centos下安装Mysql5.7.20

0、环境

本文操作系统: CentOS 7.2.1511 x86_64
MySQL 版本: 5.7.16

1、卸载系统自带的 mariadb-lib

[root@centos-linux ~]# rpm -qa|grep mariadb
mariadb-libs-5.5.44-2.el7.centos.x86_64
[root@centos-linux ~]# rpm -e mariadb-libs-5.5.44-2.el7.centos.x86_64 --nodeps

2、下载mysql5.7.16 rpm安装包，官网最新的mysql安装包是mysql-5.7.16-1.el7.x86_64.rpm-bundle.tar下载地址

[root@centos-linux ~]# wget http://dev.mysql.com/get/Downloads/MySQL-5.7/mysql-5.7.16-1.el7.x86_64.rpm-bundle.tar

然后解压

　[root@linux_node_1 src]# tar -xvf mysql-5.7.16-1.el7.x86_64.rpm-bundle.tar
mysql-community-libs-compat-5.7.16-1.el7.x86_64.rpm
mysql-community-devel-5.7.16-1.el7.x86_64.rpm
mysql-community-minimal-debuginfo-5.7.16-1.el7.x86_64.rpm
mysql-community-libs-5.7.16-1.el7.x86_64.rpm
mysql-community-common-5.7.16-1.el7.x86_64.rpm
mysql-community-embedded-compat-5.7.16-1.el7.x86_64.rpm
mysql-community-test-5.7.16-1.el7.x86_64.rpm
mysql-community-embedded-devel-5.7.16-1.el7.x86_64.rpm
mysql-community-server-minimal-5.7.16-1.el7.x86_64.rpm
mysql-community-server-5.7.16-1.el7.x86_64.rpm
mysql-community-client-5.7.16-1.el7.x86_64.rpm
mysql-community-embedded-5.7.16-1.el7.x86_64.rpm
3、安装
依次执行（几个包有依赖关系，所以执行有先后）下面命令安装
[root@centos-linux ~]# rpm -ivh mysql-community-common-5.7.16-1.el7.x86_64.rpm
[root@centos-linux ~]# rpm -ivh mysql-community-libs-5.7.16-1.el7.x86_64.rpm
[root@centos-linux ~]# rpm -ivh mysql-community-client-5.7.16-1.el7.x86_64.rpm
[root@centos-linux ~]# rpm -ivh mysql-community-server-5.7.16-1.el7.x86_64.rpm
在安装rpm -ivh mysql-community-server-5.7.16-1.el7.x86_64.rpm的时候报错如下：

[root@linux_node_1 src]# rpm -ivh mysql-community-server-5.7.16-1.el7.x86_64.rpm
warning: mysql-community-server-5.7.16-1.el7.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
error: Failed dependencies:
libaio.so.1()(64bit) is needed by mysql-community-server-5.7.16-1.el7.x86_64
libaio.so.1(LIBAIO_0.1)(64bit) is needed by mysql-community-server-5.7.16-1.el7.x86_64
libaio.so.1(LIBAIO_0.4)(64bit) is needed by mysql-community-server-5.7.16-1.el7.x86_64
net-tools is needed by mysql-community-server-5.7.16-1.el7.x86_64
这个报错的意思是需要安装libaio包和net-tools包：可以yum安装一下，安装 libaio-0.3.107-10.el6.x86_64.rpm，下载地址：
wget http://mirror.centos.org/centos/6/os/x86_64/Packages/libaio-0.3.107-10.el6.x86_64.rpm
然后yum安装net-tools yum install net-tools 完成之后就可以顺利安装
4、数据库初始化

为了保证数据库目录为与文件的所有者为 mysql 登陆用户，如果你是以 root 身份运行 mysql 服务，需要执行下面的命令初始化
mysqld --initialize --user=mysql

如果是以 mysql 身份运行，则可以去掉 --user 选项。

另外 --initialize 选项默认以“安全”模式来初始化，则会为 root 用户生成一个密码并将该密码标记为过期，登陆后你需要设置一个新的密码，而使用 --initialize-insecure 命令则不使用安全模式，则不会为 root 用户生成一个密码。

这里演示使用的 --initialize 初始化的，会生成一个 root 账户密码，密码在log文件里，红色区域的就是自动生成的密码
[root@linux_node_1 src]# cat /var/log/mysqld.log
2016-12-07T04:41:58.028558Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2016-12-07T04:41:58.315188Z 0 [Warning] InnoDB: New log files created, LSN=45790
2016-12-07T04:41:58.355114Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2016-12-07T04:41:58.418448Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: 7cc98831-bc37-11e6-a263-000c29f902dc.
2016-12-07T04:41:58.419935Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2016-12-07T04:41:58.420558Z 1 [Note] A temporary password is generated for root@localhost: )1r3gi,hjgQa
现在启动mysql数据库systemctl start mysqld.service
[root@linux_node_1 src]# systemctl start mysqld.service
[root@linux_node_1 src]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.16
Copyright (c) 2000, 2016, 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>

5、修改密码

该密码被标记为过期了，如果想正常使用还需要修改密码

mysql> show databases;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

以前的 password()函数将会被抛弃，官方建议使用下面的命令来修改密码

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'new_password';

同时，如果你设置的密码过于简单也会报错。

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements