The document outlines the procedures for backing up and restoring databases using MySQL Enterprise Backup, highlighting the importance of full and incremental backups. It details the steps for creating backups, restoring data online, and recovering from errors without disrupting user access. Key recovery methods discussed include converting existing backups into single file backups and utilizing binary logs for accurate restoration.

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2. MySQL Enterprise Backup:
PITR Partial Online Recovery
Keith Hollman
MySQL Principal Sales Consultant EMEA

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Agenda
 Objectives for today.
 Backup and what to do.
 Restore procedures.

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Objectives
 Backup Policy:
– Full Backup of the environment.
– Complemental Incremental backups & online BinLogs.
 Restore:
– Logical Restore.
– Online, Zero impact.
– Partial, single database, group of tables.
Backup & Restore

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Backup
 A working environment, with 4 databases, of which 2 will require
restoration.
 Full backup with MySQL Enterprise Backup:
mysqlbackup --user=root --socket=/tmp/mysql.sock
--backup-dir=/home/mysql/unit4/backup/ --with-timestamp backup

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Backup
 Create 4 different databases, where the structure & content is the
same.
create database u4_1; use u4_1; create table `unit4` (`ID` int(7) NOT NULL
AUTO_INCREMENT, `Name` char(20) NOT NULL DEFAULT '‘, PRIMARY KEY (`ID`) )
ENGINE=InnoDB;
create database u4_2; use u4_2; create table `unit4` (...) ;
create database u4_3; use u4_3; create table `unit4` (...) ;
create database u4_4; use u4_4; create table `unit4` (...) ;
 Insert some rows in each of the “unit4” tables,
within each database:
call Unit4Insert (1000);
Test preparation
delimiter //
DROP PROCEDURE IF EXISTS Unit4Insert//
CREATE PROCEDURE Unit4Insert (p1 INT)
BEGIN
SET @x = 0;
REPEAT
INSERT INTO unit4 SELECT NULL, '1thousand';
SET @x = @x + 1;
UNTIL @x > p1 END REPEAT;
END
//
delimiter ;

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Backup
 Then execute an incremental backup to safeguard the newly created
databases & objects and inserted rows.
mysqlbackup --user=root --socket=/tmp/mysql.sock
--incremental-backup-dir=/home/mysql/unit4/backup_inc --with-timestamp
--incremental --incremental_base=history:last_backup backup
Incremental

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Recovery

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Recovery
 We can:
1. convert the existing backup-dir to a single file backup and then extract it, or
2. go via the collection of tablespaces, locking and discarding as we go.
 Restore method also depends on whether:
1. tables have had rows deleted or modified (here we can use transportable
tablespaces)
2. if the object has been deleted, then we need to recreate it, from a
mysqldump extracted from a restored environment.
 In another separate environment or using a specific my.cnf.
2 Options for Logical Recovery.

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Recovery
 Bring the full backup up to date with all InnoDB data:
mysqlbackup --backup-dir=/home/mysql/unit4/backup/2013-07-25_01-44-43/ apply-log
 Update the Full backup with the Incremental backup:
mysqlbackup --backup-dir=/home/mysql/unit4/backup/2013-07-25_01-44-43/
--incremental-backup-dir=/home/mysql/unit4/backup_inc/2013-07-25_17-20-18
apply-incremental-backup
 And then get a single consolidated image file to work from:
mysqlbackup --backup-image=/home/mysql/unit4/backup/full_backup.mbi
--backup-dir=/home/mysql/unit4/backup/2013-07-25_01-44-43 backup-dir-to-image
Preparing backups

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Recovery
 Now let’s insert some rows, to reflect changes in the binlogs:
use u4_2
call Unit4Insert (1000);
select count(*) from unit4;
 And generate something to have to recover from:
delete from unit4 where id < 10;
select count(*) from unit4;
The Test
+----------+
| count(*) |
+----------+
| 2002 |
+----------+
+----------+
| count(*) |
+----------+
| 1993 |
+----------+

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Recovery

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The Recovery Scenario
 Objective:
– Restore the whole table with the logs applied, before the error.
– Online, without having to stop or impede access to the other users.
 So when did the error happen then? Let’s view the General_log:
vi ol63uek01.log
/delete from unit4
....
130729 13:16:29 2 Query delete from unit4 where id < 10
..

