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MYSQL数据库MySQL备份与恢复之热备（3）

作者：VEPHP   时间 2017-09-24

《MYSQL数据库MySQL备份与恢复之热备（3）》要点：
本文介绍了MYSQL数据库MySQL备份与恢复之热备（3），希望对您有用。如果有疑问，可以联系我们。

       在上两篇文章(MySQL备份与恢复之冷备,MySQL备份与恢复之真实环境使用冷备)中,我们提到了冷备和真实环境中使用冷备.那从这篇文章开始我们看下热备.显然热备和冷备是两个相对的概念,冷备是把数据库服务,比如MySQL,Oracle停下来,然后使用拷贝、打包或者压缩命令对数据目录进行备份；那么我们很容易想到热备就是在MySQL或者其他数据库服务在运行的情况下进行备份.但是,这里存在一个问题,因为生产库在运行的情况下,有对该库的读写,读写频率有可能高,也可能低,不管频率高低,总会就会造成备份出来的数据和生产库中的数据不一致的情况.热备这段时间,其他人不可以操作是不现实的,因为你总不可能终止用户访问Web程序.要解决这个问题,可以采用指定备份策略,比如哪个时间段进行备份,备份哪些数据等等,总之,保证数据的完整性和一致性,切记,备份重于一切!!!
       热备可以对多个库进行备份,可以对单张表或者某几张表进行备份.但是无法同时备份多个库多个表,只有分开备份.下面我们看下热备的示意图,并进行热备模拟.
示意图MYSQL入门

 MYSQL入门

热备模拟MYSQL入门

1、对单个库进行备份
第一步,移除LVM快照.(如果没有创建,忽略此步)
MYSQL入门

  1. [root@serv01 data]# lvremove /dev/data/smydata 
  2. Do you really want to remove active logical volume smydata? [y/n]: y
  3.  Logical volume "smydata" successfully removed

第二步,设置MySQL的密码
MYSQL入门

  1. mysql> set password=password("123456");
  2. Query OK, 0 rows affected (0.00 sec)

第三步,查看MySQL是否启动.因为是热备,所以要求MySQL服务启动
MYSQL入门

  1. [root@serv01 data]# /etc/init.d/mysqld status
  2.  SUCCESS! MySQL running (2664)

