1 常规错误的yum安装方法：

在前文中记述了CentOS 6.5系统中通过yum方式快速地搭建了LNMP环境，那么是否也能在CentOS 7或CentOS 7.1系统中依葫芦画瓢安装MySql5.6.24呢？答案是否定的。

[root@typecodes ~]# yum -y install mysql mysql-server mysql-devel

.....................。

....省略部分安装过程....

.....................。

Installed:

mariadb.x86_64 1:5.5.41-2.el7_0 mariadb-devel.x86_64 1:5.5.41-2.el7_0

Dependency Installed:

keyutils-libs-devel.x86_64 0:1.5.8-3.el7 krb5-devel.x86_64 0:1.12.2-14.el7 libcom_err-devel.x86_64 0:1.42.9-7.el7 libselinux-devel.x86_64 0:2.2.2-6.el7

libsepol-devel.x86_64 0:2.1.9-3.el7 libverto-devel.x86_64 0:0.2.5-4.el7 openssl-devel.x86_64 1:1.0.1e-42.el7.4 pcre-devel.x86_64 0:8.32-14.el7

zlib-devel.x86_64 0:1.2.7-13.el7

Complete!

从上面的安装结果可以看出，没有安装mysql数据库，而是安装了mariadb数据！因为在CentOS 7和CentOS 7.1系统中，默认安装的mysql是它的分支mariadb。这里引用下百度百科关于mariadb的描述：

MariaDB数据库管理系统是MySQL的一个分支，主要由开源社区在维护，采用GPL授权许可 MariaDB的目的是完全兼容MySQL，包括API和命令行，使之能轻松成为MySQL的代替品。

因此，下面这些正常的MySQL操作都是无效的：

#######无法把mysql服务加入系统启动

[root@typecodes ~]# chkconfig mysqld on

error reading information on service mysqld: No such file or directory

#######启动不了mysql

[root@typecodes ~]# service mysqld start

Redirecting to /bin/systemctl start mysqld.service

Failed to issue method call: Unit mysqld.service failed to load: No such file or directory.

#######没有安装mysql相关包

[root@typecodes ~]# rpm -qa |grep mysql

php-mysql-5.4.16-23.el7_0.3.x86_64

[root@typecodes ~]#

2 正确的安装方法：

众所周知，Linux系统自带的repo是不会自动更新每个软件的最新版本(基本都是比较靠后的稳定版)，所以无法通过yum方式安装MySQL的高级版本。所以我们需要先安装带有当前可用的mysql5系列社区版资源的rpm包。

#######安装rpm包

[root@typecodes ~]# rpm -Uvh http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm

Retrieving http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm

Preparing... ################################# [100%]

Updating / installing...

1:mysql-community-release-el7-5 ################################# [100%]

这时查看当前可用的mysql安装资源：

[root@typecodes ~]# yum repolist enabled | grep "mysql.*-community.*"

mysql-connectors-community/x86_64 MySQL Connectors Community 14

mysql-tools-community/x86_64 MySQL Tools Community 17

mysql56-community/x86_64 MySQL 5.6 Community Server 139

从上面的列表可以看出， mysql56-community/x86_64 和 MySQL 5.6 Community Server 可以使用。

因此，我们就可以直接用yum方式安装了MySQL5.6版本了。

[root@typecodes ~]# yum -y install mysql-community-server

Loaded plugins: axelget, langpacks

No metadata available for base

No metadata available for epel

No metadata available for extras

(Failed to load module fastestmirror: No module named fastestmirror)

repomd.xml | 2.5 kB 00:00:00

update mysql-connectors-community metadata successfully

(Failed to load module fastestmirror: No module named fastestmirror)

repomd.xml | 2.5 kB 00:00:00

update mysql-tools-community metadata successfully

(Failed to load module fastestmirror: No module named fastestmirror)

repomd.xml | 2.5 kB 00:00:00

update mysql56-community metadata successfully

No metadata available for updates

mysql-connectors-community | 2.5 kB 00:00:00

mysql-tools-community | 2.5 kB 00:00:00

mysql56-community | 2.5 kB 00:00:00

(1/3): mysql-connectors-community/x86_64/primary_db | 7.3 kB 00:00:00

(2/3): mysql56-community/x86_64/primary_db | 83 kB 00:00:01

mysql-tools-community/x86_64/p FAILED ============================================== ] 19 kB/s | 92 kB 00:00:00 ETA

http://repo.mysql.com/yum/mysql-tools-community/el/7/x86_64/repodata/3301d2eb425f300dec5a46c4201d08f2cf9232a6-primary.sqlite.bz2: [Errno 12] Timeout on http://repo.mysql.com/yum/mysql-tools-community/el/7/x86_64/repodata/3301d2eb425f300dec5a46c4201d08f2cf9232a6-primary.sqlite.bz2: (28, 'Operation too slow. Less than 1000 bytes/sec transferred the last 3 seconds')

Trying other mirror.

