MySQL系列详解五： xtrabackup实现完全备份及增量备份详解-技术流ken
xtrabackup简介
xtrabackup是一个用来对mysql做备份的工具，它可以对innodb引擎的数据库做热备。xtrabackup备份和还原速度快,备份操作不会中断正在执行的事务,备份完成之后可以自动做校验,备份结果可以压缩（节省磁盘和带宽）。实际工作中可以用来做mysql的完全备份，增量备份，以及差异备份等。
xtrabackup有两个主要的工具：innobackupex和xtrabackup，xtrabackup只能备份InnoDB和XtraDB数据表，innobackupex封装了xtrabackup，可以备份MyISAM数据表。
MySQL数据库本身提供的工具并不支持真正的增量备份，二进制日志恢复是point-in-time(时间点)的恢复而不是增量备份。Xtrabackup工具支持对InnoDB存储引擎的增量备份，工作原理如下：
1.首先完成一个完全备份，并记录下此时检查点的LSN(LogSequence Number)。
2.在进程增量备份时，比较表空间中每个页的LSN是否大于上次备份时的LSN，如果是，则备份该页，同时记录当前检查点的LSN。
xtrabackup常用选项
--incremental-basedir=name <<仅适用于backup，增量备份目录
--incremental-dir=name <<仅适用于prepare，恢复指定目录下的.delta文件和日志文件
--apply-log <<从备份恢复。
--redo-only <<该选项强制跳过rollback阶段，只进行redo。这是有必要使用的，如果备份后，要使用增量改变的。
安装xtrabackup
下载xtrabackup（下载二进制版本免安装）
# wget http://www.percona.com/redir/downloads/XtraBackup/XtraBackup-1.5/Linux/binary/x86_64/xtrabackup-1.5.tar.gz
# tar zxvfxtrabackup-1.5.tar.gz -C /usr/local/
源码安装过程具体参见源码目录下BUILD.txt文件。
演示：基于innobackupex做备份和恢复（完整备份）
第一步：完全备份到/ken下
[root@ken ~]# innobackupex -uroot -pxx /ken <<xx表示密码，输入你的数据库密码
xtrabackup: recognized server arguments: --datadir=/data/mysql/mysql3306/data --tmpdir=/data/mysql/mysql3306/tmp --open_files_limit= --server-id= --log_bin=/data/mysql/mysql3306/logs/mysql-bin --innodb_buffer_pool_size=100M --innodb_data_file_path=ibdata1:100M:autoextend --innodb_flush_log_at_trx_commit= --innodb_log_buffer_size=8M --innodb_log_file_size=100M --innodb_log_files_in_group= --innodb_max_dirty_pages_pct= --innodb_file_per_table= --innodb_io_capacity= --innodb_flush_method=O_DIRECT
xtrabackup: recognized client arguments: --datadir=/data/mysql/mysql3306/data --tmpdir=/data/mysql/mysql3306/tmp --open_files_limit= --server-id= --log_bin=/data/mysql/mysql3306/logs/mysql-bin --innodb_buffer_pool_size=100M --innodb_data_file_path=ibdata1:100M:autoextend --innodb_flush_log_at_trx_commit= --innodb_log_buffer_size=8M --innodb_log_file_size=100M --innodb_log_files_in_group= --innodb_max_dirty_pages_pct= --innodb_file_per_table= --innodb_io_capacity= --innodb_flush_method=O_DIRECT
:: 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!".
...
... :: Executing UNLOCK TABLES
:: All tables unlocked
:: [] Copying ib_buffer_pool to /ken/--23_04--/ib_buffer_pool
:: [] ...done
:: Backup created in directory '/ken/2018-10-23_04-51-51/'
MySQL binlog position: filename 'mysql-bin.000004', position ''
:: [] Writing /ken/--23_04--/backup-my.cnf
:: [] ...done
:: [] Writing /ken/--23_04--/xtrabackup_info
:: [] ...done
xtrabackup: Transaction log of lsn () to () was copied.
