Mysql实战之数据备份

author：JevonWei
版权声明：原创作品

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数据备份和恢复

mysqldump

冷备份单库(不会创建新库，需要手动创建并指定导入数据的库)
    将本机的mydb数据库备份到/app/mydb.backup-$(date +%F-%H-%M-%S)文件
    [root@danran ~]# mysqldump mydb > /app/mydb.backup-$(date +%F-%H-%M-%S)
    [root@danran ~]# ll /app/mydb.backup-2017-09-12-14-18-44 
    -rw-r--r--. 1 root root 70488 Sep 12 14:18 /app/mydb.backup-2017-09-12-14-18-44

恢复数据

新建一个数据库做示例
MariaDB [(none)]> CREATE DATABASE testdb;

将备份的数据库文件导入到testdb新建数据库中
[root@danran ~]# mysql testdb < /app/mydb.backup-2017-09-12-14-18-44

进入到testdb测试数据库中，查看数据是否恢复
MariaDB [testdb]> use testdb;
MariaDB [testdb]> SHOW TABLES;
+------------------+
| Tables_in_testdb |
+------------------+
| students         |
+------------------+

冷备份多个库文件(可自动创建新库)

mysql节点A备份数据
[root@danran ~]# mysqldump --databases mydb testdb mysql > /app/mydb-testdb-mysql-backup-$(date +F-%H-%M-%S) 

mysql及节点B远程恢复数据
创建并授权恢复数据时使用的账号
MariaDB [(none)]> GRANT ALL ON *.* TO 'admin'@'172.16.253.105' IDENTIFIED BY 'admin';
MariaDB [(none)]> GRANT ALL ON *.* TO 'admin'@'%.danran.com' IDENTIFIED BY 'admin';
MariaDB [(none)]> FLUSH PRIVILEGES;

Mysql节点A将备份的多库数据文件导入到远程mysql服务器节点B
[root@danran ~]# mysql -uadmin -h'172.16.253.108' -padmin < /app/mydb-testdb-mysql-backup-F-14-32-28 

Mysql节点B查看数据是否恢复成功,即mydb，testdb，mysql文件恢复成功
MariaDB [(none)]> SHOW DATABASES; 
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mydb               |
| mysql              |
| testdb             |
+--------------------+

InnoDB引擎热备份数据文件

备份前应该先将所有表锁定
MariaDB [testdb]> FLUSH TABLES WITH READ LOCK;
滚动数据库
MariaDB [testdb]> FLUSH LOGS;
查看二进制日志文件
MariaDB [testdb]> SHOW MASTER LOGS;
+-------------------+-----------+
| Log_name          | File_size |
+-------------------+-----------+
| master-log.000001 |       289 |
| master-log.000002 |       654 |
| master-log.000003 |     69738 |
| master-log.000004 |       245 |
+-------------------+-----------+

热备份数据库文件
[root@danran ~]# mysqldump --single-transaction mydb > /app/mydb-backup-$(date +%F-%H-%M-%S);
数据恢复如上

模拟数据温备份与数据恢复

开启二进制日志文件记录
[root@danran ~]# vim /etc/my.cnf.d/server.cnf 
[mysqld]
log_bin=master-log
[root@danran ~]# systemctl restart mariadb

有可以远程登录进行数据恢复的用户，进而使用远程恢复数据
MariaDB [(none)]> GRANT ALL ON *.* TO 'admin'@'172.16.253.%' IDENTIFIED BY 'admin';
MariaDB [(none)]> GRANT ALL ON *.* TO 'admin'@'%.danran.com' IDENTIFIED BY 'admin'; \防止反解主机名
MariaDB [(none)]> FLUSH PRIVILEGES;

滚动数据库
MariaDB [testdb]> FLUSH LOGS;

温备份所有数据库文件到远程服务器
[root@danran ~]# mysqldump -x -R -E --triggers --all-databases --master-data=1 > /tmp/alldatabases-backup-$(date +%F-%H-%M-%S);
[root@danran ~]# mysqldump -x -R -E --triggers --all-databases --master-data=2 --flush-logs > /tmp/alldatabases-backup-$(date +%F-%H-%M-%S);

创建新表,此新表不在备份的文件中，而仅仅存在于二进制日志文件中
MariaDB [mydb]> CREATE TABLE teachers (tid INT UNSIGNED PRIMARY KEY AUTO_INCREMENT,name VARCHAR(200));
插入数据
MariaDB [mydb]> INSERT INTO teachers (name) VALUES ('LI'),('WEI');
MariaDB [mydb]> SHOW MASTER STATUS; 
+-------------------+----------+--------------+------------------+
| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+-------------------+----------+--------------+------------------+
| master-log.000006 |      628 |              |                  |
+-------------------+----------+--------------+------------------+

mariadb服务器损坏，所有的数据文件丢失，但备份的二进制日志文件/var/lib/mysql/master-log.000006仍然存在
[root@danran ~]# systemctl stop mariadb

