xtrabackup full backup and recovery
1. Full backup
Create a user xbK for backup and restore and give permissions
mysql> create user xbk@'localhost' identified by '123456'; Query OK, 0 rows affected (0.00 sec) mysql> grant reload,process,lock tables,replication client on *.* to xbk@localhost; Query OK, 0 rows affected (0.00 sec)
Create backup directory
[root@qht26 u01]# mkdir backup [root@qht26 u01]# chown -R mysql.mysql /u01/backup
Perform a full database backup of the database
[root@qht26 u01]# innobackupex --defaults-file=/etc/my.cnf --user=xbk --password=123456 --stocket=/u01/mysql/mysql.sock /u01/backup
You can see the entire backup process: connect to the database, start copying the redo log, copy the innodb table file, lock the table, copy the non-innodb table file, stop copying the redo log, and unlock it .
Check out the generated file:
[root@qht26 backup]# cd 2018-04-24_11-54-46/ [root@qht26 2018-04-24_11-54-46]# ls -lth total 13M -rw-r----- 1 root root 424 Apr 24 11:55 backup-my.cnf -rw-r----- 1 root root 350 Apr 24 11:55 ib_buffer_pool drwxr-x--- 2 root root 4.0K Apr 24 11:55 mysql -rw-r----- 1 root root 113 Apr 24 11:55 xtrabackup_checkpoints -rw-r----- 1 root root 481 Apr 24 11:55 xtrabackup_info -rw-r----- 1 root root 2.5K Apr 24 11:55 xtrabackup_logfile drwxr-x--- 2 root root 12K Apr 24 11:54 sys drwxr-x--- 2 root root 4.0K Apr 24 11:54 l5m drwxr-x--- 2 root root 4.0K Apr 24 11:54 performance_schema -rw-r----- 1 root root 12M Apr 24 11:54 ibdata1
Several of the directory files mysql, sys, l5m, and performance_schema are the files stored in their respective databases.
backup-my.cnf, the configuration option information used by the backup command;
[root@qht26 2018-04-24_11-54-46]# cat backup-my.cnf # This MySQL options file was generated by innobackupex. # The MySQL server [mysqld] innodb_checksum_algorithm=crc32 innodb_log_checksum_algorithm=strict_crc32 innodb_data_file_path=ibdata1:12M:autoextend innodb_log_files_in_group=2 innodb_log_file_size=50331648 innodb_fast_checksum=false innodb_page_size=16384 innodb_log_block_size=512 innodb_undo_directory=./ innodb_undo_tablespaces=0 server_id=0 redo_log_version=1
ib_buffer_pool, the hot data in the buffer pool, when innodb_buffer_pool_dump_at_shutdown=1 is set, when MySQL is closed, the hot data in the memory will be saved in the ib_buffer_pool file on the disk, located in the data directory.
bdata1, the backed up shared tablespace file;
xtrabackup_info, records the basic information of backup, uuid, backup command, backup time, binlog, LSN, and other encryption and compression information.
[root@qht26 2018-04-24_11-54-46]# cat xtrabackup_info uuid = 442078de-4773-11e8-be9d-001a646dd15e name = tool_name = innobackupex tool_command = --defaults-file=/etc/my.cnf --user=xbk --password=... --stocket=/u01/mysql/mysql.sock /u01/backup tool_version = 2.4.10 ibbackup_version = 2.4.10 server_version = 5.7.21 start_time = 2018-04-24 11:54:46 end_time = 2018-04-24 11:55:02 lock_time = 0 binlog_pos = innodb_from_lsn = 0 innodb_to_lsn = 2556615 partial = N incremental = N format = file compact = N compressed = N encrypted = N
xtrabackup_checkpoints, backup type (such as full or incremental), backup status (such as whether it has been prepared) and LSN (log sequence number) range information;
[root@qht26 2018-04-24_11-54-46]# cat xtrabackup_checkpoints backup_type = full-backuped from_lsn = 0 to_lsn = 2556615 last_lsn = 2556624 compact = 0 recover_binlog_info = 0
trabackup_logfile, this file is the backup redo log file.
2. Full recovery
Close the database and delete all data files
[root@qht26 ~]# service mysql stop Shutting down MySQL.. [ OK ] [root@qht26 u01]# cd /u01 [root@qht26 u01]# mv mysql/ mysql_bak [root@qht26 u01]# mkdir mysql [root@qht26 u01]# chown mysql.mysql mysql
Prepare (prepare) a full backup: --apply-log /u01/backup/2018-04-24_11-54-46 is the backup directory, after execution, backup_type = full-prepared in the xtrabackup_checkpoints file)
--apply-log //Apply the xtrabackup_logfile transaction log file in BACKUP-DIR. Under normal circumstances, after the backup is completed, the data cannot be used for recovery operations, because the backed up data may contain uncommitted transactions or transactions that have been committed but have not yet been synchronized to the data file. Therefore, the data files are still in an inconsistent state at this point. The main function of "prepare" is to keep the data file in a consistent state by rolling back uncommitted transactions and synchronizing committed transactions to the data file.
