an example of Point-In-Time-Recovery, restoring & recovering 9 rows from a Full+Incremental backup via MEB and applying the binlog updates.

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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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