(3/3): mysql-tools-community/x86_64/primary_db | 15 kB 00:00:00

Resolving Dependencies

--> Running transaction check

---> Package mysql-community-server.x86_64 0:5.6.24-3.el7 will be installed

--> Processing Dependency: mysql-community-common(x86-64) = 5.6.24-3.el7 for package: mysql-community-server-5.6.24-3.el7.x86_64

--> Processing Dependency: mysql-community-client(x86-64) = 5.6.24-3.el7 for package: mysql-community-server-5.6.24-3.el7.x86_64

--> Processing Dependency: perl(DBI) for package: mysql-community-server-5.6.24-3.el7.x86_64

--> Running transaction check

---> Package mariadb.x86_64 1:5.5.41-2.el7_0 will be obsoleted

---> Package mysql-community-client.x86_64 0:5.6.24-3.el7 will be obsoleting

--> Processing Dependency: mysql-community-libs(x86-64) = 5.6.24-3.el7 for package: mysql-community-client-5.6.24-3.el7.x86_64

---> Package mysql-community-common.x86_64 0:5.6.24-3.el7 will be installed

---> Package perl-DBI.x86_64 0:1.627-4.el7 will be installed

--> Processing Dependency: perl(RPC::PlServer) >= 0.2001 for package: perl-DBI-1.627-4.el7.x86_64

--> Processing Dependency: perl(RPC::PlClient) >= 0.2000 for package: perl-DBI-1.627-4.el7.x86_64

--> Running transaction check

---> Package mariadb-libs.x86_64 1:5.5.41-2.el7_0 will be obsoleted

--> Processing Dependency: mariadb-libs(x86-64) = 1:5.5.41-2.el7_0 for package: 1:mariadb-devel-5.5.41-2.el7_0.x86_64

---> Package mysql-community-libs.x86_64 0:5.6.24-3.el7 will be obsoleting

---> Package perl-PlRPC.noarch 0:0.2020-14.el7 will be installed

--> Processing Dependency: perl(Net::Daemon) >= 0.13 for package: perl-PlRPC-0.2020-14.el7.noarch

--> Processing Dependency: perl(Net::Daemon::Test) for package: perl-PlRPC-0.2020-14.el7.noarch

--> Processing Dependency: perl(Net::Daemon::Log) for package: perl-PlRPC-0.2020-14.el7.noarch

--> Processing Dependency: perl(Compress::Zlib) for package: perl-PlRPC-0.2020-14.el7.noarch

--> Running transaction check

---> Package mariadb-devel.x86_64 1:5.5.41-2.el7_0 will be obsoleted

---> Package mysql-community-devel.x86_64 0:5.6.24-3.el7 will be obsoleting

---> Package perl-IO-Compress.noarch 0:2.061-2.el7 will be installed

--> Processing Dependency: perl(Compress::Raw::Zlib) >= 2.061 for package: perl-IO-Compress-2.061-2.el7.noarch

--> Processing Dependency: perl(Compress::Raw::Bzip2) >= 2.061 for package: perl-IO-Compress-2.061-2.el7.noarch

---> Package perl-Net-Daemon.noarch 0:0.48-5.el7 will be installed

--> Running transaction check

---> Package perl-Compress-Raw-Bzip2.x86_64 0:2.061-3.el7 will be installed

---> Package perl-Compress-Raw-Zlib.x86_64 1:2.061-4.el7 will be installed

--> Finished Dependency Resolution

Dependencies Resolved

=======================================================================================================================================================================

Package Arch Version Repository Size

=======================================================================================================================================================================

Installing:

mysql-community-client x86_64 5.6.24-3.el7 mysql56-community 19 M

replacing mariadb.x86_64 1:5.5.41-2.el7_0

mysql-community-devel x86_64 5.6.24-3.el7 mysql56-community 3.4 M

replacing mariadb-devel.x86_64 1:5.5.41-2.el7_0

mysql-community-libs x86_64 5.6.24-3.el7 mysql56-community 2.0 M

replacing mariadb-libs.x86_64 1:5.5.41-2.el7_0

mysql-community-server x86_64 5.6.24-3.el7 mysql56-community 58 M

Installing for dependencies:

mysql-community-common x86_64 5.6.24-3.el7 mysql56-community 256 k

perl-Compress-Raw-Bzip2 x86_64 2.061-3.el7 base 32 k

perl-Compress-Raw-Zlib x86_64 1:2.061-4.el7 base 57 k

perl-DBI x86_64 1.627-4.el7 base 802 k

perl-IO-Compress noarch 2.061-2.el7 base 260 k

perl-Net-Daemon noarch 0.48-5.el7 base 51 k

perl-PlRPC noarch 0.2020-14.el7 base 36 k

Transaction Summary

=======================================================================================================================================================================

