NSD DBA1 DAY06
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)