使用mysqldump模拟生产环境实现mysql数据库的备份与还原

mysql数据库的备份与还原

一、mysqldump备份单个数据库及还原过程

错误演示：

下面整个过程我们都已jiaowu库为模板，进行演示
[root@localhost ~]# ls
anaconda-ks.cfg         cmake-2.8.8               install.log         linux-2.6.38.5.tar.bz2  mysql-5.5.28.tar.gz
busybox-1.20.2          cmake-2.8.8.tar.gz        install.log.syslog  lvs-nat
busybox-1.20.2.tar.bz2  config-2.6.38.5-i686.cfg  jiaowu.sql          mysql-5.5.28
[root@localhost ~]# mysql < jiaowu.sql    #读取sql脚本，并创建jiaowu库
[root@localhost ~]# rm jiaowu.sql
rm: remove regular file `jiaowu.sql'? y   #删除jiaowu.sql
[root@localhost ~]# mysqldump -uroot -p jiaowu > /root/jiaowu.sql  #将jiaowu库备份为jiaowu.sql
Enter password:
[root@localhost ~]# ls
anaconda-ks.cfg         cmake-2.8.8               install.log         linux-2.6.38.5.tar.bz2  mysql-5.5.28.tar.gz
busybox-1.20.2          cmake-2.8.8.tar.gz        install.log.syslog  lvs-nat
busybox-1.20.2.tar.bz2  config-2.6.38.5-i686.cfg  jiaowu.sql          mysql-5.5.28
[root@localhost ~]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.5.28-log Source distribution

Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| jiaowu             |
| mysql              |
| performance_schema |
| test               |
+--------------------+
5 rows in set (0.00 sec)

mysql> drop database jiaowu;    #删除jiaowu库
Query OK, 4 rows affected (1.11 sec)

mysql> create database studb;   #创建一个库，用于jiaowu库的还原
Query OK, 1 row affected (0.03 sec)

mysql> \q
Bye
[root@localhost ~]# mysql studb < jiaowu.sql
[root@localhost ~]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 7
Server version: 5.5.28-log Source distribution

Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| studb              |
| test               |
+--------------------+
5 rows in set (0.00 sec)

 

注意：上述过程看似正确，实则不然，真正的生产环境中，会面临读写操作的同时进行，所以用上述过程备份的数据库还原时，会造成时间点上的不一致，并且用户的在备份过程中的写操作并没还原至数据库中，又造成了数据的不完整性，下面我们来模拟生产环境正确演示一遍完整过程！

 

二、mysqldump+二进制日志备份整个mysql数据库以及及时点还原的过程（温备）

 

备份策略：

 

备份策略：每周完全备份+每日增量备份
    完全备份：mysqldump
    增量备份：备份二进制日志文件（每次备份前：flush logs）

1、完全备份

[root@localhost ~]# mysqldump -uroot -p --lock-all-tables --flush-logs --all-databases --master-data=2 > /root/alldatabases.sql
Enter password:
[root@localhost ~]# ls
alldatabases.sql  busybox-1.20.2.tar.bz2  config-2.6.38.5-i686.cfg  jiaowu.sql              mysql-5.5.28
anaconda-ks.cfg   cmake-2.8.8             install.log               linux-2.6.38.5.tar.bz2  mysql-5.5.28.tar.gz
busybox-1.20.2    cmake-2.8.8.tar.gz      install.log.syslog        lvs-nat
[root@localhost ~]# vim alldatabases.sql
这只是一部分，说明一下：

-- Position to start replication or point-in-time recovery from
--

-- CHANGE MASTER TO MASTER_LOG_FILE='mysql-bin.000005', MASTER_LOG_POS=107;     #这就是记录当前二进制日志文件的位置

--
-- Current Database: `mysql`
--

CREATE DATABASE /*!32312 IF NOT EXISTS*/ `mysql` /*!40100 DEFAULT CHARACTER SET latin1 */;   #做完全备份时，还能够自动创建数据库

USE `mysql`;

