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利用binlog进行数据库的还原

2022-07-19 11:53:03
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  前言:在学习mysql备份的时候,深深的感受到mysql的备份还原功能没有oracle强大;比如一个很常见的恢复场景:基于时间点的恢复,oracle通过rman工具就能够很快的实现数据库的恢复,但是mysql在进行不完全恢复的时候很大的一部分要依赖于mysqlbinlog这个工具运行binlog语句来实现,本文档介绍通过mysqlbinlog实现各种场景的恢复;
  一、测试环境说明:使用mysqlbinlog工具的前提需要一个数据库的完整性备份,所以需要事先对数据库做一个完整的备份,本文档通过mysqlbackup进行数据库的全备(mysqlbackup的使用:http://blog.itpub.net/12679300/viewspace-1329578/);
 
  二、测试步骤说明:
  数据库的插入准备工作
  2.1 在时间点A进行一个数据库的完整备份;
  2.2 在时间点B创建一个数据库BKT,并在BKT下面创建一个表JOHN,并插入5条数据;
  2.3 在时间点C往表JOHN继续插入数据到10条;
 
  数据库的恢复工作
  2.4 恢复数据库到时间点A,然后检查数据库表的状态;
  2.5 恢复数据库到时间点B,检查相应的系统状态;
  2.6 恢复数据库到时间点C,并检查恢复的状态;
  三、场景模拟测试步骤(备份恢复是一件很重要的事情)
  3.1 执行数据库的全备份;
 
  点击(此处)折叠或打开
 
  [root@mysql01 backup]# mysqlbackup --user=root --password --backup-dir=/backup backup-and-apply-log //运行数据库的完整备份
  3.2 创建数据库、表并插入数据
  点击(此处)折叠或打开
 
  mysql> SELECT CURRENT_TIMESTAMP;
  +---------------------+
  | CURRENT_TIMESTAMP |
  +---------------------+
  | 2014-11-26 17:51:27 |
  +---------------------+
  1 row in set (0.01 sec)
 
  mysql> show databases; //尚未创建数据库BKT
  +--------------------+
  | Database |
  +--------------------+
  | information_schema |
  | john |
  | mysql |
  | performance_schema |
  +--------------------+
  4 rows in set (0.03 sec)
 
  mysql> Ctrl-C --
  Aborted
  [root@mysql02 data]# mysql -uroot -p
  Enter password:
  Welcome to the MySQL monitor. Commands end with ; or //g.
  Your MySQL connection id is 2
  Server version: 5.5.36-log Source distribution
  Copyright (c) 2000, 2014, 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 master status;
  +------------------+----------+--------------+------------------+
  | File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
  +------------------+----------+--------------+------------------+
  | mysql-bin.000001 | 107 | | | //当前数据库log的pos状态
  +------------------+----------+--------------+------------------+
  1 row in set (0.00 sec)
  mysql> SELECT CURRENT_TIMESTAMP; //当前的时间戳 当前时间点A
  +---------------------+
  | CURRENT_TIMESTAMP |
  +---------------------+
  | 2014-11-26 17:54:12 |
  +---------------------+
  1 row in set (0.00 sec)
  mysql> create database BKT; //创建数据库BKT
  Query OK, 1 row affected (0.01 sec)
  mysql> create table john (id varchar(32));
  ERROR 1046 (3D000): No database selected
  mysql> use bkt;
  ERROR 1049 (42000): Unknown database /'bkt/'
  mysql> use BKT;
  Database changed
  mysql> create table john (id varchar(32));
  Query OK, 0 rows affected (0.02 sec)
  mysql> insert into john values(/'1/');
  Query OK, 1 row affected (0.01 sec)
  mysql> insert into john values(/'2/');
  Query OK, 1 row affected (0.01 sec)
  mysql> insert into john values(/'3/');
  Query OK, 1 row affected (0.00 sec)
  mysql> insert into john values(/'4/');
  Query OK, 1 row affected (0.01 sec)
  mysql> insert into john values(/'5/');
  Query OK, 1 row affected (0.01 sec)
  mysql> SELECT CURRENT_TIMESTAMP; //插入5条数据后数据库的时间点B,记录该点便于数据库的恢复
  +---------------------+
  | CURRENT_TIMESTAMP |
  +---------------------+
  | 2014-11-26 17:55:53 |
  +---------------------+
  1 row in set (0.00 sec)
  
  mysql> show master status;
  +------------------+----------+--------------+------------------+
  | File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
  +------------------+----------+--------------+------------------+
  | mysql-bin.000001 | 1204 | | | //当前binlog的pos位置
  +------------------+----------+--------------+------------------+
  1 row in set (0.00 sec)
   3.3 设置时间点C的测试
 
