NFS共享MySQL使用DNS轮询实现Web负载均衡

Posted 2020-07-01

NFS共享mysql使用DNS轮询实现Web负载均衡

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前言：

今天学习了NFS，遂结合前面学习的LAMP+Bind做一个实验，实现两台Web服务器采用同一个MySQL数据库和相同的网页文件，对LAMP和Bind不了解的可以去查看我以前写的博客： AnyISalIn的文章

实验拓扑图

实验环境

主机名	IP地址	实现
storage.anyisalin.com	192.168.2.5	NFS
ns.anyisalin.com	192.168.2.2	dns,MySQL
www.anyisalin.com	192.168.2.3	web
www.anyisalin.com	192.168.2.4	web

本文所有主机皆关闭SElinux和IPtables

实验步骤

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搭建NFS

以下操作在storage.anyisalin.com中执行

[[email protected] ~]# yum install nfs-utils | tail -n 10  #安装nfs-utils 这里已经安装过了
Loaded plugins: fastestmirror, refresh-packagekit, security
Setting up Install Process
Loading mirror speeds from cached hostfile
 * base: mirrors.pubyun.com
 * extras: mirrors.skyshe.cn
 * updates: mirrors.pubyun.com
Package 1:nfs-utils-1.2.3-64.el6.x86_64 already installed and latest version
Nothing to do

创建文件夹并导出

[[email protected] ~]# mkdir /var/mydata
[[email protected] ~]# mkdir /var/webroot
[[email protected] var]# cd /var/webroot/
[[email protected] webroot]# unzip wordpress-4.4.1-zh_CN.zip &> /dev/null
[[email protected] webroot]# ls
wordpress  wordpress-4.4.1-zh_CN.zip
[[email protected] webroot]# chmod 777 wordpress -R
[[email protected] ~]# vim /etc/exports 
    /var/mydata   192.168.2.2(rw,no_root_squash)
    /var/webroot  192.168.2.3(rw,no_root_squash) 192.168.2.4(rw,no_root_squash)
[[email protected] ~]# service rpcbind start && service nfs start
Starting NFS services:                                     [  OK  ]
Starting NFS quotas:                                       [  OK  ]
Starting NFS mountd:                                       [  OK  ]
Starting NFS daemon:                                       [  OK  ]
Starting RPC idmapd:                                       [  OK  ]
[[email protected] ~]# showmount -e localhost   #查看当前导出的目录
Export list for localhost:
/var/webroot 192.168.2.4,192.168.2.3
/var/mydata  192.168.2.2

搭建dns,MySQL环境

以下操作在ns.anyisalin.com中执行

DNS配置

[[email protected] ~]# yum install bind mysql-server -y | tail -n 10 #信息过长遂使用tail限制
  perl-DBD-MySQL.x86_64 0:4.013-3.el6                                           
  perl-DBI.x86_64 0:1.609-4.el6                                                 
  perl-Module-Pluggable.x86_64 1:3.90-141.el6_7.1                               
  perl-Pod-Escapes.x86_64 1:1.04-141.el6_7.1                                    
  perl-Pod-Simple.x86_64 1:3.13-141.el6_7.1                                     
  perl-libs.x86_64 4:5.10.1-141.el6_7.1                                         
  perl-version.x86_64 3:0.77-141.el6_7.1                                        
  portreserve.x86_64 0:0.0.4-9.el6                                              

Complete!
[[email protected] ~]# 

在/etc/named.rfc1912.zones文件中添加以下几行

zone "anyisalin.com" IN {
        type master;
        file "anyisalin.com.zone";
};

配置区域解析库文件为如下

vim /var/named/anyisalin.com.zone

$TTL 600
$ORIGIN anyisalin.com.
@   IN SOA  ns.anyisalin.com  amdin.anyisalin.com (
        20160328
        1D
        5M
        7D
        1D
)

        IN   NS  ns
ns      IN   A   192.168.2.2
www     IN   A   192.168.2.3
www     IN   A   192.168.2.4
storage IN   A   192.168.2.5