--
-- Table structure for table `general_log`

选项说明：

--master-data={0|1|2}
    0: 表示不记录二进制日志文件及其位置
    1：以CHANGER MASTER TO 的方式记录位置，可用于恢复后直接启动从服务器
    2：以CHANGER MASTER TO 的方式记录位置，但默认为被注释
--lock-all-tables: 锁定所有表
--flush-logs: 滚动日志

如果指定库中的表类型均为InnoDB，可使用--single-transaction启动热备，这个选项不要和--lock-all-tables一起使用

mysqldump是将整个表中的数据备份为了批量插入的insert语句，但是还原时，他不能创建数据库，必须手动创建数据库，然后再将数据还原至此数据库

 

2、模拟生产环境，执行写操作（第一天的增量）

 

[root@localhost ~]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.5.28-log Source distribution

Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> purge binary logs to 'mysql-bin.000005';    #刚才完全备份时，二进制日志也备份了，我们把之前的删除，但是在生产环境中，不建议就这样删除。先复制一份，说不定有救急作用
Query OK, 0 rows affected (1.40 sec)

mysql> show binary logs;    #查看当前数据库上的二进制日志文件
+------------------+-----------+
| Log_name         | File_size |
+------------------+-----------+
| mysql-bin.000005 |       107 |
+------------------+-----------+
1 row in set (0.00 sec)

mysql> use studb;
Database changed
mysql> select * from tutors;
+-----+--------------+--------+------+
| TID | Tname        | Gender | Age  |
+-----+--------------+--------+------+
|   1 | HongQigong   | M      |   93 |
|   2 | HuangYaoshi  | M      |   63 |
|   3 | Miejueshitai | F      |   72 |
|   4 | OuYangfeng   | M      |   76 |
|   5 | YiDeng       | M      |   90 |
|   6 | YuCanghai    | M      |   56 |
|   7 | Jinlunfawang | M      |   67 |
|   8 | HuYidao      | M      |   42 |
|   9 | NingZhongze  | F      |   49 |
+-----+--------------+--------+------+
9 rows in set (0.01 sec)

mysql> delete from tutors where age>80;  #删除几行
Query OK, 2 rows affected (0.03 sec)

mysql> select * from tutors;
+-----+--------------+--------+------+
| TID | Tname        | Gender | Age  |
+-----+--------------+--------+------+
|   2 | HuangYaoshi  | M      |   63 |
|   3 | Miejueshitai | F      |   72 |
|   4 | OuYangfeng   | M      |   76 |
|   6 | YuCanghai    | M      |   56 |
|   7 | Jinlunfawang | M      |   67 |
|   8 | HuYidao      | M      |   42 |
|   9 | NingZhongze  | F      |   49 |
+-----+--------------+--------+------+
7 rows in set (0.00 sec)

mysql> \q
Bye

 

3、增量备份

 

[root@localhost ~]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.5.28-log Source distribution

Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> flush logs;  #必须执行日志滚动
Query OK, 0 rows affected (0.01 sec)

mysql> \q
Bye
[root@localhost ~]# cd /mydata/data      #mysql-bin.000005就是我们第一天的数据增量
[root@localhost data]# ls
ibdata1      ib_logfile1                localhost.localdomain.pid  mysql-bin.000005  mysql-bin.index     studb
ib_logfile0  localhost.localdomain.err  mysql                      mysql-bin.000006  performance_schema  test
[root@localhost data]# mysqlbinlog mysql-bin.000005 > /root/mon-indremental.sql    #将数据读取出来，并保存

4、模拟生产环境，mysql数据库坏了的场景

连上数据库，插入一条新数据
[root@localhost data]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.5.28-log Source distribution

Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use studb;
Database changed
mysql> insert into tutors (tname) values ('stu123');
Query OK, 1 row affected (0.01 sec)

mysql> \q
Bye
[root@localhost data]# ls
ibdata1      ib_logfile1                localhost.localdomain.pid  mysql-bin.000005  mysql-bin.index     studb
ib_logfile0  localhost.localdomain.err  mysql                      mysql-bin.000006  performance_schema  test
[root@localhost data]# cp mysql-bin.000006 /root   #把二进制日志复制出来，因为我们要用它做及时点还原

