Today, there is a sudden whim to transfer the blog to your own cloud server. Well, it's a good idea, just able to practice. In order to do this, we must first have a database, linux with mysql. Ouch, that's good.
Two words don't mention the installation method of yum
[root@VM_235_40_centos ~]# yum install mysql
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
Resolving Dependencies
--> Running transaction check
---> Package mariadb.x86_64 1:5.5.52-1.el7 will be installed
--> Processing Dependency: mariadb-libs(x86-64) = 1:5.5.52-1.el7 for package: 1: mariadb-5.5.52-1.el7.x86_64
--> Running transaction check
---> Package mariadb-libs.x86_64 1:5.5.35-3.el7 will be updated
---> Package mariadb-libs.x86_64 1:5.5.52-1.el7 will be an update
--> Finished Dependency Resolution
Dependencies Resolved
================================================================================
Package Arch Version Repository Size
================================================================================
Installing:
mariadb x86_64 1:5.5.52-1.el7 os 8.7 M
Updating for dependencies:
mariadb-libs x86_64 1:5.5.52-1.el7 os 761 k
Transaction Summary
================================================================================
Install 1 Package
Upgrade ( 1 Dependent package)
Total download size: 9.5 M
Is this ok [y/d/N]: y
Downloading packages:
Delta RPMs disabled because /usr/bin/applydeltarpm not installed.
(1/2): mariadb-libs-5.5.52-1.el7.x86_64.rpm | 761 kB 00:00
(2/2): mariadb-5.5.52-1.el7.x86_64.rpm | 8.7 MB 00:00
--------------------------------------------------------------------------------
Total 16 MB/s | 9.5 MB 00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Updating : 1:mariadb-libs-5.5.52-1.el7.x86_64 1/3
Installing : 1:mariadb-5.5.52-1.el7.x86_64 2/3
Cleanup : 1:mariadb-libs-5.5.35-3.el7.x86_64 3/3
Verifying : 1:mariadb-5.5.52-1.el7.x86_64 1/3
Verifying : 1:mariadb-libs-5.5.52-1.el7.x86_64 2/3
Verifying : 1:mariadb-libs-5.5.35-3.el7.x86_64 3/3
Installed:
mariadb.x86_64 1:5.5.52-1.el7
Dependency Updated:
mariadb-libs.x86_64 1:5.5.52-1.el7
Complete!I don't know if it was too exciting at that time, and I filled in yes without looking at the installation prompt. When I finished installing, I was foolish. What's MariaDB? Unheard of, I rushed to ask Du Niang, originally a branch of mysql. 
I want a "main room", but you set me a "third child"; want to raise a dolphin, you TM give me a seal.
Bedroom, I said this is one of the three IT giants, ah, yum library even has no mysql.
Decisively delete "Xiaosan"
[root@VM_235_40_centos ~]# yum erase mysql
Loaded plugins: fastestmirror, langpacks
Resolving Dependencies
--> Running transaction check
---> Package mariadb.x86_64 1:5.5.52-1.el7 will be erased
--> Finished Dependency Resolution
Dependencies Resolved
================================================================================
Package Arch Version Repository Size
================================================================================
Removing:
mariadb x86_64 1:5.5.52-1.el7 @os 48 M
Transaction Summary
================================================================================
Remove 1 Package
Installed size: 48 M
Is this ok [y/N]: y
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Erasing : 1:mariadb-5.5.52-1.el7.x86_64 1/1
Verifying : 1:mariadb-5.5.52-1.el7.x86_64 1/1
Removed:
mariadb.x86_64 1:5.5.52-1.el7
Complete!Alas, do your own food and clothing, go shopping on the official website. 
Foreign things are good, things for you, even the course is ready, unfortunately, I have not even CET-4 level of English ah, can not be hard to see.
