1、 download MySQL Installation package

Download what you need rpm package https://dev.mysql.com/downloads/mysql/

2、 Check if it is installed mysql perhaps mariadb

[[email protected] ~]# rpm -qa | grep mysql
[[email protected] ~]# rpm -qa | grep mariadb

If installed , The above command will check the relevant installation information , Unload it

# uninstall MySQL
rpm -qa | grep mysql | xargs  rpm -e --nodeps
# uninstall mariadb
rpm -qa | grep mariadb| xargs  rpm -e --nodeps

3、 Install in sequence as follows 4 Just one file

[[email protected] mysql]# rpm -ivh mysql-community-common-5.7.38-1.el7.x86_64.rpm
[[email protected] mysql]# rpm -ivh mysql-community-libs-5.7.38-1.el7.x86_64.rpm
[[email protected] mysql]# rpm -ivh mysql-community-client-5.7.38-1.el7.x86_64.rpm
[[email protected] mysql]# rpm -ivh mysql-community-server-5.7.38-1.el7.x86_64.rpm

In the installation server When you file , It may also prompt that other dependent packages are missing , such as ：net-tools, Download the relevant dependent packages one by one according to the prompts and install , After all dependencies are solved , Install again mysql-community-server This rpm file . The missing dependency package is recommended to download here ：https://centos.pkgs.org/7/centos-x86_64/

thus ,mysql5.7 All files are installed , The next step is to start the service .

4、 Modify the configuration file

Modify the configuration file my.cnf, Set password free login

[[email protected] ~]# vim /etc/my.cnf
###  You can refer to the following 
[mysql]
default-character-set=utf8

[mysqld]
datadir=/data/mysql
socket=/data/mysql/mysql.sock
slow_query_log = ON
slow_query_log_file = /var/log/mysql_slow_query.log
long_query_time = 3
symbolic-links=0
log-error=/data/mysql/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
log-bin=mysql-bin
thread_cache_size=100
server-id=33
back_log=500
lower_case_table_names=1
#thread_concurrency=80
#thread_concurrency=32
query_cache_limit=12M
query_cache_size=512M
query_cache_type=1
character-set-server=utf8mb4
max_connections=3000
innodb_buffer_pool_size=12G
innodb_file_per_table=ON
innodb_log_file_size=3G
expire_logs_days=5
read_only=1
lower_case_table_names=1
skip-name-resolve
[client]
socket=/data/mysql/mysql.sock

5、 start-up MySQL

systemctl restart mysqld

It takes a long time to start , It takes patience , Expected again 10 About minutes , Because you need to initialize the database .

6、 see MySQL Initial password

adopt my.cnf File found /data/mysql/mysqld.log file , In the revised document according to password Keyword query initial password

# see log-error Specified data directory 
[[email protected] ~]# cat /etc/my.cnf | grep log-error
log-error=/data/mysql/mysqld.log

# Check initialization password 
[[email protected] ~]# cat /data/mysql/mysqld.log | grep localhost
2022-07-05T16:48:26.206485Z 1 [Note] A temporary password is generated for [email protected]: B9eldAjOiu=(

After checking the password , You can use this password to log in to MySQL, And follow up

7、 Sign in MySQL

[[email protected] ~]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.38-log MySQL Community Server (GPL)

Copyright (c) 2000, 2022, Oracle and/or its affiliates.

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> set global validate_password_policy = 0;
Query OK, 0 rows affected (0.00 sec)

mysql> SET PASSWORD = PASSWORD('root');
Query OK, 0 rows affected (0.00 sec)

mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)

installation is complete ！