数据备份 恢复

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NSD DBA1 DAY06

1 数据备份与恢复

1.1 问题

本案例要求熟悉MySQL的备份与恢复,完成以下任务操作:

  • 逻辑备份工具 mysqldump
  • 使用mysql 恢复数据库

1.2 步骤

实现此案例需要按照如下步骤进行。

步骤一:使用mysqldump进行逻辑备份

1)备份MySQL服务器上的所有库

将所有的库备份为mysql-all.sql文件:

  1. [root@dbsvr1 ~]# mysqldump -u root -p --all-databases > /root/alldb.sql
  2. Enter password:                                 //验证口令
  3. [root@dbsvr1 mysql]# file /root/alldb.sql         //确认备份文件类型
  4. /root/alldb.sql: UTF-8 Unicode English text, with very long lines

查看备份文件alldb.sql的部分内容:

  1. [root@dbsvr1 ~]# grep -vE '^/|^-|^$' /root/alldb.sql | head -15
  2. CREATE DATABASE /*!32312 IF NOT EXISTS*/ `home` /*!40100 DEFAULT CHARACTER SET latin1 */;
  3. USE `home`;
  4. DROP TABLE IF EXISTS `biao01`;
  5. CREATE TABLE `biao01` (
  6. `id` int(2) NOT NULL,
  7. `name` varchar(8) DEFAULT NULL
  8. ) ENGINE=InnoDB DEFAULT CHARSET=latin1;
  9. LOCK TABLES `biao01` WRITE;
  10. UNLOCK TABLES;
  11. DROP TABLE IF EXISTS `biao02`;
  12. CREATE TABLE `biao02` (
  13. `id` int(4) NOT NULL,
  14. `name` varchar(8) DEFAULT NULL,
  15. PRIMARY KEY (`id`)
  16. ) ENGINE=InnoDB DEFAULT CHARSET=latin1;
  17. .. ..

注意:若数据库都使用MyISAM存储引擎,可以采用冷备份的方式,直接复制对应的数据库目录即可;恢复时重新复制回来就行。

2)只备份指定的某一个库

将userdb库备份为userdb.sql文件:

  1. [root@dbsvr1 ~]# mysqldump -u root -p userdb > userdb.sql
  2. Enter password:                                 //验证口令

查看备份文件userdb.sql的部分内容:

  1. [root@dbsvr1 ~]# grep -vE '^/|^-|^$' /root/userdb.sql
  2. DROP TABLE IF EXISTS `stu_info`;
  3. CREATE TABLE `stu_info` (
  4. `name` varchar(12) NOT NULL,
  5. `gender` enum('boy','girl') DEFAULT 'boy',
  6. `age` int(3) NOT NULL
  7. ) ENGINE=InnoDB DEFAULT CHARSET=latin1;
  8. LOCK TABLES `stu_info` WRITE;
  9. .. ..

3)同时备份指定的多个库

同时备份mysql、userdb库,保存为mysql+userdb.sql文件:

  1. [root@dbsvr1 ~]# mysqldump -u root -p -B mysql userdb > mysql+test+userdb.sql
  2. Enter password:                                 //验证口令

查看备份文件userdb.sql的部分内容:

  1. [root@dbsvr1 ~]# grep '^CREATE DATA' /root/mysql+userdb.sql
  2. CREATE DATABASE /*!32312 IF NOT EXISTS*/ `mysql` /*!40100 DEFAULT CHARACTER SET latin1 */;
  3. CREATE DATABASE /*!32312 IF NOT EXISTS*/ `userdb` /*!40100 DEFAULT CHARACTER SET latin1 */;

步骤二:使用mysql命令从备份中恢复数据库、表

以恢复userdb库为例,可参考下列操作。通常不建议直接覆盖旧库,而是采用建立新库并导入逻辑备份的方式执行恢复,待新库正常后即可废弃或删除旧库。

1)创建名为userdb2的新库

  1. mysql> CREATE DATABASE userdb2;
  2. Query OK, 1 row affected (0.00 sec)

2)导入备份文件,在新库中重建表及数据

  1. [root@dbsvr1 ~]# mysql -u root -p userdb2 < /root/userdb.sql
  2. Enter password:                                 //验证口令

3)确认新库正常,启用新库

  1. mysql> USE userdb2;                             //切换到新库
  2. Reading table information for completion of table and column names
  3. You can turn off this feature to get a quicker startup with -A
  4. Database changed
  5. mysql> SELECT sn,username,uid,gid,homedir         //查询数据,确认可用
  6. -> FROM userlist LIMIT 10;
  7. +----+----------+-----+-----+-----------------+
  8. | sn | username | uid | gid | homedir |
  9. +----+----------+-----+-----+-----------------+
  10. | 1 | root | 0 | 0 | /root |
  11. | 2 | bin | 1 | 1 | /bin |
  12. | 3 | daemon | 2 | 2 | /sbin |
  13. | 4 | adm | 3 | 4 | /var/adm |
  14. | 5 | lp | 4 | 7 | /var/spool/lpd |
  15. | 6 | sync | 5 | 0 | /sbin |
  16. | 7 | shutdown | 6 | 0 | /sbin |
  17. | 8 | halt | 7 | 0 | /sbin |
  18. | 9 | mail | 8 | 12 | /var/spool/mail |
  19. | 10 | operator | 11 | 0 | /root |
  20. +----+----------+-----+-----+-----------------+
  21. 10 rows in set (0.00 sec)