测试效果如下，以达到DNS实现轮询

MySQL配置

这里MySQL数据库文件通过NFS保存在远程主机

[[email protected] ~]# mkdir /mydata
[[email protected] ~]# mount -t nfs 192.168.2.5:/var/mydata /mydata

[[email protected] ~]# cd /usr/src/
[[email protected] src]# ls
debug  kernels  mariadb-5.5.32-linux-x86_64.tar.gz
[[email protected] src]# tar xf mariadb-5.5.32-linux-x86_64.tar.gz 
[[email protected] src]# cd mariadb-5.5.32-linux-x86_64
[[email protected] mariadb-5.5.32-linux-x86_64]# ls
bin  COPYING  COPYING.LESSER  data  docs  include  INSTALL-BINARY  lib  man  mysql-test  README  scripts  share  sql-bench  support-files
[[email protected] mariadb-5.5.32-linux-x86_64]# groupadd -r -g 3306 mysql 
groupadd: group ‘mysql‘ already exists
[[email protected] mariadb-5.5.32-linux-x86_64]# useradd -r -g mysql -s /sbin/nologin mysql
useradd: user ‘mysql‘ already exists
[[email protected] mariadb-5.5.32-linux-x86_64]# ./scripts/mysql_install_db --datadir=/mydata --user=mysql  #初始化数据库
Installing MariaDB/MySQL system tables in ‘/mydata‘ ...
OK
Filling help tables...
OK
#内容省略

[[email protected] mariadb-5.5.32-linux-x86_64]# ls /mydata/  #查看生成的数据库
aria_log.00000001  aria_log_control  mysql  performance_schema  test

[[email protected] src]# ln -sv /usr/src/mariadb-5.5.32-linux-x86_64 /usr/local/mysql
`/usr/local/mysql‘ -> `/usr/src/mariadb-5.5.32-linux-x86_64‘
[[email protected] mysql]# cp support-files/mysql.server /etc/rc.d/init.d/mysqld  
[[email protected] mysql]# cp support-files/my-large.cnf /etc/my.cnf
[[email protected] mysql]# vim /etc/my.cnf  #添加以下三行
datadir = /mydata
skip_name_resolve = on
innodb_file_per_table = on
[[email protected] mysql]# export PATH=/usr/local/mysql/bin/:$PATH

[[email protected] mysql]# service mysqld start    #测试MySQL是否能正常启动
Starting MySQL... SUCCESS! 
[[email protected] mysql]# mysql
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 1
Server version: 5.5.32-MariaDB-log MariaDB Server

Copyright (c) 2000, 2013, Oracle, Monty Program Ab and others.

Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.

mysql> GRANT ALL ON wp.* TO ‘wpuser‘@‘%‘ IDENTIFIED  BY ‘passwd‘;
Query OK, 0 rows affected (0.04 sec)

mysql> CREATE DATABASE wp;
Query OK, 1 row affected (0.02 sec)

mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.01 sec)

WEB配置

第一台主机安装

以下操作在www.anyisalin.com(192.168.2.3)中执行

[[email protected] ~]# yum install httpd php php-mysql -y | tail -n 10
  apr-util.x86_64 0:1.3.9-3.el6_0.1                                             
  apr-util-ldap.x86_64 0:1.3.9-3.el6_0.1                                        
  httpd-tools.x86_64 0:2.2.15-45.el6.centos                                     
  libedit.x86_64 0:2.11-4.20080712cvs.1.el6                                     
  mailcap.noarch 0:2.1.31-2.el6                                                 
  php-cli.x86_64 0:5.3.3-40.el6_6                                               
  php-common.x86_64 0:5.3.3-40.el6_6                                            
  php-pdo.x86_64 0:5.3.3-40.el6_6                                               

Complete!
[[email protected] ~]# vi /etc/httpd/conf.d/virt.conf  #编辑配置文件

NameVirtualHost 192.168.2.3:80
NameVirtualHost 192.168.2.3:80
<VirtualHost 192.168.2.3:80>
   ServerName www.anyisalin.com
   DocumentRoot /webroot/wordpress
</VirtualHost>

