Centos7 Sample code for implementing MySQL log based data restoration
- 2021-08-12 04:18:44
- OfStack
Brief introduction
Binlog log, namely binary log file, is used to record the SQL statement information of the user's operation to the database. When the data is deleted by mistake, we can restore the deleted data through binlog log. The methods of restoring data are divided into traditional binary file restoration data and binary file restoration data based on GTID
Pre-preparation
Prepare an Centos7 virtual machine, close the firewall and selinux, configure the IP address, synchronize the system time, and install the MySQL database
Traditional binary log restores data
Modify the configuration file
[root@localhost ~]# vi /etc/my.cnf
server-id=1
log-bin=binlog
# Restart the database service
[root@localhost ~]# systemctl restart mysqld
Operational database
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;
View binary log information
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)
# Find the points of creating and deleting libraries , For 219 And 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 |
+---------------+------+----------------+-----------+-------------+--------------------------------------------------------------------+Save as binary log information
[root@localhost ~]# mysqlbinlog --start-position=219 --stop-position=1868 /var/lib/mysql/binlog.000001 > /tmp/binlog.sql
Recovery of data
# Temporary closure 2 Binary log records to avoid duplicate records
mysql> set sql_log_bin=0;
# Recovery of data
mysql> source /tmp/binlog.sql
# Restart 2 Binary log record
mysql> set sql_log_bin=1;
View data recovery
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) ,
Restore data based on GTID2 binary log
Modify the configuration file
[root@localhost ~]# vi /etc/my.cnf
server-id=1
log-bin=binlog
gtid_mode=ON
enforce_gtid_consistency=true
log_slave_updates=1
# Restart the database service
[root@localhost ~]# systemctl restart mysqldOperational database
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;
View binary log information
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 |
+---------------+------+----------------+-----------+-------------+-------------------------------------------------------------------+
Save as binary log information
#8 The transaction record is to delete the database, so only the recovery is needed 1-7 Number transaction record can be used
[root@localhost ~]# mysqlbinlog --skip-gtids --include-gtids='51d3db57-bf69-11ea-976c-000c2911a022:1-7' /var/lib/mysql/binlog.000003 > /tmp/gtid.sql
Parameter description:
--include-gtids: Include transactions
--exclude-gtids: Exclude transactions
--skip-gtids: Skipping Transactions
Recovery of data
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;
View data recovery
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;