增量備份,就是將新增加的數(shù)據(jù)進(jìn)行備份。假如你一個(gè)數(shù)據(jù)庫(kù),有10G的數(shù)據(jù),每天會(huì)增加10M的數(shù)據(jù),數(shù)據(jù)庫(kù)每天都要備份一次,這么多數(shù)據(jù)是不是都要備份呢?還是只要備份增加的數(shù)據(jù)呢,很顯然,我只要備份增加的數(shù)據(jù)。這樣減少服務(wù)器的負(fù)擔(dān)。
二,啟用binlog
vi my.cnf
log-bin=/var/lib/mysql/mysql-bin.log,如果是這樣的話log-bin=mysql-bin.log默認(rèn)在datadir目錄下面
[root@BlackGhost mysql]# ls |grep mysql-bin
mysql-bin.000001
mysql-bin.000002
mysql-bin.000003
mysql-bin.000004
mysql-bin.000005
mysql-bin.000006
mysql-bin.index
啟動(dòng)后會(huì)產(chǎn)生mysql-bin這樣的文件,每啟動(dòng)一次,就會(huì)增加一個(gè)或者多個(gè)。
mysql-bin.000002這樣文件存放的是數(shù)據(jù)庫(kù)每天增加的數(shù)據(jù),所有數(shù)據(jù)庫(kù)的數(shù)據(jù)增量都在這里面。
三,查看mysql-bin.000002這樣的文件里面到底是什么東西
[root@BlackGhost mysql]# mysqlbinlog /var/lib/mysql/mysql-bin.000002 > /tmp/add.sql
- [root@BlackGhost mysql]# cat /tmp/add.sql // 下面是根據(jù)mysql-bin生成的文件(部分內(nèi)容)
- /*!40019 SET @@session.max_insert_delayed_threads=0*/;
- /*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
- DELIMITER /*!*/;
- # at 4
- #100929 21:23:52 server id 1 end_log_pos 106 Start: binlog v 4, server v 5.1.50-log created 100929 21:23:52 at startup
- # Warning: this binlog was not closed properly. Most probably mysqld crashed writing it.
- ROLLBACK/*!*/;
- BINLOG '
- 6D2jTA8BAAAAZgAAAGoAAAABAAQANS4xLjUwLWxvZwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
- AAAAAAAAAAAAAAAAAADoPaNMEzgNAAgAEgAEBAQEEgAAUwAEGggAAAAICAgC
- '/*!*/;
- # at 106
- #100929 21:29:35 server id 1 end_log_pos 134 Intvar
- SET INSERT_ID=16/*!*/;
- # at 134
- #100929 21:29:35 server id 1 end_log_pos 237 Query thread_id=1 exec_time=0 error_code=0
- use test/*!*/; //這里是test數(shù)據(jù)庫(kù)
- SET TIMESTAMP=1285766975/*!*/;
- SET @@session.pseudo_thread_id=1/*!*/;
- SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=1, @@session.unique_checks=1/*!*/;
- SET @@session.sql_mode=0/*!*/;
- SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
- /*!\C utf8 *//*!*/;
- SET @@session.character_set_client=33,@@session.collation_connection=33,@@session.collation_server=33/*!*/;
- SET @@session.lc_time_names=0/*!*/;
- SET @@session.collation_database=DEFAULT/*!*/;
- insert into aa(name)values('cccccccccc')
- /*!*/;
- # at 237
- #100929 21:32:21 server id 1 end_log_pos 265 Intvar
- SET INSERT_ID=12/*!*/;
- # at 265
- #100929 21:32:21 server id 1 end_log_pos 370 Query thread_id=1 exec_time=0 error_code=0
- SET TIMESTAMP=1285767141/*!*/;
- insert into user(name)values('cccccccccc')
- /*!*/;
- # at 370
- #100929 21:35:25 server id 1 end_log_pos 440 Query thread_id=1 exec_time=0 error_code=0
- SET TIMESTAMP=1285767325/*!*/;
- BEGIN
- /*!*/;
- # at 440
- #100929 21:35:25 server id 1 end_log_pos 468 Intvar
- SET INSERT_ID=45/*!*/;
- # at 468
- #100929 21:35:25 server id 1 end_log_pos 573 Query thread_id=1 exec_time=0 error_code=0
- use blog/*!*/; //這里是blog數(shù)據(jù)庫(kù)
- SET TIMESTAMP=1285767325/*!*/;
- insert into city(CityName)values('asdf')
- /*!*/;
- # at 573
- #100929 21:35:25 server id 1 end_log_pos 600 Xid = 205
- COMMIT/*!*/;
- DELIMITER ;
- # End of log file
- ROLLBACK /* added by mysqlbinlog */;
- /*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
下面還有一個(gè)重要索引文件就是mysql-bin.index
- [root@BlackGhost mysql]# cat mysql-bin.index
- ./mysql-bin.000001
- ./mysql-bin.000002
- ./mysql-bin.000003
- ./mysql-bin.000004
- ./mysql-bin.000005
- ./mysql-bin.000006
四,增量備份和增量還原
1,增量備份
既然我們知道了,mysql里面新增加的數(shù)據(jù)在mysql-bin這樣的文件里面,我們只要把mysql-bin這樣的文件進(jìn)行備份就可以了。