第四步,导出单个数据库
MYSQL入门

  1. [root@serv01 data]# cd /databackup/
  2. #本质是导出为SQL
  3. [root@serv01 databackup]# mysqldump -uroot -p123456 --database larrydb
  4. -- MySQL dump 10.13 Distrib 5.5.29, for Linux (x86_64)
  5. --
  6. -- Host: localhost Database: larrydb
  7. -- ------------------------------------------------------
  8. -- Server version 5.5.29-log
  9. /*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
  10. /*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
  11. /*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
  12. /*!40101 SET NAMES utf8 */;
  13. /*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
  14. /*!40103 SET TIME_ZONE='+00:00' */;
  15. /*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
  16. /*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
  17. /*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
  18. /*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;
  19. --
  20. -- Current Database: `larrydb`
  21. --
  22. CREATE DATABASE /*!32312 IF NOT EXISTS*/ `larrydb` /*!40100 DEFAULT CHARACTER SET latin1 */;
  23. USE `larrydb`;
  24. --
  25. -- Table structure for table `class`
  26. --
  27. DROP TABLE IF EXISTS `class`;
  28. /*!40101 SET @saved_cs_client = @@character_set_client */;
  29. /*!40101 SET character_set_client = utf8 */;
  30. CREATE TABLE `class` (
  31.  `cid` int(11) DEFAULT NULL,
  32.  `cname` varchar(30) DEFAULT NULL
  33. ) ENGINE=InnoDB DEFAULT CHARSET=latin1;
  34. /*!40101 SET character_set_client = @saved_cs_client */;
  35. --
  36. -- Dumping data for table `class`
  37. --
  38. LOCK TABLES `class` WRITE;
  39. /*!40000 ALTER TABLE `class` DISABLE KEYS */;
  40. INSERT INTO `class` VALUES (1,'linux'),(2,'oracle');
  41. /*!40000 ALTER TABLE `class` ENABLE KEYS */;
  42. UNLOCK TABLES;
  43. --
  44. -- Table structure for table `stu`
  45. --
  46. DROP TABLE IF EXISTS `stu`;
  47. /*!40101 SET @saved_cs_client = @@character_set_client */;
  48. /*!40101 SET character_set_client = utf8 */;
  49. CREATE TABLE `stu` (
  50.  `sid` int(11) DEFAULT NULL,
  51.  `sname` varchar(30) DEFAULT NULL,
  52.  `cid` int(11) DEFAULT NULL
  53. ) ENGINE=MyISAM DEFAULT CHARSET=latin1;
  54. /*!40101 SET character_set_client = @saved_cs_client */;
  55. --
  56. -- Dumping data for table `stu`
  57. --
  58. LOCK TABLES `stu` WRITE;
  59. /*!40000 ALTER TABLE `stu` DISABLE KEYS */;
  60. INSERT INTO `stu` VALUES (1,'larry01',1),(2,'larry02',2);
  61. /*!40000 ALTER TABLE `stu` ENABLE KEYS */;
  62. UNLOCK TABLES;
  63. /*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;
  64. /*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
  65. /*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
  66. /*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
  67. /*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
  68. /*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
  69. /*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
  70. /*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;
  71.  Dump completed on 2013-09-10 18:56:06
  72. #将输出结果保存到文件中
  73. [root@serv01 databackup]# mysqldump -uroot -p123456 --database larrydb > larrydb.sql

第五步,模拟数据丢失,进入MySQL,删除数据库
MYSQL入门

  1. [root@serv01 data]# mysql -uroot -p123456
  2. Welcome to the MySQL monitor. Commands end with ; or \g.
  3. Your MySQL connection id is 4
  4. Server version: 5.5.29-log Source distribution
  5. Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
  6. Oracle is a registered trademark of Oracle Corporation and/or its
  7. affiliates. Other names may be trademarks of their respective
  8. owners.
  9. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
  10. mysql> show databases;
  11. +--------------------+
  12. | Database  |
  13. +--------------------+
  14. | information_schema |
  15. | crm  |
  16. | game  |
  17. | hello  |
  18. | larrydb  |
  19. | mnt  |
  20. | mysql  |
  21. | performance_schema |
  22. | test  |
  23. +--------------------+
  24. 9 rows in set (0.00 sec)
  25. mysql> drop database larrydb;
  26. Query OK, 2 rows affected (0.01 sec)
  27. mysql> show databases;
  28. +--------------------+
  29. | Database  |
  30. +--------------------+
  31. | information_schema |
  32. | crm  |
  33. | game  |
  34. | hello  |
  35. | mnt  |
  36. | mysql  |
  37. | performance_schema |
  38. | test  |
  39. +--------------------+
  40. 8 rows in set (0.00 sec)
  41. mysql> exit
  42. Bye

