时间:2021-07-01 10:21:17 帮助过:9人阅读
周日全备份 -- 周一10:00删库db1,-- 10:10发现某些页面无法访问,如何恢复数据?
注意:
由于库不仅仅一个,因此db1删除,用户可能正常的访问db2,但是多个数据库之间往往是有关联的, 如商品数据库和订单数据库,因此为了避免数据的不一致性,往往会导致逻辑上出现问题的; 此时应当停止服务;即暂停用户的访问,这是一个大的问题,这是需要慎重选择的,是服务重要还是数据 更重要,最好向上级报告。
处理逻辑:
1、停止服务:断开数据库与远程应用之间的网络连接,这样只有本地用户可以管理; 2、逻辑梳理: 全备份恢复:周日的全备份; 周日至周1的10:00间的数据;刨除删除的SQL命令; 周一10:00 - 10:10的数据; 如果业务数据不是十分的重要,那么就恢复周日的全备份,丢失全备份至周1 10:00的数据。
[root@centos7x ~]$mysqldump -A -F --master-data=2 --single-transaction > all_`date +%F_%T`.sql [root@centos7x ~]$less all_2018-02-24_21\:46\:13.sql -- Position to start replication or point-in-time recovery from -- -- CHANGE MASTER TO MASTER_LOG_FILE='mariadb-bin.000010', MASTER_LOG_POS=245; -- -- Current Database: `hellodb` 那么对于测试环境,'mariadb-bin.000010', MASTER_LOG_POS=245之前的二进制日志数据都是可以删除的; 单机备份时,--master-data=1或者2都是可以的;但是如果是主动复制那么最好是1;
模拟故障:
模拟修改和删除操作; MariaDB [hellodb]> select * from students; +-------+---------------+-----+--------+---------+-----------+ | StuID | Name | Age | Gender | ClassID | TeacherID | +-------+---------------+-----+--------+---------+-----------+ | 1 | Shi Zhongyu | 22 | M | 2 | 3 | | 2 | Shi Potian | 22 | M | 1 | 7 | | 3 | Xie Yanke | 53 | M | 2 | 16 | | 4 | Ding Dian | 32 | M | 4 | 4 | | 5 | Yu Yutong | 26 | M | 3 | 1 | | 6 | Shi Qing | 46 | M | 5 | NULL | | 7 | Xi Ren | 19 | F | 3 | NULL | | 8 | Lin Daiyu | 17 | F | 7 | NULL | | 9 | Ren Yingying | 20 | F | 6 | NULL | | 10 | Yue Lingshan | 19 | F | 3 | NULL | | 11 | Yuan Chengzhi | 23 | M | 6 | NULL | | 12 | Wen Qingqing | 19 | F | 1 | NULL | | 13 | Tian Boguang | 33 | M | 2 | NULL | | 14 | Lu Wushuang | 17 | F | 3 | NULL | | 15 | Duan Yu | 19 | M | 4 | NULL | | 16 | Xu Zhu | 21 | M | 1 | NULL | | 17 | Lin Chong | 25 | M | 4 | NULL | | 18 | Hua Rong | 23 | M | 7 | NULL | | 19 | Xue Baochai | 18 | F | 6 | NULL | | 20 | Diao Chan | 19 | F | 7 | NULL | | 21 | Huang Yueying | 22 | F | 6 | NULL | | 22 | Xiao Qiao | 20 | F | 1 | NULL | | 23 | Ma Chao | 23 | M | 4 | NULL | | 24 | Xu Xian | 27 | M | NULL | NULL | | 25 | Sun Dasheng | 100 | M | NULL | NULL | +-------+---------------+-----+--------+---------+-----------+ 25 rows in set (0.00 sec) MariaDB [hellodb]> insert into students (name,age,gender) values('a','29','F'); Query OK, 1 row affected (0.01 sec) MariaDB [hellodb]> select * from students; +-------+---------------+-----+--------+---------+-----------+ | StuID | Name | Age | Gender | ClassID | TeacherID | +-------+---------------+-----+--------+---------+-----------+ | 1 | Shi Zhongyu | 22 | M | 2 | 3 | | 2 | Shi Potian | 22 | M | 1 | 7 | | 3 | Xie Yanke | 53 | M | 2 | 16 | | 4 | Ding Dian | 32 | M | 4 | 4 | | 5 | Yu Yutong | 26 | M | 3 | 1 | | 6 | Shi Qing | 46 | M | 5 | NULL | | 7 | Xi Ren | 19 | F | 3 | NULL | | 8 | Lin Daiyu | 17 | F | 7 | NULL | | 9 | Ren Yingying | 20 | F | 6 | NULL | | 10 | Yue Lingshan | 19 | F | 3 | NULL | | 11 | Yuan Chengzhi | 23 | M | 6 | NULL | | 12 | Wen Qingqing | 19 | F | 1 | NULL | | 13 | Tian Boguang | 33 | M | 2 | NULL | | 14 | Lu Wushuang | 17 | F | 3 | NULL | | 15 | Duan Yu | 19 | M | 4 | NULL | | 16 | Xu Zhu | 21 | M | 1 | NULL | | 17 | Lin Chong | 25 | M | 4 | NULL | | 18 | Hua Rong | 23 | M | 7 | NULL | | 19 | Xue Baochai | 18 | F | 6 | NULL | | 20 | Diao Chan | 19 | F | 7 | NULL | | 21 | Huang Yueying | 22 | F | 6 | NULL | | 22 | Xiao Qiao | 20 | F | 1 | NULL | | 23 | Ma Chao | 23 | M | 4 | NULL | | 24 | Xu Xian | 27 | M | NULL | NULL | | 25 | Sun Dasheng | 100 | M | NULL | NULL | | 26 | a | 29 | F | NULL | NULL | +-------+---------------+-----+--------+---------+-----------+ 26 rows in set (0.00 sec) MariaDB [hellodb]> MariaDB [hellodb]> drop database hellodb ; Query OK, 7 rows affected (0.01 sec) MariaDB [(none)]> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | test | +--------------------+ 4 rows in set (0.00 sec) MariaDB [(none)]> use test; Database changed MariaDB [test]> create table t1(id int); Query OK, 0 rows affected (0.01 sec) MariaDB [test]> select * from test; ERROR 1146 (42S02): Table 'test.test' doesn''t exist MariaDB [test]> MariaDB [test]> show tables; +----------------+ | Tables_in_test | +----------------+ | t1 | +----------------+ 1 row in set (0.00 sec) MariaDB [test]> flush tables with read lock; Query OK, 0 rows affected (0.00 sec) MariaDB [test]> select * from t1; Empty set (0.00 sec) MariaDB [test]> insert t1 values(1); ERROR 1223 (HY000): Can''t execute the query because you have a conflicting read lock MariaDB [test]>
数据恢复操作: MariaDB [test]> show master logs; +--------------------+-----------+ | Log_name | File_size | +--------------------+-----------+ | mariadb-bin.000001 | 7700 | | mariadb-bin.000002 | 290 | | mariadb-bin.000003 | 290 | | mariadb-bin.000004 | 290 | | mariadb-bin.000005 | 290 | | mariadb-bin.000006 | 290 | | mariadb-bin.000007 | 290 | | mariadb-bin.000008 | 290 | | mariadb-bin.000009 | 290 | | mariadb-bin.000010 | 669 | +--------------------+-----------+ 10 rows in set (0.00 sec)
刷新日志: 那么'mariadb-bin.000010', MASTER_LOG_POS=245之前的数据使用全备份恢复; 'mariadb-bin.000010', MASTER_LOG_POS=245与'mariadb-bin.000011', MASTER_LOG_POS=245 之间的数据使用二进制日志进行恢复; MariaDB [test]> flush logs; Query OK, 0 rows affected (0.01 sec) MariaDB [test]> show master logs; +--------------------+-----------+ | Log_name | File_size | +--------------------+-----------+ | mariadb-bin.000001 | 7700 | | mariadb-bin.000002 | 290 | | mariadb-bin.000003 | 290 | | mariadb-bin.000004 | 290 | | mariadb-bin.000005 | 290 | | mariadb-bin.000006 | 290 | | mariadb-bin.000007 | 290 | | mariadb-bin.000008 | 290 | | mariadb-bin.000009 | 290 | | mariadb-bin.000010 | 714 | | mariadb-bin.000011 | 245 | +--------------------+-----------+ 11 rows in set (0.01 sec)
如果是全备份后的二进制日志有多个,那么需要都复制出来,并且合并; [root@centos7x ~]$cp /var/lib/mysql/mariadb-bin.000010 . [root@centos7x ~]$ls all_2018-02-24_21:46:13.sql all.sql anaconda-ks.cfg hellodb_InnoDB.sql initial-setup-ks.cfg mariadb-bin.000010 [root@centos7x ~]$mysqlbinlog --start-position=245 mariadb-bin.000010 [root@centos7x ~]$mysqlbinlog --start-position=245 mariadb-bin.000010 > binlog.sql
删除二进制日志中的删除数据库的SQL语句; [root@centos7x ~]$vim binlog.sql drop database hellodb 恢复数据之前还需要临时将记录二进制日志的功能暂时关掉; MariaDB [test]> show variables like 'sql_log_bin'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | sql_log_bin | ON | +---------------+-------+ 1 row in set (0.00 sec) MariaDB [test]> set sql_log_bin=0; Query OK, 0 rows affected (0.00 sec) MariaDB [test]> show variables like 'sql_log_bin'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | sql_log_bin | OFF | +---------------+-------+ 1 row in set (0.00 sec) sql_log_bin和/etc/my.cnf中的log_bin选项,都是可以影响二进制记录的选项,但是其中一个关闭,那么 二进制日志记录功能就关闭了;其中log_bin在配置文件中,修改的话是需要重启MySQL服务的; 而sql_log_bin是回话级别的,即时生效; 解锁数据库的读锁; MariaDB [test]> unlock tables ; Query OK, 0 rows affected (0.01 sec)
恢复全备份: MariaDB [test]> source all_2018-02-24_21:46:13.sql MariaDB [(none)]> select * from hellodb.students; 二进制日志恢复: 最后就是记录二进制日志,恢复用户的访问; MariaDB [(none)]> source binlog.sql MariaDB [(none)]> select * from hellodb.students; | 25 | Sun Dasheng | 100 | M | NULL | NULL | | 26 | a | 29 | F | NULL | NULL | +-------+---------------+-----+--------+---------+-----------+ MariaDB [test]> set sql_log_bin=1; Query OK, 0 rows affected (0.00 sec) MariaDB [test]> show variables like 'sql_log_bin'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | sql_log_bin | ON | +---------------+-------+ 1 row in set (0.00 sec)
mysql, mariadb删库、恢复的模拟实现
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