MySQL real-time online backup and recovery plan: Replication + LVM Snapsho

Combined with snapshot and replication technology to ensure that we can get a real-time online MySQL backup solution, when the main library misuse, only need to restore the snapshot on the standby database, and then perform the recovery binlog according to a point-in-time.

Next, assume a scenario:

Master-slave architecture, there is no delay, a malfunction DBA: drop database

Next, we performed backup and recovery simulation testing in accordance with the above scenario

⑴ main library ready to test data

mysql> create database cnfol;
Query OK, 1 row affected (0.00 sec)


mysql> create table cnfol.t (id int primary key);
Query OK, 0 rows affected (0.02 sec)


mysql> insert into cnfol.t select 1;
Query OK, 1 row affected (0.01 sec)
Records: 1  Duplicates: 0  Warnings: 0


mysql> insert into cnfol.t select 2;
Query OK, 1 row affected (0.00 sec)
Records: 1  Duplicates: 0  Warnings: 0

Library equipment to confirm:

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| cnfol              |
| mysql              |
| test               |
+--------------------+
4 rows in set (0.00 sec)

mysql> select * from cnfol.t;
+----+
| id |
+----+
|  1 |
|  2 |
+----+
2 rows in set (0.00 sec)

⑵ add a global read lock

In standby database:

mysql> flush tables with read lock;
Query OK, 0 rows affected (0.00 sec)

⑶ create a snapshot for the partition where the library equipment

[root@localhost ~]# lvcreate --size 1G --snapshot --name backup_mysql /dev/vg/mysql
  Logical volume "backup_mysql" created

[root@localhost ~]# lvs
  LV           VG   Attr   LSize Origin Snap%  Move Log Copy%  Convert
  backup_mysql vg   swi-a- 1.00G mysql    0.00                        
  mysql        vg   owi-ao 2.00G                                      

⑷ obtain binary log coordinates

In standby database:

mysql> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000003 |      727 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

⑸ Unlock

In standby database:

mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)

⑹ Mount Snapshot

[root@localhost ~]# mount /dev/vg/backup_mysql  /mnt/backup
[root@localhost ~]# cd /mnt/backup/mysql/data/cnfol/ && ls -alh
总计 32K
drwx------ 2 mysql dba 4.0K 10-14 09:57 .
drwx------ 5 mysql dba 4.0K 10-14 09:57 ..
-rw-rw---- 1 mysql dba   61 10-14 09:57 db.opt
-rw-rw---- 1 mysql dba 8.4K 10-14 09:57 t.frm
-rw-rw---- 1 mysql dba   14 10-14 09:57 t.MYD
-rw-rw---- 1 mysql dba 2.0K 10-14 10:06 t.MYI

⑺ a main library inexperienced DBA misuse

mysql> drop database cnfol;
Query OK, 1 row affected (0.05 sec)

At this time, the recording time: 2013-10-14 10:17:10

Prepared by the library to confirm whether there is a library cnfol:

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| test               |
+--------------------+
3 rows in set (0.01 sec)

⑻ backup snapshot

[root@localhost backup]# pwd
/mnt/backup

[root@localhost backup]# tar -jcv -f /mnt/snapshot/mysql.tar.bz2 *

There are reasons for doing backups 2:00

  • First, expensive IO, because the head back and forth in the area and the system area ran snapshot
  • Second, the lack of space snapshots area, because it is the principle COW

⑼ delete snapshots

[root@localhost ~]# umount /mnt/backup
[root@localhost ~]# lvremove --force /dev/vg/backup_mysql 
  Logical volume "backup_mysql" successfully removed

Format the partition by the library where ⑽

[mysql@localhost ~]$ mysqladmin -uroot -p shutdown
131014 10:32:40 mysqld_safe mysqld from pid file /mnt/lvm/mysql/data/localhost.localdomain.pid ended
[1]+  Done                    mysqld_safe

[root@localhost ~]# umount /mnt/lvm
[root@localhost ~]# mkfs -t ext3 /dev/vg/mysql 

[root@localhost ~]# mount /dev/vg/mysql  /mnt/lvm
[root@localhost ~]# lvs
  LV    VG   Attr   LSize Origin Snap%  Move Log Copy%  Convert
  mysql vg   -wi-ao 2.00G                                      

[root@localhost ~]# vgs
  VG   #PV #LV #SN Attr   VSize VFree
  vg     4   1   0 wz--n- 3.81G 1.81G

⑾ decompress the partition where the snapshot to the backup repository

# tar -jxv -f /mnt/snapshot/mysql.tar.bz2 -C /mnt/lvm/
[root@localhost lvm]# pwd
/mnt/lvm

[root@localhost lvm]# ls
lost+found  mysql

⑿ start MySQL

⒀ use binlog perform point-in-time recovery

[mysql@localhost ~]$ mysqlbinlog --stop-datetime="2013-10-14 10:17:10" /mnt/lvm/mysql/data/mysql-bin.000003 | mysql -uroot -poracle

⒁ confirmation data

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| cnfol              |
| mysql              |
| test               |
+--------------------+
4 rows in set (0.00 sec)

mysql> select * from cnfol.t;
+----+
| id |
+----+
|  1 |
|  2 |
+----+
2 rows in set (0.00 sec)

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