数据备份与恢复
XtraBackup备份工具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：
使用mysqldump备份数据库
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：
[root@dbsvr1 ~]# mysqldump -u root -p --all-databases > /root/alldb.sql
Enter password: //验证口令
[root@dbsvr1 mysql]# file /root/alldb.sql //确认备份文件类型
/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：
[root@dbsvr1 ~]# grep -vE '^/|^-|^$' /root/alldb.sql | head -15
CREATE DATABASE /*!32312 IF NOT EXISTS*/ `home` /*!40100 DEFAULT CHARACTER SET latin1 */;
USE `home`;
DROP TABLE IF EXISTS `biao01`;
CREATE TABLE `biao01` (
`id` int(2) NOT NULL,
`name` varchar(8) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
LOCK TABLES `biao01` WRITE;
UNLOCK TABLES;
DROP TABLE IF EXISTS `biao02`;
CREATE TABLE `biao02` (
`id` int(4) NOT NULL,
`name` varchar(8) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
.. ..注意：若数据库都使用MyISAM存储引擎，可以采用冷备份的方式，直接复制对应的数据库目录即可；恢复时重新复制回来就行。
2）只备份指定的某一个库
将userdb库备份为userdb.sql文件：
[root@dbsvr1 ~]# mysqldump -u root -p userdb > userdb.sql
Enter password: //验证口令查看备份文件userdb.sql的部分内容：
[root@dbsvr1 ~]# grep -vE '^/|^-|^$' /root/userdb.sql
DROP TABLE IF EXISTS `stu_info`;
CREATE TABLE `stu_info` (
`name` varchar(12) NOT NULL,
`gender` enum('boy','girl') DEFAULT 'boy',
`age` int(3) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
LOCK TABLES `stu_info` WRITE;
.. ..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：
[root@dbsvr1 ~]# mysqldump -u root -p -B mysql userdb > mysql+test+userdb.sql
Enter password: //验证口令查看备份文件userdb.sql的部分内容：
[root@dbsvr1 ~]# grep '^CREATE DATA' /root/mysql+userdb.sql
CREATE DATABASE /*!32312 IF NOT EXISTS*/ `mysql` /*!40100 DEFAULT CHARACTER SET latin1 */;
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
mysql> CREATE DATABASE userdb2;
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
[root@dbsvr1 ~]# mysql -u root -p userdb2 < /root/userdb.sql
Enter password: //验证口令3）确认新库正常，启用新库
mysql> USE userdb2; //切换到新库
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> SELECT sn,username,uid,gid,homedir //查询数据，确认可用
-> FROM userlist LIMIT 10;
+----+----------+-----+-----+-----------------+
| sn | username | uid | gid | homedir |
+----+----------+-----+-----+-----------------+
| 1 | root | 0 | 0 | /root |
| 2 | bin | 1 | 1 | /bin |
| 3 | daemon | 2 | 2 | /sbin |
| 4 | adm | 3 | 4 | /var/adm |
| 5 | lp | 4 | 7 | /var/spool/lpd |
| 6 | sync | 5 | 0 | /sbin |
| 7 | shutdown | 6 | 0 | /sbin |
| 8 | halt | 7 | 0 | /sbin |
| 9 | mail | 8 | 12 | /var/spool/mail |
| 10 | operator | 11 | 0 | /root |
+----+----------+-----+-----+-----------------+
10 rows in set (0.00 sec)4）废弃或删除旧库
mysql> DROP DATABASE userdb;
Query OK, 2 rows affected (0.09 sec)2 XtraBackup备份工具
2.1 问题
安装XtraBackup软件包。
使用XtraBackup执行完整备份、增量备份。
准备数据恢复目录。2.2 步骤
实现此案例需要按照如下步骤进行。
步骤一：安装XtraBackup软件包
1）了解软件包描述信息
[root@dbsvr1 pub]# rpm -qpi percona-xtrabackup-24-2.4.6-2.el7.x86_64.rpm
Name : percona-xtrabackup-24
Version : 2.4.6
Release : 2.el7
Architecture: x86_64
Install Date: (not installed)
Group : Applications/Databases
Size : 32416340
License : GPLv2
Signature : DSA/SHA1, 2017年02月27日 星期一 20时28分17秒, Key ID 1c4cbdcdcd2efd2a
Source RPM : percona-xtrabackup-24-2.4.6-2.el7.src.rpm
Build Date : 2017年02月27日 星期一 20时27分21秒
Build Host : vps-centos7-x64-01.ci.percona.com
Relocations : (not relocatable)
URL : http://www.percona.com/software/percona-xtrabackup
