基于binlog二进制日志的MySQL恢复笔记
刚好复习到这里,顺手做个小实验,记录下。
总的操作流程:
step0、关掉数据库的对外访问【防止用户操作继续写入这个库】
step1、mysqlbinlog 导出相关时间段数据库的二进制日志
step2、编辑today.sql找到误操作的那几条数据,删除并保存。
step3、执行全备份恢复 mysql -e 'source /root/backup.sql;'
step4、用二进制日志恢复今天的修改 mysql -e 'source /root/today.sql;'
step5、登录mysql,验证数据是否回来了。
原始数据库某表的内容如下:
MariaDB [hellodb]> select * from students;
+-------+---------------+-----+--------+---------+-----------+
| StuID | Name | Age | Gender | ClassID | TeacherID |
+-------+---------------+-----+--------+---------+-----------+
| 1 | Shi Zhongyu | 22 | M | 2 | 3 |
| 2 | Shi Potian | 22 | M | 1 | 7 |
| 3 | Xie Yanke | 53 | M | 2 | 16 |
| 4 | Ding Dian | 32 | M | 4 | 4 |
| 5 | Yu Yutong | 26 | M | 3 | 1 |
| 6 | Shi Qing | 46 | M | 5 | NULL |
| 7 | Xi Ren | 19 | F | 3 | NULL |
| 8 | Lin Daiyu | 17 | F | 7 | NULL |
| 9 | Ren Yingying | 20 | F | 6 | NULL |
| 10 | Yue Lingshan | 19 | F | 3 | NULL |
| 11 | Yuan Chengzhi | 23 | M | 6 | NULL |
| 12 | Wen Qingqing | 19 | F | 1 | NULL |
| 13 | Tian Boguang | 33 | M | 2 | NULL |
| 14 | Lu Wushuang | 17 | F | 3 | NULL |
| 15 | Duan Yu | 19 | M | 4 | NULL |
+-------+---------------+-----+--------+---------+-----------+
备份了下数据,备份为backup.sql,模拟当做前一天的全备份文件。
然后随便进行了一些操作,如下:
INSERT INTO students VALUES(30,'lee',21,'M',2,1);
DELETE FROM students where `StuID`=10;
update students set age=10 where `StuID`=1;
执行后效果如下:
MariaDB [hellodb]> select * from students;
+-------+---------------+-----+--------+---------+-----------+
| StuID | Name | Age | Gender | ClassID | TeacherID |
+-------+---------------+-----+--------+---------+-----------+
| 1 | Shi Zhongyu | 10 | M | 2 | 3 |
| 2 | Shi Potian | 22 | M | 1 | 7 |
| 3 | Xie Yanke | 53 | M | 2 | 16 |
| 4 | Ding Dian | 32 | M | 4 | 4 |
| 5 | Yu Yutong | 26 | M | 3 | 1 |
| 6 | Shi Qing | 46 | M | 5 | NULL |
| 7 | Xi Ren | 19 | F | 3 | NULL |
| 8 | Lin Daiyu | 17 | F | 7 | NULL |
| 9 | Ren Yingying | 20 | F | 6 | NULL |
| 11 | Yuan Chengzhi | 23 | M | 6 | NULL |
| 12 | Wen Qingqing | 19 | F | 1 | NULL |
| 13 | Tian Boguang | 33 | M | 2 | NULL |
| 14 | Lu Wushuang | 17 | F | 3 | NULL |
| 15 | Duan Yu | 19 | M | 4 | NULL |
| 30 | lee | 21 | M | 2 | 1 |
+-------+---------------+-----+--------+---------+-----------+
假如突然DBA发现刚才的DELETE不应该执行,必需要恢复这条数据。
step0、这时候,首先,我们要关掉数据库对外访问的权限,防止有用户写入数据,干扰恢复操作。
(可以修改前端的web连接数据库的文件,将其改到其它从节点,虽然用户无法写,但最起码比网站无法访问要强些)