将备份之后的所有二进制日志文件读取出来并保存到文件中
[root@danran ~]# mysqlbinlog /var/lib/mysql/master-log.000006 > /app/alldatabase.binlog

模拟数据文件全部丢失
[root@danran ~]# rm -rf /var/lib/mysql/*

数据库恢复启动之后，所有库文件丢失
[root@danran ~]# systemctl start mariadb
MariaDB [(none)]> SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
+--------------------+

先暂时关闭二进制日志文件
[root@danran ~]# vim /etc/my.cnf.d/server.cnf 
[mysqld]
#log_bin=master-log
[root@danran ~]# systemctl restart mariadb

将备份文件和二进制日志文件依次恢复数据
[root@danran ~]# mysql -uadmin -h172.16.253.108 -padmin < /tmp/alldatabases-backup-2017-09-12-15-07-37;
[root@danran ~]# mysql -uadmin -h172.16.253.108 -padmin < /app/alldatabase.binlog 
登录数据库，数据以完全恢复
MariaDB [(none)]> SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mydb               |
| mysql              |
| performance_schema |
| test               |
| testdb             |
+--------------------+

MariaDB [(none)]> use mydb;
MariaDB [mydb]> SHOW TABLES;  \teachers表是从二进制日志文件中恢复而来
+----------------+
| Tables_in_mydb |
+----------------+
| students       |
| teachers       |
+----------------+

开启二进制日志文件记录
[root@danran ~]# vim /etc/my.cnf.d/server.cnf 
[mysqld]
log_bin=master-log
[root@danran ~]# systemctl restart mariadb

Xtrabackup

下载Xtrabackup软件包，官网为http://www.percona.com/software/percona-xtrabackup/ 
安装Xtrabackup软件包 
[root@danran ~]# ls percona-xtrabackup-24-2.4.7-2.el7.x86_64.rpm 
percona-xtrabackup-24-2.4.7-2.el7.x86_64.rpm
[root@danran ~]# yum -y install ./percona-xtrabackup-24-2.4.7-2.el7.x86_64.rpm 
[root@danran ~]# rpm -ql  percona-xtrabackup-24
[root@danran ~]# man xtrabackup

创建备份存放目录
[root@danran ~]# mkdir /mydata/xbdata -pv

备份本地数据库文件到mydata/xbdata
[root@danran ~]# innobackupex --user=root --host=localhost [--password] /mydata/xbdata
[root@danran ~]# ls /mydata/xbdata/2017-09-12_16-45-10/
backup-my.cnf  mydb   performance_schema  testdb                  xtrabackup_info
ibdata1        mysql  test                xtrabackup_checkpoints  xtrabackup_logfile
	
[root@danran ~]# less /mydata/xbdata/2017-09-12_16-45-10/backup-my.cnf   \	mysql关键配置文件信息 
[root@danran ~]# less /mydata/xbdata/2017-09-12_16-45-10/ibdata1  \表空间文件
[root@danran ~]# less /mydata/xbdata/2017-09-12_16-45-10/xtrabackup_binlog_info \备份时自动记录处于二进制日志文件的哪个位置 
[root@danran ~]# less /mydata/xbdata/2017-09-12_16-45-10/xtrabackup_checkpoints 
backup_type = full-backuped  记录了备份类型为 full-backuped
from_lsn = 0  范围内的所有数据
to_lsn = 2085723
last_lsn = 2085723
compact = 0
recover_binlog_info = 0
[root@danran ~]# less /mydata/xbdata/2017-09-12_16-45-10/xtrabackup_info  \记录了备份程序文件的信息

基于全量备份恢复数据

模拟数据库损坏
[root@danran ~]# systemctl stop mariadb
[root@danran mysql]# rm -rf /var/lib/mysql/*

恢复还原数据

[root@danran ~]# cd /mydata/xbdata/2017-09-12_16-45-10/
同步该同步的数据
[root@danran 2017-09-12_16-45-10]# innobackupex --apply-log ./
将当前目录拷贝到/var/lib/mysql
[root@danran 2017-09-12_16-45-10]# innobackupex --copy-back ./
[root@danran 2017-09-12_16-45-10]# cd /var/lib/mysql
修改/var/lib/mysql目录下的所有文件属主、属组为mysql
[root@danran mysql]# chown -R mysql.mysql ./*
启动mariadb服务
[root@danran mysql]# systemctl start mariadb

登录数据库，数据已完全恢复
MariaDB [(none)]> SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mydb               |
| mysql              |
| performance_schema |
| test               |
| testdb             |
+--------------------+

