Varnsih调用多台后端主机

author：JevonWei
版权声明：原创作品

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Varnsih调用多个后端主机

环境

Varnish      192.168.198.139
图片服务端    192.168.198.120
程序服务端    192.168.198.128

程序服务端(httpd+php)

[root@danran /]# yum -y install httpd php
[root@danran /]# vim /var/www/html/index.html
    <h1> Test Page @BE Server
[root@danran /]# vim //var/www/html/index.php
<?php
    phpinfo();
?>
[root@danran /]# systemctl start httpd
[root@danran /]# setenforce 0
[root@danran /]# iptables -F
[root@danran /]# ss -ntl  

图片服务端(nginx，epel源)

[root@centos6 ~]# yum -y install nginx \epel源
[root@centos6 ~]# vim /etc/nginx/conf.d/default.conf  \修改默认的网页根文件
    server {
        root /data/web/images;
    }
[root@centos6 ~]# mkdir /data/web/images -pv
[root@centos6 ~]# find /usr/share/ -iname "*.jpg" -exec cp {} /data/web/images/ ; \复制一些图片到/data/web/images目录下做测试用
[root@centos6 ~]# service nginx start
[root@centos6 ~]# iptables -F

vernish(epel源)

[root@danran ~]# yum -y install varnish  
[root@danran varnish]# vim /etc/varnish/varnish.params
    VARNISH_LISTEN_PORT=80 \监听端口为80，默认为6081
    VARNISH_ADMIN_LISTEN_ADDRESS=127.0.0.1 \监听管理接口的IP，默认为本机
    VARNISH_ADMIN_LISTEN_PORT=6082 \管理接口的端口，默认为6082
    VARNISH_SECRET_FILE=/etc/varnish/secret \认证密码文件
    #DAEMON_OPTS="-p thread_pool_min=5 -p thread_pool_max=500 -p thread_pool_timeout=300" \定义运行时参数
[root@danran varnish]# vim /etc/varnish/default.vcl
    backend appsrv1 {  \定义appsrv1用来存放网页文件
        .host = "192.168.198.128";
        .port = "80";
    }
    backend imgsrv1 { \定义imgsrv1用来存放图片等静态文件
        .host = "192.168.198.120";
        .port = "80";
    }
    
    sub vcl_recv {
        if (req.url ~ "(?i).(jpg|jpeg|png|gif|svg)$") {
            set req.backend_hint = imgsrv1;
        } else {
            set req.backend_hint = appsrv1;
        }
    }
    
[root@danran varnish]# systemctl start varnish

client

[root@danran ~]# curl 192.168.198.139/index.html
<h1> Test Page @BE Server  \数据来自程序服务端
[root@danran ~]# curl 192.168.198.139/cloud.jpg  数据来自图片服务端

Varnish调用后端服务器组

Director配置后端服务组

将图片保存在后端的图片服务器组中，多台图片服务器组成图片服务器组
受条件限制，在此创建一个虚拟主机做物理主机使用，虚拟主机使用8080端口，从而使虚拟主机的8080端口和原有的80端口组成我们需要的后端图片服务器组

图片服务端创建虚拟主机

[root@centos6 ~]# vim /etc/nginx/conf.d/vhost2.conf
    server {
        listen 8080;
        server_name img1.danran.com;
        root "/data/web/image2";
    }  
[root@centos6 ~]# vim /data/web/image2/test.txt  
Image Server 2

[root@centos6 ~]# nginx -t
[root@centos6 ~]# nginx -s reload

80和8080两个端口作为两个物理主机使用，从而构建服务器组
[root@centos6 ~]# ss -ntl  
State       Recv-Q Send-Q              Local Address:Port                Peer Address:Port 
LISTEN      0      128                            :::52622                         :::*     
LISTEN      0      128                            :::111                           :::*     
LISTEN      0      128                             *:111                            *:*     
LISTEN      0      128                             *:8080                           *:*     
LISTEN      0      128                            :::80                            :::*     
LISTEN      0      128                             *:80                             *:*  

Vernish

[root@danran ~]# vim /etc/varnish/default.vcl  
    导入directors模块
    import directors; 
    
    定义一个app程序后端服务器
    backend appsrv1 {
        .host = "192.168.198.128";
        .port = "80";
    }

    定义两个图片服务端
    backend imgsrv1 {
        .host = "192.168.198.120";
        .port = "80";
    }
    backend imgsrv2 {
        .host = "192.168.198.120";
        .port = "8080";
    }

    定义一个图片服务器组imgsrvs，并将imgsrv1和imgsrv2两个后端图片服务器添加进imgsrvs组中
    sub vcl_init {
        new imgsrvs =  directors.round_robin();  \指定调度算法为轮询
        imgsrvs.add_backend(imgsrv1);
        imgsrvs.add_backend(imgsrv2);
    }
    
    sub vcl_recv {
        if (req.url ~ "(?i).(jpg|jpeg|png|gif|svg|txt)$") {
            set req.backend_hint = imgsrvs.backend();
        } else {
            set req.backend_hint = appsrv1;
        }
    }
[root@danran ~]# varnish_reload_vcl    \重新加载/etc/varnish/default.vcl参数文件

client(imgsrv1和imgsrv2轮询调度)

[root@danran ~]# curl 192.168.198.139/test.txt
Image Server 1
[root@danran ~]# curl -I 192.168.198.139/test.txt
HTTP/1.1 200 OK
Server: nginx/1.10.2
Date: Tue, 23 May 2017 04:16:31 GMT
Content-Type: text/plain
Content-Length: 15
Last-Modified: Tue, 23 May 2017 04:11:20 GMT
ETag: "5923b668-f"
X-Varnish: 32831 67
Age: 37
Via: 1.1 varnish-v4
X-Cache: Hit via 192.168.198.139
Connection: keep-alive

Vernish清除缓存 
[root@danran ~]# curl -X PURGE 192.168.198.139/test.txt
<!DOCTYPE html>
<html>
    <head>
        <title>200 Purged</title>
    </head>
    <body>
        <h1>Error 200 Purged</h1>
        <p>Purged</p>
        <h3>Guru Meditation:</h3>
        <p>XID: 71</p>
        <hr>
        <p>Varnish cache server</p>
    </body>
</html>
[root@danran ~]# curl 192.168.198.139/test.txt   
Image Server 2

基于cookie的session sticky

Vernish

[root@danran ~]# vim /etc/varnish/default.vcl    
    导入directors模块
    import directors; 
    
    定义一个app程序后端服务器
    backend appsrv1 {
        .host = "192.168.198.128";
        .port = "80";
    }

    定义两个图片服务端
    backend imgsrv1 {
        .host = "192.168.198.120";
        .port = "80";
    }
    backend imgsrv2 {
        .host = "192.168.198.120";
        .port = "8080";
    }
    
    sub vcl_init {
        new h = directors.hash();
        h.add_backend(imgsrv1, 1);   // backend 'imgsrv1' with weight '1'
        h.add_backend(imgsrv2, 1);   // backend 'imgsrv2' with weight '1'
    }

    sub vcl_recv {
    // pick a backend based on the cookie header of the client
        set req.backend_hint = h.backend(req.http.cookie);
    }