1 数据备份与恢复
1.1 问题
本案例要求熟悉MySQL的备份与恢复,完成以下任务操作:
逻辑备份工具 mysqldump
使用mysql 恢复数据库
1.2 步骤
实现此案例需要按照如下步骤进行。
步骤一:使用mysqldump进行逻辑备份
1)备份MySQL服务器上的所有库
将所有的库备份为mysql-all.sql文件:
[root@dbsvr1 ~]# mysqldump -u root -p --all-databases > /root/alldb.sql
Enter password: //验证口令
[root@dbsvr1 mysql]# file /root/alldb.sql //确认备份文件类型
/root/alldb.sql: UTF-8 Unicode English text, with very long lines
查看备份文件alldb.sql的部分内容:
[root@dbsvr1 ~]# grep -vE '^/|^-|^$' /root/alldb.sql | head -15
CREATE DATABASE /*!32312 IF NOT EXISTS*/ `home` /*!40100 DEFAULT CHARACTER SET latin1 */;
USE `home`;
DROP TABLE IF EXISTS `biao01`;
CREATE TABLE `biao01` (
`id` int(2) NOT NULL,
`name` varchar(8) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
LOCK TABLES `biao01` WRITE;
UNLOCK TABLES;
DROP TABLE IF EXISTS `biao02`;
CREATE TABLE `biao02` (
`id` int(4) NOT NULL,
`name` varchar(8) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
.. ..
注意:若数据库都使用MyISAM存储引擎,可以采用冷备份的方式,直接复制对应的数据库目录即可;恢复时重新复制回来就行。
2)只备份指定的某一个库
将userdb库备份为userdb.sql文件:
[root@dbsvr1 ~]# mysqldump -u root -p userdb > userdb.sql
Enter password: //验证口令
查看备份文件userdb.sql的部分内容:
[root@dbsvr1 ~]# grep -vE '^/|^-|^$' /root/userdb.sql
DROP TABLE IF EXISTS `stu_info`;
CREATE TABLE `stu_info` (
`name` varchar(12) NOT NULL,
`gender` enum('boy','girl') DEFAULT 'boy',
`age` int(3) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
LOCK TABLES `stu_info` WRITE;
.. ..
3)同时备份指定的多个库
同时备份mysql、userdb库,保存为mysql+userdb.sql文件:
[root@dbsvr1 ~]# mysqldump -u root -p -B mysql userdb > mysql+test+userdb.sql
Enter password: //验证口令
查看备份文件userdb.sql的部分内容:
[root@dbsvr1 ~]# grep '^CREATE DATA' /root/mysql+userdb.sql
CREATE DATABASE /*!32312 IF NOT EXISTS*/ `mysql` /*!40100 DEFAULT CHARACTER SET latin1 */;
CREATE DATABASE /*!32312 IF NOT EXISTS*/ `userdb` /*!40100 DEFAULT CHARACTER SET latin1 */;
步骤二:使用mysql命令从备份中恢复数据库、表
以恢复userdb库为例,可参考下列操作。通常不建议直接覆盖旧库,而是采用建立新库并导入逻辑备份的方式执行恢复,待新库正常后即可废弃或删除旧库。
1)创建名为userdb2的新库
mysql> CREATE DATABASE userdb2;
Query OK, 1 row affected (0.00 sec)
2)导入备份文件,在新库中重建表及数据
[root@dbsvr1 ~]# mysql -u root -p userdb2 < /root/userdb.sql
Enter password: //验证口令
3)确认新库正常,启用新库
mysql> USE userdb2; //切换到新库
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> SELECT sn,username,uid,gid,homedir //查询数据,确认可用
-> FROM userlist LIMIT 10;
+----+----------+-----+-----+-----------------+
| sn | username | uid | gid | homedir |
+----+----------+-----+-----+-----------------+
| 1 | root | 0 | 0 | /root |
| 2 | bin | 1 | 1 | /bin |
| 3 | daemon | 2 | 2 | /sbin |
| 4 | adm | 3 | 4 | /var/adm |
| 5 | lp | 4 | 7 | /var/spool/lpd |
| 6 | sync | 5 | 0 | /sbin |
| 7 | shutdown | 6 | 0 | /sbin |
| 8 | halt | 7 | 0 | /sbin |
| 9 | mail | 8 | 12 | /var/spool/mail |
| 10 | operator | 11 | 0 | /root |
+----+----------+-----+-----+-----------------+
10 rows in set (0.00 sec)
4)废弃或删除旧库
mysql> DROP DATABASE userdb;
Query OK, 2 rows affected (0.09 sec)
2 使用binlog日志
2.1 问题
利用binlog恢复库表,要求如下:
启用binlog日志
创建db1库tb1表,插入3条记录
删除tb1表中刚插入的3条记录
使用mysqlbinlog恢复删除的3条记录
2.2 步骤
实现此案例需要按照如下步骤进行。
步骤一:启用binlog日志
1)调整/etc/my.cnf配置,并重启服务
[root@dbsvr1 ~]# vim /etc/my.cnf
[mysqld]
.. ..