4)废弃或删除旧库

  1. mysql> DROP DATABASE userdb;
  2. Query OK, 2 rows affected (0.09 sec)

 

2 使用binlog日志

2.1 问题

利用binlog恢复库表,要求如下:

  • 启用binlog日志
  • 创建db1库tb1表,插入3条记录
  • 删除tb1表中刚插入的3条记录
  • 使用mysqlbinlog恢复删除的3条记录

2.2 步骤

实现此案例需要按照如下步骤进行。

步骤一:启用binlog日志

1)调整/etc/my.cnf配置,并重启服务

  1. [root@dbsvr1 ~]# vim /etc/my.cnf
  2. [mysqld]
  3. .. ..
  4. log-bin-index=mysql-bin                             //启用二进制日志,并指定前缀
  5. server_id=1
  6. binlog_format=STATEMENT
  7. //在Mysql5.7中,binlog日志格式默认为ROW,但它不记录sql语句上下文相关信息。需要将binlog日志格式修改为STATEMENT
  8. .. ..
  9. [root@dbsvr1 ~]# systemctl restart mysqld.service

2)确认binlog日志文件

新启用binlog后,每次启动MySQl服务都会新生成一份日志文件:

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

其中mysql-bin.index文件记录了当前保持的二进制文件列表:

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

重启MySQL服务程序,或者执行SQL操作“FLUSH LOGS;”,会生成一份新的日志:

  1. [root@dbsvr1 ~]# ls /var/lib/mysql/mysql-bin.*
  2. /var/lib/mysql/mysql-bin.000001 /var/lib/mysql/mysql-bin.index
  3. /var/lib/mysql/mysql-bin.000002
  4. [root@dbsvr1 ~]# cat /var/lib/mysql/mysql-bin.index
  5. ./mysql-bin.000001
  6. ./mysql-bin.000002

步骤二:利用binlog日志重做数据库操作

1)执行数据库表添加操作

创建db1·库tb1表,表结构自定义:

  1. mysql> CREATE DATABASE db1;
  2. Query OK, 1 row affected (0.05 sec)
  3. mysql> USE db1;
  4. Database changed
  5. mysql> CREATE TABLE tb1(
  6. -> id int(4) NOT NULL,name varchar(24)
  7. -> );
  8. Query OK, 0 rows affected (0.28 sec)

插入3条表记录:

  1. mysql> INSERT INTO tb1 VALUES
  2. -> (1,'Jack'),
  3. -> (2,'Kenthy'),
  4. -> (3,'Bob');
  5. Query OK, 3 rows affected (0.12 sec)
  6. Records: 3 Duplicates: 0 Warnings: 0

确认插入的表记录数据:

  1. mysql> SELECT * FROM tb1;
  2. +----+--------+
  3. | id | name |
  4. +----+--------+
  5. | 1 | Jack |
  6. | 2 | Kenthy |
  7. | 3 | Bob |
  8. +----+--------+
  9. 3 rows in set (0.00 sec)

2)删除前一步添加的3条表记录

执行删除所有表记录操作:

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

确认删除结果:

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

步骤三:通过binlog日志恢复表记录

binlog会记录所有的数据库、表更改操作,所以可在必要的时候重新执行以前做过的一部分数据操作,但对于启用binlog之前已经存在的库、表数据将不适用。

根据上述“恢复被删除的3条表记录”的需求,应通过mysqlbinlog工具查看相关日志文件,找到删除这些表记录的时间点,只要恢复此前的SQL操作(主要是插入那3条记录的操作)即可。