cp /var/lib/mysql/mysql-bin* /data/mysql_newbak/
2,增量還原,講幾個(gè)常用的,比較有用的
a),根據(jù)時(shí)間來(lái)還原 --start-date,--stop-date
[root@BlackGhost mysql]# /usr/local/mysql/bin/mysqlbinlog --start-date="2010-09-29 18:00:00" --stop-date="2010-09-29 23:00:00" /var/lib/mysql/mysql-bin.000002 |mysql -u root -p
根據(jù)條件看一下數(shù)據(jù)
- [root@BlackGhost mysql]# /usr/local/mysql/bin/mysqlbinlog --start-date="2010-09-29 18:00:00"
- --stop-date="2010-09-29 23:00:00" /var/lib/mysql/mysql-bin.000002
- //下面是部分內(nèi)容,其實(shí)也就是一些對(duì)數(shù)據(jù)進(jìn)行操作的sql語(yǔ)句
- # at 237
- #100929 21:32:21 server id 1 end_log_pos 265 Intvar
- SET INSERT_ID=12/*!*/;
- # at 265
- #100929 21:32:21 server id 1 end_log_pos 370 Query thread_id=1 exec_time=0 error_code=0
- SET TIMESTAMP=1285767141/*!*/;
- insert into user(name)values('cccccccccc')
- /*!*/;
- # at 370
- #100929 21:35:25 server id 1 end_log_pos 440 Query thread_id=1 exec_time=0 error_code=0
- SET TIMESTAMP=1285767325/*!*/;
- BEGIN
- /*!*/;
- # at 440
- #100929 21:35:25 server id 1 end_log_pos 468 Intvar
- SET INSERT_ID=45/*!*/;
- # at 468
- #100929 21:35:25 server id 1 end_log_pos 573 Query thread_id=1 exec_time=0 error_code=0
b),根據(jù)起始位置來(lái)還原,--start-position,--stop-position
[root@BlackGhost mysql]# /usr/local/mysql/bin/mysqlbinlog --start-position=370 --stop-position=440 /var/lib/mysql/mysql-bin.000002 |mysql -u root -p
//查看插入的內(nèi)容,根a)中是一樣的
[root@BlackGhost mysql]# /usr/local/mysql/bin/mysqlbinlog --start-position=370 --stop-position=440 /var/lib/mysql/mysql-bin.000002
--start-position=370 --stop-position=440 這里面數(shù)字從哪兒來(lái)的呢?
# at 370
#100929 21:35:25 server id 1 end_log_pos 440 Query thread_id=1 exec_time=0 error_code=0
SET TIMESTAMP=1285767325/*!*/;
上面的紅色加粗的就是,一個(gè)是start-position,一個(gè)是stop-position
c),根據(jù)數(shù)據(jù)庫(kù)名來(lái)進(jìn)行還原 -d
在這里是小寫(xiě)的d,請(qǐng)不要把它和mysqldump中的-D搞混了。哈哈。
[root@BlackGhost mysql]# /usr/local/mysql/bin/mysqlbinlog -d test /var/lib/mysql/mysql-bin.000002
查看內(nèi)容,請(qǐng)參考a)
d),根據(jù)數(shù)據(jù)庫(kù)所在IP來(lái)分-h(huán)
[root@BlackGhost mysql]# /usr/local/mysql/bin/mysqlbinlog -h 192.1681.102 /var/lib/mysql/mysql-bin.000002
查看內(nèi)容,請(qǐng)參考a)
e),根據(jù)數(shù)據(jù)庫(kù)所占用的端口來(lái)分-P
有的時(shí)候,我們的mysql用的不一定是3306端口,注意是大寫(xiě)的P
[root@BlackGhost mysql]# /usr/local/mysql/bin/mysqlbinlog -p 13306 /var/lib/mysql/mysql-bin.000002
查看內(nèi)容,請(qǐng)參考a)
f),根據(jù)數(shù)據(jù)庫(kù)serverid來(lái)還原--server-id
在數(shù)據(jù)庫(kù)的配置文件中,都有一個(gè)serverid并且同一集群中serverid是不能相同的。
[root@BlackGhost mysql]# /usr/local/mysql/bin/mysqlbinlog --server-id=1 /var/lib/mysql/mysql-bin.000002
查看內(nèi)容,請(qǐng)參考a)
注意:上面的幾個(gè)例子,我都是一個(gè)一個(gè)說(shuō)的,其實(shí)可以排列組合的。例如
[root@BlackGhost mysql]# /usr/local/mysql/bin/mysqlbinlog --start-position="2010-09-29 18:00:00" -d test -h 127.0.0.1 /var/lib/mysql/mysql-bin.000002 |mysql -u root -p
五,后續(xù)
增量備份的時(shí)候,有一點(diǎn)讓人不爽,就是mysql-bin這樣的文件,每啟動(dòng)一次mysql就會(huì)增加一些,如果你不去管他的話,時(shí)間長(zhǎng)了,他會(huì)把你的磁盤(pán)占滿。
./mysqldump --flush-logs -u root myblog > /tmp/myblog.sql
備份myblog數(shù)據(jù)庫(kù),清除增量備份里面的有關(guān)myblog的數(shù)據(jù)
./mysqldump --flush-logs -u root --all-databases > /tmp/alldatabase.sql
備份所有數(shù)據(jù)庫(kù),清除增量備份
mysql-bin.index的起索引作用,因?yàn)樵隽康臄?shù)據(jù)不一定在一個(gè)mysql-bin000這樣的文件里面,這個(gè)時(shí)候,我們就要根據(jù)mysql-bin.index來(lái)找mysql-bin這樣的增量文件了。
如果mysql里面做了這樣的配置binlog-do-db=test1,增量備份里面只會(huì)有test1這個(gè)數(shù)據(jù)庫(kù)的數(shù)據(jù)