Summary : XtraBackup online backup for MySQL / InnoDB
Description :
Percona XtraBackup is OpenSource online (non-blockable) backup solution for InnoDB and XtraDB engines2）安装依赖包perl-DBD-MySQL perl-Digest-MD5 libev
使用RHEL 7自带的即可，yum方式安装：
[root@dbsvr1 pub]# yum -y install perl-DBD-MySQL perl-Digest-MD5
libev使用网上找的rpm包 libev-4.15-1.el6.rf.x86_64.rpm //该包由讲师提供
[root@dbsvr1 pub]#rpm –ivh libev-4.15-1.el6.rf.x86_64.rpm如果未安装这些依赖包，则直接安装percona-xtrabackup时会报错：
代码
3）安装percona-xtrabackup
[root@dbsvr1 pub]#rpm -ivh percona-xtrabackup-*.rpm
警告：percona-xtrabackup-24-2.4.6-2.el7.x86_64.rpm: 头V4 DSA/SHA1 Signature, 密钥 ID cd2efd2a: NOKEY
准备中... ################################# [100%]
正在升级/安装...
1:percona-xtrabackup-24-2.4.6-2.el7################################# [ 33%]
2:percona-xtrabackup-test-24-2.4.6-################################# [ 67%]
3:percona-xtrabackup-24-debuginfo-2################################# [100%]4）确认安装的主要程序/脚本
[root@dbsvr1 pub]# rpm -ql percona-xtrabackup-24-2.4.6-2.el7.x86_64
/usr/bin/innobackupex
/usr/bin/xbcloud
/usr/bin/xbcloud_osenv
/usr/bin/xbcrypt
/usr/bin/xbstream
/usr/bin/xtrabackup
/usr/share/doc/percona-xtrabackup-24-2.4.6
/usr/share/doc/percona-xtrabackup-24-2.4.6/COPYING
/usr/share/man/man1/innobackupex.1.gz
/usr/share/man/man1/xbcrypt.1.gz
/usr/share/man/man1/xbstream.1.gz
/usr/share/man/man1/xtrabackup.1.gz步骤二：使用XtraBackup执行数据库备份
--host 主机名
--port 3306
--user 用户名
--password 密码
--databases="库名"
--databases="库1 库2"
--databases="库.表"
--no-timestamp 不用日期命名备份文件存储的子目录，使用备份的数据库名做备份目录名
--no-timestmap 不使用日期命名备份目录名
1）做一个完整备份
默认情况下，备份文件存储的子目录会用日期命名，
innobackupex作为客户端工具，以mysql协议连入mysqld，将数据备份到/backup文件夹：
[root@dbsvr1 ~]# innobackupex --user=root --password=1234567 /backup/mysql –no-timestamp
170425 11:05:44 innobackupex: Starting the backup operation
IMPORTANT: Please check that the backup run completes successfully.
At the end of a successful backup run innobackupex
prints "completed OK!".
Unrecognized character \x01; marked by <-- HERE after <-- HERE near column 1 at - line 1374.
170425 11:05:45 Connecting to MySQL server host: localhost, user: root, password: set, port: not set, socket: not set
Using server version 5.7.17
innobackupex version 2.4.6 based on MySQL server 5.7.13 Linux (x86_64) (revision id: 8ec05b7)
xtrabackup: uses posix_fadvise().
xtrabackup: cd to /var/lib/mysql
xtrabackup: open files limit requested 0, set to 1024
xtrabackup: using the following InnoDB configuration:
xtrabackup: innodb_data_home_dir = .
xtrabackup: innodb_data_file_path = ibdata1:12M:autoextend
xtrabackup: innodb_log_group_home_dir = ./
xtrabackup: innodb_log_files_in_group = 2
xtrabackup: innodb_log_file_size = 50331648
InnoDB: Number of pools: 1
170425 11:05:45 >> log scanned up to (2543893)
xtrabackup: Generating a list of tablespaces
InnoDB: Allocated tablespace ID 2 for mysql/plugin, old maximum was 0
170425 11:05:45 [01] Copying ./ibdata1 to /backup/ibdata1
170425 11:05:45 [01] ...done
170425 11:05:46 [01] Copying ./mysql/plugin.ibd to /backup/mysql/plugin.ibd
170425 11:05:46 [01] ...done
170425 11:05:46 [01] Copying ./mysql/servers.ibd to /backup/mysql/servers.ibd
170425 11:05:46 [01] ...done
170425 11:05:46 [01] Copying ./mysql/help_topic.ibd to /backup/mysql/help_topic.ibd
170425 11:05:46 [01] ...done
170425 11:05:46 >> log scanned up to (2543893)
.. ..
