YltProject/操作文档/7、Mysql数据库下载与还原.md

云数据库 RDS

RDS为5.7版本,有自动备份设置，每天都会有一个新的备份生成。这个备份是物理备份。

下载的文件名称类似于：

hins25487844_data_20240730052418_qp.xb
hins25487844_data_20240813052415_qp.xb 

阿里云官方参考文档

安装Percona XtraBackup 和 qpress

在自建库所在服务器中安装Percona XtraBackup和qpress后，再执行以下解压命令。若不安装，后续执行如下命令将失败。

参考文档

yum install https://repo.percona.com/yum/percona-release-latest.noarch.rpm
percona-release enable-only tools release
yum install lz4 zstd -y
yum install percona-xtrabackup-80 -y
yum -y install qpress

# 检查安装的版本
 xtrabackup --version

冷知识：为什么不使用MysqlDump备份数据库，而是采用了XtraBackup进行备份数据库?

答：因为逻辑备份时，会导致锁表，数据库性能下降，如果此时有大量用户使用，就带来的非常不好的体验，这时，XtraBackup的无感备份机制就有了用武之地。

上传备份文件到主机

cd /usr/local

因为备份文件太大，无法使用rz -be,所以选择sftp上传

hins25487844_data_20240813052415_qp.xb 

前提条件

要执行恢复备份，必须满足以下条件：

• 备份集要完成准备。

• 数据目录**datadir必须为空**。

• 不能恢复到正在运行的mysqld实例的数据目录(除非导入部分备份)，在执行恢复之前需要关闭MySQL服务器。

还原

rm -rf /var/mysql_bkdata/ && mkdir /var/mysql_bkdata/ -p

# 解压
cat hins25487844_data_20240813052415_qp.xb | xbstream -x -v -C /var/mysql_bkdata/

innobackupex --decompress --remove-original /var/mysql_bkdata/

# 应用日志
innobackupex --defaults-file=/var/mysql_bkdata/backup-my.cnf --apply-log /var/mysql_bkdata/

# 修改数据库文件属性
chown -R mysql:mysql /var/mysql_bkdata

编辑数据库配置文件

vi /etc/my.cnf

内容如下：

[mysqld]
user=mysql
basedir=/usr/local/mysql
#datadir=/data/mysql
datadir=/var/mysql_bkdata
server_id=1
port=22066
socket=/tmp/mysql.sock

lower_case_table_names=1
max_connections = 2048
max_connect_errors = 30
table_open_cache = 2048
open_files_limit = 16384
max_allowed_packet = 16M
read_buffer_size = 8M
read_rnd_buffer_size = 32M
sort_buffer_size = 2M
join_buffer_size = 2M
thread_cache_size = 16
query_cache_size = 128M
query_cache_limit = 4M
slow_query_log = 1
long_query_time = 2
innodb_file_per_table = 1
max_allowed_packet = 64M

innodb_data_file_path = ibdata1:10M:autoextend
innodb_buffer_pool_size = 2G
innodb_write_io_threads = 8
innodb_read_io_threads = 8
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 16M
innodb_log_file_size = 170M
innodb_lock_wait_timeout = 60

#sql_mode=ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

sql-mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

[mysql]
socket=/tmp/mysql.sock

启动Mysql

/usr/local/mysql/bin/mysqld --defaults-file=/etc/my.cnf --user=mysql --datadir=/var/mysql_bkdata/&

进入Mysql

/etc/init.d/mysqld stop

mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
mysql

删除多余的触发器

mysql> select trigger_schema,trigger_name from information_schema.triggers;
+----------------+----------------------------+
| trigger_schema | trigger_name               |
+----------------+----------------------------+
| sys            | sys_config_insert_set_user |
| sys            | sys_config_update_set_user |
+----------------+----------------------------+
2 rows in set (0.02 sec)

有两个没有删除掉的触发器，会导致后面的修改密码失败，

找到自己数据恢复的目录，查找以“.trg”为结尾的触发器文件，这里数据恢复目录为/var/mysql_bkdata/，执行find查找口令:

find /var/mysql_bkdata/ -iname *.trg

rm -rf /var/mysql_bkdata/mysql/user.TRG
rm -rf /var/mysql_bkdata/mysql/proxies_priv.TRG

授权与创建用户

退出Mysql，重新登录进来，切换到mysql.user表，重新更新密码

update mysql.user set authentication_string=PASSWORD("DsideaL147258369") where user='root' and host='localhost';

flush privileges;

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%'IDENTIFIED BY 'DsideaL147258369' WITH GRANT OPTION; 

flush privileges;
exit

/etc/init.d/mysqld restart
mysql -uroot -pDsideaL147258369

# 添加上项目中的ycharge用户
CREATE USER 'ycharge'@'localhost' IDENTIFIED BY 'ycharge';
GRANT ALL PRIVILEGES ON *.* TO 'ycharge'@'%'IDENTIFIED BY 'ycharge' WITH GRANT OPTION; 
flush privileges;


# 切换三张表的引擎为MyISAM,防止出现  1105 ER_UNKNOWN_ERROR
use mysql;

ALTER TABLE `mysql`.`proc` ENGINE = MyISAM;
ALTER TABLE `mysql`.`event`  ENGINE = MyISAM;
ALTER TABLE `mysql`.`func`  ENGINE = MyISAM;

移动到SSD硬盘上

df -h

[root@RockyLinux local]# df -h
Filesystem           Size  Used Avail Use% Mounted on
devtmpfs             4.0M     0  4.0M   0% /dev
tmpfs                7.7G  112K  7.7G   1% /dev/shm
tmpfs                3.1G  8.8M  3.1G   1% /run
/dev/mapper/rl-root  491G   80G  412G  17% /
/dev/sda2            960M  220M  741M  23% /boot
/dev/sda1            599M  7.1M  592M   2% /boot/efi
tmpfs                1.6G     0  1.6G   0% /run/user/0
/dev/sdb1             98G   28G   65G  31% /usr/local/db

cd /usr/local/db
rm -rf mysql_newdata
cp -r  /var/mysql_bkdata/  mysql_bkdata/

service mysqld stop
修改一下 /etc/my.cnf

data_dir=/usr/local/db/mysql_bkdata

# 修改数据库文件属性
chown -R mysql:mysql /usr/local/db/mysql_bkdata

service mysqld start