:: completed OK! <<最后出现comleted ok表示备份成功
第二步：删除mysql数据库（模拟故障）
[root@ken ~]# mysql -uroot -p <<登录数据库
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7.-log MySQL Community Server (GPL) Copyright (c) , , 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; <<查看现有数据库
+--------------------+
| Database |
+--------------------+
| information_schema |
| jobs |
| ke |
| mysql |
| performance_schema |
| sys |
| test |
| test5 |
+--------------------+
rows in set (0.06 sec) mysql> drop database mysql; <<删除mysql数据库
Query OK, rows affected, warnings (0.24 sec)
第三步：退出mysql并关闭mysql
[root@ken ~]# mysqladmin -uroot -p shutdown <<关闭mysql
[root@ken ~]# ss -tnl | grep 3306 <<查看mysql进程是否关闭
第四步：整理备份数据（将备份整理就绪）
[root@ken ~]# innobackupex --apply-log /ken/--23_04--/
xtrabackup: recognized server arguments: --innodb_checksum_algorithm=crc32 --innodb_log_checksum_algorithm=strict_crc32 --innodb_data_file_path=ibdata1:100M:autoextend --innodb_log_files_in_group= --innodb_log_file_size= --innodb_fast_checksum= --innodb_page_size= --innodb_log_block_size= --innodb_undo_directory=./ --innodb_undo_tablespaces= --server-id= --redo-log-version=
xtrabackup: recognized client arguments: --innodb_checksum_algorithm=crc32 --innodb_log_checksum_algorithm=strict_crc32 --innodb_data_file_path=ibdata1:100M:autoextend --innodb_log_files_in_group= --innodb_log_file_size= --innodb_fast_checksum= --innodb_page_size= --innodb_log_block_size= --innodb_undo_directory=./ --innodb_undo_tablespaces= --server-id= --redo-log-version=
:: 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!".
...
...
InnoDB: Renaming log file ./ib_logfile101 to ./ib_logfile0
InnoDB: New log files created, LSN=
InnoDB: Highest supported file format is Barracuda.
InnoDB: Log scan progressed past the checkpoint lsn
InnoDB: Doing recovery: scanned up to log sequence number (%)
InnoDB: Database was not shutdown normally!
InnoDB: Starting crash recovery.
InnoDB: xtrabackup: Last MySQL binlog file position , file name mysql-bin.
InnoDB: Removed temporary tablespace data file: "ibtmp1"
InnoDB: Creating shared tablespace for temporary tables
InnoDB: Setting file './ibtmp1' size to MB. Physically writing the file full; Please wait ...
InnoDB: File './ibtmp1' size is now MB.
InnoDB: redo rollback segment(s) found. redo rollback segment(s) are active.
InnoDB: non-redo rollback segment(s) are active.
InnoDB: Waiting for purge to start
InnoDB: 5.7. started; log sequence number
xtrabackup: starting shutdown with innodb_fast_shutdown =
InnoDB: FTS optimize thread exiting.
InnoDB: Starting shutdown...
InnoDB: Shutdown completed; log sequence number
:: completed OK!
第五步：确认是否可以进行恢复
[root@ken ~]# ss -tnl <<确保数据库已经关闭
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN *: *:*
LISTEN *: *:*
LISTEN ::: :::*
LISTEN ::: :::*
[root@ken ~]# rm -rf /data/mysql/mysql3306/data/* <<删除保存数据的目录下的全部文件（找到你自己的数据保存位置）
第六步：进行恢复
[root@ken ~]# innobackupex --copy-back /ken/--23_04--/
xtrabackup: recognized server arguments: --datadir=/data/mysql/mysql3306/data --tmpdir=/data/mysql/mysql3306/tmp --open_files_limit= --server-id= --log_bin=/data/mysql/mysql3306/logs/mysql-bin --innodb_buffer_pool_size=100M --innodb_data_file_path=ibdata1:100M:autoextend --innodb_flush_log_at_trx_commit= --innodb_log_buffer_size=8M --innodb_log_file_size=100M --innodb_log_files_in_group= --innodb_max_dirty_pages_pct= --innodb_file_per_table= --innodb_io_capacity= --innodb_flush_method=O_DIRECT
xtrabackup: recognized client arguments: --datadir=/data/mysql/mysql3306/data --tmpdir=/data/mysql/mysql3306/tmp --open_files_limit= --server-id= --log_bin=/data/mysql/mysql3306/logs/mysql-bin --innodb_buffer_pool_size=100M --innodb_data_file_path=ibdata1:100M:autoextend --innodb_flush_log_at_trx_commit= --innodb_log_buffer_size=8M --innodb_log_file_size=100M --innodb_log_files_in_group= --innodb_max_dirty_pages_pct= --innodb_file_per_table= --innodb_io_capacity= --innodb_flush_method=O_DIRECT
:: innobackupex: Starting the copy-back operation IMPORTANT: Please check that the copy-back run completes successfully.