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The Recovery Scenario
 What’s the backup history:
use mysql
select backup_id, start_time, end_time, binlog_pos, binlog_file, backup_type, backup_format,
backup_destination, exit_state from backup_history;
 Position =1654141 binlog = mysql-bin.000008
Backup status
+-------------------+---------------------+---------------------+------------+------------------+-------------+---------------
+---------------------------------------------------+------------+
| backup_id | start_time | end_time | binlog_pos | binlog_file | backup_type | backup_format
| backup_destination | exit_state |
+-------------------+---------------------+---------------------+------------+------------------+-------------+---------------
+---------------------------------------------------+------------+
| 13747094837220932 | 2013-07-25 01:44:43 | 2013-07-25 01:45:26 | 829045 | mysql-bin.000008 | FULL | DIRECTORY
| /home/mysql/unit4/backup/2013-07-25_01-44-43 | SUCCESS |
| 13747656186636058 | 2013-07-25 17:20:18 | 2013-07-25 17:20:46 | 1654141 | mysql-bin.000008 | INCREMENTAL | DIRECTORY
| /home/mysql/unit4/backup_inc/2013-07-25_17-20-18 | SUCCESS |

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The Recovery Scenario
 To list single-file image contents:
mysqlbackup --backup-image=/home/mysql/unit4/backup/full_backup.mbi list-image
 Now we know where the 2 databases are, u4_2 & u4_4, extract them:
mysqlbackup --backup-image=/home/mysql/unit4/backup/full_backup.mbi
--src-entry=datadir/u4_2 --dst-entry=/home/mysql/unit4/reco/u4_2 extract
mysqlbackup --backup-image=/home/mysql/unit4/backup/full_backup.mbi
--src-entry=datadir/u4_4 --dst-entry=/home/mysql/unit4/reco/u4_4 extract
List contents & Extract

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The Recovery Scenario
 We also know which binlog to start reading from, and from what
position, in order to gather all changes after the Incremental backup
and just before the "delete" occurred.
 Also, as there is more than 1 binlog, we pass the list on a single line:
mysqlbinlog --start-position=1654141 --stop-datetime="2013-07-29 13:16:28"
/binlogs/mysql-bin.000008 /binlogs/mysql-bin.000009 --base64-output=decode-rows
--verbose --database=u4_2 > recover_1654141_20130729131628.sql
 with this file, recover_1654141_20130729131628.sql, we can see the sql
commands COMMENTED OUT, i.e. any execution of this file will not
restore anything.
Next steps

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The Recovery Scenario
 Now discard the original tables, and replace with the recovered ones
from the Full+INC image result set:
 Generate the ‘lock’ and ‘discard’ sql syntax:
select 'use u4_2' db, concat_ws(' ','lock tables',table_name,'write;') 'lock',
concat_ws(' ','alter table',table_name,'discard tablespace;') 'discard' from
tables where table_schema = 'u4_2';
select 'use u4_4' db, concat_ws(' ','lock tables',table_name,'write;') 'lock',
concat_ws(' ','alter table',table_name,'discard tablespace;') 'discard' from
tables where table_schema = 'u4_4';
use u4_2; lock tables unit4 write; alter table unit4 discard tablespace;
use u4_4; lock tables unit4 write; alter table unit4 discard tablespace;
Transportable tablespaces.

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The Recovery Scenario
 Copy the recovered .ibd files from the single file backup image:
cd /opt/mysql/mysql/data/u4_2
cp ~/unit4/reco/u4_2/*.ibd .
 Import the tablespaces:
select concat_ws(' ','alter table',table_name,'import tablespace;') 'import' from
tables where table_schema = 'u4_2';
alter table unit4 import tablespace;
 Unlock the tables (execute only once for all tables):
unlock tables;
Transportable tablespaces continued.

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The Recovery Scenario
 Time to apply the data extracted from the binlogs, after the incremental
backup:
mysqlbinlog --start-position=1654141 --stop-datetime="2013-07-29 13:16:28"
/binlogs/mysql-bin.000008 /binlogs/mysql-bin.000009 --verbose --database=u4_2
| mysql –uroot
 Confirm that we have restored the table with all its rows:
mysql> select count(*) from u4_2.unit4;
Transportable tablespaces continued.
+----------+
| count(*) |
+----------+
| 2002 |
+----------+

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Other details
 Just some further details of the procedure and impact of restoring, at a
space requirement level:
/opt/mysql/mysql/data 546996 Kb
/home/mysql/unit4 1461780 Kb
- 1 full backup (uncompressed) 538984 Kb
- 1 incremental backup 383412 Kb
- 1 Full+INC single file image 538450 Kb
- Recovered db's (u4_2+u4_4) 328 Kb
- recover sql w/ comments script 576 Kb
- meta & datadir dir's 8 Kb

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