Cdn
Cdn是一个代理缓存服务器。其实就是减少网络中冗余数据的重复传输。Cdn就是将网站内容发布到最接近用户的网络“边缘”，使用户可以就近快速的取得自己想要的内容。在cdn整体部署的时候包括分布式存储，负载均衡，网络重定向。
传统的网络访问方式
Cdn加速
Server2 varnish 关闭防火墙，selinux时disabled状态
Server3 apache
Server4 apache
[root@server2 ~]#yum localinstall -yvarnish-3.0.3-1.el6.x86_64.rpm varnish-libs-3.0.3-1.el6.x86_64.rpm
[root@server2 ~]# vim/etc/varnish/default.vcl ###### 配置一个后端服务器
backend default {
.host = "172.25.137.3"; #########后端的server的ip
.port = "80";
}
sub vcl_deliver { ###########查看缓存命中情况
if (obj.hits > 0) {
set resp.http.X-Cache ="HIT from westos cache";
}
else {
set resp.http.X-Cache ="MISS from westos cache";
}
return (deliver);
}
[root@server2 ~]# vim/etc/sysconfig/varnish ####配置varniash服务器监听端口
VARNISH_LISTEN_PORT=80 ########66行，varnish监听的端口
VARNISH_TTL=60 ########缓存的时间
[root@server2 ~]# /etc/init.d/varnish start
[root@server3 ~]# /etc/init.d/httpd start
[root@server3 html]# vim/var/www/html/index.html 给server3做一个测试页
server3.example.com
浏览器测试页，当访问server2，其实时时访问的后端的server3
[root@foundation137cdn]# curl -I 172.25.137.2 测试缓存
HTTP/1.1200 OK
Server:Apache/2.2.15 (Red Hat)
Last-Modified:Fri, 05 Aug 2016 10:20:17 GMT
ETag:"2087-14-5395069bc66f6"
Content-Type:text/html; charset=UTF-8
Content-Length:20
Accept-Ranges:bytes
Date:Fri, 05 Aug 2016 12:51:41 GMT
X-Varnish:565160603
Age:0
Via:1.1 varnish
Connection:keep-alive
X-Cache:MISS from westos cache
[root@server2varnish]# varnishadm ban.url .*$ 清空缓存
[root@server2varnish]# varnishadm ban.url /index.html 清空页面缓存
定义多个不同域名站点的后端服务器
backend web1 {
.host = "172.25.137.3";
.port = "80";
}
backend web2 {
.host = "172.25.137.4";
.port = "80";
}
当访问www.westos.org域名时从web1上取数据，访问bbs.redhat.org域名时到web2上取数据，其他报错
subvcl_recv {
if (req.http.host ~"^(www.)?westos.org") {
set req.http.host ="www.westos.org";
set req.backend = web1;
}elsif (req.http.host ~ "^bbs.redhat.org") {
set req.backend = web2;
} else {
error 404 "westos cache";
}
}
[root@server2varnish]# /etc/init.d/varnish reload
物理界解析
[root@foundation137~]# vim /etc/hosts
[root@server2~]# vim /etc/varnish/default.vcl
directorIB round-robin{ #######把多个后端聚合为一个组，并检测后端健康状态
{.backend = web1; }
{.backend = web2; }
}
subvcl_recv {
if (req.http.host ~"^(www.)?westos.org") {
set req.http.host ="www.westos.org";
set req.backend = IB; ####后端组
return (pass); ####为了测试方便，不进行缓存
}elsif (req.http.host ~ "^bbs.redhat.org") {
set req.backend = web2;
} else {
error 404 "westos cache";
}
}
[root@server2~]# /etc/init.d/varnish reload
[root@server4html]# vim /etc/httpd/conf/httpd.conf
[root@server4html]# /etc/init.d/httpd restart
[root@server2~]# varnishadm ban.url .*$ 清空缓存
#####varniashcdn推送平台 （推送主要是清空缓存）
需要安装php ，apache
[root@server2~]# yum install -y httpd -y
[root@server2~]# yum install php -y
[root@server2~]# yum install unzip
[root@server2~]# unzip bansys.zip -d /var/www/html/
[root@server2html]# cd bansys/
[root@server2bansys]# mv * ..
[root@server2html]# vim config.php 文件中的多于的可以注释
对于群组的定义值有定义了群组了才能推送（推送是因为当后端服务器内容更新后，cdn里有健康检查，会进行内容推送）
[root@server2html]# vim /etc/httpd/conf/httpd.conf 修改apache监听的端口，因为varnish监听的端口是80，把apache监听端口改为8080
[root@server2html]# /etc/init.d/httpd start
aclwestos { ###########设置控制访问
"127.0.0.1";
"172.25.0.0"/24;
}
backendweb1 {
.host = "172.25.137.3";
.port = "80";
}
backendweb2 {
.host = "172.25.137.4";
.port = "80";
}
directorIB round-robin{
{.backend = web1; }
{.backend = web2; }
}
subvcl_deliver {
if (obj.hits > 0) {
set resp.http.X-Cache = "HITfrom westos cache";
}
else {
set resp.http.X-Cache ="MISS from westos cache";
}
return(deliver);
}
subvcl_recv {
if (req.http.host ~"^(www.)?westos.org") {
set req.http.host ="www.westos.org";
set req.backend = IB;
return (pass);
}elsif (req.http.host ~ "^bbs.redhat.org") {
set req.backend = web2;
} else {
error 404 "westos cache";
}
if (req.request == "BAN") {
if (!client.ip ~ westos) {
error 405 "Notallowed.";
}
ban("req.url ~ " +req.url);
error 200 "banadded";
}
}
[root@server2html]# /etc/init.d/varnish reload
Bansys有两种工作模式，分别是：telnet和http
telnet模式需要关闭 varnish 服务管理端口的验证,注释掉/etc/sysconfig/varnish 文件中的“-S $
{VARNISH_SECRET_FILE}”这行,重启 varnish 服务即可。此实验中是用的http方式