1)查看mysql-bin.000002日志内容

  1. [root@dbsvr1 ~]# mysqlbinlog /var/lib/mysql/mysql-bin.000002
  2. /*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
  3. /*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
  4. DELIMITER /*!*/;
  5. # at 4
  6. #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
  7. # Warning: this binlog is either in use or was not closed properly.
  8. ROLLBACK/*!*/;
  9. BINLOG '
  10. jKftWA8BAAAAdwAAAHsAAAABAAQANS43LjE3LWxvZwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
  11. AAAAAAAAAAAAAAAAAACMp+1YEzgNAAgAEgAEBAQEEgAAXwAEGggAAAAICAgCAAAACgoKKioAEjQA
  12. AZwGjG0=
  13. '/*!*/;
  14. # at 123
  15. #170412 12:05:32 server id 1 end_log_pos 154 CRC32 0x17f50164 Previous-GTIDs
  16. # [empty]
  17. # at 154
  18. #170412 12:05:59 server id 1 end_log_pos 219 CRC32 0x4ba5a976 Anonymous_GTID last_committed=0 sequence_number=1
  19. SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
  20. # at 219
  21. #170412 12:05:59 server id 1 end_log_pos 310 CRC32 0x5b66ae13 Query thread_id=3 exec_time=0 error_code=0
  22. SET TIMESTAMP=1491969959/*!*/;
  23. SET @@session.pseudo_thread_id=3/*!*/;
  24. SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
  25. SET @@session.sql_mode=1436549152/*!*/;
  26. SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
  27. /*!\C utf8 *//*!*/;
  28. SET @@session.character_set_client=33,@@session.collation_connection=33,@@session.collation_server=8/*!*/;
  29. SET @@session.lc_time_names=0/*!*/;
  30. SET @@session.collation_database=DEFAULT/*!*/;
  31. CREATE DATABASE db1
  32. /*!*/;
  33. # at 310
  34. #170412 12:06:23 server id 1 end_log_pos 375 CRC32 0x2967cc28 Anonymous_GTID last_committed=1 sequence_number=2
  35. SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
  36. # at 375
  37. #170412 12:06:23 server id 1 end_log_pos 502 CRC32 0x5de09aae Query thread_id=3 exec_time=0 error_code=0
  38. use `db1`/*!*/;
  39. SET TIMESTAMP=1491969983/*!*/;
  40. CREATE TABLE tb1(
  41. id int(4) NOT NULL,name varchar(24)
  42. )
  43. /*!*/;
  44. # at 502
  45. #170412 12:06:55 server id 1 end_log_pos 567 CRC32 0x0b8cd418 Anonymous_GTID last_committed=2 sequence_number=3
  46. SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
  47. # at 567
  48. #170412 12:06:55 server id 1 end_log_pos 644 CRC32 0x7e8f2fa0 Query thread_id=3 exec_time=0 error_code=0
  49. SET TIMESTAMP=1491970015/*!*/;
  50. BEGIN
  51. /*!*/;
  52. # at 644
  53. #170412 12:06:55 server id 1 end_log_pos 772 CRC32 0x4e3f728e Query thread_id=3 exec_time=0 error_code=0 //插入表记录的起始时间点
  54. SET TIMESTAMP=1491970015/*!*/;
  55. INSERT INTO tb1 VALUES(1,'Jack'),(2,'Kenthy'), (3,'Bob')
  56. /*!*/;
  57. # at 772
  58. #170412 12:06:55 server id 1 end_log_pos 803 CRC32 0x6138b21f Xid = 10
  59. //确认事务的时间点
  60. COMMIT/*!*/;
  61. # at 803
  62. #170412 12:07:24 server id 1 end_log_pos 868 CRC32 0xbef3f472 Anonymous_GTID last_committed=3 sequence_number=4
  63. SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
  64. # at 868
  65. #170412 12:07:24 server id 1 end_log_pos 945 CRC32 0x5684e92c Query thread_id=3 exec_time=0 error_code=0
  66. SET TIMESTAMP=1491970044/*!*/;
  67. BEGIN
  68. /*!*/;
  69. # at 945
  70. #170412 12:07:24 server id 1 end_log_pos 1032 CRC32 0x4c1c75fc Query thread_id=3 exec_time=0 error_code=0 //删除表记录的时间点
  71. SET TIMESTAMP=1491970044/*!*/;
  72. DELETE FROM tb1
  73. /*!*/;
  74. # at 1032
  75. #170412 12:07:24 server id 1 end_log_pos 1063 CRC32 0xccf549b2 Xid = 12
  76. COMMIT/*!*/;
  77. SET @@SESSION.GTID_NEXT= 'AUTOMATIC' /* added by mysqlbinlog */ /*!*/;
  78. DELIMITER ;
  79. # End of log file
  80. /*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
  81. /*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;

2) 执行指定Pos节点范围内的sql命令恢复数据

根据上述日志分析,只要恢复从2014.01.12 20:12:14到2014.01.12 20:13:50之间的操作即可。可通过mysqlbinlog指定时间范围输出,结合管道交给msyql命令执行导入重做:

  1. [root@dbsvr1 ~]# mysqlbinlog \
  2. --start-datetime="2017-04-12 12:06:55" \
  3. --stop-datetime="2017-04-12 12:07:23" \
  4. /var/lib/mysql/mysql-bin.000002 | mysql -u root -p
  5. Enter password:                                  //验证口令

3)确认恢复结果

  1. mysql> SELECT * FROM db1.tb1;
  2. +----+--------+
  3. | id | name |
  4. +----+--------+
  5. | 1 | Jack |
  6. | 2 | Kenthy |
  7. | 3 | Bob |
  8. +----+--------+
  9. 3 rows in set (0.00 sec)

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转载自www.cnblogs.com/tiki/p/10783399.html