170425 11:06:00 [01] Copying ./sys/x@0024waits_global_by_latency.frm to /backup/sys/x@0024waits_global_by_latency.frm
170425 11:06:00 [01] ...done
170425 11:06:00 [01] Copying ./sys/session_ssl_status.frm to /backup/sys/session_ssl_status.frm
170425 11:06:00 [01] ...done
170425 11:06:00 [01] Copying ./db1/db.opt to /backup/db1/db.opt
170425 11:06:00 [01] ...done
170425 11:06:00 [01] Copying ./db1/tb1.frm to /backup/db1/tb1.frm
170425 11:06:00 [01] ...done
170425 11:06:00 Finished backing up non-InnoDB tables and files
170425 11:06:00 Executing FLUSH NO_WRITE_TO_BINLOG ENGINE LOGS...
xtrabackup: The latest check point (for incremental): '2543884'
xtrabackup: Stopping log copying thread.
.170425 11:06:00 >> log scanned up to (2543893)
170425 11:06:00 Executing UNLOCK TABLES
170425 11:06:00 All tables unlocked
170425 11:06:00 [00] Copying ib_buffer_pool to /backup/ib_buffer_pool
170425 11:06:00 [00] ...done
170425 11:06:00 Backup created in directory '/backup/'
170425 11:06:00 [00] Writing backup-my.cnf
170425 11:06:00 [00] ...done
170425 11:06:00 [00] Writing xtrabackup_info
170425 11:06:00 [00] ...done
xtrabackup: Transaction log of lsn (2543884) to (2543893) was copied.
170425 11:06:01 completed OK确认备份好的文件数据：
[root@dbsvr1 ~]#ls /backup/
backup-my.cnf ib_buffer_pool mysql sys xtrabackup_info
db1 ibdata1 performance_schema xtrabackup_checkpoints xtrabackup_logfile2）做一个增量备份（基于前一步的完整备份）
随意做一些新增或更改库表的操作，比如在db1库中新建一个mytb的表：
mysql> USE db1;
Database changed
mysql> CREATE TABLE mytb(id int(4), name varchar(24));
Query OK, 0 rows affected (0.38 sec)
mysql> INSERT INTO tb1 VALUES
-> (1,'bon'),
-> (2,'bo'),
Query OK, 2 rows affected (0.12 sec)
Records: 2 Duplicates: 0 Warnings: 0
mysql> SELECT * FROM tb1;
+------+------+
| id | name |
+------+------+
| 1 | bob |
| 2 | bo |
+------+------+
2 rows in set (0.00 sec)以前一次保存到/backup的完整备份为基础，做一个增量备份，保存到/incr01/，指定增量备份参照的基本目录（完整备份目录）需要用到选项--incremental-basedir。相关操作如下：
[root@dbsvr1 ~]# innobackupex --user=root --password=12345678 --incremental /incr01 --incremental-basedir=/backup/ --no-timestamp
170425 11:30:14 innobackupex: Starting the backup operation
IMPORTANT: Please check that the backup run completes successfully.
At the end of a successful backup run innobackupex
prints "completed OK!".
Unrecognized character \x01; marked by <-- HERE after <-- HERE near column 1 at - line 1374.