Look at the specific steps given by the official website:
1. Add mysql yum Library
a. First, go to the download page of MySQL yum Library http://dev.mysql.com/downloads/repo/yum/
b. Find a distribution package that matches your platform and use the uname command to see your platform version
c. wget command to wrap the corresponding rpm, which is very small and only a few k
[root@VM_235_40_centos ~]# wget https://repo.mysql.com//mysql57-community-release-el7-9.ch.rpm
--2017-04-05 16:32:26-- https://repo.mysql.com//mysql57-community-release-el7-9.noarch.rpm
Resolving repo.mysql.com (repo.mysql.com)... 23.50.25.213
Connecting to repo.mysql.com (repo.mysql.com)|23.50.25.213|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 9224 (9.0K) [application/x-redhat-package-manager]
Saving to: 'mysql57-community-release-el7-9.noarch.rpm'
100%[============================================================>] 9,224 --.-K/s in 0s
2017-04-05 16:32:28 (75.1 MB/s) - 'mysql57-community-release-el7-9.noarch.rpm' saved [9224/9224]d. Install this package
[root@VM_235_40_centos ~]# rpm -Uvh mysql57-community-release-el7-9.noarch.rpm
warning: mysql57-community-release-el7-9.noarch.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5KEY
Preparing... ################################# [100%]
Updating / installing...
1:mysql57-community-release-el7-9 ################################# [100%]
[root@VM_235_40_centos ~]cd /etc/yum.repos.d
#When the installation is complete, you will find that / etc/yum.repos.d has two more repo files for mysql
[root@VM_235_40_centos yum.repos.d]# ls
CentOS-Base.repo mysql-community-source.repo
CentOS-Epel.repo mysql-community.repo2. Look at what's in the file.
[root@VM_235_40_centos yum.repos.d]# more mysql-community.repo
[mysql-connectors-community]
name=MySQL Connectors Community
baseurl=http://repo.mysql.com/yum/mysql-connectors-community/el/7/$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
[mysql-tools-community]
name=MySQL Tools Community
baseurl=http://repo.mysql.com/yum/mysql-tools-community/el/7/$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
# Enable to use MySQL 5.5
[mysql55-community]
name=MySQL 5.5 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.5-community/el/7/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
# Enable to use MySQL 5.6
[mysql56-community]
name=MySQL 5.6 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.6-community/el/7/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
[mysql57-community]
name=MySQL 5.7 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.7-community/el/7/$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
[mysql80-community]
name=MySQL 8.0 Community Server
baseurl=http://repo.mysql.com/yum/mysql-8.0-community/el/7/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql
[mysql-tools-preview]
name=MySQL Tools Preview
baseurl=http://repo.mysql.com/yum/mysql-tools-preview/el/7/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysqlAccording to the official website, you can configure the version of mysql you want to install in this file. If you need to install this version, you can set enabled=1, and if you don't need it, you can set it to 0. Here I install version 5.7
3. Once you're done, you can install mysql
[root@VM_235_40_centos yum.repos.d]# yum install mysql-community-server
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-server.x86_64 0:5.7.17-1.el6 will be installed
--> Processing Dependency: mysql-community-common(x86-64) = 5.7.17-1.el6 for package: mysql-communserver-5.7.17-1.el6.x86_64
......
---> Package mysql-community-libs.x86_64 0:5.7.17-1.el6 will be obsoleting
--> Finished Dependency Resolution
Error: Package: 2:postfix-2.10.1-6.el7.x86_64 (@anaconda)
Requires: libmysqlclient.so.18()(64bit)
Removing: 1:mariadb-libs-5.5.52-1.el7.x86_64 (@os)
libmysqlclient.so.18()(64bit)
Obsoleted By: mysql-community-libs-5.7.17-1.el6.x86_64 (mysql57-community)
~libmysqlclient.so.20()(64bit)
Error: Package: 2:postfix-2.10.1-6.el7.x86_64 (@anaconda)
Requires: libmysqlclient.so.18(libmysqlclient_18)(64bit)
Removing: 1:mariadb-libs-5.5.52-1.el7.x86_64 (@os)
libmysqlclient.so.18(libmysqlclient_18)(64bit)
Obsoleted By: mysql-community-libs-5.7.17-1.el6.x86_64 (mysql57-community)
Not found
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigestNanny, what the hell is wrong with the installation? It turned out that mariadb hadn't been deleted cleanly. My God, dig a hole and jump by yourself.
