁奇, [MySQL闪回方案讨论及实现](http://dinglin.iteye.com/blog/1539167)
|
||||
|
||||
[4] xiaobin lin, [flashback from binlog for MySQL](https://bugs.mysql.com/bug.php?id=65861)
|
||||
|
||||
[5] 王竹峰, [去哪儿inception](https://github.com/mysql-inception/inception)
|
||||
|
||||
[6] danfengcao, [binlog2sql: Parse MySQL binlog to SQL you want](https://github.com/danfengcao/binlog2sql)
|
||||
|
||||
Loading…
Reference in New Issue