[[email protected] ~]# service rpcbind start
Starting rpcbind:                                          [  OK  ]
[[email protected] ~]# mount ^C
[[email protected] ~]# mkdir /webroot
[[email protected] ~]# mount -t nfs 192.168.2.5:/var/webroot /webroot/
[[email protected] ~]# ls /webroot/
wordpress  wordpress-4.4.1-zh_CN.zip
[[email protected] ~]# service httpd start
Starting httpd: 
httpd: apr_sockaddr_info_get() failed for www.anyisalin.com
httpd: Could not reliably determine the server‘s fully qualified domain name, using 127.0.0.1 for ServerName
[Wed Mar 23 18:05:15 2016] [warn] NameVirtualHost 192.168.2.3:80 has no VirtualHosts
                                                           [  OK  ]

安装前我们需要先将dns服务器中对192.168.2.4的解析注释,避免安装时出现解析问题

安装过程不做演示

第二台主机安装

以下操作在www.anyisalin.com(192.168.2.4)中执行 
我们要将dns服务器中的A记录恢复到初始轮询的状态

[[email protected] ~]# yum install httpd php php-mysql nfs-utils -y | tail -n 10
Installed:
  httpd.x86_64 0:2.2.15-45.el6.centos               nfs-utils.x86_64 1:1.2.3-64.el6               php.x86_64 0:5.3.3-40.el6_6               php-mysql.x86_64 0:5.3.3-40.el6_6              

Dependency Installed:
  apr.x86_64 0:1.3.9-5.el6_2                apr-util.x86_64 0:1.3.9-3.el6_0.1                apr-util-ldap.x86_64 0:1.3.9-3.el6_0.1        httpd-tools.x86_64 0:2.2.15-45.el6.centos       
  keyutils.x86_64 0:1.4-5.el6               libedit.x86_64 0:2.11-4.20080712cvs.1.el6        libevent.x86_64 0:1.4.13-4.el6                libgssglue.x86_64 0:0.1-11.el6                  
  libtirpc.x86_64 0:0.2.1-10.el6            mailcap.noarch 0:2.1.31-2.el6                    nfs-utils-lib.x86_64 0:1.1.5-11.el6           php-cli.x86_64 0:5.3.3-40.el6_6                 
  php-common.x86_64 0:5.3.3-40.el6_6        php-pdo.x86_64 0:5.3.3-40.el6_6                  python-argparse.noarch 0:1.2.1-2.1.el6        rpcbind.x86_64 0:0.2.0-11.el6                   

Complete!

[[email protected] ~]# vim /etc/httpd/conf.d/virt.conf

NameVirtualHost 192.168.2.4:80
<VirtualHost 192.168.2.4:80>
   ServerName www.anyisalin.com
   DocumentRoot /webroot/wordpress
</VirtualHost>
[[email protected] ~]# service rpcbind start
Starting rpcbind:                                          [  OK  ]
[[email protected] ~]# mkdir /webroot
[[email protected] ~]# mount -t nfs 192.168.2.5:/var/webroot /webroot/
[[email protected] ~]# service httpd start
Starting httpd: httpd: Could not reliably determine the server‘s fully qualified domain name, using www.anyisalin.com for ServerName
                                                           [  OK  ]
[[email protected] ~]# 

确保DNS服务能提供以下效果 

测试

由于在Windows我们不好进行模拟, 遂修改HOSTS文件达到测试效果

web1测试

现在访问web1主机

发布一篇文章测试

web2测试

现在访问web2主机

 

还能够看到刚才发的文章

 

再发布一篇文章

回到web1测试

再次访问web1主机

 

虽然页面一样, 但是主机已经是web2了

总结

虽然本文最后测试时只修改了hosts文件进行测试，但是如果指定DNS地址为192.168.2.2的话是能够完成负载均衡的效果的，但是NFS的网络传输文件的效率并不好，后期会学习LVS和nginx, HAproxy等专用负载均衡软件再给大家写一篇。 
作者: AnyISalIn 
感谢: MagEdu

本文出自 “The AnyISalIn blog” 博客，请务必保留此出处http://anyisalin.blog.51cto.com/10917514/1757942