Install 4 Packages (+7 Dependent packages)

Total download size: 83 M

Downloading packages:

mysql-community-devel-5.6.24-3.el7.x86_64.rpm | 3.4 MB 00:00:03

mysql-community-client-5.6.24-3.el7.x86_64.rpm | 19 MB 00:00:05

mysql-community-server-5.6.24-3.el7.x86_64.rpm | 58 MB 00:00:11

mysql-community-libs-5.6.24-3.el7.x86_64.rpm | 2.0 MB 00:00:02

perl-DBI-1.627-4.el7.x86_64.rpm | 0 B 00:00:01 ...

perl-DBI-1.627-4.el7.x86_64.rpm | 802 kB 00:00:00

(1/6): perl-Compress-Raw-Zlib-2.061-4.el7.x86_64.rpm | 57 kB 00:00:00

(2/6): perl-Net-Daemon-0.48-5.el7.noarch.rpm | 51 kB 00:00:00

(3/6): perl-PlRPC-0.2020-14.el7.noarch.rpm | 36 kB 00:00:00

(4/6): perl-Compress-Raw-Bzip2-2.061-3.el7.x86_64.rpm | 32 kB 00:00:00

(5/6): perl-IO-Compress-2.061-2.el7.noarch.rpm | 260 kB 00:00:00

warning: /var/cache/yum/x86_64/7/mysql56-community/packages/mysql-community-common-5.6.24-3.el7.x86_64.rpm: V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY 00:00:01 ETA

Public key for mysql-community-common-5.6.24-3.el7.x86_64.rpm is not installed

(6/6): mysql-community-common-5.6.24-3.el7.x86_64.rpm | 256 kB 00:00:01

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------

Total 388 kB/s | 692 kB 00:00:01

Retrieving key from file:/etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

Importing GPG key 0x5072E1F5:

Userid : "MySQL Release Engineering "

Fingerprint: a4a9 4068 76fc bd3c 4567 70c8 8c71 8d3b 5072 e1f5

Package : mysql-community-release-el7-5.noarch (installed)

From : file:/etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

Running transaction check

Running transaction test

Transaction test succeeded

Running transaction

Warning: RPMDB altered outside of yum.

Installing : mysql-community-common-5.6.24-3.el7.x86_64 1/14

Installing : mysql-community-libs-5.6.24-3.el7.x86_64 2/14

Installing : mysql-community-client-5.6.24-3.el7.x86_64 3/14

Installing : perl-Net-Daemon-0.48-5.el7.noarch 4/14

Installing : 1:perl-Compress-Raw-Zlib-2.061-4.el7.x86_64 5/14

Installing : perl-Compress-Raw-Bzip2-2.061-3.el7.x86_64 6/14

Installing : perl-IO-Compress-2.061-2.el7.noarch 7/14

Installing : perl-PlRPC-0.2020-14.el7.noarch 8/14

Installing : perl-DBI-1.627-4.el7.x86_64 9/14

Installing : mysql-community-server-5.6.24-3.el7.x86_64 10/14

Installing : mysql-community-devel-5.6.24-3.el7.x86_64 11/14

Erasing : 1:mariadb-devel-5.5.41-2.el7_0.x86_64 12/14

Erasing : 1:mariadb-5.5.41-2.el7_0.x86_64 13/14

Erasing : 1:mariadb-libs-5.5.41-2.el7_0.x86_64 14/14

Verifying : perl-Compress-Raw-Bzip2-2.061-3.el7.x86_64 1/14

Verifying : mysql-community-common-5.6.24-3.el7.x86_64 2/14

Verifying : mysql-community-devel-5.6.24-3.el7.x86_64 3/14

Verifying : mysql-community-client-5.6.24-3.el7.x86_64 4/14

Verifying : perl-PlRPC-0.2020-14.el7.noarch 5/14

Verifying : mysql-community-server-5.6.24-3.el7.x86_64 6/14

Verifying : 1:perl-Compress-Raw-Zlib-2.061-4.el7.x86_64 7/14

Verifying : mysql-community-libs-5.6.24-3.el7.x86_64 8/14

Verifying : perl-Net-Daemon-0.48-5.el7.noarch 9/14

Verifying : perl-DBI-1.627-4.el7.x86_64 10/14

Verifying : perl-IO-Compress-2.061-2.el7.noarch 11/14

Verifying : 1:mariadb-5.5.41-2.el7_0.x86_64 12/14

Verifying : 1:mariadb-devel-5.5.41-2.el7_0.x86_64 13/14

Verifying : 1:mariadb-libs-5.5.41-2.el7_0.x86_64 14/14

Installed:

