經過binlog日誌恢復表記錄

使用binlog日誌

1 使用binlog日誌
1.1 問題

利用binlog恢復庫表，要求以下：

啓用binlog日誌
建立db1庫tb1表，插入3條記錄
刪除tb1表中剛插入的3條記錄
使用mysqlbinlog恢復刪除的3條記錄

1.2 步驟

實現此案例須要按照以下步驟進行。

步驟一：啓用binlog日誌

1）調整/etc/my.cnf配置，並重啓服務

[root@dbsvr1 ~]# vim  /etc/my.cnf
[mysqld]
.. ..
log-bin-index=mysql-bin                              //啓用二進制日誌，並指定前綴
server_id=1
binlog_format=STATEMENT                               //在Mysql5.7中，binlog日誌格式默認爲ROW，但它不記錄sql語句上下文相關信息。須要將binlog日誌格式修改成STATEMENT
.. ..
[root@dbsvr1 ~]# systemctl  restart mysqld.service

2）確認binlog日誌文件

新啓用binlog後，每次啓動MySQl服務都會新生成一份日誌文件：

[root@dbsvr1 ~]# ls /var/lib/mysql/mysql-bin.*
/var/lib/mysql/mysql-bin.000001  /var/lib/mysql/mysql-bin.index

其中mysql-bin.index文件記錄了當前保持的二進制文件列表：

[root@dbsvr1 ~]# cat /var/lib/mysql/mysql-bin.index
./mysql-bin.000001

重啓MySQL服務程序，或者執行SQL操做「FLUSH LOGS;」，會生成一份新的日誌：

[root@dbsvr1 ~]# 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@dbsvr1 ~]# cat /var/lib/mysql/mysql-bin.index
./mysql-bin.000001
./mysql-bin.000002

步驟二：利用binlog日誌重作數據庫操做

1）執行數據庫表添加操做

建立db1·庫tb1表，表結構自定義：

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條表記錄：

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

確認插入的表記錄數據：

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

2）刪除前一步添加的3條表記錄

執行刪除全部表記錄操做：

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

確認刪除結果：

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

步驟三：經過binlog日誌恢復表記錄

binlog會記錄全部的數據庫、表更改操做，因此可在必要的時候從新執行之前作過的一部分數據操做，但對於啓用binlog以前已經存在的庫、表數據將不適用。

根據上述「恢復被刪除的3條表記錄」的需求，應經過mysqlbinlog工具查看相關日誌文件，找到刪除這些表記錄的時間點，只要恢復此前的SQL操做（主要是插入那3條記錄的操做）便可。

1）查看mysql-bin.000002日誌內容

[root@dbsvr1 ~]# 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
#170412 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
#170412 12:05:32 server id 1  end_log_pos 154 CRC32 0x17f50164  Previous-GTIDs
# [empty]
# at 154
#170412 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
#170412 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
#170412 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
#170412 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
#170412 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
#170412 12:06:55 server id 1  end_log_pos 772 CRC32 0x4e3f728e  Query   thread_id=3     exec_time=0     error_code=0                            //插入表記錄的起始時間點 
SET TIMESTAMP=1491970015/*!*/;
INSERT INTO tb1 VALUES(1,'Jack'),(2,'Kenthy'), (3,'Bob')
/*!*/;
# at 772
#170412 12:06:55 server id 1  end_log_pos 803 CRC32 0x6138b21f  Xid = 10
                                                      //確認事務的時間點 
COMMIT/*!*/;
# at 803
#170412 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
#170412 12:07:24 server id 1  end_log_pos 1032 CRC32 0x4c1c75fc         Query   thread_id=3     exec_time=0     error_code=0            //刪除表記錄的時間點
SET TIMESTAMP=1491970044/*!*/;
DELETE FROM tb1
/*!*/;
# at 1032
#170412 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） 執行指定Pos節點範圍內的sql命令恢復數據

根據上述日誌分析，只要恢復從2014.01.12 20:12:14到2014.01.12 20:13:50之間的操做便可。可經過mysqlbinlog指定時間範圍輸出，結合管道交給msyql命令執行導入重作：

[root@dbsvr1 ~]# 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:                                     //驗證口令

3）確認恢復結果

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