[root@qht26 u01]# innobackupex --apply-log /u01/backup/2018-04-24_11-54-46/
。。。 InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ... InnoDB: File './ibtmp1' size is now 12 MB. InnoDB: 96 redo rollback segment(s) found. 1 redo rollback segment(s) are active. InnoDB: 32 non-redo rollback segment(s) are active. InnoDB: Waiting for purge to start InnoDB: 5.7.19 started; log sequence number 2556949 xtrabackup: starting shutdown with innodb_fast_shutdown = 1 InnoDB: FTS optimize thread exiting. InnoDB: Starting shutdown... InnoDB: Shutdown completed; log sequence number 2556968 180424 13:15:12 completed OK!
[root@qht26 2018-04-24_11-54-46]# cat xtrabackup_checkpoints backup_type = full-prepared from_lsn = 0 to_lsn = 2556615 last_lsn = 2556624 compact = 0 recover_binlog_info = 0
To perform a restore operation:
--copy-back //Copy all files previously backed up to their original paths. But there cannot be any files or directories under the original path unless the --force-non-empty-directories option is specified.
[root@qht26 ~]# innobackupex --defaults-file=/etc/my.cnf --copy-back --rsync /u01/backup/2018-04-24_11-54-46/
。。。 180424 13:20:37 [01] Copying ./mysql/tables_priv.MYI to /u01/mysql/mysql/tables_priv.MYI 180424 13:20:37 [01] ...done 180424 13:20:37 [01] Copying ./mysql/ndb_binlog_index.MYD to /u01/mysql/mysql/ndb_binlog_index.MYD 180424 13:20:37 [01] ...done 180424 13:20:37 [01] Copying ./mysql/user.frm to /u01/mysql/mysql/user.frm 180424 13:20:37 [01] ...done 180424 13:20:37 [01] Copying ./mysql/event.MYI to /u01/mysql/mysql/event.MYI 180424 13:20:37 [01] ...done 180424 13:20:37 [01] Copying ./mysql/time_zone_transition_type.ibd to /u01/mysql/mysql/time_zone_transition_type.ibd 180424 13:20:37 [01] ...done 180424 13:20:37 [01] Copying ./mysql/gtid_executed.frm to /u01/mysql/mysql/gtid_executed.frm 180424 13:20:37 [01] ...done 180424 13:20:37 completed OK!
The data files are all restored:
[root@qht26 mysql]# ls -lth total 121M drwxr-x--- 2 root root 4.0K Apr 24 13:20 mysql drwxr-x--- 2 root root 12K Apr 24 13:20 sys drwxr-x--- 2 root root 4.0K Apr 24 13:20 l5m -rw-r----- 1 root root 481 Apr 24 13:20 xtrabackup_info -rw-r----- 1 root root 350 Apr 24 13:20 ib_buffer_pool -rw-r----- 1 root root 12M Apr 24 13:20 ibtmp1 drwxr-x--- 2 root root 4.0K Apr 24 13:20 performance_schema -rw-r----- 1 root root 12M Apr 24 13:20 ibdata1 -rw-r----- 1 root root 48M Apr 24 13:20 ib_logfile0 -rw-r----- 1 root root 48M Apr 24 13:20 ib_logfile1
Start the database after modifying the permissions:
[root@qht26 mysql]# chown -R mysql.mysql /u01/mysql [root@qht26 mysql]# service mysql start Starting MySQL.. [ OK ]
Data has been fully recovered
mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | l5m | | mysql | | performance_schema | | sys | +--------------------+ 5 rows in set (0.00 sec) mysql> use l5m Database changed mysql> show tables; +---------------+ | Tables_in_l5m | +---------------+ | tab1 | +---------------+ 1 row in set (0.00 sec)
xtrabackup incremental backup recovery
We use the previous full backup as the benchmark and make incremental backups based on it:
Make some changes to the database first:
mysql> use l5m Database changed mysql> create table tab2 (id int); Query OK, 0 rows affected (0.25 sec) mysql> insert into tab2 values(100); Query OK, 1 row affected (0.06 sec) mysql> insert into tab1 values(2); Query OK, 1 row affected (0.05 sec) mysql> commit; Query OK, 0 rows affected (0.00 sec)
mysql> select * from tab1; +------+ | id | +------+ | 1 | | 2 | +------+ 2 rows in set (0.03 sec) mysql> select * from tab2; +------+ | id | +------+ | 100 | +------+ 1 row in set (0.02 sec)
Incremental backup 1, based on the full backup above
[root@qht26 mysql]# innobackupex --defaults-file=/etc/my.cnf --user=xbk --password=123456 --socket=/u01/mysql/mysql.sock --incremental /u01/backup/inc --incremental-basedir=/u01/backup/2018-04-24_11-54-46/ --parallel=2
