MySQL-binlog日志查询和恢复-数据库技术

利用binlog恢复库表：

• 启用binlog日志
• 创建db1库tb1表，插入3条记录
• 删除tb1表中刚插入的3条记录
• 使用mysqlbinlog恢复删除的3条记录

步骤一：启用binlog日志

1）调整/etc/my.cnf配置，并重启服务

[root@zhangyx ~]# vim  /etc/my.cnf
[mysqld]
.. ..
log-bin-index=mysql-bin                              //启用二进制日志，并指定前缀
server_id=1
binlog_format=STATEMENT
//在Mysql5.7中，binlog日志格式默认为ROW，但它不记录sql语句上下文相关信息。需要将binlog日志格式修改为STATEMENT
.. ..
[root@zhangyx ~]# systemctl  restart mysqld.service

2）确认binlog日志文件

新启用binlog后，每次启动MySQl服务都会新生成一份日志文件：

[root@zhangyx ~]# ls /var/lib/mysql/mysql-bin.*
/var/lib/mysql/mysql-bin.000001  /var/lib/mysql/mysql-bin.index

其中mysql-bin.index文件记录了当前保持的二进制文件列表：

[root@zhangyx ~]# cat /var/lib/mysql/mysql-bin.index
./mysql-bin.000001

重启MySQL服务程序，或者执行SQL操作“FLUSH LOGS;”，会生成一份新的日志：

[root@zhangyx ~]# ls /var/lib/mysql/mysql-bin.*
/var/lib/mysql/mysql-bin.000001  /var/lib/mysql/mysql-bin.index/var/lib/mysql/mysql-bin.000002

[root@zhangyx ~]# cat /var/lib/mysql/mysql-bin.index
./mysql-bin.000001./mysql-bin.000002

步骤二：利用binlog日志重做数据库操作

1）执行数据库表添加操作

创建db1•库tb1表，表结构自定义：

mysql> CREATE DATABASE db1;
Query OK, 1 row affected (0.05 sec)

mysql> USE db1;
Database changed
mysql> CREATE TABLE tb1(
-> id int(4) NOT NULL,name varchar(24)
-> );
Query OK, 0 rows affected (0.28 sec)

插入3条表记录：

mysql> INSERT INTO tb1 VALUES
-> (1,'Jack'),
-> (2,'Kenthy'),
-> (3,'Bob');
Query OK, 3 rows affected (0.12 sec)
Records: 3  Duplicates: 0  Warnings: 0

确认插入的表记录数据：

mysql> SELECT * FROM tb1;
+----+--------+
| id | name   |
+----+--------+
|  1 | Jack   |
|  2 | Kenthy |
|  3 | Bob    |
+----+--------+
3 rows in set (0.00 sec)

2）删除前一步添加的3条表记录

执行删除所有表记录操作：

mysql> DELETE FROM tb1;
Query OK, 3 rows affected (0.09  sec)

确认删除结果：

mysql> SELECT * FROM tb1;
Empty set (0.00 sec)

步骤三：通过binlog日志恢复表记录

binlog会记录所有的数据库、表更改操作，所以可在必要的时候重新执行以前做过的一部分数据操作，但对于启用binlog之前已经存在的库、表数据将不适用。
根据上述“恢复被删除的3条表记录”的需求，应通过mysqlbinlog工具查看相关日志文件，找到删除这些表记录的时间点，只要恢复此前的SQL操作（主要是插入那3条记录的操作）即可。