第六步,导入数据
MYSQL入门

  1. [root@serv01 databackup]# mysql -uroot -p123456 <larrydb.sql

 
第七步,登录MySQL,查看数据是否正常
MYSQL入门

  1. [root@serv01 data]# mysql -uroot -p123456
  2. Welcome to the MySQL monitor. Commands end with ; or \g.
  3. Your MySQL connection id is 6
  4. Server version: 5.5.29-log Source distribution
  5. Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
  6. Oracle is a registered trademark of Oracle Corporation and/or its
  7. affiliates. Other names may be trademarks of their respective
  8. owners.
  9. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
  10. mysql> show database;
  11. ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'database' at line 1
  12. mysql> show databases;
  13. +--------------------+
  14. | Database  |
  15. +--------------------+
  16. | information_schema |
  17. | crm  |
  18. | game  |
  19. | hello  |
  20. | larrydb  |
  21. | mnt  |
  22. | mysql  |
  23. | performance_schema |
  24. | test  |
  25. +--------------------+
  26. 9 rows in set (0.00 sec)
  27. mysql> use larrydb;
  28. Database changed
  29. mysql> select * from class;
  30. +------+--------+
  31. | cid | cname |
  32. +------+--------+
  33. | 1 | linux |
  34. | 2 | oracle |
  35. +------+--------+
  36. 2 rows in set (0.00 sec)
  37. mysql> select * from stu;
  38. +------+---------+------+
  39. | sid | sname | cid |
  40. +------+---------+------+
  41. | 1 | larry01 | 1 |
  42. | 2 | larry02 | 2 |
  43. +------+---------+------+
  44. 2 rows in set (0.00 sec)

对多个库进行备份
第一步,查看有哪些数据库
MYSQL入门

  1. mysql> show databases;
  2. +--------------------+
  3. | Database  |
  4. +--------------------+
  5. | information_schema |
  6. | crm  |
  7. | game  |
  8. | hello  |
  9. | larrydb  |
  10. | mnt  |
  11. | mysql  |
  12. | performance_schema |
  13. | test  |
  14. +--------------------+
  15. 9 rows in set (0.00 sec)
  16. mysql> use game;
  17. Database changed
  18. mysql> show tables;
  19. +----------------+
  20. | Tables_in_game |
  21. +----------------+
  22. | country |
  23. | fight  |
  24. | hero  |
  25. +----------------+
  26. 3 rows in set (0.00 sec)
  27. mysql> select * from country;
  28. +-----+---------+----------+
  29. | cno | cname | location |
  30. +-----+---------+----------+
  31. | 10 | caowei | luoyang |
  32. | 20 | shuhan | chengdou |
  33. | 30 | sunwu | nanjing |
  34. | 40 | houhan | luoyang |
  35. | 50 | beisong | kaifeng |
  36. | 60 | 魏国 | 洛阳 |
  37. +-----+---------+----------+
  38. 6 rows in set (0.00 sec)

第二步,备份多个库
MYSQL入门

  1. [root@serv01 databackup]# mysqldump -uroot -p123456 --databases larrydb game > larrydb_game.sql
  2. [root@serv01 databackup]# ll larrydb_game.sql 
  3. -rw-r--r--. 1 root root 6159 Sep 10 19:05 larrydb_game.sql

第三步,模拟数据丢失.
MYSQL入门

  1. mysql> drop database game;
  2. Query OK, 3 rows affected (0.01 sec)
  3. mysql> drop database larrydb;
  4. Query OK, 2 rows affected (0.00 sec)
  5. mysql> use crm;
  6. Database changed
  7. mysql> show tables;
  8. +---------------+
  9. | Tables_in_crm |
  10. +---------------+
  11. | test  |
  12. +---------------+
  13. 1 row in set (0.00 sec)
  14. mysql> select * from test;
  15. Empty set (0.00 sec)
  16. mysql> drop database crm;
  17. Query OK, 1 row affected (0.00 sec)