  点击(此处)折叠或打开
 
  mysql> insert into john values(/'6/');
  Query OK, 1 row affected (0.02 sec)
  mysql> insert into john values(/'7/');
  Query OK, 1 row affected (0.01 sec)
  mysql> insert into john values(/'8/');
  Query OK, 1 row affected (0.01 sec)
  mysql> insert into john values(/'9/');
  Query OK, 1 row affected (0.01 sec)
  mysql> insert into john values(/'10/');
  Query OK, 1 row affected (0.03 sec)
  mysql> show master status;
  +------------------+----------+--------------+------------------+
  | File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
  +------------------+----------+--------------+------------------+
  | mysql-bin.000001 | 2125 | | |
  +------------------+----------+--------------+------------------+
  1 row in set (0.00 sec)
  mysql> SELECT CURRENT_TIMESTAMP;
  +---------------------+
  | CURRENT_TIMESTAMP |
  +---------------------+
  | 2014-11-26 17:58:08 |
  +---------------------+
  1 row in set (0.00 sec)
   3.4 以上的操作完成之后,便可以执行数据库的恢复测试
 
  点击(此处)折叠或打开
 
  [root@mysql02 data]# mysqlbackup --defaults-file=/backup/server-my.cnf --datadir=/data/mysql --backup-dir=/backup/ copy-back
  MySQL Enterprise Backup version 3.11.0 Linux-3.8.13-16.2.1.el6uek.x86_64-x86_64 [2014/08/26]
  Copyright (c) 2003, 2014, Oracle and/or its affiliates. All Rights Reserved.
   mysqlbackup: INFO: Starting with following command line ...
   mysqlbackup --defaults-file=/backup/server-my.cnf --datadir=/data/mysql
          --backup-dir=/backup/ copy-back
   mysqlbackup: INFO:
  IMPORTANT: Please check that mysqlbackup run completes successfully.
             At the end of a successful /'copy-back/' run mysqlbackup
             prints /"mysqlbackup completed OK!/".
  141126 17:59:58 mysqlbackup: INFO: MEB logfile created at /backup/meta/MEB_2014-11-26.17-59-58_copy_back.log
  --------------------------------------------------------------------
                         Server Repository Options:
  --------------------------------------------------------------------
    datadir = /data/mysql
    innodb_data_home_dir = /data/mysql
    innodb_data_file_path = ibdata1:10M:autoextend
    innodb_log_group_home_dir = /data/mysql/
    innodb_log_files_in_group = 2
    innodb_log_file_size = 5242880
    innodb_page_size = Null
    innodb_checksum_algorithm = none
  --------------------------------------------------------------------
                         Backup Config Options:
  --------------------------------------------------------------------
    datadir = /backup/datadir
    innodb_data_home_dir = /backup/datadir
    innodb_data_file_path = ibdata1:10M:autoextend
    innodb_log_group_home_dir = /backup/datadir
    innodb_log_files_in_group = 2
    innodb_log_file_size = 5242880
    innodb_page_size = 16384
    innodb_checksum_algorithm = none
   mysqlbackup: INFO: Creating 14 buffers each of size 16777216.
  141126 17:59:58 mysqlbackup: INFO: Copy-back operation starts with following threads
          1 read-threads 1 write-threads
   mysqlbackup: INFO: Could not find binlog index file. If this is online backup then server may not have started with --log-bin.
          Hence, binlogs will not be copied for this backup. Point-In-Time-Recovery will not be possible.
  141126 17:59:58 mysqlbackup: INFO: Copying /backup/datadir/ibdata1.
   mysqlbackup: Progress in MB: 200 400 600
  141126 18:00:22 mysqlbackup: INFO: Copying the database directory /'john/'
  141126 18:00:23 mysqlbackup: INFO: Copying the database directory /'mysql/'
  141126 18:00:23 mysqlbackup: INFO: Copying the database directory /'performance_schema/'
  141126 18:00:23 mysqlbackup: INFO: Completing the copy of all non-innodb files.
  141126 18:00:23 mysqlbackup: INFO: Copying the log file /'ib_logfile0/'
  141126 18:00:23 mysqlbackup: INFO: Copying the log file /'ib_logfile1/'
  141126 18:00:24 mysqlbackup: INFO: Creating server config files server-my.cnf and server-all.cnf in /data/mysql
  141126 18:00:24 mysqlbackup: INFO: Copy-back operation completed successfully.
  141126 18:00:24 mysqlbackup: INFO: Finished copying backup files to /'/data/mysql/'
  mysqlbackup completed //数据库恢复完成
   授权并打开数据库
 
