一、下载
CentOS 7及以上需要先卸载自带的MariaDB
# 查看mariadb
rpm -qa|grep mariadb
# 卸载mariadb（替换名称）
rpm -e –nodeps mariadb-libs-5.5.68-1.el7.x86_64
# 复查mariadb
rpm -qa|grep mariadb
下载安装，官网下载 mysql-8.0.20-linux-glibc2.12-x86_64.tar.xz 或者 wget
# 下载解压
cd /usr/local
wget https://dev.mysql.com/get/Downloads/MySQL-8.0/mysql-8.0.20-linux-glibc2.12-x86_64.tar.xz
# 解压
tar -Jxvf mysql-8.0.20-linux-glibc2.12-x86_64.tar.xz
# 重命名
mv mysql-8.0.20-linux-glibc2.12-x86_64 mysql
# 环境变量
vim /etc/profile
# 添加以下内容
MYSQL_HOME=/usr/local/mysql
PATH=$PATH:$MYSQL_HOME/bin
export MYSQL_HOME PATH
# 环境变量生效
source /etc/profile
# 创建一个用户组：mysql
groupadd mysql
# 创建一个系统用户：mysql，指定用户组为mysql
useradd -r -g mysql mysql
# 创建目录
mkdir -p /usr/local/mysql/datas
# 授权：
# 更改属主和数组
chown -R mysql:mysql /usr/local/mysql/datas
# 更改模式
chmod -R 750 /usr/local/mysql/datas
二、配置
在/usr/local/mysql/下，创建my.cnf配置文件，用于初始化MySQL数据库
[mysql]
# 默认字符集
default-character-set=utf8mb4
[client]
port = 3306
socket = /tmp/mysql.sock
[mysqld]
port = 3306
server-id = 3306
user = mysql
socket = /tmp/mysql.sock
# 安装目录
basedir = /usr/local/mysql
# 数据存放目录
datadir = /usr/local/mysql/datas/mysql
log-bin = /usr/local/mysql/datas/mysql/mysql-bin
innodb_data_home_dir =/usr/local/mysql/datas/mysql
innodb_log_group_home_dir =/usr/local/mysql/datas/mysql
#日志及进程数据的存放目录
log-error =/usr/local/mysql/datas/mysql/mysql.log
pid-file =/usr/local/mysql/datas/mysql/mysql.pid
# 服务端使用的字符集默认为8比特编码
character-set-server=utf8mb4
lower_case_table_names=1
autocommit =1
##################以上要修改的########################
skip-external-locking
key_buffer_size = 256M
max_allowed_packet = 16M
table_open_cache = 1024
sort_buffer_size = 4M
net_buffer_length = 8K
read_buffer_size = 4M
read_rnd_buffer_size = 512K
myisam_sort_buffer_size = 64M
thread_cache_size = 128
#query_cache_size = 128M
tmp_table_size = 128M
explicit_defaults_for_timestamp = true
max_connections = 500
max_connect_errors = 100
open_files_limit = 65535
binlog_format=mixed
binlog_expire_logs_seconds =864000
# 创建新表时将使用的默认存储引擎
default_storage_engine = InnoDB
innodb_data_file_path = ibdata1:10M:autoextend
innodb_buffer_pool_size = 1024M
innodb_log_file_size = 256M
innodb_log_buffer_size = 8M
innodb_flush_log_at_trx_commit = 1
innodb_lock_wait_timeout = 50
transaction-isolation=READ-COMMITTED
[mysqldump]
quick
max_allowed_packet = 16M
[myisamchk]
key_buffer_size = 256M
sort_buffer_size = 4M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
三、初始化
# 安装libaio
yum install -y libaio
# 初始化
mysqld –defaults-file=/usr/local/mysql/my.cnf –basedir=/usr/local/mysql/ –datadir=/usr/local/mysql/datas/mysql –user=mysql –initialize-insecure
# 启动
mysqld_safe –defaults-file=/usr/local/mysql/my.cnf &
# 查看进程
ps -ef | grep mysqld
# 无密码登录
/usr/local/mysql/bin/mysql -u root –skip-password
# 修改密码
ALTER USER ‘root’@’localhost’ IDENTIFIED WITH mysql_native_password BY ‘root’;
# 刷新权限
FLUSH PRIVILEGES;
# 设置访问权限
mysql> use mysql
mysql> update user set user.Host=’%’where user.User=’root’;
mysql> flush privileges;
mysql> quit
# 打开防火墙/安全组的端口号
# Navicat连接测试
# 正常关闭
mysqladmin -h127.0.0.1 -uroot -p shutdown
注意：
用mysqld_safe起的mysql是守护进程，直接kill它会检测到数据库非正常关闭，会自动尝试起数据库。你可以选择先kill掉mysqld_safe的进程然后再kill mysql；或者使用这个命令：kill -9 `ps -ef | grep ‘mysqld’ | grep -v grep|awk ‘{print $2}’`
当然，最好还是用mysqladmin -h127.0.0.1 -uroot -p shutdown来正常关闭mysql。
四、配置服务
# 尝试启动服务
service mysql start
# Redirecting to /bin/systemctl start mysql.service
# Failed to start mysql.service: Unit not found.
# 无法启动，原因是未配置.server文件到/etc/init.d/ 目录下，mysql.server一般在你安装的mysql目录下，自己是编译安装，所以知道目录在哪里，不知道的这样看一下
#执行复制操作，/usr/local/mysql/是我自己的mysql安装目录，大家根据查询出来的结果复制
# 查询mysql.server
find / -name mysql.server
# /usr/local/mysql/support-files/mysql.server
# 复制.server文件
cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysql
五、服务命令
# 启动
service mysql start
# 停止
service mysql stop
# 重启
service mysql restart