170425 11:30:14 Connecting to MySQL server host: localhost, user: root, password: set, port: not set, socket: not set
Using server version 5.7.17
innobackupex version 2.4.6 based on MySQL server 5.7.13 Linux (x86_64) (revision id: 8ec05b7)
incremental backup from 2543884 is enabled.
xtrabackup: uses posix_fadvise().
xtrabackup: cd to /var/lib/mysql
xtrabackup: open files limit requested 0, set to 1024
xtrabackup: using the following InnoDB configuration:
xtrabackup: innodb_data_home_dir = .
xtrabackup: innodb_data_file_path = ibdata1:12M:autoextend
xtrabackup: innodb_log_group_home_dir = ./
xtrabackup: innodb_log_files_in_group = 2
xtrabackup: innodb_log_file_size = 50331648
InnoDB: Number of pools: 1
170425 11:30:14 >> log scanned up to (2549933)
xtrabackup: Generating a list of tablespaces
InnoDB: Allocated tablespace ID 2 for mysql/plugin, old maximum was 0
xtrabackup: using the full scan for incremental backup
170425 11:30:15 [01] Copying ./ibdata1 to /incr01/ibdata1.delta
170425 11:30:15 [01] ...done
170425 11:30:15 >> log scanned up to (2549933)
170425 11:30:15 [01] Copying ./mysql/plugin.ibd to /incr01/mysql/plugin.ibd.delta
170425 11:30:15 [01] ...done
... ...
170425 11:30:35 Executing UNLOCK TABLES
170425 11:30:35 All tables unlocked
170425 11:30:35 [00] Copying ib_buffer_pool to /incr01/ib_buffer_pool
170425 11:30:35 [00] ...done
170425 11:30:35 Backup created in directory '/incr01/'
170425 11:30:35 [00] Writing backup-my.cnf
170425 11:30:35 [00] ...done
170425 11:30:35 [00] Writing xtrabackup_info
170425 11:30:35 [00] ...done
xtrabackup: Transaction log of lsn (2549924) to (2549933) was copied.
170425 11:30:35 completed OK!确认备份好的文件数据：
[root@dbsvr1 ~]# ls /incr01/
backup-my.cnf ib_buffer_pool ibdata1.meta performance_schema xtrabackup_checkpoints xtrabackup_logfile
db1 ibdata1.delta mysql sys 对比完整备份、增量备份的大小：
[root@dbsvr1 ~]# du -sh /backup/ /incr01/
142M /backup/ //完整备份的大小
3.5M /incr01/ //增量备份的大小步骤三：准备用于恢复的数据库目录
通过XtraBackup工具备份的数据库目录，若要恢复到另一个MySQL服务器，需要先做一个“--apply-log --redo-only ”的准备操作。
1）准备恢复“完整备份”
完成准备以后，最终/backup可用来重建MySQL服务器。这种情况下，需要先做一个“--apply-log --redo-only ”的准备操作，以确保数据一致性：
[root@dbsvr1 ~]#innobackupex --user=root --password=12345678 --apply-log --redo-only /backup/
170425 11:42:19 innobackupex: Starting the apply-log operation
IMPORTANT: Please check that the apply-log run completes successfully.
At the end of a successful apply-log run innobackupex
prints "completed OK!".
innobackupex version 2.4.6 based on MySQL server 5.7.13 Linux (x86_64) (revision id: 8ec05b7)
xtrabackup: cd to /backup/
xtrabackup: This target seems to be already prepared.
InnoDB: Number of pools: 1
xtrabackup: notice: xtrabackup_logfile was already used to '--prepare'.
xtrabackup: using the following InnoDB configuration for recovery:
xtrabackup: innodb_data_home_dir = .
xtrabackup: innodb_data_file_path = ibdata1:12M:autoextend
xtrabackup: innodb_log_group_home_dir = .
xtrabackup: innodb_log_files_in_group = 2
xtrabackup: innodb_log_file_size = 50331648
xtrabackup: using the following InnoDB configuration for recovery:
xtrabackup: innodb_data_home_dir = .
xtrabackup: innodb_data_file_path = ibdata1:12M:autoextend
xtrabackup: innodb_log_group_home_dir = .
xtrabackup: innodb_log_files_in_group = 2
xtrabackup: innodb_log_file_size = 50331648
xtrabackup: Starting InnoDB instance for recovery.
xtrabackup: Using 104857600 bytes for buffer pool (set by --use-memory parameter)
InnoDB: PUNCH HOLE support available
InnoDB: Mutexes and rw_locks use GCC atomic builtins
InnoDB: Uses event mutexes
InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
InnoDB: Compressed tables use zlib 1.2.7
InnoDB: Number of pools: 1
InnoDB: Not using CPU crc32 instructions
InnoDB: Initializing buffer pool, total size = 100M, instances = 1, chunk size = 100M
InnoDB: Completed initialization of buffer pool
InnoDB: page_cleaner coordinator priority: -20
InnoDB: Highest supported file format is Barracuda.
xtrabackup: starting shutdown with innodb_fast_shutdown = 1
InnoDB: Starting shutdown...