At the end of a successful copy-back run innobackupex
prints "completed OK!".
...
...
:: [] ...done
:: [] Copying ./test5/db.opt to /data/mysql/mysql3306/data/test5/db.opt
:: [] ...done
:: [] Copying ./test5/ken.frm to /data/mysql/mysql3306/data/test5/ken.frm
:: [] ...done
:: [] Copying ./test5/ken.MYI to /data/mysql/mysql3306/data/test5/ken.MYI
:: [] ...done
:: [] Copying ./test5/ken.MYD to /data/mysql/mysql3306/data/test5/ken.MYD
:: [] ...done
:: [] Copying ./ib_buffer_pool to /data/mysql/mysql3306/data/ib_buffer_pool
:: [] ...done
:: [] Copying ./xtrabackup_info to /data/mysql/mysql3306/data/xtrabackup_info
:: [] ...done
:: [] Copying ./xtrabackup_binlog_pos_innodb to /data/mysql/mysql3306/data/xtrabackup_binlog_pos_innodb
:: [] ...done
:: [] Copying ./xtrabackup_master_key_id to /data/mysql/mysql3306/data/xtrabackup_master_key_id
:: [] ...done
:: [] Copying ./ibtmp1 to /data/mysql/mysql3306/data/ibtmp1
:: [] ...done
:: completed OK!
第七步：更改数据权限
[root@ken ~]# ls -l /data/mysql/mysql3306/data/
total
-rw-r----- root root Oct : ib_buffer_pool
-rw-r----- root root Oct : ibdata1
-rw-r----- root root Oct : ib_logfile0
-rw-r----- root root Oct : ib_logfile1
-rw-r----- root root Oct : ib_logfile2
-rw-r----- root root Oct : ibtmp1
drwxr-x--- root root Oct : jobs
drwxr-x--- root root Oct : ke
drwxr-x--- root root Oct : mysql
drwxr-x--- root root Oct : performance_schema
drwxr-x--- root root Oct : sys
drwxr-x--- root root Oct : test
drwxr-x--- root root Oct : test5
-rw-r----- root root Oct : xtrabackup_binlog_pos_innodb
-rw-r----- root root Oct : xtrabackup_info
-rw-r----- root root Oct : xtrabackup_master_key_id
可以看到下面恢复的数据文件的属主已经变成root,需要更改为mysql
[root@ken ~]# chown -R mysql.mysql /data/mysql/mysql3306/data
第八步：启动mysql并查看mysql数据库是否已经恢复
[root@ken ~]# mysqld & <<启动mysql数据库
[]
[root@ken ~]# mysql -uroot -p <<登录mysql
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7.-log MySQL Community Server (GPL) Copyright (c) , , 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; <<查看数据库
+--------------------+
| Database |
+--------------------+
| information_schema |
| jobs |
| ke |
| mysql | <<mysql数据库已经恢复
| performance_schema |
| sys |
| test |
| test5 |
+--------------------+
rows in set (0.07 sec)
演示：基于innobackupex做增量备份和恢复（增量备份）
第一步：首先做一次完全备份
[root@ken ~]# innobackupex -uroot -pxx /ken <<xx表示你的数据库密码
第二步：创建一张表
mysql> use jobs;
Database changed
mysql> create table ken1 as select * from teachers; <<创建一张ken1的表
Query OK, rows affected (0.09 sec)
Records: Duplicates: Warnings:
第三步：做一次增量备份
[root@ken ~]# innobackupex -uroot -pxx --incremental --incremental-basedir=/ken/--23_04--/ /ken
xtrabackup: recognized server arguments: --datadir=/data/mysql/mysql3306/data --tmpdir=/data/mysql/mysql3306/tmp --open_files_limit= --server-id= --log_bin=/data/mysql/mysql3306/logs/mysql-bin --innodb_buffer_pool_size=100M --innodb_data_file_path=ibdata1:100M:autoextend --innodb_flush_log_at_trx_commit= --innodb_log_buffer_size=8M --innodb_log_file_size=100M --innodb_log_files_in_group= --innodb_max_dirty_pages_pct= --innodb_file_per_table= --innodb_io_capacity= --innodb_flush_method=O_DIRECT
xtrabackup: recognized client arguments: --datadir=/data/mysql/mysql3306/data --tmpdir=/data/mysql/mysql3306/tmp --open_files_limit= --server-id= --log_bin=/data/mysql/mysql3306/logs/mysql-bin --innodb_buffer_pool_size=100M --innodb_data_file_path=ibdata1:100M:autoextend --innodb_flush_log_at_trx_commit= --innodb_log_buffer_size=8M --innodb_log_file_size=100M --innodb_log_files_in_group= --innodb_max_dirty_pages_pct= --innodb_file_per_table= --innodb_io_capacity= --innodb_flush_method=O_DIRECT
:: 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!".