这是我们把数据库的所有数据都删除，数据库已坏
[root@localhost data]# rm -rf ./*

服务停止不了，我们杀死进程
[root@localhost data]# service mysqld stop
MySQL server PID file could not be found!                  [FAILED]
[root@localhost data]# killall mysqld

这是我们千万不要试图启动mysql，先初始化数据库
[root@localhost data]# cd /usr/local/mysql/
[root@localhost mysql]# ls
bin  COPYING  data  docs  include  INSTALL-BINARY  lib  man  mysql-test  README  scripts  share  sql-bench  support-files
[root@localhost mysql]# scripts
scripts
[root@localhost mysql]# scripts/mysql_install_db --user=mysql --datadir=/mydata/data

初始化完成以后再启动mysql
[root@localhost mysql]# service mysqld start
Starting MySQL.....                                        [  OK  ]
[root@localhost mysql]# cd

5、数据还原

完全备份还原

[root@localhost ~]# mysql < alldatabases.sql
[root@localhost ~]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.5.28-log Source distribution

Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use studb;
Database changed
mysql> select * from tutors;      #此时大于80的连个用户都在
+-----+--------------+--------+------+
| TID | Tname        | Gender | Age  |
+-----+--------------+--------+------+
|   1 | HongQigong   | M      |   93 |
|   2 | HuangYaoshi  | M      |   63 |
|   3 | Miejueshitai | F      |   72 |
|   4 | OuYangfeng   | M      |   76 |
|   5 | YiDeng       | M      |   90 |
|   6 | YuCanghai    | M      |   56 |
|   7 | Jinlunfawang | M      |   67 |
|   8 | HuYidao      | M      |   42 |
|   9 | NingZhongze  | F      |   49 |
+-----+--------------+--------+------+
9 rows in set (0.00 sec)

增量备份还原

[root@localhost ~]# mysql < mon-indremental.sql
[root@localhost ~]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.5.28-log Source distribution

Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use studb;
Database changed
mysql> select * from tutors;    #此时大于80的两个用户已没有了
+-----+--------------+--------+------+
| TID | Tname        | Gender | Age  |
+-----+--------------+--------+------+
|   2 | HuangYaoshi  | M      |   63 |
|   3 | Miejueshitai | F      |   72 |
|   4 | OuYangfeng   | M      |   76 |
|   6 | YuCanghai    | M      |   56 |
|   7 | Jinlunfawang | M      |   67 |
|   8 | HuYidao      | M      |   42 |
|   9 | NingZhongze  | F      |   49 |
+-----+--------------+--------+------+
7 rows in set (0.00 sec)


及时点还原

[root@localhost ~]# mysqlbinlog mysql-bin.000006 > temp.sql
[root@localhost ~]# mysql < temp.sql
[root@localhost ~]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.5.28-log Source distribution

Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use studb;
Database changed
mysql> select * from tutors;   #插入的数据也存在了
+-----+--------------+--------+------+
| TID | Tname        | Gender | Age  |
+-----+--------------+--------+------+
|   2 | HuangYaoshi  | M      |   63 |
|   3 | Miejueshitai | F      |   72 |
|   4 | OuYangfeng   | M      |   76 |
|   6 | YuCanghai    | M      |   56 |
|   7 | Jinlunfawang | M      |   67 |
|   8 | HuYidao      | M      |   42 |
|   9 | NingZhongze  | F      |   49 |
|  10 | stu123       | M      | NULL |
+-----+--------------+--------+------+
8 rows in set (0.00 sec)

   

    这时我们的mysql数据库已还原至我们损坏时的那一刻了，大家都来试试吧，但是使mysqldump来实现mysql的备份与还原，只能应用于那些读写量不大的小企业，因为备份过程太慢了，会造成精度的丢失！

 

 

 

 

 

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