InnoDB: Shutdown completed; log sequence number 2544177
InnoDB: Number of pools: 1
170425 11:42:20 completed OK!准备恢复“增量备份”
[root@dbsvr1 ~]#innobackupex --user=root --password=12345678 --apply-log --redo-only /backup/ --incremental-dir=/incr01
170425 11:42:55 innobackupex: Starting the apply-log operation
IMPORTANT: Please check that the apply-log run completes successfully.
At the end of a successful apply-log run innobackupex
prints "completed OK!".
innobackupex version 2.4.6 based on MySQL server 5.7.13 Linux (x86_64) (revision id: 8ec05b7)
incremental backup from 2543884 is enabled.
xtrabackup: cd to /backup/
xtrabackup: This target seems to be already prepared with --apply-log-only.
InnoDB: Number of pools: 1
xtrabackup: xtrabackup_logfile detected: size=8388608, start_lsn=(2549924)
xtrabackup: using the following InnoDB configuration for recovery:
xtrabackup: innodb_data_home_dir = .
xtrabackup: innodb_data_file_path = ibdata1:12M:autoextend
xtrabackup: innodb_log_group_home_dir = /incr01/
xtrabackup: innodb_log_files_in_group = 1
xtrabackup: innodb_log_file_size = 8388608
xtrabackup: Generating a list of tablespaces
InnoDB: Allocated tablespace ID 2 for mysql/plugin, old maximum was 0
xtrabackup: page size for /incr01//ibdata1.delta is 16384 bytes
Applying /incr01//ibdata1.delta to ./ibdata1...
... ...
170425 11:43:09 [01] Copying /incr01/performance_schema/global_status.frm to ./performance_schema/global_status.frm
170425 11:43:09 [01] ...done
170425 11:43:09 [01] Copying /incr01/performance_schema/session_status.frm to ./performance_schema/session_status.frm
170425 11:43:09 [01] ...done
170425 11:43:09 [00] Copying /incr01//xtrabackup_info to ./xtrabackup_info
170425 11:43:09 [00] ...done
170425 11:43:10 completed OK!2）关闭mysql服务，并将/var/lib/mysql/下的文件删除，假设数据被删除。
[root@dbsvr1 ~]#systemctl stop mysqld
[root@dbsvr1 ~]#rm -rf /var/lib/mysql3）恢复“完整备份+增量备份”
完成准备以后，最终仍然是/backup用来重建MySQL服务器，但这种情况下需提前合并相关增量备份的数据
[root@dbsvr1 ~]# innobackupex --user=root --password=12345678 --copy-back /backup/
... ...
170425 11:51:39 [01] Copying ./performance_schema/global_status.frm to /var/lib/mysql/performance_schema/glo.frm
170425 11:51:39 [01] ...done
170425 11:51:39 [01] Copying ./performance_schema/session_status.frm to /var/lib/mysql/performance_schema/seus.frm
170425 11:51:39 [01] ...done
170425 11:51:39 [01] Copying ./ib_buffer_pool to /var/lib/mysql/ib_buffer_pool
170425 11:51:39 [01] ...done
170425 11:51:39 [01] Copying ./ibtmp1 to /var/lib/mysql/ibtmp1
170425 11:51:39 [01] ...done
170425 11:51:39 [01] Copying ./xtrabackup_info to /var/lib/mysql/xtrabackup_info
170425 11:51:39 [01] ...done
170425 11:51:39 completed OK!4）修改/var/lib/mysql/下文件属主与属组,查看数据：
恢复后，/var/lib/mysql下文件属组与属主皆为root，需要更改为mysql
[root@dbsvr1 ~]#chown -R mysql:mysql /var/lib/mysql
[root@dbsvr1 ~]#systemctl start mysqld.service
[root@dbsvr1 ~]#mysql -uroot -p12345678 -e "select * from db1.tb1"
mysql: [Warning] Using a password on the command line interface can be insecure.
+------+------+
| id | name |
+------+------+
| 1 | bob |
| 2 | bo |
+------+------+