...
...
:: Executing UNLOCK TABLES
:: All tables unlocked
:: [] Copying ib_buffer_pool to /ken/--23_05--/ib_buffer_pool
:: [] ...done
:: Backup created in directory '/ken/2018-10-23_05-17-04/'
MySQL binlog position: filename 'mysql-bin.000005', position ''
:: [] Writing /ken/--23_05--/backup-my.cnf
:: [] ...done
:: [] Writing /ken/--23_05--/xtrabackup_info
:: [] ...done
xtrabackup: Transaction log of lsn () to () was copied.
:: completed OK!
第四步：删除刚才创建的表（模拟故障）
mysql> use jobs;
Database changed
mysql> drop table ken1;
Query OK, rows affected (0.03 sec)
第五步：整理完整备份
[root@ken ~]# innobackupex --apply-log --redo-only /ken/--23_04--/
xtrabackup: recognized server arguments: --innodb_checksum_algorithm=crc32 --innodb_log_checksum_algorithm=strict_crc32 --innodb_data_file_path=ibdata1:100M:autoextend --innodb_log_files_in_group= --innodb_log_file_size= --innodb_fast_checksum= --innodb_page_size= --innodb_log_block_size= --innodb_undo_directory=./ --innodb_undo_tablespaces= --server-id= --redo-log-version=
xtrabackup: recognized client arguments: --innodb_checksum_algorithm=crc32 --innodb_log_checksum_algorithm=strict_crc32 --innodb_data_file_path=ibdata1:100M:autoextend --innodb_log_files_in_group= --innodb_log_file_size= --innodb_fast_checksum= --innodb_page_size= --innodb_log_block_size= --innodb_undo_directory=./ --innodb_undo_tablespaces= --server-id= --redo-log-version=
:: 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!".
...
...
xtrabackup: starting shutdown with innodb_fast_shutdown =
InnoDB: Starting shutdown...
InnoDB: Shutdown completed; log sequence number
InnoDB: Number of pools:
:: completed OK!
第六步：将第一个增量备份文件合并到完全备份中
[root@ken ~]# innobackupex --apply-log --redo-only /ken/--23_04--/ --incremental-dir=/ken/--23_05--/
xtrabackup: recognized server arguments: --innodb_checksum_algorithm=crc32 --innodb_log_checksum_algorithm=strict_crc32 --innodb_data_file_path=ibdata1:100M:autoextend --innodb_log_files_in_group= --innodb_log_file_size= --innodb_fast_checksum= --innodb_page_size= --innodb_log_block_size= --innodb_undo_directory=./ --innodb_undo_tablespaces= --server-id= --redo-log-version=
xtrabackup: recognized client arguments: --innodb_checksum_algorithm=crc32 --innodb_log_checksum_algorithm=strict_crc32 --innodb_data_file_path=ibdata1:100M:autoextend --innodb_log_files_in_group= --innodb_log_file_size= --innodb_fast_checksum= --innodb_page_size= --innodb_log_block_size= --innodb_undo_directory=./ --innodb_undo_tablespaces= --server-id= --redo-log-version=
:: 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!".
...
...
