centos7服务器安装mysql8

前言

CentOS 7 版本将MySQL数据库软件从默认的程序列表中移除，用mariadb代替了。
本文记录了在线安装mysql及离线安装mysql的方法和常见问题。
如果需要继续使用MySQL，可参考本文操作。

在线安装

获取yum源

0. 在MySQL官网中下载YUM源rpm安装包，复制下载链接使用wget下载。

wget https://dev.mysql.com/get/mysql80-community-release-el7-1.noarch.rpm

1. 安装yum源

yum localinstall mysql80-community-release-el7-1.noarch.rpm

2. 检查yum源

yum repolist enabled | grep "mysql.*-community.*"

可能遇到的问题：

• 安装了较旧的yum源，先删除旧版本

  1. 查询yum源

     rpm -qa |grep -i repo-name

  2. 删除该yum源

     rpm -e repo-name

  （参考博客地址）

安装mysql

0. 可以修改/etc/yum.repos.d/mysql-community.repo源，改变默认安装的mysql版本，enabled=0禁用，enabled=1启用。

1. 安装默认版本

   ※ 此处会耗费很长时间，可以先忙别的。

yum install -y mysql-community-server

执行完毕即安装完成。受服务器网速影响（预估耗时30h+），在线安装到此截止。改用离线安装。↓

离线安装

0. 官网下载RPM Bundle包

1. 上传Bundle包至服务器，rz -be上传、或xftp上传。

2. 解压Bundle包至/usr/local/mysql目录下。

3. 依次安装common、libs、client、server

[root@VM-0-4-centos mysql]# tar -xvf mysql-8.0.21-1.el7.x86_64.rpm-bundle.tar 
mysql-community-common-8.0.21-1.el7.x86_64.rpm
mysql-community-embedded-compat-8.0.21-1.el7.x86_64.rpm
mysql-community-libs-8.0.21-1.el7.x86_64.rpm
mysql-community-devel-8.0.21-1.el7.x86_64.rpm
mysql-community-server-8.0.21-1.el7.x86_64.rpm
mysql-community-client-8.0.21-1.el7.x86_64.rpm
mysql-community-libs-compat-8.0.21-1.el7.x86_64.rpm
mysql-community-test-8.0.21-1.el7.x86_64.rpm
[root@VM-0-4-centos mysql]# rpm -qa | grep mariadb
[root@VM-0-4-centos mysql]# rpm -ivh mysql-community-common-8.0.21-1.el7.x86_64.rpm 
Preparing...                          ################################# [100%]
Updating / installing...
   1:mysql-community-common-8.0.21-1.e################################# [100%]
[root@VM-0-4-centos mysql]# rpm -ivh mysql-community-libs-8.0.21-1.el7.x86_64.rpm 
Preparing...                          ################################# [100%]
Updating / installing...
   1:mysql-community-libs-8.0.21-1.el7################################# [100%]
[root@VM-0-4-centos mysql]# rpm -ivh mysql-community-client-8.0.21-1.el7.x86_64.rpm 
Preparing...                          ################################# [100%]
Updating / installing...
   1:mysql-community-client-8.0.21-1.e################################# [100%]
[root@VM-0-4-centos mysql]# rpm -ivh mysql-community-server-8.0.21-1.el7.x86_64.rpm 
Preparing...                          ################################# [100%]
Updating / installing...
   1:mysql-community-server-8.0.21-1.e################################# [100%]

至此，mysql已安装完毕。

服务启停

0. 查看服务状态

   systemctl status mysqld.service

1. 启动服务

   service mysqld start

2. 停止服务

   service mysqld stop

# 启动服务
[root@VM-0-4-centos etc]# service mysqld start
Redirecting to /bin/systemctl start mysqld.service
# 查看服务
[root@VM-0-4-centos etc]# systemctl status mysqld.service 
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since Tue 2020-09-01 00:08:51 CST; 37s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 21087 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 21110 (mysqld)
   Status: "Server is operational"
   CGroup: /system.slice/mysqld.service
           └─21110 /usr/sbin/mysqld

