# 查看系统自带的Mariadb
# rpm -qa|grep mariadb
mariadb-libs-5.5.44-2.el7.centos.x86_64
# 卸载系统自带的Mariadb
# rpm -e --nodeps mariadb-libs-5.5.44-2.el7.centos.x86_64
# 删除etc目录下的my.cnf ，一定要删掉，等下再重新建，之前我将就用这个文件，后面改配置各种不生效
# rm /etc/my.cnf

cd /usr/local/   -- 进入local目录，下载mysql tar.gz包
 
1、# wget下载或者本地下载后上传
wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.35-el7-x86_64.tar.gz
 
2、官网下载：
https://dev.mysql.com/downloads/mysql/
 
3、解压安装mysql  自行下载解压
tar -zxvf mysql-5.7.31-linux-glibc2.12-x86_64.tar.gz
 
4、将解压的文件做文件改名
mv mysql-5.7.31-linux-glibc2.12-x86_64 mysql

//检查mysql 用户组是否存在
cat /etc/group | grep mysql
 
cat /etc/passwd |grep mysql
 
 
// 创建mysql 用户组和用户
groupadd mysql
 
useradd -r -g mysql mysql
 
更改mysql 目录下所有文件夹所属的用户组和用户，以及权限
chown -R mysql:mysql /usr/local/mysql
chmod -R 755 /usr/local/mysql

1、创建mysql 相关目录
mkdir -p /data/mysql/{data,logs,tmp}
# 更改文件夹所属
chown -R mysql.mysql /data/mysql/
 
2、编辑my.cnf文件：vi /etc/my.cnf
# 简单模板如下：
[client]
port = 3306
socket = /data/mysql/tmp/mysql.sock
[mysqld]
user = mysql
basedir = /usr/local/mysql 
datadir = /data/mysql/data 
port = 3306 
socket = /data/mysql/tmp/mysql.sock
pid-file = /data/mysql/tmp/mysqld.pid
tmpdir = /data/mysql/tmp 
skip_name_resolve = 1
symbolic-links=0
max_connections = 2000
group_concat_max_len = 1024000
sql_mode = NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
lower_case_table_names = 1
log_timestamps=SYSTEM
character-set-server = utf8
interactive_timeout = 1800 
wait_timeout = 1800
max_allowed_packet = 32M
binlog_cache_size = 4M
sort_buffer_size = 2M
read_buffer_size = 4M
join_buffer_size = 4M
tmp_table_size = 96M
max_heap_table_size = 96M
max_length_for_sort_data = 8096
#logs
server-id = 1003306
log-error = /data/mysql/logs/error.log
slow_query_log = 1
slow_query_log_file = /data/mysql/logs/slow.log
long_query_time = 3
log-bin = /data/mysql/logs/binlog
binlog_format = row
expire_logs_days = 15
log_bin_trust_function_creators = 1
relay-log = /data/mysql/logs/relay-bin
relay-log-recovery = 1 
relay_log_purge = 1 
#innodb 
innodb_file_per_table = 1
innodb_log_buffer_size = 16M
innodb_log_file_size = 256M
innodb_log_files_in_group = 2
innodb_io_capacity = 2000
innodb_io_capacity_max = 4000
innodb_flush_neighbors = 0
innodb_flush_method = O_DIRECT
innodb_autoinc_lock_mode = 2
innodb_read_io_threads = 8
innodb_write_io_threads = 8
innodb_buffer_pool_size = 2G
 
3、配置mysql.server
cd /usr/local/mysql/support-files
cp mysql.server /etc/init.d/mysql
vi /etc/init.d/mysql
# 修改目录位置
basedir=/usr/local/mysql
datadir=/data/mysql/data
# 注册开机启动服务
chkconfig --add mysql
chkconfig --list
 
4、添加环境变量
echo "PATH=$PATH:/usr/local/mysql/bin " >> /etc/profile 
source /etc/profile
 
5、初始化mysql
/usr/local/mysql/bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql/data
# 临时密码保存在errlog中 
# 获取临时密码
more /data/mysql/logs/error.log |grep password

1、启动mysql服务，并修改密码
# 启动mysql服务
service mysql start
# 使用初始密码登录mysql服务 并修改密码
mysql -uroot -p
alter user 'root'@'localhost' identified by '123456';
flush privileges;
 
2、使用前面随机生成的密码登录mysql数据库，再重置密码；
mysql -u root -p（回车后输入前面的随机密码）
ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
flush privileges;
 
3、开启mysql的远程访问权限
use mysql;
create user 'root'@'%' identified by '123456';
grant all on *.* to 'root'@'%' with grant option;
flush privileges;
 
4、退出
exit
 
 

service mysql stop

service mysql start