log-bin-index=mysql-bin //启用二进制日志,并指定前缀
server_id=1
binlog_format=STATEMENT
//在Mysql5.7中,binlog日志格式默认为ROW,但它不记录sql语句上下文相关信息。需要将binlog日志格式修改为STATEMENT
.. ..
[root@dbsvr1 ~]# systemctl restart mysqld.service
2)确认binlog日志文件
新启用binlog后,每次启动MySQl服务都会新生成一份日志文件:
[root@dbsvr1 ~]# ls /var/lib/mysql/mysql-bin.*
/var/lib/mysql/mysql-bin.000001 /var/lib/mysql/mysql-bin.index
其中mysql-bin.index文件记录了当前保持的二进制文件列表:
[root@dbsvr1 ~]# cat /var/lib/mysql/mysql-bin.index
./mysql-bin.000001
重启MySQL服务程序,或者执行SQL操作“FLUSH LOGS;”,会生成一份新的日志:
[root@dbsvr1 ~]# ls /var/lib/mysql/mysql-bin.*
/var/lib/mysql/mysql-bin.000001 /var/lib/mysql/mysql-bin.index
/var/lib/mysql/mysql-bin.000002
[root@dbsvr1 ~]# cat /var/lib/mysql/mysql-bin.index
./mysql-bin.000001
./mysql-bin.000002
步骤二:利用binlog日志重做数据库操作
1)执行数据库表添加操作
创建db1·库tb1表,表结构自定义:
mysql> CREATE DATABASE db1;
Query OK, 1 row affected (0.05 sec)
mysql> USE db1;
Database changed
mysql> CREATE TABLE tb1(
-> id int(4) NOT NULL,name varchar(24)
-> );
Query OK, 0 rows affected (0.28 sec)
插入3条表记录:
mysql> INSERT INTO tb1 VALUES
-> (1,'Jack'),
-> (2,'Kenthy'),
-> (3,'Bob');
Query OK, 3 rows affected (0.12 sec)
Records: 3 Duplicates: 0 Warnings: 0
确认插入的表记录数据:
mysql> SELECT * FROM tb1;
+----+--------+
| id | name |
+----+--------+
| 1 | Jack |
| 2 | Kenthy |
| 3 | Bob |
+----+--------+
3 rows in set (0.00 sec)
2)删除前一步添加的3条表记录
执行删除所有表记录操作:
mysql> DELETE FROM tb1;
Query OK, 3 rows affected (0.09 sec)
确认删除结果:
mysql> SELECT * FROM tb1;
Empty set (0.00 sec)
步骤三:通过binlog日志恢复表记录
binlog会记录所有的数据库、表更改操作,所以可在必要的时候重新执行以前做过的一部分数据操作,但对于启用binlog之前已经存在的库、表数据将不适用。
根据上述“恢复被删除的3条表记录”的需求,应通过mysqlbinlog工具查看相关日志文件,找到删除这些表记录的时间点,只要恢复此前的SQL操作(主要是插入那3条记录的操作)即可。
1)查看mysql-bin.000002日志内容
[root@dbsvr1 ~]# mysqlbinlog /var/lib/mysql/mysql-bin.000002
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
DELIMITER /*!*/;
# at 4
#170412 12:05:32 server id 1 end_log_pos 123 CRC32 0x6d8c069c Start: binlog v 4, server v 5.7.17-log created 170412 12:05:32 at startup