# 关闭服务
[root@VM-0-4-centos etc]# service mysqld stop
Redirecting to /bin/systemctl stop mysqld.service
[root@VM-0-4-centos etc]# systemctl status mysqld.service 
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: inactive (dead) since Tue 2020-09-01 00:09:49 CST; 11s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 21110 ExecStart=/usr/sbin/mysqld $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
  Process: 21087 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 21110 (code=exited, status=0/SUCCESS)
   Status: "Server shutdown complete"

3. 遇到问题

   [ERROR] [MY-012271] [InnoDB] The innodb_system data file 'ibdata1' must be writable

   查看日志发现是ibdata1无写权限，修改/var/lib/mysql权限为777

   chmod -R 777 mysql

数据库设置

0. 数据库初始化

   使用指令1对数据库进行初始化mysqld --initialize;，并得到临时密码。

[root@VM-0-4-centos etc]# mysqld --initialize;
2020-08-31T16:13:01.986611Z 0 [System] [MY-013169] [Server] /usr/sbin/mysqld (mysqld 8.0.21) initializing of server in progress as process 21288
2020-08-31T16:13:01.995195Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2020-08-31T16:13:04.085829Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2020-08-31T16:13:07.225825Z 6 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: fu-k1yjtnllY	《==============临时密码

​ 或查看日志获取临时密码(我安装了两次所以两种方式显示密码不一致，请忽略)

[root@VM-0-4-centos mysql]# cat /var/log/mysqld.log |grep pass
2020-08-31T17:45:15.371100Z 6 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: gX:Uey-fg2JV	《==============临时密码

1. 登录mysql

   使用临时密码登录mysql

[root@VM-0-4-centos mysql]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or g.
Your MySQL connection id is 9
Server version: 8.0.21

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

mysql> 

2. 修改root密码

   使用 alter USER 'root'@'localhost' IDENTIFIED BY 'root';修改root密码。

mysql> alter USER 'root'@'localhost' IDENTIFIED BY 'root';
Query OK, 0 rows affected (0.05 sec)
mysql> quit
Bye
[root@VM-0-4-centos mysql]# mysql -uroot -p
Enter password: <===========================输入新密码root
Welcome to the MySQL monitor.  Commands end with ; or g.
Your MySQL connection id is 11
Server version: 8.0.21 MySQL Community Server - GPL

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

mysql>

3. 授权远程连接

# 切换数据库
mysql> use mysql;
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
# 修改root host为%
mysql> update user set host = "%" where user='root';
Query OK, 1 row affected (0.02 sec)
Rows matched: 1  Changed: 1  Warnings: 0
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
# 修改远程登录密码为root
mysql> alter USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY 'root';
Query OK, 0 rows affected (0.01 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

4. 使用Navicat测试连接，可在/etc/my.cnf中配置端口号，默认为3306。

END

mysql的安装出现了挺多error，不过还好大部分都能在网上找到答案，总结起来大概包含以下内容

• rpm安装需要先移除旧版本。

  rpm -qa|grep XXX

  rpm -e XXX

• 移除旧版本时报错缺少依赖。

  rpm -ev XXX --force --nodeps

• mysql安装完成后初始化失败。

  清空/var/lib/mysql目录。有些版本是data目录。

• mysql服务启动失败。

  查看/var/log/mysqld.log错误日志定位问题，缺路径就建文件夹，少权限就授权。

• 登录mysql失败，需要密码。

  初始化后查看日志获取临时密码cat /var/log/mysqld.log |grep pass

另外说句题外话：

​ 服务器上安装任何软件都尽量修改其访问端口，使用默认端口很危险，在学习redis、mysql、filebeat等软件时，都曾因使用默认端口被残忍挖矿，血泪教训。o(╥﹏╥)o