模拟数据备份与恢复

数据库中插入大量数据，用做测试
	MariaDB [mydb]> create table students (stuid INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,name VARCHAR(200),age TINYINT UNSIGNED,gender ENUM('F','M'),major VARCHAR(200)); 
	[root@danran ~]# for i in {5..1000};do mysql -e "INSERT INTO mydb.students VALUES ('$i','stu$i',$[$RANDOM%100+1],'F','major$i')";done
	[root@danran ~]# for i in {1001..2000};do mysql -e "INSERT INTO mydb.students VALUES ('$i','stu$i',$[$RANDOM%100+1],'M','major$i')";done

开启二进制日志文件记录
[root@danran ~]# vim /etc/my.cnf.d/server.cnf
[mysqld]
log_bin=master-log

1. 数据库创建备份用户并授予最小权限
	mysql> CREATE USER ’bkpuser’@’localhost’ IDENTIFIED BY ’admin’;
	mysql> REVOKE ALL PRIVILEGES, GRANT OPTION FROM ’bkpuser’;
	mysql> GRANT RELOAD, LOCK TABLES, REPLICATION CLIENT ON *.* TO ’bkpuser’@’localhost’;
	mysql> FLUSH PRIVILEGES;
2. 完全备份所有库，即全量备份
	[root@danran ~]# innobackupex /mydata/xbdata/   \备份所有库文件到/mydata/xbdata/
	[root@danran ~]# cd /mydata/xbdata/2017-09-12_17-09-40/
	[root@danran 2017-09-12_17-09-40]# cat xtrabackup_checkpoints 
	backup_type = full-backuped  \完全备份
	from_lsn = 0  
	to_lsn = 2085937   \结束日志序列号为2085937
	last_lsn = 2085937
	compact = 0
	recover_binlog_info = 0
3. 登录数据库，修改数据
	MariaDB [(none)]> use mydb;
	MariaDB [mydb]> DELETE FROM students WHERE stuid=1300; \修改数据文件
	MariaDB [mydb]> DELETE FROM students WHERE stuid=1400;

4. 增量备份
	[root@danran ~]# innobackupex --incremental /mydata/xbdata/ --incremental-basedir=/mydata/xbdata/2017-09-12_17-09-40 \--incremental意为当前为增量备份，--incremental-basedir意为以哪个目录为基准做增量备份
	[root@danran ~]# cd /mydata/xbdata/2017-09-12_17-18-39/  \增量备份文件
	[root@danran 2017-09-12_17-18-39]# ls
	backup-my.cnf  mydb                test                    xtrabackup_info
	ibdata1.delta  mysql               testdb                  xtrabackup_logfile
	ibdata1.meta   performance_schema  xtrabackup_checkpoints
	[root@danran 2017-09-12_17-18-39]# less xtrabackup_checkpoints 
	backup_type = incremental
	from_lsn = 2085937 \增量备份的开始，同时也为完全备份的结束点
	to_lsn = 2088070 \结束日志序列号为2085937
	last_lsn = 2088070
	compact = 0
	recover_binlog_info = 0