第四步,恢复数据
MYSQL入门

  1. [root@serv01 databackup]# mysql -uroot -p123456 < larrydb_game.sql

 
第五步,查看数据是否正常
MYSQL入门

  1. [root@serv01 data]# mysql -uroot -p123456
  2. Welcome to the MySQL monitor. Commands end with ; or \g.
  3. Your MySQL connection id is 9
  4. Server version: 5.5.29-log Source distribution
  5. Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.
  6. Oracle is a registered trademark of Oracle Corporation and/or its
  7. affiliates. Other names may be trademarks of their respective
  8. owners.
  9. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
  10. mysql> show databases;
  11. +--------------------+
  12. | Database  |
  13. +--------------------+
  14. | information_schema |
  15. | game  |
  16. | hello  |
  17. | larrydb  |
  18. | mnt  |
  19. | mysql  |
  20. | performance_schema |
  21. | test  |
  22. +--------------------+
  23. 8 rows in set (0.00 sec)
  24. mysql> use game;
  25. Database changed
  26. mysql> select * from country;
  27. +-----+---------+----------+
  28. | cno | cname | location |
  29. +-----+---------+----------+
  30. | 10 | caowei | luoyang |
  31. | 20 | shuhan | chengdou |
  32. | 30 | sunwu | nanjing |
  33. | 40 | houhan | luoyang |
  34. | 50 | beisong | kaifeng |
  35. | 60 | 魏国 | 洛阳 |
  36. +-----+---------+----------+
  37. 6 rows in set (0.00 sec)
  38. mysql> use larrydb;
  39. Database changed
  40. mysql> select * from class;
  41. +------+--------+
  42. | cid | cname |
  43. +------+--------+
  44. | 1 | linux |
  45. | 2 | oracle |
  46. +------+--------+
  47. 2 rows in set (0.00 sec)

 
备份所有的库
MYSQL入门

  1. [root@serv01 databackup]# mysqldump --help | grep all-database
  2. OR mysqldump [OPTIONS] --all-databases [OPTIONS]
  3.  -A, --all-databases Dump all the databases. This will be same as --databases
  4.    --databases= or --all-databases), the logs will be
  5.    --all-databases or --databases is given.
  6. all-databases   FALSE
  7. [root@serv01 databackup]# mysqldump -uroot -p123456 --all-databases > all_databases.sql
  8. [root@serv01 databackup]# ll all_databases.sql -h
  9. -rw-r--r--. 1 root root 506K Sep 10 19:16 all_databases.sql

备份某张表或者某几张表
第一步,备份某张表和某几张表MYSQL入门

  1. [root@serv01 databackup]# mysqldump game hero country -uroot -p123456 > game_hero_country.sql
  2. [root@serv01 databackup]# ll game_hero_country.sql 
  3. -rw-r--r―. 1 root root 3955 Sep 10 19:11 game_hero_country.sql

第二步,模拟数据丢失
MYSQL入门

  1. mysql> use game;
  2. Database changed
  3. mysql> show tables;
  4. +----------------+
  5. | Tables_in_game |
  6. +----------------+
  7. | country |
  8. | fight  |
  9. | hero  |
  10. +----------------+
  11. 3 rows in set (0.00 sec)
  12. mysql> drop table hero;
  13. Query OK, 0 rows affected (0.00 sec)
  14. mysql> drop table country;
  15. Query OK, 0 rows affected (0.00 sec)
  16.

第三步,查看数据是否正常
MYSQL入门

  1. [root@serv01 databackup]# mysql -uroot -p123456 < game_hero_country.sql 
  2. ERROR 1046 (3D000) at line 22: No database selected
  3. [root@serv01 databackup]# mysql -uroot -p123456 --database game < game_hero_country.sql 
  4. [root@serv01 databackup]# mysql -uroot -p123456 -e "select * from game.country"
  5. +-----+---------+----------+
  6. | cno | cname | location |
  7. +-----+---------+----------+
  8. | 10 | caowei | luoyang |
  9. | 20 | shuhan | chengdou |
  10. | 30 | sunwu | nanjing |
  11. | 40 | houhan | luoyang |
  12. | 50 | beisong | kaifeng |
  13. | 60 | 魏国 | 洛阳 |
  14. +-----+---------+----------+

通过这两天关于MySQL热备和冷备的学习,大家是不是对MySQL备份与恢复的了解更加深入了,不管是冷备还是热备其目的都是一致的保证数据的完整性和一致性,切记,备份重于一切!!!
MYSQL入门

相信今天所学的知识在之后的学习工作中对大家有所帮助.MYSQL入门

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