一、原理

用server1当作缓存的&＃xff0c;主机请求server1&＃xff0c;server1通过varnish设置&＃xff0c;访问server2&＃xff0c;将server2信息缓存下来&＃xff0c;显示给主机&＃xff0c;server1 起到一个缓存效果。

二、配置过程

1.安装varnish&＃xff0c;获得如下安装包

并且在你做缓存的主机上安装它们

2.步骤&＃xff1a;

(1)server1配置&＃xff1a;
vim /etc/sysconfig/varnish
 

VARNISH_LISTEN_PORT&＃61;80 配置varnish服务端口&＃xff0c;主机在访问的时候就不需要输入端口号&＃xff0c;因为http端口就是80

/etc/init.d/varnish start  打开varnish服务

vim /etc/varnish/default.vcl
 

backend default { #配置后端服务器&＃xff08;请求缓存的主机server2&＃xff09;.host &＃61; "172.25.39.2";.port &＃61; "80";
}
sub vcl_deliver { #查看缓存命中情况&＃xff0c;若有缓存&＃xff0c;就得到&＃xff0c;没有就miss&＃xff0c;缓存刷新时间为120s
if (obj.hits > 0) {
set resp.http.X-Cache &＃61; "HIT from westos cache";
}
else {
set resp.http.X-Cache &＃61; "MISS from westos cache"
}
return (deliver);
}

/etc/init.d/varnish reload  #重启varnish服务

netstat -antlp  查看server1端口开向主机
(2)后台主机server2配置:

安装httpd服务  
 

yum install httpd -y
/etc/init.d/httpd start
cd /var/www/html
vim index.html


server2


curl localhost 查看http配置是否正确
netstat -antl 查看实际访问自己的是谁

(3)250主机&＃xff08;访问主机&＃xff09;&＃xff1a;

curl -I 172.25.39.1 访问server1&＃xff0c;其实server1从server2缓存数据&＃xff0c;显示给主机

三、定义多个不同域名站点的后端服务器

1.server1配置&＃xff0c;加一台server3&＃xff0c;输入不同的域名&＃xff0c;从不同的服务器缓存

server3操作如图&＃xff1a;

vim /etc/sysconfig/varnish
backend web1 {.host &＃61; "172.25.39.2";.port &＃61; "80";
}
backend web2 { .host &＃61; "172.25.39.3";.port &＃61; "80";
}sub vcl_recv {
if (req.http.host ~ "^(www.)?westos.org") {
set req.http.host &＃61; "www.westos.org";
set req.backend &＃61; web1; #当访问www.westos.org域名时&＃xff0c;从web1上取数据
}elsif (req.http.host ~ "^bbs.westos.org") {
set req.backend &＃61; web2; #当访问bbs.westos.org域名时&＃xff0c;从web2上取数据
}else {error 404 "westos cache"; #访问其他页面显示报错
}
}sub vcl_deliver {
if (obj.hits > 0) {
set resp.http.X-Cache &＃61; "HIT from westos cache";
}
else {
set resp.http.X-Cache &＃61; "MISS from westos cache";
}
return (deliver);
}

测试主机配置如图&＃xff1a;

四、限定参数

1.vim  /etc/sysconfig/varnish

NFILES&＃61;65535 # Locked shared memory (for ulimit -l)
# Default log size is 82MB &＃43; header
MEMLOCK&＃61;82000# Maximum number of threads (for ulimit -u)
NPROCS&＃61;"unlimited"

2.vim  /etc/security/limits.conf

varnish - nofile 65535
varnish - memlock 82000
varnish - nproc unlimited

3.sysctl -a | grep file
4.cat /etc/passwd  查看varnish用户的密码和所属shell
5.usermod -s /bin/bash  varnish
6.su - varnish
7.ulimit -n
8.ulimit -l

五、清理缓存

varnishadm ban.url /index.html  清理此文件缓存
varnishadm ban.url .*$          清理全部缓存&＃xff08;慎做&＃xff09;
varnishadm ban.url /admin/$     清理admin目录缓存

