巧用Mysqlbinlog恢复数据库数据

iyuytre

binlog日志用于记录所有更新了数据或者已经潜在更新了数据的所有语句。语句以“事件”的形式保存，它描述数据更改。当我们因为某种原因导致数据库出现故障时，就可以利用binlog日志来挽回（前提是已经配置好了binlog），接下来我们来配置

一、开启mysql-binlog日志
在mysql配置文件my.cnf加上如下配置
[mysqld]
log-bin=mysql-bin
binlog_do_db=bin_test

重启mysql
service mysqld restart


二、备份数据库

1）先查看一下当前数据库情况及binlog日志情况：
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| test |
+--------------------+
3 rows in set (0.00 sec)

mysql> show master status;
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000001 | 106 | bin_test | |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)


2）创建库及数据：bin_test

mysql> create database bin_test;
Query OK, 1 row affected (0.00 sec)

mysql> use bin_test;
Database changed
mysql> create table abc(id int(10) primary key auto_increment,name varchar(255));
Query OK, 0 rows affected (0.00 sec)

mysql> insert into abc(name) value('zhangsan');
Query OK, 1 row affected (0.00 sec)

mysql> insert into abc(name) value('lisi');
Query OK, 1 row affected (0.00 sec)

mysql> insert into abc(name) value('wangwu');
Query OK, 1 row affected (0.00 sec)

mysql> select * from abc;
+----+----------+
| id | name |
+----+----------+
| 1 | zhangsan |
| 2 | lisi |
| 3 | wangwu |
+----+----------+
3 rows in set (0.00 sec)


3）备份数据到/tmp/test.sql

[iyunv@localhost ~]# whereis mysqldump
mysqldump: /usr/bin/mysqldump /usr/share/man/man1/mysqldump.1.gz
[iyunv@localhost ~]# /usr/bin/mysqldump -uroot -p123456 bin_test > /tmp/test.sql


4）查看下binlog日志情况：

mysql> show binlog events in 'mysql-bin.000001';
+------------------+-----+-------------+-----------+-------------+-------------------------------------------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+-----+-------------+-----------+-------------+-------------------------------------------------------------------------------------------+
| mysql-bin.000001 | 4 | Format_desc | 1 | 106 | Server ver: 5.1.73-log, Binlog ver: 4 |
| mysql-bin.000001 | 106 | Query | 1 | 197 | create database bin_test |
| mysql-bin.000001 | 197 | Query | 1 | 337 | use `bin_test`; create table abc(id int(10) primary key auto_increment,name varchar(255)) |
| mysql-bin.000001 | 337 | Intvar | 1 | 365 | INSERT_ID=1 |
| mysql-bin.000001 | 365 | Query | 1 | 471 | use `bin_test`; insert into abc(name) value('zhangsan') |
| mysql-bin.000001 | 471 | Intvar | 1 | 499 | INSERT_ID=2 |
| mysql-bin.000001 | 499 | Query | 1 | 601 | use `bin_test`; insert into abc(name) value('lisi') |
| mysql-bin.000001 | 601 | Intvar | 1 | 629 | INSERT_ID=3 |
| mysql-bin.000001 | 629 | Query | 1 | 733 | use `bin_test`; insert into abc(name) value('wangwu') |
+------------------+-----+-------------+-----------+-------------+-------------------------------------------------------------------------------------------+
9 rows in set (0.00 sec)

三、这时模拟误操作（删除数据库）

此时突然数据库损坏或者人为删除

mysql> drop database bin_test;

Query OK, 1 row affected (0.00 sec)

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| test |
+--------------------+
3 rows in set (0.00 sec)


再查看下binlog日志有没有记录删库的操作：

mysql> show binlog events in "mysql-bin.000001";
+------------------+-----+-------------+-----------+-------------+-------------------------------------------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+-----+-------------+-----------+-------------+-------------------------------------------------------------------------------------------+
| mysql-bin.000001 | 4 | Format_desc | 1 | 106 | Server ver: 5.1.73-log, Binlog ver: 4 |
| mysql-bin.000001 | 106 | Query | 1 | 197 | create database bin_test |
| mysql-bin.000001 | 197 | Query | 1 | 337 | use `bin_test`; create table abc(id int(10) primary key auto_increment,name varchar(255)) |
| mysql-bin.000001 | 337 | Intvar | 1 | 365 | INSERT_ID=1 |
| mysql-bin.000001 | 365 | Query | 1 | 471 | use `bin_test`; insert into abc(name) value('zhangsan') |
| mysql-bin.000001 | 471 | Intvar | 1 | 499 | INSERT_ID=2 |
| mysql-bin.000001 | 499 | Query | 1 | 601 | use `bin_test`; insert into abc(name) value('lisi') |
| mysql-bin.000001 | 601 | Intvar | 1 | 629 | INSERT_ID=3 |
| mysql-bin.000001 | 629 | Query | 1 | 733 | use `bin_test`; insert into abc(name) value('wangwu') |
| mysql-bin.000001 | 733 | Query | 1 | 822 | drop database bin_test |
+------------------+-----+-------------+-----------+-------------+-------------------------------------------------------------------------------------------+
10 rows in set (0.00 sec)


可以看到第20条的操作为删除数据库的操作。



四、此时数据库已经被完全破坏

1）使用mysqlbinlog命令进行恢复；首先在恢复前要确认正确的position起始值与终止值：
mysql> show binlog events in "mysql-bin.000001";
+------------------+-----+-------------+-----------+-------------+-------------------------------------------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+-----+-------------+-----------+-------------+-------------------------------------------------------------------------------------------+
| mysql-bin.000001 | 4 | Format_desc | 1 | 106 | Server ver: 5.1.73-log, Binlog ver: 4 |
| mysql-bin.000001 | 106 | Query | 1 | 197 | create database bin_test |
| mysql-bin.000001 | 197 | Query | 1 | 337 | use `bin_test`; create table abc(id int(10) primary key auto_increment,name varchar(255)) |
| mysql-bin.000001 | 337 | Intvar | 1 | 365 | INSERT_ID=1 |
| mysql-bin.000001 | 365 | Query | 1 | 471 | use `bin_test`; insert into abc(name) value('zhangsan') |
| mysql-bin.000001 | 471 | Intvar | 1 | 499 | INSERT_ID=2 |
| mysql-bin.000001 | 499 | Query | 1 | 601 | use `bin_test`; insert into abc(name) value('lisi') |
| mysql-bin.000001 | 601 | Intvar | 1 | 629 | INSERT_ID=3 |
| mysql-bin.000001 | 629 | Query | 1 | 733 | use `bin_test`; insert into abc(name) value('wangwu') |
| mysql-bin.000001 | 733 | Query | 1 | 822 | drop database bin_test |
+------------------+-----+-------------+-----------+-------------+-------------------------------------------------------------------------------------------+
10 rows in set (0.00 sec)


此时我们已经确认“起始值”为创建库时的起始：106；"终止值"为drop库时的前一句的结束：733

2）使用mysqlbinlog进行恢复：
mysqlbinlog --no-defaults --start-position="106" --stop-position="733" /var/lib/mysql/mysql-bin.000001 |mysql -uroot -p
Enter password:

3）查看下数据是否恢复成功：

11mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| bin_test |
| mysql |
| test |
+--------------------+
4 rows in set (0.00 sec)

11mysql> select * from bin_test.abc;
+----+----------+
| id | name |
+----+----------+
| 1 | zhangsan |
| 2 | lisi |
| 3 | wangwu |
+----+----------+
3 rows in set (0.00 sec)

3）恢复成功

【总结】：mysql备份和bin-log日志

备份数据：
mysqldump -uroot -p123456 bin_test -l -F '/tmp/test.sql'
-l:读锁（只能读取，不能更新）
-F:即flush logs，可以重新生成新的日志文件，当然包括log-bin日志

查看binlog日志：
mysql>show master status
如果数据较多，先导入之前备份数据：

mysql -uroot -p123456 bin_test -v -f </tmp/test.sql
-v查看导入的详细信息
-f是当中间遇到错误时，可以skip过去，继续执行下面的语句

恢复binlog-file二进制日志文件：
mysqlbinlog --no-defaults binlog-file | mysql -uroot -p123456

从某一(567)点开始恢复：
mysqlbinlog --no-defaults --start-position="567" mysql-bin.000001| mysql -uroot -p123456 test

先查好那一点（用more来查看）
[iyunv@localhost mysql]# /usr/bin/mysqlbinlog --no-defaults mysql-bin.000001 --start-position="794" --stop-position="1055" | more

然后恢复：
[iyunv@localhost mysql]# /usr/bin/mysqlbinlog --no-defaults mysql-bin.000001 --start-position="794" --stop-position="1055" | /usr/bin/mysql -uroot -p123456 test

重置binlog日志
mysql> reset master;
Query OK, 0 rows affected (0.01 sec)

mysql> show master status;
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000001 | 106 | | |
+------------------+----------+--------------+------------------+
mysql> flush logs;#关闭当前的二进制日志文件并创建一个新文件，新的二进制日志文件的名字在当前的二进制文件的编号上加1。