mysql, mariadb刪庫、恢復的模擬實現
阿新 • • 發佈:2018-03-18
數據 數據恢復 mysql mariadb 刪庫 模擬場景:
周日全備份 -- 周一10:00刪庫db1,-- 10:10發現某些頁面無法訪問,如何恢復數據?
註意:
由於庫不僅僅一個,因此db1刪除,用戶可能正常的訪問db2,但是多個數據庫之間往往是有關聯的, 如商品數據庫和訂單數據庫,因此為了避免數據的不一致性,往往會導致邏輯上出現問題的; 此時應當停止服務;即暫停用戶的訪問,這是一個大的問題,這是需要慎重選擇的,是服務重要還是數據 更重要,最好向上級報告。
處理邏輯:
1、停止服務:斷開數據庫與遠程應用之間的網絡連接,這樣只有本地用戶可以管理; 2、邏輯梳理: 全備份恢復:周日的全備份; 周日至周1的10:00間的數據;刨除刪除的SQL命令; 周一10:00 - 10:10的數據; 如果業務數據不是十分的重要,那麽就恢復周日的全備份,丟失全備份至周1 10:00的數據。
[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` 那麽對於測試環境,'mariadb-bin.000010', MASTER_LOG_POS=245之前的二進制日誌數據都是可以刪除的; 單機備份時,--master-data=1或者2都是可以的;但是如果是主動復制那麽最好是1;
模擬故障:
模擬修改和刪除操作; 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]>
數據恢復操作: 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)
刷新日誌: 那麽'mariadb-bin.000010', MASTER_LOG_POS=245之前的數據使用全備份恢復; 'mariadb-bin.000010', MASTER_LOG_POS=245與'mariadb-bin.000011', MASTER_LOG_POS=245 之間的數據使用二進制日誌進行恢復; 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)
如果是全備份後的二進制日誌有多個,那麽需要都復制出來,並且合並; [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
刪除二進制日誌中的刪除數據庫的SQL語句; [root@centos7x ~]$vim binlog.sql drop database hellodb 恢復數據之前還需要臨時將記錄二進制日誌的功能暫時關掉; 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選項,都是可以影響二進制記錄的選項,但是其中一個關閉,那麽 二進制日誌記錄功能就關閉了;其中log_bin在配置文件中,修改的話是需要重啟MySQL服務的; 而sql_log_bin是回話級別的,即時生效; 解鎖數據庫的讀鎖; MariaDB [test]> unlock tables ; Query OK, 0 rows affected (0.01 sec)
恢復全備份: MariaDB [test]> source all_2018-02-24_21:46:13.sql MariaDB [(none)]> select * from hellodb.students; 二進制日誌恢復: 最後就是記錄二進制日誌,恢復用戶的訪問; 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刪庫、恢復的模擬實現