:: [] ...done
:: [] Copying /ken/--23_05--/test5/db.opt to ./test5/db.opt
:: [] ...done
:: [] Copying /ken/--23_05--/test5/ken.frm to ./test5/ken.frm
:: [] ...done
:: [] Copying /ken/--23_05--/test5/ken.MYI to ./test5/ken.MYI
:: [] ...done
:: [] Copying /ken/--23_05--/test5/ken.MYD to ./test5/ken.MYD
:: [] ...done
:: [] Copying /ken/--23_05--//xtrabackup_binlog_info to ./xtrabackup_binlog_info
:: [] ...done
:: [] Copying /ken/--23_05--//xtrabackup_info to ./xtrabackup_info
:: [] ...done
:: completed OK!
第七步：确认是否可以进行恢复
[root@ken ~]# ss -tnl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN *: *:*
LISTEN *: *:*
LISTEN ::: :::*
LISTEN ::: :::*
[root@ken ~]# rm -rf /data/mysql/mysql3306/data/*
第八步：数据恢复
[root@ken ~]# innobackupex --copy-back /ken/--23_04--/
xtrabackup: recognized server arguments: --datadir=/data/mysql/mysql3306/data --tmpdir=/data/mysql/mysql3306/tmp --open_files_limit= --server-id= --log_bin=/data/mysql/mysql3306/logs/mysql-bin --innodb_buffer_pool_size=100M --innodb_data_file_path=ibdata1:100M:autoextend --innodb_flush_log_at_trx_commit= --innodb_log_buffer_size=8M --innodb_log_file_size=100M --innodb_log_files_in_group= --innodb_max_dirty_pages_pct= --innodb_file_per_table= --innodb_io_capacity= --innodb_flush_method=O_DIRECT
xtrabackup: recognized client arguments: --datadir=/data/mysql/mysql3306/data --tmpdir=/data/mysql/mysql3306/tmp --open_files_limit= --server-id= --log_bin=/data/mysql/mysql3306/logs/mysql-bin --innodb_buffer_pool_size=100M --innodb_data_file_path=ibdata1:100M:autoextend --innodb_flush_log_at_trx_commit= --innodb_log_buffer_size=8M --innodb_log_file_size=100M --innodb_log_files_in_group= --innodb_max_dirty_pages_pct= --innodb_file_per_table= --innodb_io_capacity= --innodb_flush_method=O_DIRECT
:: innobackupex: Starting the copy-back operation IMPORTANT: Please check that the copy-back run completes successfully.
At the end of a successful copy-back run innobackupex
prints "completed OK!".
...
...
:: [] Copying ./test5/db.opt to /data/mysql/mysql3306/data/test5/db.opt
:: [] ...done
:: [] Copying ./test5/ken.frm to /data/mysql/mysql3306/data/test5/ken.frm
:: [] ...done
:: [] Copying ./test5/ken.MYI to /data/mysql/mysql3306/data/test5/ken.MYI
:: [] ...done
:: [] Copying ./test5/ken.MYD to /data/mysql/mysql3306/data/test5/ken.MYD
:: [] ...done
:: [] Copying ./ib_buffer_pool to /data/mysql/mysql3306/data/ib_buffer_pool
:: [] ...done
:: [] Copying ./xtrabackup_binlog_pos_innodb to /data/mysql/mysql3306/data/xtrabackup_binlog_pos_innodb
:: [] ...done
:: [] Copying ./xtrabackup_master_key_id to /data/mysql/mysql3306/data/xtrabackup_master_key_id
:: [] ...done
:: [] Copying ./ibtmp1 to /data/mysql/mysql3306/data/ibtmp1
:: [] ...done
:: [] Copying ./xtrabackup_info to /data/mysql/mysql3306/data/xtrabackup_info
:: [] ...done
:: completed OK!
第九步：数据权限修改
[root@ken ~]# chown -R mysql.mysql /data/mysql/mysql3306/data/
第十步：启动mysql并查看删除的表是否应恢复
[root@ken ~]# mysqld &
[]
[root@ken ~]# mysql -uroot -pxx
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7.-log MySQL Community Server (GPL) Copyright (c) , , 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 jobs;
Database changed
mysql> show tables;
+----------------+
| Tables_in_jobs |
+----------------+
| classes |
| courses |
| ken |
| ken1 | <<删除的ken1表已经恢复
| ken4 |
| kenken |
| kenken1 |
| scores |
| students |
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