MySQL 5.7 installation and configuration tutorial under CentOS7 (YUM)

Installation environment: CentOS7 64-bit, MySQL5.7

1. Configure YUM source

Download the YUM source rpm installation package from the MySQL official website: http://dev.mysql.com/downloads/repo/yum/

# Download the mysql source installation package shell> wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm
# Install mysql source shell> yum localinstall mysql57-community-release-el7-8.noarch.rpm

Check whether the mysql source is installed successfully

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

The above picture shows that the installation is successful.
You can modify the vim /etc/yum.repos.d/mysql-community.repo source to change the default installed MySQL version. For example, to install version 5.6, change enabled=1 of the 5.7 source to enabled=0. Then change the enabled=0 of the 5.6 source to enabled=1. The effect after the modification is as follows:

2. Install MySQL

shell> yum install mysql-community-server

3. Start MySQL service

shell> systemctl start mysqld

Check the startup status of MySQL

shell> systemctl status mysqld
● mysqld.service – MySQL Server
 Loaded: loaded (/usr/lib/systemd/system/mysqld.service; disabled; vendor preset: disabled)
 Active: active (running) since 2016-06-24 04:37:37 CST; 35 minutes ago
 Main PID: 2888 (mysqld)
 CGroup: /system.slice/mysqld.service
   └─2888 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid

Jun 24 04:37:36 localhost.localdomain systemd[1]: Starting MySQL Server...
Jun 24 04:37:37 localhost.localdomain systemd[1]: Started MySQL Server.

4. Start the machine

shell> systemctl enable mysqld
shell> systemctl daemon-reload

5. Modify the root local login password

After mysql is installed, a default password is generated for root in the /var/log/mysqld.log file. Find the root default password in the following way, and then log in to mysql to modify it:

shell> grep 'temporary password' /var/log/mysqld.log

shell>mysql -uroot -p
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass4!'; 

or

mysql> set password for 'root'@'localhost'=password('MyNewPass4!'); 

Note: MySQL 5.7 has a password security check plug-in (validate_password) installed by default. The default password check policy requires that the password must contain uppercase and lowercase letters, numbers, and special symbols, and the length must not be less than 8 characters. Otherwise, the error message ERROR 1819 (HY000): Your password does not satisfy the current policy requirements will be displayed, as shown in the following figure:

You can view password policy information through the msyql environment variable:

mysql> show variables like '%password%'; 

validate_password_policy: Password policy, the default is MEDIUM policy
validate_password_dictionary_file: Password policy file, required only if the policy is STRONG
validate_password_length: minimum password length
validate_password_mixed_case_count: length of uppercase and lowercase characters, at least 1
validate_password_number_count: at least 1 number
validate_password_special_char_count: at least 1 special character
The above parameters are the password checking rules for the default policy MEDIUM.

There are the following password policies: