Installing and configuring MySQL database under Linux centos

If you want to do a Java EE development on Linux, first build the Java EE development environment, including the JDK, Tomcat, Eclipse installation (this in a previous essay has explained in detail the Linux learning CentOS (vii)- CentOS under the Java Environment Build ), if you want to develop a Web project, we can certainly install a myeclipse to the Linux system, this installation method and installation eclipse is identical, there is no record, with the JDK, Tomcat, Eclipse we have been able to carry out our program development, but if you want to do a project, even small can not be small projects are inseparable from the storage of data!!! Yes, we are still one of the most important software is not installed, that is, the database!!! If there is no database, we do the project is simply utopian, so, for the database installation this piece, specifically for the installation of MySQL database wrote this essay ...

First, MySQL Introduction

When it comes to databases, we mostly think of relational databases, such as MySQL, Oracle, SQL Server, and so on, which are very easy to install on Windows, and if you want to install a database on Linux, I have to recommend MySQL database first. And the first version of the MySQL database is distributed on Linux systems.

MySQL is a relational database management system developed by the Swedish MySQL AB company, currently owned by Oracle Corporation. MySQL is an associated database management system that keeps data in separate tables rather than putting all of the data in a large warehouse, which increases speed and increases flexibility. MySQL's SQL language is the most commonly used standardized language for accessing databases. MySQL software uses a dual licensing policy (this term "authorization policy"), it is divided into community and commercial version, because of its small size, speed, low total cost of ownership, especially the open source of this feature, the general small and medium-sized web site development has chosen MySQL as the site database. Thanks to the performance of its community edition, PHP and Apache make a good development environment.

To install MySQL database on Linux, we can download the MySQL database rpm package on its official website, Http://dev.mysql.com/downloads/mysql/5.6.html#downloads, Everyone can download the corresponding database files according to their operating system, the latest version is 5.6.10.

Here I am the installation of MySQL database through Yum, this way to install, can be related to MySQL some services, jar packages are installed to us, so save a lot of unnecessary trouble!!!

Second, uninstall the original MySQL

Because MySQL database is very popular on Linux, so the mainstream Linux version of the current download basically integrates the MySQL database inside, we can use the following command to see if the MySQL database is installed on our operating system

grep mysql//This command will check if the MySQL database is already installed on the operating system

If there is, we can unload it by RPM-E command or rpm-e--nodeps command.

[[Email protected] ~]# RPM- normal Delete mode Brute force Delete mode, if you use the above command to delete, prompted to have other dependent files, then use this command can be strongly deleted

After the deletion we can pass Rpm-qa | grep mysql command to see if MySQL has been uninstalled successfully!!

Third, the installation of MySQL through Yum

I am using yum to perform MySQL database installation, first we can enter Yum List | grep mysql command to view the downloadable version of the MySQL database available on Yum:

Yum grep MySQL

You can get the downloadable version of the MySQL database on the Yum server:

Then we can install the MySQL mysql-server mysql-devel by entering the yum install-y mysql-server mysql mysql-devel command ( Note: When we installed MySQL, we did not install the MySQL client, which is equivalent to installing the MySQL database, we also need to install the Mysql-server server .

Yum Install -y mysql-server mysql Mysql-deve

After waiting for some time, Yum will help us choose the software needed to install the MySQL database and some other ancillary software.

We found that the installation of the MySQL database through the Yum method eliminates a lot of unnecessary hassle, and when the following results occur, the MySQL database installation is successful.

At this point we can view the version of the mysql-server that we just installed with the following command

[Email protected] ~]# Rpm-qi mysql-server

We installed the Mysql-server is not the latest version, if you want to try the latest version, then go to the MySQL website to download rpm package installation, so that our MySQL database has been installed.

Iv. initialization of MySQL database and related configuration

After we install the MySQL database, we will find a mysqld service, this is our database service, we can start our MySQL service by entering the service mysqld start command.

Note : If we are starting the MySQL service for the first time, the MySQL server will first initialize the configuration, such as:

[[Email protected] ~]# Service mysqld start initializing MySQL database: Warning:the host'Xiaoluo'Could not being looked up with Resolveip. This probably means that your libc libraries is not -%compatiblewith This binary MySQL version. The MySQL daemon, mysqld, should worknormally with the exception that host name resolving won't work. This means, should use IP addresses instead of Hostnameswhen specifying MySQL privileges!Installing MySQL system tables ... Okfilling Help Tables ... OKto start mysqld at boot TimeYou have to Copysupport-files/mysql.server to the right place foryour systemplease REMEMBER to SET A PASSWORD for the MySQL root USER! to DoSo, start the server, Thenissue the following commands:/usr/bin/mysqladmin-u Root Password'New-password'/usr/bin/mysqladmin-u root-h xiaoluo Password'New-password'Alternatively you can run:/usr/bin/mysql_secure_installationwhichWould also give you the option of removing the testdatabases and anonymous user created by default. This isstrongly recommended forproduction servers. See the manual for  Moreinstructions. You can start the MySQL daemon with:cd/usr; /usr/bin/mysqld_safe &can test the MySQL daemon with MySQL-test-RUN.PLCD/usr/mysql-test;Perlmysql-test-run.plplease Report any problems with the/usr/bin/mysqlbug script![OK] is starting mysqld: [OK]

At this point we will see that the first time you start the MySQL server will prompt a lot of information, the purpose is to initialize the MySQL database, when we restart the MySQL service again, will not prompt so much information, such as:

[[Email protected] ~Service mysqld Restart stop mysqld:                                             [OK] starting mysqld:                                          [OK]

When we use MySQL database, we have to start the Mysqld service first, we can check the MySQL service is not started automatically by chkconfig--list | grep mysqld command, such as:

grep mysqldmysqld              0: Off    1: Off    2: Off    3: Off    4: Off    5: Off    6: Off

We found that the MYSQLD service did not start automatically, and of course we can set it to boot up with the chkconfig mysqld on command, so you don't have to start it manually every time.

[[Email protected] ~grep  mysqlmysqld             0: Off    1: Off    2 : Enable    3: Enable    4: Enable    5: Enable    6: Off

MySQL database after installation will only have a root administrator account, but at this time the root account has not set a password for it, the first time the MySQL service started, the database will be some initialization work, in the output of a large string of information, we see a line of information:

/usr/bin/mysqladmin-u root password ' New-password  ' //Set the password for the root account

So we can use this command to set the password for our root account ( Note : This root account is the root account of MySQL, not the root account of Linux )

mysqladmin-u root Password ' Root '//Use this command to set the root account password to root

At this point we can log in to our MySQL database via the mysql-u root-p command.

V. Major configuration files for MySQL database

1./etc/my.cnf This is the main configuration file for MySQL

We can take a look at some information about this file

LScat  my.cnf [mysqld]datadir=/var/lib/mysqlsocket=/var/lib/mysql/  Mysql.sockuser=mysql# Disabling symbolic-links are recommended to prevent assorted security Riskssymbolic-links=0[mysqld_safe]log-error=/var/log/mysqld.logpid-file =/var/run/mysqld/mysqld.pid

2. Storage location of database files for/var/lib/mysql MySQL Database

The database files for our MySQL database are usually stored in the/ver/lib/mysql directory.

[Email protected] ~]# cd/var/lib/mysql/[email protected] mysql]#ls-L Total Dosage20488-RW-RW----.1MySQL MySQL10485760April6  A: onibdata1-RW-RW----.1MySQL MySQL5242880April6  A: onIb_logfile0-RW-RW----.1MySQL MySQL5242880April6  +: -ib_logfile1drwx------.2MySQL MySQL4096April6  +: - MySQL//These two are the default two database file srwxrwxrwx when the MySQL database is installed .1MySQL MySQL0April6  A: onmysql.sockdrwx------.2MySQL MySQL4096April6  +: - Test //These two are the default two database files when the MySQL database is installed 

We can create a database ourselves to verify where the database files are stored

 Create a database of our own:MySQL>CREATE DATABASE Xiaoluo; Query OK,1Row affected (0.00sec) [Email protected] mysql]#ls-L Total Dosage20492-RW-RW----.1MySQL MySQL10485760April6  A: onibdata1-RW-RW----.1MySQL MySQL5242880April6  A: onIb_logfile0-RW-RW----.1MySQL MySQL5242880April6  +: -ib_logfile1drwx------.2MySQL MySQL4096April6  +: -mysqlsrwxrwxrwx.1MySQL MySQL0April6  A: onmysql.sockdrwx------.2MySQL MySQL4096April6  +: -testdrwx------.2MySQL MySQL4096April6  A: the Xiaoluo//This is the Xiaoluo database we just created [[email protected] mysql]# CD Xiaoluo/[email protected] xiaoluo]#lsdb.opt

3./var/log MySQL database log output storage location

Some of our MySQL database's log output is stored in the/var/log directory

[ Email protected] xiaoluo]# CD [[email protected]~]# cd/var/Log[[email protected] log]#lsAmanda Cron Maillog-20130331spice-Vdagent.loganaconda.ifcfg.log Cron-20130331Mcelog spooleranaconda.log cups messages spooler-20130331anaconda.program.log dirsrv Messages-20130331sssdanaconda.storage.log dmesg mysqld.log tallyloganaconda.syslog dmesg.old NT Pstats tomcat6anaconda.xlog dracut.log Piranha Wpa_supplicant.loganaconda.Yum. log GDM pm-powersave.log wtmpaudit httpd PPP Xorg.0. Logboot.log ibacm.log prelink Xorg.0. log.oldbtmp lastlog sa Xorg.1. Logbtmp-20130401Libvirt Samba Xorg.2. Logcluster Luci Secure Xorg.9. Logconsolekit Maillog Secure-20130331    Yum. log

Which mysqld.log this file is the log information we have to store our operations with the MySQL database, and we can get a lot of information by looking at the log file.

Because our MySQL database is accessible over the network, not a stand-alone database, where the protocol used is the TCP/IP protocol, we all know that the MySQL database binding port number is 3306, so we can through the NETSTAT-ANP command to see if the Linux system is listening on the 3306 port number:

As shown above, the Linux system listens on the 3306 port number is our MySQL database!!!!

This essay details the installation of MySQL database under CentOS6.4 with Yum and the basic configuration of the database, in the subsequent Linux learning will adhere to record their own experience and experience!!!!