mySQL配置文件、备份与恢复

mysql配置文件

mysql的配置文件为/etc/my.cnf

配置文件查找次序：若在多个配置文件中均有设定，则最后找到的最终生效

/etc/my.cnf --> /etc/mysql/my.cnf --> --default-extra-file=/PATH/TO/CONF_FILE --> ~/.my.cnf

mysql常用配置文件参数：

参数	说明
port = 3306	设置监听端口
socket = /tmp/mysql.sock	指定套接字文件位置
basedir = /usr/local/mysql	指定MySQL的安装路径
datadir = /data/mysql	指定MySQL的数据存放路径
pid-file = /data/mysql/mysql.pid	指定进程ID文件存放路径
user = mysql	指定MySQL以什么用户的身份提供服务
skip-name-resolve	禁止MySQL对外部连接进行DNS解析，使用这一选项可以消除MySQL进行DNS解析的时间。若开启该选项，则所有远程主机连接授权都要使用IP地址方式，否则MySQL将无法正常处理连接请求

mysql数据库备份

数据库常用备份方案

数据库备份方案：

• 全量备份：全量备份就是指对某一个时间点上的所有数据或应用进行的一个完全拷贝。
  • 数据恢复快。
  • 备份时间长
• 增量备份：增量备份是指在一次全备份或上一次增量备份后，以后每次的备份只需备份与前一次相比增加和者被修改的文件。这就意味着，第一次增量备份的对象是进行全备后所产生的增加和修改的文件；第二次增量备份的对象是进行第一次增量备份后所产生的增加和修改的文件，如此类推。
  • 没有重复的备份数据
  • 备份时间短
  • 恢复数据时必须按一定的顺序进行
• 差异备份：备份上一次的完全备份后发生变化的所有文件。差异备份是指在一次全备份后到进行差异备份的这段时间内对那些增加或者修改文件的备份。在进行恢复时，我们只需对第一次全量备份和最后一次差异备份进行恢复。

mysql备份工具mysqldump

语法：

mysqldump [OPTIONS] database [tables ...]
mysqldump [OPTIONS] --all-databases [OPTIONS]
mysqldump [OPTIONS] --databases [OPTIONS] DB1 [DB2 DB3...]

常用选项：

-uUSERNAME 指定数据库用户名
-hHOST     指定服务器主机，请使用ip地址
-pPASSWORD 指定数据库用户的密码
-P#        指定数据库监听的端口，这里的#需用实际的端口号代替，如-P3

mysql> show tables;
+----------------+
| Tables_in_lynk |
+----------------+
| armor          |
| mastersword    |
+----------------+
2 rows in set (0.00 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| lynk               |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.01 sec)

mysql> use lynk
Database changed
mysql> show tables;
+----------------+
| Tables_in_lynk |
+----------------+
| armor          |
| mastersword    |
+----------------+
2 rows in set (0.00 sec)

#全备
[root@lynk ~]# mysqldump -uroot -p -h127.0.0.1 --all-databases > all-201902211531.sql
Enter password: 
[root@lynk ~]# ls
all-201902211531.sql  anaconda-ks.cfg

#备份lynk库的mastersword和armor表
[root@lynk ~]# mysqldump -uroot -p -h127.0.0.1 lynk mastersword armor > table-201902211533.sql
Enter password: 
[root@lynk ~]# ls
all-201902211531.sql  anaconda-ks.cfg  table-201902211533.sql

#备份lynk库
[root@lynk ~]# mysqldump -uroot -p -h127.0.0.1 --databases lynk > lynk-201902211536.sql
Enter password: 
[root@lynk ~]# ls
all-201902211531.sql  anaconda-ks.cfg  lynk-201902211536.sql  table-201902211533.sql

数据恢复

#模拟误删数据库
mysql> drop database lynk;
Query OK, 2 rows affected (0.03 sec)

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

#恢复lynk数据库
[root@lynk ~]# mysql -uroot -p -h127.0.0.1 < all-201902211531.sql 
Enter password: 
[root@lynk ~]# mysql -uroot -p
Enter password: 

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| lynk               |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.01 sec)

#恢复表
mysql> use lynk
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> source table-201902211533.sql
Query OK, 0 rows affected (0.00 sec)
···
mysql> show tables;
+----------------+
| Tables_in_lynk |
+----------------+
| armor          |
| mastersword    |
+----------------+
2 rows in set (0.00 sec)

#模拟删除整个数据库
mysql> drop database lynk;
Query OK, 2 rows affected (0.04 sec)