  点击(此处)折叠或打开
 
  [root@mysql02 data]# chmod -R 777 mysql //需要授权后才能打开
  [root@mysql02 data]# cd mysql
  [root@mysql02 mysql]# ll
  总用量 733220
  -rwxrwxrwx. 1 root root 305 11月 26 18:00 backup_variables.txt
  -rwxrwxrwx. 1 root root 740294656 11月 26 18:00 ibdata1
  -rwxrwxrwx. 1 root root 5242880 11月 26 18:00 ib_logfile0
  -rwxrwxrwx. 1 root root 5242880 11月 26 18:00 ib_logfile1
  drwxrwxrwx. 2 root root 4096 11月 26 18:00 john
  drwxrwxrwx. 2 root root 4096 11月 26 18:00 mysql
  drwxrwxrwx. 2 root root 4096 11月 26 18:00 performance_schema
  -rwxrwxrwx. 1 root root 8488 11月 26 18:00 server-all.cnf
  -rwxrwxrwx. 1 root root 1815 11月 26 18:00 server-my.cnf //没有BKT数据库
  [root@mysql02 mysql]# service mysqld start //启动数据库
   3.5 进行数据库的恢复到时间点B
 
  点击(此处)折叠或打开
 
  [root@mysql02 mysql2]# pwd //备份的时候,需要备份binlog日志,之前的binlog目录为/data/mysql2
  /data/mysql2
  [root@mysql02 mysql2]# mysqlbinlog --start-position=107 --stop-position=1203 mysql-bin.000001| mysql -uroot -p //根据post的位置进行恢复,当前的pos位置为107,恢复到pos位置到1203
  Enter password:
  [root@mysql02 mysql2]# mysql -uroot -p
  Enter password:
  Welcome to the MySQL monitor. Commands end with ; or //g.
  Your MySQL connection id is 3
  Server version: 5.5.36-log Source distribution
  Copyright (c) 2000, 2014, 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 |
  | BKT |
  | john |
  | mysql |
  | performance_schema |
  +--------------------+
  5 rows in set (0.02 sec)
  mysql> use BKT
  Database changed
  mysql> show tables;
  +---------------+
  | Tables_in_BKT |
  +---------------+
  | john |
  +---------------+
  1 row in set (0.00 sec)
  mysql> select * from john;
  +------+
  | id |
  +------+
  | 1 |
  | 2 |
  | 3 |
  | 4 |
  | 5 |
  +------+
  5 rows in set (0.01 sec) //查看数据库恢复成功
   3.6 恢复数据库到时间点C
 
  点击(此处)折叠或打开
 
  [root@mysql02 mysql2]# mysqlbinlog --start-date=/"2014-11-27 09:21:56/" --stop-date=/"2014-11-27 09:22:33/" mysql-bin.000001| mysql -uroot -p123456 //本次通过基于时间点的恢复,恢复到时间点C
  Warning: Using unique option prefix start-date instead of start-datetime is deprecated and will be removed in a future release. Please use the full name instead.
  Warning: Using unique option prefix stop-date instead of stop-datetime is deprecated and will be removed in a future release. Please use the full name instead.
  [root@mysql02 mysql2]# mysql -uroot -p
  Enter password:
  Welcome to the MySQL monitor. Commands end with ; or //g.
  Your MySQL connection id is 6
  Server version: 5.5.36-log Source distribution
  Copyright (c) 2000, 2014, 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 |
  | BKT |
  | john |
  | mysql |
  | performance_schema |
  +--------------------+
  5 rows in set (0.00 sec)
  mysql> use BKT
  Database changed
  mysql> select * from john;
  +------+
  | id |
  +------+
  | 1 |
  | 2 |
  | 3 |
  | 4 |
  | 5 |
  | 6 |
  | 7 |
  | 8 |
  | 9 |
  | 10 |
  +------+
  10 rows in set (0.00 sec) //经过检查成功恢复到时间点C
  
  四、mysqlbinlog的其他总结:以上是利用binlog文件进行基于时间点和binlog的POS位置恢复的测试,mysqlbinlog的使用还有很多功能,运行mysqlbinlog --help可以查看相应参数;
  4.1 查看binlog的内容:[root@mysql02 mysql2]# mysqlbinlog mysql-bin.000001
  4.2 mysqlbinlog的其他常用参数:
  -h  根据数据库的IP
  -P  根据数据库所占用的端口来分
  -server-id 根据数据库serverid来还原(在集群中很有用)
  -d  根据数据库名称
 
  例如: [root@mysql02 mysql2]# mysqlbinlog -d BKT mysql-bin.000001//还原BKT数据库的信息
 
  参数的组合使用:
  点击(此处)折叠或打开
 
  [root@mysql02 mysql2]# mysqlbinlog --start-date=/"2014-11-27 09:21:56/" --stop-date=/"2014-11-27 09:22:33/" -d BKT -h 127.0.0.1 /var/lib/mysql/mysql-bin.000001 |mysql -u root -p
  #如果有多个binlog文件,用逗号隔开;
  
  4.4 恢复是一件很重要的事情,如果不知道具体要恢复的时间点,请把binlog文件先转换成文本文件,详细查看完相应的内容再进行恢复;
  [root@mysql02 mysql2]# mysqlbinlog mysql-bin.000001 > /tmp/00001.sql
 
  总结:备份有时候永远都用不上,但是你永远也不知道什么时候会用上,正所谓养兵千日用兵一时,作为一个合格的DBA有个可用的备份,就可以做到胸有成竹。

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