step1、先提取出误操作这段时间的二进制日志,取名为today.sql,如下:
mysqlbinlog --start-datetime='2016-07-12 23:51:48' --stop-datetime='2016-07-12 23:53:00' \
/usr/local/mariadb/var/mysql-bin.000033 > /root/today.sql
step2、编辑这个today.sql,找到刚才的那条DELETE操作,剔除DELETE语句,保存退出。
step3、用全备份backup.sql恢复数据:
mysql -e 'source backup.sql;'
恢复完的效果如下:
MariaDB [hellodb]> select * from students;
+-------+---------------+-----+--------+---------+-----------+
| StuID | Name | Age | Gender | ClassID | TeacherID |
+-------+---------------+-----+--------+---------+-----------+
| 1 | Shi Zhongyu | 22 | M | 2 | 3 |
| 2 | Shi Potian | 22 | M | 1 | 7 |
| 3 | Xie Yanke | 53 | M | 2 | 16 |
| 4 | Ding Dian | 32 | M | 4 | 4 |
| 5 | Yu Yutong | 26 | M | 3 | 1 |
| 6 | Shi Qing | 46 | M | 5 | NULL |
| 7 | Xi Ren | 19 | F | 3 | NULL |
| 8 | Lin Daiyu | 17 | F | 7 | NULL |
| 9 | Ren Yingying | 20 | F | 6 | NULL |
| 10 | Yue Lingshan | 19 | F | 3 | NULL |
| 11 | Yuan Chengzhi | 23 | M | 6 | NULL |
| 12 | Wen Qingqing | 19 | F | 1 | NULL |
| 13 | Tian Boguang | 33 | M | 2 | NULL |
| 14 | Lu Wushuang | 17 | F | 3 | NULL |
| 15 | Duan Yu | 19 | M | 4 | NULL |
+-------+---------------+-----+--------+---------+-----------+
15 rows in set (0.00 sec)
可以看到第一天数据又恢复了最原始的状态,第10条数据又恢复回来了,但是INSERT的那条数据却没有了,因此我们还要使用二进制日志继续恢复。
step4、继续用二进制日志恢复:
mysql -e 'source today.sql;'
step5、查看恢复后的结果:
恢复完的效果如下:
MariaDB [hellodb]> select * from students;
+-------+---------------+-----+--------+---------+-----------+
| StuID | Name | Age | Gender | ClassID | TeacherID |
+-------+---------------+-----+--------+---------+-----------+
| 1 | Shi Zhongyu | 10 | M | 2 | 3 |
| 2 | Shi Potian | 22 | M | 1 | 7 |
| 3 | Xie Yanke | 53 | M | 2 | 16 |
| 4 | Ding Dian | 32 | M | 4 | 4 |
| 5 | Yu Yutong | 26 | M | 3 | 1 |
| 6 | Shi Qing | 46 | M | 5 | NULL |
| 7 | Xi Ren | 19 | F | 3 | NULL |
| 8 | Lin Daiyu | 17 | F | 7 | NULL |
| 9 | Ren Yingying | 20 | F | 6 | NULL |
| 10 | Yue Lingshan | 19 | F | 3 | NULL |
| 11 | Yuan Chengzhi | 23 | M | 6 | NULL |
| 12 | Wen Qingqing | 19 | F | 1 | NULL |
| 13 | Tian Boguang | 33 | M | 2 | NULL |
| 14 | Lu Wushuang | 17 | F | 3 | NULL |
| 15 | Duan Yu | 19 | M | 4 | NULL |
| 30 | lee | 21 | M | 2 | 1 |
+-------+---------------+-----+--------+---------+-----------+
16 rows in set (0.00 sec)
可以看到,第一条数据的Age已经改为我们要求的值了,INSERT的最后一条数据也恢复回来了, 误删除的StuID为10的数据也恢复了。
至此,我们的恢复就完成了。