The backed up files are as follows:
[root@qht26 2018-04-24_14-36-17]# pwd /u01/backup/inc/2018-04-24_14-36-17
[root@qht26 2018-04-24_14-36-17]# ls -lth total 532K -rw-r----- 1 root root 424 Apr 24 14:36 backup-my.cnf -rw-r----- 1 root root 350 Apr 24 14:36 ib_buffer_pool drwxr-x--- 2 root root 4.0K Apr 24 14:36 mysql -rw-r----- 1 root root 117 Apr 24 14:36 xtrabackup_checkpoints -rw-r----- 1 root root 572 Apr 24 14:36 xtrabackup_info -rw-r----- 1 root root 2.5K Apr 24 14:36 xtrabackup_logfile drwxr-x--- 2 root root 12K Apr 24 14:36 sys drwxr-x--- 2 root root 4.0K Apr 24 14:36 l5m drwxr-x--- 2 root root 4.0K Apr 24 14:36 performance_schema -rw-r----- 1 root root 480K Apr 24 14:36 ibdata1.delta -rw-r----- 1 root root 44 Apr 24 14:36 ibdata1.meta
Insert some data into the table again:
mysql> insert into tab1 values(3); Query OK, 1 row affected (0.06 sec) mysql> insert into tab1 values(4); Query OK, 1 row affected (0.01 sec) mysql> insert into tab2 values(200); Query OK, 1 row affected (0.06 sec) mysql> commit; Query OK, 0 rows affected (0.00 sec) mysql> select * from tab1; +------+ | id | +------+ | 1 | | 2 | | 3 | | 4 | +------+ 4 rows in set (0.00 sec) mysql> select * from tab2; +------+ | id | +------+ | 100 | | 200 | +------+ 2 rows in set (0.00 sec)
Do an incremental backup based on the last incremental backup again (backup based on /u01/backup/inc/2018-04-24_14-36-17/)
[root@qht26 ~]# innobackupex --defaults-file=/etc/my.cnf --user=xbk --password=123456 --socket=/u01/mysql/mysql.sock --incremental /u01/backup/inc --incremental-basedir=/u01/backup/inc/2018-04-24_14-36-17/ --parallel=2
[root@qht26 inc]# ls -lth total 8.0K drwxr-x--- 6 root root 4.0K Apr 24 14:42 2018-04-24_14-41-43 drwxr-x--- 6 root root 4.0K Apr 24 14:36 2018-04-24_14-36-17
[root@qht26 inc]# pwd /u01/backup/inc
Restoration of incremental backups:
There are 3 steps to restore incremental backups
- Restoring a full backup
- Restore the incremental backup to the full backup (add the --redo-only parameter to the incremental backup that starts to restore, and remove the --redo-only parameter to the last incremental backup)
- Restore the entire full backup and roll back uncommitted data
#To prepare a full backup, you need to add redo-only
[root@qht26 backup]# innobackupex --apply-log --redo-only /u01/backup/2018-04-24_11-54-46/#Apply increment 1 to full backup
Need to add redo-only[root@qht26 backup]# innobackupex --apply-log --redo-only /u01/backup/2018-04-24_11-54-46/ --incremental-dir=/u01/backup/inc/2018-04-24_14-36-17/
#Apply increment 2 to full backup [root@qht26 backup]# innobackupex --apply-log --redo-only /u01/backup/2018-04-24_11-54-46/ --incremental-dir=/u01/backup/inc/2018-04-24_14-41-43/
##把所有合在一起的完全备份整体进行一次apply操作，回滚未提交的数据## [root@qht26 2018-04-24_11-54-46]# innobackupex --apply-log /u01/backup/2018-04-24_11-54-46 xtrabackup: Log applied to lsn 2556977 xtrabackup: The intended lsn is 2564716
模拟数据损坏：
mysql> use l5m Database changed mysql> drop table tab2; Query OK, 0 rows affected (0.15 sec) mysql> drop table tab1; Query OK, 0 rows affected (0.04 sec)
[root@qht26 ~]# service mysql stop [root@qht26 ~]# mv /u01/mysql /u01/mysql_bk2 [root@qht26 ~]# mkdir /u01/mysql [root@qht26 ~]# chown -R mysql.mysql /u01/mysql [root@qht26 ~]# innobackupex --defaults-file=/etc/my.cnf --copy-back --rsync /u01/backup/2018-04-24_11-54-46/ [root@qht26 ~]# chown -R mysql.mysql /u01/mysql [root@qht26 ~]# service mysql start Starting MySQL.. [ OK ]
#数据已全部恢复
mysql> use l5m Database changed mysql> show tables; +---------------+ | Tables_in_l5m | +---------------+ | tab1 | | tab2 | +---------------+ 2 rows in set (0.00 sec) mysql> select * from tab1; +------+ | id | +------+ | 1 | | 2 | | 3 | | 4 | +------+ 4 rows in set (0.01 sec) mysql> select * from tab2; +------+ | id | +------+ | 100 | | 200 | +------+ 2 rows in set (0.00 sec)