# Warning: this binlog is either in use or was not closed properly.
ROLLBACK/*!*/;
BINLOG '
jKftWA8BAAAAdwAAAHsAAAABAAQANS43LjE3LWxvZwAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAACMp+1YEzgNAAgAEgAEBAQEEgAAXwAEGggAAAAICAgCAAAACgoKKioAEjQA
AZwGjG0=
'/*!*/;
# at 123
#170412 12:05:32 server id 1 end_log_pos 154 CRC32 0x17f50164 Previous-GTIDs
# [empty]
# at 154
#170412 12:05:59 server id 1 end_log_pos 219 CRC32 0x4ba5a976 Anonymous_GTID last_committed=0 sequence_number=1
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 219
#170412 12:05:59 server id 1 end_log_pos 310 CRC32 0x5b66ae13 Query thread_id=3 exec_time=0 error_code=0
SET TIMESTAMP=1491969959/*!*/;
SET @@session.pseudo_thread_id=3/*!*/;
SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
SET @@session.sql_mode=1436549152/*!*/;
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=8/*!*/;
SET @@session.lc_time_names=0/*!*/;
SET @@session.collation_database=DEFAULT/*!*/;
CREATE DATABASE db1
/*!*/;
# at 310
#170412 12:06:23 server id 1 end_log_pos 375 CRC32 0x2967cc28 Anonymous_GTID last_committed=1 sequence_number=2
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 375
#170412 12:06:23 server id 1 end_log_pos 502 CRC32 0x5de09aae Query thread_id=3 exec_time=0 error_code=0
use `db1`/*!*/;
SET TIMESTAMP=1491969983/*!*/;
CREATE TABLE tb1(
id int(4) NOT NULL,name varchar(24)
)
/*!*/;
# at 502
#170412 12:06:55 server id 1 end_log_pos 567 CRC32 0x0b8cd418 Anonymous_GTID last_committed=2 sequence_number=3
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 567
#170412 12:06:55 server id 1 end_log_pos 644 CRC32 0x7e8f2fa0 Query thread_id=3 exec_time=0 error_code=0
SET TIMESTAMP=1491970015/*!*/;
BEGIN
/*!*/;
# at 644
#170412 12:06:55 server id 1 end_log_pos 772 CRC32 0x4e3f728e Query thread_id=3 exec_time=0 error_code=0 //插入表记录的起始时间点
SET TIMESTAMP=1491970015/*!*/;
INSERT INTO tb1 VALUES(1,'Jack'),(2,'Kenthy'), (3,'Bob')
/*!*/;
# at 772
#170412 12:06:55 server id 1 end_log_pos 803 CRC32 0x6138b21f Xid = 10
//确认事务的时间点
COMMIT/*!*/;
# at 803
#170412 12:07:24 server id 1 end_log_pos 868 CRC32 0xbef3f472 Anonymous_GTID last_committed=3 sequence_number=4
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 868
#170412 12:07:24 server id 1 end_log_pos 945 CRC32 0x5684e92c Query thread_id=3 exec_time=0 error_code=0
SET TIMESTAMP=1491970044/*!*/;
BEGIN
/*!*/;
# at 945
#170412 12:07:24 server id 1 end_log_pos 1032 CRC32 0x4c1c75fc Query thread_id=3 exec_time=0 error_code=0 //删除表记录的时间点
SET TIMESTAMP=1491970044/*!*/;
DELETE FROM tb1
/*!*/;
# at 1032
#170412 12:07:24 server id 1 end_log_pos 1063 CRC32 0xccf549b2 Xid = 12
COMMIT/*!*/;
SET @@SESSION.GTID_NEXT= 'AUTOMATIC' /* added by mysqlbinlog */ /*!*/;
DELIMITER ;
# End of log file
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
2) 执行指定Pos节点范围内的sql命令恢复数据
根据上述日志分析,只要恢复从2014.01.12 20:12:14到2014.01.12 20:13:50之间的操作即可。可通过mysqlbinlog指定时间范围输出,结合管道交给msyql命令执行导入重做:
[root@dbsvr1 ~]# mysqlbinlog \
--start-datetime="2017-04-12 12:06:55" \
--stop-datetime="2017-04-12 12:07:23" \
/var/lib/mysql/mysql-bin.000002 | mysql -u root -p
Enter password: //验证口令
3)确认恢复结果
mysql> SELECT * FROM db1.tb1;
+----+--------+
| id | name |
+----+--------+
| 1 | Jack |
| 2 | Kenthy |
| 3 | Bob |
+----+--------+
3 rows in set (0.00 sec)