Linux 安装MySQL 8.0.12之 RPM 安装体验
MySQL 8.0.12 版本于2018.07.27日发布，距离上一个版本MySQL8.0.11版本（2018.04.19）相距三个月多，其中新版本加入了一些新的功能，尤其是instand add column功能蛮令人期待的。
1.Instant Add Column。由腾讯游戏团队贡献代码，MariaDB 自10.3.2版本已经支持该功能。
2.BLOB小批量更新优化，这里的小批量更新是修改的数据大小为100bytes。
核心思想是撤销（undo）BLOB的更新向量，从而避免将前后镜像写入到表空间，从而节省时间和空间。
经过sysbench压力测试，更新JSON文档的单个整数 QPS的性能提高2到3倍。
3.MTS的参数 slave_pending_jobs_size_max默认值由16M增加到128M，增加MTS的event applier的buffer。
4.Group Replication增加对GCX/Xcom的内存使用的监控，可以在performance_schema中查看。
5.Query Rewrite Plugin：增加了对insert、update、delete操作的支持，之前此插件仅支持select语句。
6.windows functions： 新增窗口聚合函数BIT_AND, BIT_OR and BIT_XOR 。
7.GIS新增函数ST_Latitude() and ST_Longitude()来获取经纬度。
随着MySQL8.0.12版本的发布下列MySQL的产品线也更新到8.0.12版本：
MySQL workbench
MySQL Shell
MySQL router
MySQL on Windows (Installer & Tools) 一系列驱动程序的更新：
mysql-connector-odbc
mysql-connector-java
mysql-connector-net
mysql-connector-nodejs
mysql-connector-python
支持Python2.7 3.5 和3.6版本
MySQL Connector/C
MySQL Connector/C++国内可以通过镜像网站快速下载：（不过国内的网站只能镜像2个最新的小版本，下载历史版本还要要到mysql官方下载的）
#wget http://mirrors.ustc.edu.cn/mysql-ftp/Downloads/MySQL-8.0/mysql-8.0.12-1.el7.x86_64.rpm-bundle.tar
官方下载地址：
#wget https://dev.mysql.com/get/Downloads/MySQL-8.0/mysql-8.0.12-1.el7.x86_64.rpm-bundle.tar
查看操作系统：
# cat /etc/centos-release
CentOS Linux release 7.5.1804 (Core)
--解压文件：
tar -xvf mysql-8.0.12-1.el7.x86_64.rpm-bundle.tar
可以看到解压后的文件有10个RPM包：
mysql-community-client-8.0.12-1.el7.x86_64.rpm
mysql-community-common-8.0.12-1.el7.x86_64.rpm
mysql-community-devel-8.0.12-1.el7.x86_64.rpm
mysql-community-embedded-compat-8.0.12-1.el7.x86_64.rpm
mysql-community-libs-8.0.12-1.el7.x86_64.rpm
mysql-community-libs-compat-8.0.12-1.el7.x86_64.rpm
mysql-community-minimal-debuginfo-8.0.12-1.el7.x86_64.rpm
mysql-community-server-8.0.12-1.el7.x86_64.rpm
mysql-community-server-minimal-8.0.12-1.el7.x86_64.rpm
mysql-community-test-8.0.12-1.el7.x86_64.rpm
我们只需要依次安装需要的几个RPM包即可，安装之前需要卸载掉centos自带的mariadb-libs：
rpm -e --nodeps mariadb-libs
rpm -ivh mysql-community-common-8.0.12-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-8.0.12-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-8.0.12-1.el7.x86_64.rpm
rpm -ivh mysql-community-server-8.0.12-1.el7.x86_64.rpm
#systemctl start mysqld
#systemctl status mysqld
● mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
Active: active (running) since Sat 2018-07-28 22:55:26 CST; 41min ago
Docs: man:mysqld(8)
http://dev.mysql.com/doc/refman/en/using-systemd.html
Process: 3834 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
Main PID: 3902 (mysqld)
Status: "SERVER_OPERATING"
CGroup: /system.slice/mysqld.service
└─3902 /usr/sbin/mysqld
Jul 28 22:55:22 node4.example.com systemd[1]: Starting MySQL Server...
Jul 28 22:55:26 node4.example.com systemd[1]: Started MySQL Server.