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

#恢复整个数据库
[root@lynk ~]# mysql -uroot -p -h127.0.0.1 < all-201902211531.sql 
Enter password: 
[root@lynk ~]# mysql -uroot -p -h127.0.0.1 -e 'show databases;'
Enter password: 
+--------------------+
| Database           |
+--------------------+
| information_schema |
| lynk               |
| mysql              |
| performance_schema |
| sys                |
+--------------------+

差异备份

差异备份与全备和增备的操作不同，
差异备份是通过记录对数据库的操作而进行备份还原，其优点在于可以恢复到任意状态，而不是备份时的状态。

#开启mysql二进制日志功能
[root@lynk ~]# cat >> /etc/my.cnf <<EOF
server-id=1
log-bin=mysql_bin
EOF
[root@lynk ~]# service mysqld restart

#这是我的数据库表格
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| lynk               |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

mysql> show tables from lynk;
+----------------+
| Tables_in_lynk |
+----------------+
| student        |
+----------------+
1 row in set (0.00 sec)

mysql> select * from lynk.student;
+------+-------------+------+
| id   | name        | age  |
+------+-------------+------+
|    1 | tom         |   20 |
|    2 | jerry       |   23 |
|    3 | wangqing    |   25 |
|    4 | sean        |   28 |
|    5 | zhangshan   |   26 |
|    6 | zhangshan   |   20 |
|    7 | lisi        | NULL |
|    8 | chenshuo    |   10 |
|    9 | wangwu      |    3 |
|   10 | qiuyi       |   15 |
|   11 | qiuxiaotian |   20 |
+------+-------------+------+
11 rows in set (0.00 sec)

#先对数据库进行一次全备
[root@lynk ~]# mysqldump -uroot -plynk123~ --single-transaction --flush-logs --master-data=2 --all-databases --delete-master-logs > all-20190222.sql
mysqldump: [Warning] Using a password on the command line interface can be insecure.
[root@lynk ~]# ll
总用量 630088
-rw-r--r--. 1 root root    802782 2月  22 19:18 all-20190222.sql
-rw-------. 1 root root      1269 2月  18 17:34 anaconda-ks.cfg

#新增内容
mysql> use lynk
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 * from student;
+------+-------------+------+
| id   | name        | age  |
+------+-------------+------+
|    1 | tom         |   20 |
|    2 | jerry       |   23 |
|    3 | wangqing    |   25 |
|    4 | sean        |   28 |
|    5 | zhangshan   |   26 |
|    6 | zhangshan   |   20 |
|    7 | lisi        | NULL |
|    8 | chenshuo    |   10 |
|    9 | wangwu      |    3 |
|   10 | qiuyi       |   15 |
|   11 | qiuxiaotian |   20 |
+------+-------------+------+
11 rows in set (0.00 sec)

mysql> update student set age = 4 where id = 1;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from student;
+------+-------------+------+
| id   | name        | age  |
+------+-------------+------+
|    1 | tom         |    4 |
|    2 | jerry       |   23 |
|    3 | wangqing    |   25 |
|    4 | sean        |   28 |
|    5 | zhangshan   |   26 |
|    6 | zhangshan   |   20 |
|    7 | lisi        | NULL |
|    8 | chenshuo    |   10 |
|    9 | wangwu      |    3 |
|   10 | qiuyi       |   15 |
|   11 | qiuxiaotian |   20 |
+------+-------------+------+
11 rows in set (0.00 sec)

mysql差异备份恢复数据

#模拟删库
[root@lynk ~]# mysql -uroot -plynk123~ -e 'drop database lynk;'
mysql: [Warning] Using a password on the command line interface can be insecure.
[root@lynk ~]# mysql -uroot -plynk123~ -e 'show databases;'
mysql: [Warning] Using a password on the command line interface can be insecure.
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+