[root@VM_235_40_centos yum.repos.d]# rpm -qa|grep mariadb
mariadb-libs-5.5.52-1.el7.x86_64
[root@VM_235_40_centos yum.repos.d]# rpm -ev mariadb-libs-5.5.52-1.el7.x86_64 --nodeps
Preparing packages...
mariadb-libs-1:5.5.52-1.el7.x86_64Once again
[root@VM_235_40_centos yum.repos.d]# yum install mysql-community-server
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-server.x86_64 0:5.7.17-1.el6 will be installed
......
---> Package mysql-community-libs.x86_64 0:5.7.17-1.el6 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
==================================================================================================
Package Arch Version Repository Size
==================================================================================================
Installing:
mysql-community-server x86_64 5.7.17-1.el6 mysql57-community 151 M
Installing for dependencies:
mysql-community-client x86_64 5.7.17-1.el6 mysql57-community 23 M
mysql-community-common x86_64 5.7.17-1.el6 mysql57-community 328 k
mysql-community-libs x86_64 5.7.17-1.el6 mysql57-community 2.1 M
numactl-libs x86_64 2.0.9-6.el7_2 os 29 k
Transaction Summary
==================================================================================================
Install 1 Package (+4 Dependent packages)
Total download size: 177 M
Installed size: 879 M
Is this ok [y/d/N]: y
Downloading packages:
mysql-community-common-5.7.17- FAILED
http://repo.mysql.com/yum/mysql-5.7-community/el/7/x86_64/mysql-community-common-5.7.17-1.el6.x86_64.rpm: [Errno 14] HTTP Error 404 - Not Found
Trying other mirror.
mysql-community-client-5.7.17- FAILED
http://repo.mysql.com/yum/mysql-5.7-community/el/7/x86_64/mysql-community-client-5.7.17-1.el6.x86_64.rpm: [Errno 14] HTTP Error 404 - Not Found
Trying other mirror.
......
Error downloading packages:
mysql-community-server-5.7.17-1.el6.x86_64: [Errno 256] No more mirrors to try.
mysql-community-common-5.7.17-1.el6.x86_64: [Errno 256] No more mirrors to try.
mysql-community-libs-5.7.17-1.el6.x86_64: [Errno 256] No more mirrors to try.
mysql-community-client-5.7.17-1.el6.x86_64: [Errno 256] No more mirrors to try.Nima, there was another mistake. The software installed on Linux is a pain in the egg. The 404 error request failed. What the hell is this? I have poked around the installation process, or made a mistake, no way, silently asked Du Niang to go.
Here There is a blog, which says yum caching problem, okay, clear caching.
[root@VM_235_40_centos yum.repos.d]# cd /var/cache
[root@VM_235_40_centos cache]# ls
httpd ldconfig man yum
[root@VM_235_40_centos cache]# cd yum
[root@VM_235_40_centos yum]# ls
x86_64
[root@VM_235_40_centos yum]# rm -drf x86_64
[root@VM_235_40_centos yum]# lsCome back again
[root@VM_235_40_centos yum]# yum install mysql-community-server
Loaded plugins: fastestmirror, langpacks
epel | 4.3 kB 00:00:00
extras | 3.4 kB 00:00:00
mysql-connectors-community | 2.5 kB 00:00:00
mysql-tools-community | 2.5 kB 00:00:00
mysql57-community | 2.5 kB 00:00:00
os | 3.6 kB 00:00:00
updates | 3.4 kB 00:00:00
(1/10): epel/7/x86_64/group_gz | 170 kB 00:00:00
(2/10): epel/7/x86_64/updateinfo | 762 kB 00:00:00
(3/10): epel/7/x86_64/primary_db | 4.6 MB 00:00:00
(4/10): extras/7/x86_64/primary_db | 139 kB 00:00:00
(5/10): os/7/x86_64/group_gz | 155 kB 00:00:00
(6/10): updates/7/x86_64/primary_db | 3.8 MB 00:00:00
(7/10): os/7/x86_64/primary_db | 5.6 MB 00:00:00
(8/10): mysql-connectors-community/x86_64/primary_db | 13 kB 00:00:00
(9/10): mysql-tools-community/x86_64/primary_db | 32 kB 00:00:00
(10/10): mysql57-community/x86_64/primary_db | 96 kB 00:00:01
Determining fastest mirrors
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-server.x86_64 0:5.7.17-1.el7 will be installed
......