# systemctl enable mysqld
# systemctl list-unit-files | grep -i mysql
mysqld.service enabled
[email protected] disabled
--登录MySQL：
由于RPM默认安装会找my.cnf去生产错误日志文件和数据文件，在MySQL5.7之后使用安全的安装方式会随机生产一个临时密码存放在错误日志文件中。
# cat /etc/my.cnf | grep -v ^#
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
# cat /var/log/mysqld.log | grep -i temporary
2018-07-28T14:55:23.475303Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: Tt8S./Tc;HuB
输入随机产生的密码：
# mysql -p -S /var/lib/mysql/mysql.sock
Enter password:
登录之后需要修改密码并创建一个可以远程登录的用户：
mysql> alter user root@'localhost' identified by 'oracle';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> alter user root@'localhost' identified by 'oracle@2018';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> alter user root@'localhost' identified by 'Oracle@2018';
Query OK, 0 rows affected (0.11 sec)
mysql> show variables like '%valid%';
+--------------------------------------+--------+
| Variable_name | Value |
+--------------------------------------+--------+
| validate_password.check_user_name | ON |
| validate_password.dictionary_file | |
| validate_password.length | 8 |
| validate_password.mixed_case_count | 1 |
| validate_password.number_count | 1 |
| validate_password.policy | MEDIUM |
| validate_password.special_char_count | 1 |
+--------------------------------------+--------+
7 rows in set (0.00 sec)
可以看到自MySQL5.7一来的RPM安装后的密码强度至少一个大写字母+一个数字+一个特殊符号。
使用传统语句创建远程登录的用户，可以看到MySQL8.0版本开始不支持传统的创建用户和授权写到一起的方法，需要将创建用户和授权分开：
mysql> grant all privileges on *.* to root@'%' identified by 'Oracle@2018' with grant option;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'identified by 'Oracle@2018' with grant option' at line 1
mysql> create user root@'%' identified by 'Oracle@2018';
Query OK, 0 rows affected (0.07 sec)
mysql> grant all privileges on *.* to root@'%' with grant option;
Query OK, 0 rows affected (0.06 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
查看错误日志的信息时候会发现时区和北京时间的时区不一致，相差八个小时，不太习惯于平常的日志查看：
mysql> select now();
+---------------------+
| now() |
+---------------------+
| 2018-07-28 23:07:03 |
+---------------------+
1 row in set (0.00 sec)
mysql> system cat /var/log/mysqld.log
2018-07-28T14:55:22.384191Z 0 [System] [MY-013169] [Server] /usr/sbin/mysqld (mysqld 8.0.12) initializing of server in progress as process 3855
2018-07-28T14:55:23.475303Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: Tt8S./Tc;HuB
2018-07-28T14:55:24.124940Z 0 [System] [MY-013170] [Server] /usr/sbin/mysqld (mysqld 8.0.12) initializing of server has completed
2018-07-28T14:55:26.149309Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.12) starting as process 3902
2018-07-28T14:55:26.440808Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2018-07-28T14:55:26.458527Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.12' socket: '/var/lib/mysql/mysql.sock' port: 3306 MySQL Community Server - GPL.
mysql>
此时需要参数为：
mysql> set global log_timestamps=system;
Query OK, 0 rows affected (0.00 sec)
不过若要重启MySQL生效的话还需要写到配置文件my.cnf:
若使用SQLyog等客户端登录MySQL会报错（MySQL workbench 8.0.12则不会报错）：
error 2059: Authentication plugin 'caching_sha2_password' cannot be loaded
解决办法为修改认证插件：
mysql> select host,user,authentication_string ,plugin from mysql.user where user='root';
+-----------+------+------------------------------------------------------------------------+-----------------------+
| host | user | authentication_string | plugin |
+-----------+------+------------------------------------------------------------------------+-----------------------+
| % | root | $A$005$z`}{.J~ht)Dv2M%o.i&2ZxkUAe8TuCngYYWT5qjGl8zPL1.1C3/f68wFeLycFB | caching_sha2_password |
| localhost | root | $A$005$?yI;3Ws_ U!2lYXRno46hSXNTL9Hz7t.apqvDebR5kGvPprMDvH27z1 | caching_sha2_password |
+-----------+------+------------------------------------------------------------------------+-----------------------+
2 rows in set (0.00 sec)
mysql> alter user root@'%' identified WITH mysql_native_password by 'Oracle@2018';
Query OK, 0 rows affected (0.07 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> select host,user,authentication_string ,plugin from mysql.user where user='root';
+-----------+------+------------------------------------------------------------------------+-----------------------+
| host | user | authentication_string | plugin |
+-----------+------+------------------------------------------------------------------------+-----------------------+
| % | root | *FFB4B151EBAD3082A29A4BED121A7F09718E934D | mysql_native_password |
| localhost | root | $A$005$?yI;3Ws_ U!2lYXRno46hSXNTL9Hz7t.apqvDebR5kGvPprMDvH27z1 | caching_sha2_password |
+-----------+------+------------------------------------------------------------------------+-----------------------+
2 rows in set (0.00 sec)
若需要后续的新创建的用户默认使用mysql_native_password 还需要写入到参数文件。
由于Linux系统默认是区分大小写的，在MYSQL中也是区分，为了便于平时的开发和书写需要修改参数以支持不区分大小写。
所以my.cnf文件中至少需要加上如下配置，然后重启MySQL：
[mysqld]
log_timestamps = SYSTEM
lower_case_table_names = 1
default-authentication-plugin =mysql_native_password
此时还会报错：
[ERROR] [MY-011087] [Server] Different lower_case_table_names settings for server ('1') and data dictionary ('0').
若要不区分大小写则在启动mysql之前将lower_case_table_names = 1写入到配置文件或者
需要删除datadir目录下的所有文件重新启动初始化数据文件。
若要在8.0版本中关闭密码强度验证只需要卸载组件即可：
mysql> UNINSTALL COMPONENT 'file://component_validate_password';
Query OK, 0 rows affected (0.01 sec)
mysql> show variables like 'valid%pass%';
Empty set (0.00 sec)
而在MySQL5.6 和5.7版本中则需要在my.cnf文件中写入：
validate_password=OFF
若不想使用RPM安装后的MySQL则可以卸载：
# rpm -qa | grep -i mysql
mysql-community-common-8.0.12-1.el7.x86_64
mysql-community-client-8.0.12-1.el7.x86_64
mysql-community-libs-8.0.12-1.el7.x86_64
mysql-community-server-8.0.12-1.el7.x86_64
# rpm -e --nodeps `rpm -qa | grep -i mysql`
卸载之后删除数据目录文件和日志文件即可：
# rm -rf /var/lib/mysql/*
# rm -rf /var/log/mysqld.log
参考：
https://mysqlserverteam.com/the-mysql-8-0-12-maintenance-release-is-generally-available/