六、把多个后端聚合成一个组&＃xff0c;并检测后端健康情况

1.vim  /etc/sysconfig/varnish

director lb round-robin {{ .backend &＃61; web1; } #当主机web1挂掉&＃xff08;stop&＃xff09;&＃xff0c;就访问web2&＃xff0c;不挂掉&＃xff0c;进行轮询{ .backend &＃61; web2; } #访问到web2时访问的是www.westos.org
}
sub vcl_recv {
if (req.http.host ~ "^(www.)?westos.org") {
set req.http.host &＃61; "www.westos.org";
set req.backend &＃61; lb; #当访问www.westos.org时&＃xff0c;web1和web2进行轮询显示
return (pass); #为了测试方便&＃xff0c;不进行缓存&＃xff0c;浏览器就会轮询显示不同的页面
}elsif (req.http.host ~ "^bbs.westos.org") {
set req.backend &＃61; web2;
}else {error 404 "westos cache";
}
}

2.server3设置apache虚拟主机&＃xff0c;不同域名访问的页面不一样
 

vim /etc/httpd/conf/httpd.conf
NameVirtualHost *:80DocumentRoot /var/www/htmlServerName bbs.westos.org

DocumentRoot /wwwServerName www.westos.org
mddir /www
cd /www
vim index.html


www.westos.org-server3

3.测试&＃xff1a;

curl www.westos.org
curl bbs.westos.org
显示结果为不同的页面&＃xff0c;表示虚拟主机配置成功CD

七、CDN推送管理

cd pub/docs/varnish/ #在老师的主机上下载bansys,zip
get bansys.zip
yum install unzip -y #安装解压命令unzip
yum install php -y #安装php&＃xff0c;因为cdn是php的一个页面
unzip bansys.zip #解压bansys.zip文件
cd bansys #切换到bansys目录
mv * /var/www/html/ #将解压的东西移动到/var/www/html目录下vim /etc/httpd/conf/httpd.conf #编辑httpd配置文件&＃xff0c;改一下端口为8080
listen 8080vim config.php #修改此文件内容如下
前面没用的可以删掉
$var_group1 &＃61; array(&＃39;host&＃39; &＃61;> array(&＃39;172.25.39.1&＃39;),&＃39;port&＃39; &＃61;> &＃39;80&＃39;,);//varnish群组定义//对主机列表进行绑定$VAR_CLUSTER &＃61; array(&＃39;www.westos.org&＃39; &＃61;> $var_group1,);/etc/init.d/httpd start #重启httpd服务

若不修改http文件里面的80端口会出现以下错误&＃xff1a;

若修改了&＃xff0c;结果为&＃xff1a;

vim /etc/varnish/default.vcl
acl westos { #设置访问控制
"127.0.0.1";
"172.25.0.0"/24;
}backend web1 {.host &＃61; "172.25.39.2";.port &＃61; "80";
}
backend web2 {.host &＃61; "172.25.39.3";.port &＃61; "80";
}
director lb round-robin {{ .backend &＃61; web1; }{ .backend &＃61; web2; }
}sub vcl_recv {
if (req.request &＃61;&＃61; "BAN") {
if (!client.ip ~ westos) {
error 405 "Not allowed";
}
ban("req.url ~" &＃43; req.url);
error 200 "ban added";
}
if (req.http.host ~ "^(www.)?westos.org") {
set req.http.host &＃61; "www.westos.org";
set req.backend &＃61; lb;
}elsif (req.http.host ~ "^bbs.westos.org") {
set req.backend &＃61; web2;
}else {error 404 "westos cache";
}
}
sub vcl_deliver {
if (obj.hits > 0) {
set resp.http.X-Cache &＃61; "HIT from westos cache";
}
else {
set resp.http.X-Cache &＃61; "MISS from westos cache";
}
return (deliver);
}/etc/init.d/varnish reload #重启varnish服务

推送后就清理缓存&＃xff0c;访问www.westos.org就会出现轮询现象