1）查看mysql-bin.000002日志内容

[root@zhangyx ~]# mysqlbinlog /var/lib/mysql/mysql-bin.000002
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
DELIMITER /*!*/;
# at 4
#200725 12:05:32 server id 1  end_log_pos 123 CRC32 0x6d8c069c  Start: binlog v 4, server v 5.7.17-log created 170412 12:05:32 at startup
# Warning: this binlog is either in use or was not closed properly.
ROLLBACK/*!*/;
BINLOG '
jKftWA8BAAAAdwAAAHsAAAABAAQANS43LjE3LWxvZwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAACMp+1YEzgNAAgAEgAEBAQEEgAAXwAEGggAAAAICAgCAAAACgoKKioAEjQA
AZwGjG0=
'/*!*/;
# at 123
#200725 12:05:32 server id 1  end_log_pos 154 CRC32 0x17f50164  Previous-GTIDs
# [empty]
# at 154
#200725 12:05:59 server id 1  end_log_pos 219 CRC32 0x4ba5a976  Anonymous_GTID  last_committed=0        sequence_number=1
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 219
#170412 12:05:59 server id 1  end_log_pos 310 CRC32 0x5b66ae13  Query   thread_id=3     exec_time=0     error_code=0
SET TIMESTAMP=1491969959/*!*/;
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=1436549152/*!*/;
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=8/*!*/;
SET @@session.lc_time_names=0/*!*/;
SET @@session.collation_database=DEFAULT/*!*/;
CREATE DATABASE db1
/*!*/;
# at 310
#200725 12:06:23 server id 1  end_log_pos 375 CRC32 0x2967cc28  Anonymous_GTID  last_committed=1        sequence_number=2
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 375
#200725 12:06:23 server id 1  end_log_pos 502 CRC32 0x5de09aae  Query   thread_id=3     exec_time=0     error_code=0
use `db1`/*!*/;
SET TIMESTAMP=1491969983/*!*/;
CREATE TABLE tb1(
id int(4) NOT NULL,name varchar(24)
)
/*!*/;
# at 502
#200725 12:06:55 server id 1  end_log_pos 567 CRC32 0x0b8cd418  Anonymous_GTID  last_committed=2        sequence_number=3
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 567
#200725 12:06:55 server id 1  end_log_pos 644 CRC32 0x7e8f2fa0  Query   thread_id=3     exec_time=0     error_code=0
SET TIMESTAMP=1491970015/*!*/;
BEGIN
/*!*/;
# at 644
#200725 12:06:55 server id 1  end_log_pos 772 CRC32 0x4e3f728e  Query   thread_id=3     exec_time=0     error_code=0          //插入表记录的起始时间点
SET TIMESTAMP=1491970015/*!*/;
INSERT INTO tb1 VALUES(1,'Jack'),(2,'Kenthy'), (3,'Bob')
/*!*/;
# at 772
#200725 12:06:55 server id 1  end_log_pos 803 CRC32 0x6138b21f  Xid = 10    //确认事务的时间点
COMMIT/*!*/;
# at 803
#200725 12:07:24 server id 1  end_log_pos 868 CRC32 0xbef3f472  Anonymous_GTID  last_committed=3        sequence_number=4
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 868
#170412 12:07:24 server id 1  end_log_pos 945 CRC32 0x5684e92c  Query   thread_id=3     exec_time=0     error_code=0
SET TIMESTAMP=1491970044/*!*/;
BEGIN
/*!*/;
# at 945
#200725 12:07:24 server id 1  end_log_pos 1032 CRC32 0x4c1c75fc         Query   thread_id=3     exec_time=0     error_code=0      //删除表记录的时间点
SET TIMESTAMP=1491970044/*!*/;
DELETE FROM tb1
/*!*/;
# at 1032
#200725 12:07:24 server id 1  end_log_pos 1063 CRC32 0xccf549b2     Xid = 12
COMMIT/*!*/;
SET @@SESSION.GTID_NEXT= 'AUTOMATIC' /* added by mysqlbinlog */ /*!*/;
DELIMITER ;
# End of log file
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;

2） 执行指定Pos节点范围内的sql命令恢复数据

根据上述日志分析，只要恢复从2014.01.12 20:12:14到2014.01.12 20:13:50之间的操作即可。可通过mysqlbinlog指定时间范围输出，结合管道交给msyql命令执行导入重做：

[root@zhangyx ~]# mysqlbinlog \
--start-datetime="2017-04-12 12:06:55" \
--stop-datetime="2017-04-12 12:07:23" \
/var/lib/mysql/mysql-bin.000002 | mysql -u root -p
Enter password:                                   //验证口令

3）确认恢复结果

mysql> SELECT * FROM db1.tb1;
+----+--------+
| id | name   |
+----+--------+
|  1 | Jack   |
|  2 | Kenthy |
|  3 | Bob    |
+----+--------+
3 rows in set (0.00 sec)

注：
三种记录格式：
1.statement：每一条修改数据的sql命令都会记录在binlog日志中
2.row：不记录sql语句上下文相关信息，仅保存哪条记录被修改
3.mixed：是以上两种格式的混和使用