#模拟跑路ε=ε=(ﾉ ﾟД ﾟ)ﾉ（误）

#刷新二进制文件来创建一个新的
[root@lynk ~]# mysqladmin -uroot -plynk123~ flush-logs
mysqladmin: [Warning] Using a password on the command line interface can be insecure.
[root@lynk ~]# ll /opt/data
总用量 122952
-rw-r-----. 1 mysql mysql       56 2月  22 15:20 auto.cnf
-rw-r-----. 1 mysql mysql      346 2月  22 19:12 ib_buffer_pool
-rw-r-----. 1 mysql mysql 12582912 2月  22 19:24 ibdata1
-rw-r-----. 1 mysql mysql 50331648 2月  22 19:24 ib_logfile0
-rw-r-----. 1 mysql mysql 50331648 2月  22 15:20 ib_logfile1
-rw-r-----. 1 mysql mysql 12582912 2月  22 19:18 ibtmp1
-rw-r-----. 1 mysql mysql     8648 2月  22 19:12 localhost.localdomain.err
-rw-r-----. 1 mysql mysql     4315 2月  22 19:12 lynk.err
drwxr-x---. 2 mysql mysql     4096 2月  22 15:20 mysql
-rw-r-----. 1 mysql mysql      636 2月  22 19:26 mysql_bin.000002
-rw-r-----. 1 mysql mysql      154 2月  22 19:26 mysql_bin.000003
-rw-r-----. 1 mysql mysql       38 2月  22 19:26 mysql_bin.index
-rw-r-----. 1 mysql mysql        6 2月  22 19:12 mysql.pid
drwxr-x---. 2 mysql mysql     8192 2月  22 15:20 performance_schema
drwxr-x---. 2 mysql mysql     8192 2月  22 15:20 sys

#进行全备恢复
[root@lynk ~]# mysql -uroot -plynk123~ < all-20190222.sql 
mysql: [Warning] Using a password on the command line interface can be insecure.
#但是我们将进行过全备之后，我们的数据是处于新增内容之前的状态
[root@lynk ~]# mysql -uroot -plynk123~ -e 'select * from lynk.student;'
mysql: [Warning] Using a password on the command line interface can be insecure.
+------+-------------+------+
| id   | name        | age  |
+------+-------------+------+
|    1 | tom         |   20 |
|    2 | jerry       |   23 |
|    3 | wangqing    |   25 |
|    4 | sean        |   28 |
|    5 | zhangshan   |   26 |
|    6 | zhangshan   |   20 |
|    7 | lisi        | NULL |
|    8 | chenshuo    |   10 |
|    9 | wangwu      |    3 |
|   10 | qiuyi       |   15 |
|   11 | qiuxiaotian |   20 |
+------+-------------+------+

#进行差备恢复
#查询误删数据库位置
mysql> show binlog events in 'mysql_bin.000002';
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
| Log_name         | Pos | Event_type     | Server_id | End_log_pos | Info                                  |
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
| mysql_bin.000002 |   4 | Format_desc    |         1 |         123 | Server ver: 5.7.23-log, Binlog ver: 4 |
| mysql_bin.000002 | 123 | Previous_gtids |         1 |         154 |                                       |
| mysql_bin.000002 | 154 | Anonymous_Gtid |         1 |         219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS'  |
| mysql_bin.000002 | 219 | Query          |         1 |         291 | BEGIN                                 |
| mysql_bin.000002 | 291 | Table_map      |         1 |         345 | table_id: 110 (lynk.student)          |
| mysql_bin.000002 | 345 | Update_rows    |         1 |         401 | table_id: 110 flags: STMT_END_F       |
| mysql_bin.000002 | 401 | Xid            |         1 |         432 | COMMIT /* xid=479 */                  |
| mysql_bin.000002 | 432 | Anonymous_Gtid |         1 |         497 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS'  |
| mysql_bin.000002 | 497 | Query          |         1 |         589 | drop database lynk                    |
| mysql_bin.000002 | 589 | Rotate         |         1 |         636 | mysql_bin.000003;pos=4                |
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
10 rows in set (0.00 sec)
#可以看到是在位置497进行了drop操作，所以我们要从497的位置进行恢复
[root@lynk ~]# mysqlbinlog --stop-position=497 /opt/data/mysql_bin.000002 |mysql -uroot -plynk123~
mysql: [Warning] Using a password on the command line interface can be insecure.
[root@lynk ~]# mysql -uroot -plynk123~ -e 'select * from lynk.student;'
mysql: [Warning] Using a password on the command line interface can be insecure.
+------+-------------+------+
| id   | name        | age  |
+------+-------------+------+
|    1 | tom         |    4 |
|    2 | jerry       |   23 |
|    3 | wangqing    |   25 |
|    4 | sean        |   28 |
|    5 | zhangshan   |   26 |
|    6 | zhangshan   |   20 |
|    7 | lisi        | NULL |
|    8 | chenshuo    |   10 |
|    9 | wangwu      |    3 |
|   10 | qiuyi       |   15 |
|   11 | qiuxiaotian |   20 |
+------+-------------+------+