Centos7实现MySQL基于日志还原数据的示例代码

简介

Binlog日志，即二进制日志文件，用于记录用户对数据库操作的SQL语句信息，当发生数据误删除的时候我们可以通过binlog日志来还原已经删除的数据，还原数据的方法分为传统二进制文件还原数据和基于GTID的二进制文件还原数据

前期准备

准备一台Centos7虚拟机，关闭防火墙和selinux，配置IP地址,同步系统时间,安装MySQL数据库

传统二进制日志还原数据

修改配置文件

[root@localhost ~]# vi /etc/my.cnf
server-id=1
log-bin=binlog

#重启数据库服务
[root@localhost ~]# systemctl restart mysqld

操作数据库

mysql> create database mydb charset utf8mb4;
mysql> use mydb;
mysql> create table test(id int)engine=innodb charset=utf8mb4;
mysql> insert into test values(1);
mysql> insert into test values(2);
mysql> insert into test values(3);
mysql> insert into test values(4);
mysql> commit;
mysql> update test set id=10 where id=4;
mysql> commit;
mysql> select * from test;
+------+
| id  |
+------+
|  1 |
|  2 |
|  3 |
|  10 |
+------+
4 rows in set (0.00 sec)
mysql> drop database mydb;

查看二进制日志信息

mysql> show master status\G;
*************************** 1. row ***************************
       File: binlog.000001
     Position: 1960
   Binlog_Do_DB: 
 Binlog_Ignore_DB: 
Executed_Gtid_Set: 
1 row in set (0.00 sec)

 
#查找创库和删库的点,为219和1868
mysql> show binlog events in 'binlog.000001';
+---------------+------+----------------+-----------+-------------+--------------------------------------------------------------------+
| Log_name   | Pos | Event_type   | Server_id | End_log_pos | Info                                |
+---------------+------+----------------+-----------+-------------+--------------------------------------------------------------------+
| binlog.000001 | 219 | Query     |     1 |     329 | create database mydb charset utf8mb4                |
| binlog.000001 | 1868 | Query     |     1 |    1960 | drop database mydb                         |
+---------------+------+----------------+-----------+-------------+--------------------------------------------------------------------+

另存为二进制日志信息

[root@localhost ~]# mysqlbinlog --start-position=219 --stop-position=1868 /var/lib/mysql/binlog.000001 > /tmp/binlog.sql

恢复数据

#临时关闭二进制日志记录以免重复记录
mysql> set sql_log_bin=0;
#恢复数据
mysql> source /tmp/binlog.sql
#重启二进制日志记录
mysql> set sql_log_bin=1;

查看数据恢复情况

mysql> show databases;
+--------------------+
| Database      |
+--------------------+
| information_schema |
| mydb        |
| mysql       |
| performance_schema |
| sys        |
+--------------------+
5 rows in set (0.00 sec)

mysql> use mydb;
Database changed
mysql> select * from test;
+------+
| id  |
+------+
|  1 |
|  2 |
|  3 |
|  10 |
+------+
4 rows in set (0.00 sec)、

基于GTID二进制日志还原数据

修改配置文件

[root@localhost ~]# vi /etc/my.cnf
server-id=1
log-bin=binlog
gtid_mode=ON
enforce_gtid_consistency=true
log_slave_updates=1

#重启数据库服务
[root@localhost ~]# systemctl restart mysqld

操作数据库

mysql> create database mydb1;
mysql> use mydb1;
Database changed
mysql> create table t1(id int)engine=innodb charset=utf8mb4;
mysql> insert into t1 values(1);
mysql> insert into t1 values(2);
mysql> insert into t1 values(3);
mysql> insert into t1 values(11);
mysql> insert into t1 values(12);
mysql> commit;
mysql> select * from t1;
+------+
| id  |
+------+
|  1 |
|  2 |
|  3 |
|  11 |
|  12 |
+------+
5 rows in set (0.00 sec)
mysql> drop database mydb1;

查看二进制日志信息

mysql> show master status\G;
*************************** 1. row ***************************
       File: binlog.000003
     Position: 1944
   Binlog_Do_DB: 
 Binlog_Ignore_DB: 
Executed_Gtid_Set: 51d3db57-bf69-11ea-976c-000c2911a022:1-8
1 row in set (0.00 sec)

mysql> show binlog events in 'binlog.000003';
+---------------+------+----------------+-----------+-------------+-------------------------------------------------------------------+
| Log_name   | Pos | Event_type   | Server_id | End_log_pos | Info                               |
+---------------+------+----------------+-----------+-------------+-------------------------------------------------------------------+
| binlog.000003 | 154 | Gtid      |     1 |     219 | SET @@SESSION.GTID_NEXT= '51d3db57-bf69-11ea-976c-000c2911a022:1' |
| binlog.000003 | 219 | Query     |     1 |     316 | create database mydb1                       |
| binlog.000003 | 1784 | Gtid      |     1 |    1849 | SET @@SESSION.GTID_NEXT= '51d3db57-bf69-11ea-976c-000c2911a022:8' |
| binlog.000003 | 1849 | Query     |     1 |    1944 | drop database mydb1                        |
+---------------+------+----------------+-----------+-------------+-------------------------------------------------------------------+

另存为二进制日志信息

#8号事务记录为删除数据库，因此只需恢复1-7号事务记录即可
[root@localhost ~]# mysqlbinlog --skip-gtids --include-gtids='51d3db57-bf69-11ea-976c-000c2911a022:1-7' /var/lib/mysql/binlog.000003 > /tmp/gtid.sql

参数说明:
--include-gtids:包含事务
--exclude-gtids:排除事务
--skip-gtids:跳过事务

恢复数据

mysql> set sql_log_bin=0;
mysql> source /tmp/gtid.sql
mysql> set sql_log_bin=1;

查看数据恢复情况

mysql> show databases;
+--------------------+
| Database      |
+--------------------+
| information_schema |
| mydb        |
| mydb1       |
| mysql       |
| performance_schema |
| sys        |
+--------------------+
6 rows in set (0.00 sec)

mysql> use mydb1;
Database changed
mysql> select * from t1;
+------+
| id  |
+------+
|  1 |
|  2 |
|  3 |
|  11 |
|  12 |
+------+
5 rows in set (0.00 sec)

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