本案例采用四層模式實現，主要分為前端反向代理、web層、數據庫緩存層和數據庫層。

• 前端反向代理采用主備模式
• web層采用群集模式
• 數據庫緩存層采用主備模式
• 數據庫層采用主從模式

由於實驗條件限制，本次實驗共打開四臺虛擬機，此處實驗將前端代理層、數據庫緩存層、數據庫層服務搭建在前兩臺虛擬服務器上，web層采用群集模式，用於單獨放置兩臺虛擬機。故本次實驗實際模型為了模擬實際環境，服務搭建按照如下拓撲搭建。

二、實驗環境

三、實驗部署

3.1、master和slave設置keepalive與Nginx反向代理

• 配置yum源

rpm -ivh http://nginx.org/packages/centos/7/noarch/RPMS/nginx-release-centos-7-0.el7.ngx.noarch.rpm

• 安裝keepalive軟件和Nginx

yum install -y keepalived nginx

3.1.1配置keepalive

• 配置主從的keepalive，兩臺配置基本相同，配置文件不同處已做說明

vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
    route_id NGINX_HA    //主從不同
}

vrrp_script nginx {
    script "/opt/shell/nginx.sh"    //配置帶動Nginx啟動腳本
    interval 2   //每隔2s響應
}

vrrp_instance VI_1 {
    state MASTER    //備為BACKUP
    interface ens33 //註意主機網卡端口名稱
    virtual_router_id 51   //從需不同
    priority 100    //從需比主低
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
}

track_script {
    nginx        //調度Nginx啟動腳本的函數名
}

virtual_ipaddress {
    192.168.144.188    //設置虛擬IP
    }
}
 

3.1.2創建keepalive帶動Nginx啟動腳本

mkdir -p /opt/shell
vim /opt/shell/nginx.sh

#!/bin/bash
k=`ps -ef | grep keepalived | grep -v grep | wc -l`
if [ $k -gt 0 ];then
    /bin/systemctl start nginx.service
else
/bin/systemctl stop nginx.service
fi

chmod +x /opt/shell/nginx.sh

3.1.3配置Nginx前端調度功能

vim /etc/nginx/nginx.conf

• 在include 上面一行新增

upstream tomcat_pool {
                server 192.168.144.113:8080;
                server 192.168.144.114:8080;
                ip_hash;        //會話穩固功能，否則無法通過vip地址登陸
        }
        server {
                listen 80;
                server_name 192.168.144.188;  //虛擬IP
                location / {
                        proxy_pass http://tomcat_pool;
                        proxy_set_header X-Real-IP $remote_addr;
                }
        }

• 配置完成後，檢查Nginx配置文件語法

nginx -t -c /etc/nginx/nginx.conf

• 關閉防火墻和SELinux，準備啟動keepalive，隨後會通過配置文件帶動腳本，啟動Nginx，此處需要註意，若要停止Nginx，則需要先關閉keepalive，然後才可以。

• 查看Nginx是否啟動

netstat -ntap | grep nginx

3.2、部署兩臺web服務器

3.2.1兩臺web服務器部署tomcat，部署步驟完全相同，為了試驗區分，需要在首頁內容做區別

tar xf apache-tomcat-8.5.23.tar.gz
tar xf jdk-8u144-linux-x64.tar.gz
mv jdk1.8.0_144/ /usr/local/java
mv apache-tomcat-8.5.23/ tomcat8

• 解壓完成後，配置jdk環境變量,讓jdk的各種命令為系統識別

vim /etc/profile

export JAVA_HOME=/usr/local/java
export JRE_HOME=/usr/local/java/jre
export PATH=$PATH:/usr/local/java/bin
export CLASSPATH=./:/usr/local/java/lib:/usr/local/java/jre/lib

source /etc/profile

• 配置tomcat啟動與關閉命令為系統識別

  ln -s /usr/local/tomcat8/bin/startup.sh /usr/bin/tomcatup
  ln -s /usr/local/tomcat8/bin/shutdown.sh /usr/bin/tomcatdown

• 啟動服務，查看端口狀態，使用自身網頁測試，觀察服務是否能夠提供。

tomcatup
netstat -anpt | grep 8080

http://192.168.144.113:8080/ //測試默認測試頁是否正常顯示
http://192.168.144.114:8080/

• 為了試驗區分兩臺web服務器，修改首頁內容

vim /usr/local/tomcat8/webapps/ROOT/index.jsp

<h1>Server 129！！</h1>    //註意，web2需要首頁內容不同

• 輸入調度器地址，也就是虛擬地址，測試兩臺節點的調度情況。

http://192.168.175.188/

3.2.2搭建會員商城

• 首先在tomcat配置文件中添加支持商城模塊

cd /usr/local/tomcat8/conf/
vim server.xml

• 跳到行尾，在Host name下新增 在148行位置

  <Context path="" docBase="SLSaleSystem" reloadable="true" debug="0"></Context>
  //日誌調試信息debug為0表示信息越少，docBase指定訪問目錄

• 將會員商城軟件包解壓縮

tar zxvf SLSaleSystem.tar.gz -C /usr/local/tomcat8/webapps/

cd /usr/local/tomcat8/webapps/SLSaleSystem/WEB-INF/classes

vim jdbc.properties //修改數據庫IP地址是VRRP的虛擬IP，以及授權的用戶名root和密碼abc123。

driverClassName=com.mysql.jdbc.Driver
url=jdbc\:mysql\://192.168.144.188\:3306/slsaledb?useUnicode\=true&characterEncoding\=UTF-8  //該成我們設定的虛擬IP
uname=root
password=123456
minIdle=10
maxIdle=50
initialSize=5
maxActive=100
maxWait=100
removeAbandonedTimeout=180
removeAbandoned=true