mysql-community-client.x86_64 0:5.6.24-3.el7 mysql-community-devel.x86_64 0:5.6.24-3.el7 mysql-community-libs.x86_64 0:5.6.24-3.el7

mysql-community-server.x86_64 0:5.6.24-3.el7

Dependency Installed:

mysql-community-common.x86_64 0:5.6.24-3.el7 perl-Compress-Raw-Bzip2.x86_64 0:2.061-3.el7 perl-Compress-Raw-Zlib.x86_64 1:2.061-4.el7 perl-DBI.x86_64 0:1.627-4.el7

perl-IO-Compress.noarch 0:2.061-2.el7 perl-Net-Daemon.noarch 0:0.48-5.el7 perl-PlRPC.noarch 0:0.2020-14.el7

Replaced:

mariadb.x86_64 1:5.5.41-2.el7_0 mariadb-devel.x86_64 1:5.5.41-2.el7_0 mariadb-libs.x86_64 1:5.5.41-2.el7_0

Complete!

3 MySQL安装完成后，进行相关配置

安装完MySQL后，需要进行一些基础配置工作：

#######安装成功后，将其加入开机启动

[root@typecodes ~]# systemctl enable mysqld

#######启动mysql服务进程

[root@typecodes ~]# systemctl start mysqld

#######配置mysql(设置密码等)

[root@typecodes ~]# mysql_secure_installation

NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MySQL

SERVERS IN PRODUCTION USE! PLEASE READ EACH STEP CAREFULLY!

In order to log into MySQL to secure it, we'll need the current

password for the root user. If you've just installed MySQL, and

you haven't set the root password yet, the password will be blank,

so you should just press enter here.

Enter current password for root (enter for none):

OK, successfully used password, moving on...

Setting the root password ensures that nobody can log into the MySQL

root user without the proper authorisation.

Set root password? [Y/n] y [设置root用户密码]

New password:

Re-enter new password:

Password updated successfully!

Reloading privilege tables..

... Success!

By default, a MySQL installation has an anonymous user, allowing anyone

to log into MySQL without having to have a user account created for

them. This is intended only for testing, and to make the installation

go a bit smoother. You should remove them before moving into a

production environment.

Remove anonymous users? [Y/n] y [删除匿名用户]

... Success!

Normally, root should only be allowed to connect from 'localhost'. This

ensures that someone cannot guess at the root password from the network.

Disallow root login remotely? [Y/n] y [禁止root远程登录]

... Success!

By default, MySQL comes with a database named 'test' that anyone can

access. This is also intended only for testing, and should be removed

before moving into a production environment.

Remove test database and access to it? [Y/n] y [删除test数据库]

- Dropping test database...

ERROR 1008 (HY000) at line 1: Can't drop database 'test'; database doesn't exist

... Failed! Not critical, keep moving...

- Removing privileges on test database...

... Success!

Reloading the privilege tables will ensure that all changes made so far

will take effect immediately.

Reload privilege tables now? [Y/n] y [刷新权限]

... Success!

All done! If you've completed all of the above steps, your MySQL

installation should now be secure.

Thanks for using MySQL!

Cleaning up...

4.可能有效的MySQL配置优化

在原始配置文件  /etc/my.cnf 基础上，在 [mysqld] 节内增加配置参数。实际应用中，请按硬件及负载酌情修改。

#add by feng 120418 --------------------------

#skip-locking

skip-name-resolve

skip-external-locking

key_buffer_size = 256M

#table_cache = 3072

table_open_cache = 3072

read_buffer_size = 2M

read_rnd_buffer_size = 2M

sort_buffer_size = 2M

myisam_sort_buffer_size = 256M

thread_cache_size = 8

query_cache_size= 512M

query_cache_limit= 5M

tmp_table_size=1024M

max_heap_table_size=3000M

max_allowed_packet = 16M

innodb_buffer_pool_size = 512M

innodb_log_file_size = 512M

innodb_additional_mem_pool_size=512M

innodb_log_buffer_size=64M

max_connections=2000

max_user_connections=800

join_buffer_size = 8M

open_files_limit = 65535

#tmpdir=/dev/shm

max_connect_errors=1000

#add by feng 120418 end ---------------------