4. 数据库中的数据再次发生变化
	MariaDB [mydb]> INSERT INTO teachers (name) VALUES ('xin'); \teschers表中插入数据，从而使数数据发生变化
	MariaDB [mydb]> SELECT * FROM teachers;
	+-----+------+
	| tid | name |
	+-----+------+
	|   1 | LI   |
	|   2 | WEI  |
	|   3 | xin  |
	+-----+------+
5. 再次增量备份
	[root@danran ~]# innobackupex --incremental /mydata/xbdata/ --incremental-basedir=/mydata/xbdata/2017-09-12_17-18-39 \以上次增量为基准做增量备份
	[root@danran ~]# cat /mydata/xbdata/2017-09-12_17-27-51/xtrabackup_checkpoints 
	backup_type = incremental
	from_lsn = 2088070  \日志序列号开始，同时为上一此增量序列号的结束
	to_lsn = 2088893   \当前结束序列号
	last_lsn = 2088893
	compact = 0
	recover_binlog_info = 0
6. 数据库中的数据再次发生变化
	MariaDB [mydb]> DELETE FROM teachers WHERE name='LI';
	MariaDB [mydb]> SELECT * FROM teachers;              
	+-----+------+
	| tid | name |
	+-----+------+
	|   2 | WEI  |
	|   3 | xin  |
	+-----+------+
7. 查看最后一次备份的xtrabackup_info文件中的binlog_pos位置
	[root@danran ~]# cat /mydata/xbdata/2017-09-12_17-38-44/xtrabackup_info 
	uuid = 2c60babb-979e-11e7-b88f-000c290e4787
	name = 
	tool_name = innobackupex
	tool_command = --incremental /mydata/xbdata/ --incremental-basedir=/mydata/xbdata/2017-09-12_17-27-51
	tool_version = 2.4.7
	ibbackup_version = 2.4.7
	server_version = 5.5.52-MariaDB
	start_time = 2017-09-12 17:38:44
	end_time = 2017-09-12 17:38:46
	lock_time = 0
	binlog_pos = filename 'master-log.000001', position '709'  \binlog_pos位置为master-log.000001中的709
	innodb_from_lsn = 2088893
	innodb_to_lsn = 2090173
	partial = N
	incremental = Y
	format = file
	compact = N
	compressed = N
	encrypted = N
8. 读取二进制日志文件
	[root@danran ~]# mkdir /mydata/binlogs  \新建存放读取二进制文件后数据的目录
	[root@danran ~]# mysqlbinlog -j 709 /var/lib/mysql/master-log.000001 > /mydata/binlogs/2017-09-12_17-38-44-binlog
		从master-log.000001二进制文件的709节点开始读取数据并保存在/mydata/binlogs/2017-09-12_17-38-44-binlog文件中
9. 模拟服务器损坏
	[root@danran ~]# systemctl stop mariadb
	[root@danran ~]# rm -rf  /var/lib/mysql/* 
10. 恢复数据
	[root@danran ~]# cd /mydata/xbdata/2017-09-12_17-09-40/  \进入完全备份目录
	[root@danran 2017-09-12_17-09-40]# innobackupex --apply-log --redo-only ./  \对当前目录仅做重做，不做撤销回滚
	[root@danran 2017-09-12_17-09-40]# innobackupex --apply-log --redo-only ./ --incremental-dir=/mydata/xbdata/2017-09-12_17-18-39 
		在完全备份目录下，指定第一次增量备份的目录，做重做操作
	[root@danran 2017-09-12_17-09-40]# innobackupex --apply-log --redo-only ./ --incremental-dir=/mydata/xbdata/2017-09-12_17-27-51
		在完全备份目录下，指定第二次增量备份的目录，做重做操作
	[root@danran 2017-09-12_17-09-40]# innobackupex --apply-log --redo-only ./ --incremental-dir=/mydata/xbdata/2017-09-12_17-38-44
		在完全备份目录下，指定第三次增量备份的目录，做重做操作
	[root@danran 2017-09-12_17-09-40]# cat xtrabackup_checkpoints 
	backup_type = log-applied
	from_lsn = 0
	to_lsn = 2090173   日志序列号已重读到最后一次备份的时刻
	last_lsn = 2090173
	compact = 0
	recover_binlog_info = 0
	
	增量命令执行完毕后，在当前完全备份目录下执行回滚操作
	[root@danran 2017-09-12_17-09-40]# innobackupex --apply-log ./

	将当前目录拷贝到/var/lib/mysql
	[root@danran 2017-09-12_17-09-40]# innobackupex --copy-back ./
11. 修改/var/lib/mysql目录下的所有文件属主、属组为mysql
	[root@danran 2017-09-12_17-09-40]# cd /var/lib/mysql
	[root@danran mysql]# chown -R mysql.mysql ./*
12. 启动mariadb服务
	[root@danran mysql]# systemctl start mariadb
13. 登录数据库查看数据，数据恢复到最后一次增量备份前的数据，最后一次增量备份后删除的数据LI没有恢复
	MariaDB [mydb]> SELECT * FROM students WHERE stuid=1300;  \数据以删除
	MariaDB [mydb]> SELECT * FROM students WHERE stuid=1400;  \数据以删除
	
	MariaDB [mydb]> SELECT * FROM teachers;  
	+-----+------+
	tid | name |
	+-----+------+
	|   1 | LI   |
	|   2 | WEI  |
	|   3 | xin  |
	+-----+------+
14. 重放二进制日志文件重记录的sql语句 
	MariaDB [mydb]> SET @@session.sql_log_bin=OFF  \暂时关闭会话中的写操作记录二进制日志
	MariaDB [mydb]> . /mydata/binlogs/2017-09-12_17-38-44-binlog
15. 登录数据库，查看数据恢复情况，数据恢复到mysql服务器崩溃前的状态
	MariaDB [mydb]> SELECT * FROM teachers;
	+-----+------+
	| tid | name |
	+-----+------+
	|   2 | WEI  |
	|   3 | xin  |
	+-----+------+
16. 打开之前关闭的写操作记录日志的功能
	MariaDB [mydb]> SET @@session.sql_log_bin=ON;

17. 即刻在做一次全量备份
	[root@danran ~]# innobackupex /mydata/xbdata/
18. mysql数据库上线