• 客戶端測試

http://192.168.144.113:8080/ //默認的用戶名admin 密碼：123456
http://192.168.144.114:8080/

http://192.168.175.188 //輸入虛擬地址測試登錄，並且關閉主再測試登錄

3.3、部署MySQL以及主從

3.3.1安裝mysql

• 在實際生產環境中，此處應當搭建MySQL服務，但由於實驗條件限制，本實驗使用mariadb代替MySQL。

yum install -y mariadb-server mariadb

systemctl start mariadb.service
systemctl enable mariadb.service

netstat -anpt | grep 3306

mysql_secure_installation //

Set root password? [Y/n] y         //設置MySQL管理員賬戶的密碼，我選擇密碼為abc123
New password: 
Re-enter new password: 
Password updated successfully!
Reloading privilege tables..
 ... Success!

By default, a MariaDB installation has an anonymous user, allowing anyone
to log into MariaDB 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] n        //刪除匿名用戶？
 ... skipping.

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] n   //拒絕root用戶遠程登錄？
 ... skipping.

By default, MariaDB 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] n  //刪除test數據庫？
 ... skipping.

Reloading the privilege tables will ensure that all changes made so far
will take effect immediately.

Reload privilege tables now? [Y/n] y    //重新加載數據庫的所有表？
 ... Success!

Cleaning up...

All done!  If you‘ve completed all of the above steps, your MariaDB
installation should now be secure.

Thanks for using MariaDB!

mysql -uroot -p //進入數據庫

3.3.2導入數據庫，授權

mysql -u root -p < slsaledb-2014-4-10.sql
mysql -uroot -p

show databases;

GRANT all ON slsaledb.* TO ‘root‘@‘%‘ IDENTIFIED BY ‘abc123‘;    //授予slsaledb數據庫所有表所有權限給root用戶在任意網段登錄，密碼為abc123

flush privileges; 

3.3.3 MySQL主從配置

• mysql主服務器下。

vim /etc/my.cnf

[mysqld]下添加

binlog-ignore-db=mysql,information_schema       //二進制日誌格式
character_set_server=utf8
log_bin=mysql_bin  //開啟二進制日誌
server_id=1  
log_slave_updates=true
sync_binlog=1   //同步日誌

systemctl restart mariadb

netstat -anpt | grep 3306

mysql -u root -p

show master status; //記錄日誌文件名稱和 位置值

+------------------+----------+--------------+--------------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB         |
+------------------+----------+--------------+--------------------------+
| mysql_bin.000001 |      626 |              | mysql,information_schema |
+------------------+----------+--------------+--------------------------+

grant replication slave on *.* to ‘rep‘@‘192.168.144.%‘ identified by ‘123456‘;  //授予主從狀態

flush privileges;

• MySQL從服務器下

vim /etc/my.cnf

[mysqld]下添加

server_id=2

systemctl restart mariadb

netstat -anpt | grep 3306
mysql -u root -p

change master to master_host=‘192.168.144.112‘,master_user=‘rep‘,master_password=‘123456‘,master_log_file=‘mysql_bin.000001‘,master_log_pos=2626;

start slave;

show slave status;

            Slave_IO_Running: Yes
            Slave_SQL_Running: Yes

• 測試主從狀態是否可行，方可進行下一步驟。

3.4部署Redis數據庫緩存層

3.4.1安裝redis

• 很對主從redis數據庫緩存，首先需要安裝redis軟件

yum install -y epel-release //安裝擴展源
yum install redis -y

3.4.2設置主從關系

• 配置主Redis

vim /etc/redis.conf

bind 0.0.0.0   //將監聽網址修改成任意網段

systemctl start redis.service
netstat -anpt | grep 6379

• 測試本身安裝完成能否使用

redis-cli -h 192.168.144.112 -p 6379 //測試連接

192.168.144.112:6379> set name test //設置name 值是test

192.168.144.112:6379> get name //獲取name值

• 配置從Redis

vim /etc/redis.conf

bind 0.0.0.0   //61行，修改監聽地址
...
slaveof 192.168.114.112  6379 //266行下添加主服務器的IP，不是虛擬IP

• 兩臺redis服務器服務重啟

systemctl restart redis.service

• 從服務器上進入redis，發現已經復制完成

redis-cli -h 192.168.144.111 -p 6379
192.168.144.111:6379> get name
"test"

• 至此，redis主從配置完成。

3.4.3配置商城項目中連接redis的參數

• web節點中配置商城項目，指定Redis虛擬IP

vim /usr/local/tomcat8/webapps/SLSaleSystem/WEB-INF/classes/applicationContext-mybatis.xml

      <!--redis 配置 開始-->

         <constructor-arg value="192.168.144.188"/>    //47行
         <constructor-arg value="6379"/>              //48行

3.4.4測試緩存效果

redis-cli -h 192.168.144.188 -p 6379

192.168.175.188:6379> info

keyspace_hits:1  或者 keyspace_misses:2//關註這個值，命中數和未命中數

登錄商城，然後反復點擊需要數據庫參與的操作頁面，再回來檢查keyspace_hits或者keyspace_misses: 值變化。

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