--> Finished Dependency Resolution
Dependencies Resolved
==================================================================================================
Package Arch Version Repository Size
==================================================================================================
Installing:
mysql-community-server x86_64 5.7.17-1.el7 mysql57-community 162 M
Installing for dependencies:
mysql-community-client x86_64 5.7.17-1.el7 mysql57-community 24 M
mysql-community-common x86_64 5.7.17-1.el7 mysql57-community 271 k
mysql-community-libs x86_64 5.7.17-1.el7 mysql57-community 2.1 M
numactl-libs x86_64 2.0.9-6.el7_2 os 29 k
Transaction Summary
==================================================================================================
Install 1 Package (+4 Dependent packages)
Total download size: 188 M
Installed size: 847 M
Is this ok [y/d/N]: y
Downloading packages:
warning: /var/cache/yum/x86_64/7/mysql57-community/packages/mysql-community-common-5.7.17-1.el7.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
Public key for mysql-community-common-5.7.17-1.el7.x86_64.rpm is not installed
(1/5): mysql-community-common-5.7.17-1.el7.x86_64.rpm | 271 kB 00:00:03
(2/5): mysql-community-libs-5.7.17-1.el7.x86_64.rpm | 2.1 MB 00:00:52
(3/5): numactl-libs-2.0.9-6.el7_2.x86_64.rpm | 29 kB 00:00:00
(4/5): mysql-community-client-5.7. 6% [=- ] 101 kB/s | 12 MB 00:29:51 ETANo problem, but my server bandwidth is not good, wait in silence.
Installed:
mysql-community-server.x86_64 0:5.7.17-1.el7
Dependency Installed:
mysql-community-client.x86_64 0:5.7.17-1.el7
mysql-community-common.x86_64 0:5.7.17-1.el7
mysql-community-libs.x86_64 0:5.7.17-1.el7
numactl-libs.x86_64 0:2.0.9-6.el7_2
Complete!There should be applause here.
4. The last step is to start the service.
The installation guide of the official website uses service mysqld start, and CentOS7 uses the system CTL command to start the service. By default, the service command will switch to calling the system CTL command.
Additional steps to modify MySQL password
Previous versions of MySQL 5.7, if installed in this way, default to no password. For MySQL 5.7, which is a bit special, the following is the official website description of the installation process of MySQL 5.7:
- Service initialization
- Generate SSL certificates and keys in the data folder
- Install validate_password plug-in and take effect
- Create a database superadministrator'root@localhost'and generate a password for him
That is to say, MySQL 5.7 generated a password for the root superadministrator, which is in the / var/log/mysqld.log file.
shell> sudo grep 'temporary password' /var/log/mysqld.log
The red circle part above is the instant password generated, and then enter mysql to modify the password. Of course, there are many ways to modify the password, which can be Baidu itself. 
After two classes, TM finally ran out.
Summary of commands
Yum: Yellow dog Updater, Modified, a software installation tool to solve the dependence of RPM packages, can configure Yum in / etc/yum.config file. Yum data source is placed in / etc/yum.repos.d / folder by default. It can be considered as an enhanced version of rpm.
rpm: Red Hat Package Manager, the manager of software installation packages, can be used to install or delete software.
wget: World Wide Web Get, wget is a free tool for automatically downloading files from the network, supporting common protocols such as HTTP, HTTPS and FTP.
uname: Unix Name, which displays the name of the host operating system.