Ⅰ. Backup type
Here are three full backups
hot backup
- Online backup
- Basically no impact on the application (application reading and writing will not block, but the performance will still decline, so try not to do backup on the master, do it on the slave library)
cold backup
- Backup data files, requires downtime
- Backup all files in the datadir directory
Is it ok to just copy this directory? The actual undo, redo, binlog can be configured in different directories, which may not be under datadir
Special case:
create table zz(a int) data directory = '/tmp/'What should I do in this situation? Parse the data directory of each table during backup? So it is not recommended to use this thing to build a table
tips：
Put redo, undo, and binlog on hdd and data on ssd?
No need, ssd is very cheap now, and the sequence is not bad. It is good to make a raid with three or four disks. There is no need to separate them.
Having said that, there are not many opportunities for cold backup, and it is unacceptable to shut down
warm backup
- For myisam backup (myisam does not support hot backup), the instance is read-only but not writable during backup
- Great impact on applications
- Usually add a read lock
Ⅱ. MySQL hot standby tool
ibbackup
- Official Backup Tool
- toll
- physical backup
xtrabackup
- Open source community backup tool
- Open source is free, the free version of the above thing (there are problems with the old version, the data backed up may have problems)
- physical backup
mysqldump
- The official self-contained backup tool is open source and free
- Logical backup (slow)
- don't block dml, block ddl
Ⅲ. Logical backup vs physical backup
| - | logic | physics |
|---|---|---|
| Backup method | Backup database logical content | Backup database physical files |
| advantage | The backup file is relatively small, only the data and structure in the table are backed up | The recovery speed is relatively fast (the physical file recovery has basically completed the recovery) |
| shortcoming | Slower recovery (requires index rebuilding, stored procedures, etc.) | The backup file is relatively large (backup tablespace, including data and indexes, fragmentation) |
| business impact | Buffer pool pollution (read all data once, read into bp), I/O load increases | Increased I/O load |
| Representative tool | mysqldump | ibbackup xt xtrabackup |
tips:
The backup method is generally considered from the following dimensions
- Backup speed
- recovery speed
- Backup size
- business impact