lunhuishizhe 2013-09-10
Varnish是一款强大的反向代理加速软件,关于其工作原理可以参考上图,其具体流程及VCL语法我这里就不做说明,网上资料多,大家还可以对照参考其官方网站和《Varnish中文权威指南》。
Varnish中文权威指南 PDF 下载
具体下载目录在 /2013年资料/9月/10日/CentOS 5.8下Varnish-2.1.5的安装配置
相关阅读:
一、安装CentOS5.8系统环境下的依耐关系
12 yum install gcc gcc-c++
yum install automake autoconflibtool ncurses-devel libxslt groff pcre-devel pkgconfig libtool -y
二、下载varnish-2.1.5源码包,并进行编译安装。
cd /usr/local/src
wget http://repo.varnish-cache.org/source/varnish-2.1.5.tar.gz
tar zxvf varnish-2.1.5.tar.gz
cd varnish-2.1.5.
./autogen.sh
#autogen.sh命令是用来检查软件的依耐关系是否满足,如果报错的话, 则应该如下
正常所示:
+ aclocal
+ libtoolize --copy --force
+ autoheader
+ automake --add-missing --copy --foreign
+ autoconf
继续编译安装:
12 ./configure --prefix=/usr/local/varnish --enable-dependency-tracking --enable-debugging-symbols --enable-developer-warnings -enable-extra-warnings
make && make install && cd ../
三、创建varnish用户和组,以及varnish缓存文件和日志存放目录:
/usr/sbin/groupadd varnish
/usr/sbin/useradd -s /sbin/nologin -g varnish varnish
mkdir -p /data/varnish/{cache,log}
chown -R varnish:varnish /data/varnish/{cache,log}
四、我的测试环境是两台Web机器,IP为192.168.1.103(域名为http://www.linuxidc.net)的varnish机器对后端IP为192.168.1.104和192.168.1.105的机器进行反向代理加速,其配置文件/usr/local/varnish/etc/varnish/better.vcl如下所示:
backend rserver1
{
.host ="192.168.1.104";
.port = "80";
.probe = {
.timeout = 5s; #等待多长时间超时
.interval = 2s; #检查时间间隔
.window = 10; #varnish将维持10个sliding windows的结果
.threshold = 8; #如果是8次.windows检查是成功的,就宣告后端的Web机器
是健康的
}
}
backend rserver2
{
.host ="192.168.1.105";
.port = "80";
.probe = {
.timeout = 5s;
.interval = 2s;
.window = 10;
.threshold = 8;
}
}
#指定一个名为realserver组,使用random机制,权重越大,分配的访问越多,可根据
服务器性能来设定;而round-robin(轮询)机制是不能指定weight的
director realserver random {
{
.backend = rserver1;
.weight = 5;
}
{
.backend = rserver2;
.weight = 6;
}
}
#定义能清理缓存的机器,这里只允许本机能用purge的方式清理
acl purge {
"localhost";
"127.0.0.1";
}
sub vcl_recv
{
if (req.http.host ~"^(.*).linuxidc.net")
{
set req.backend =realserver;
}
else
{
error 200 "Nocahce for this domain";
}
if (req.request =="PURGE")
{
if (!client.ip ~purge)
{
error 405"Not allowed.";
}
else
{
return (pipe);
}
}
#获取客户端真实IP地址
if(req.http.x-forwarded-for)
{
set req.http.X-Forwarded-For =
req.http.X-Forwarded-For "," client.ip;
}
else
{
set req.http.X-Forwarded-For =client.ip;
}
#对HTTP协议中的GET、HEAD请求进行缓存,对POST请求透过,让其直接访问后端Web服
务器。之所以这样配置,是因为POST请求一般是发送数据给服务器的,需要服务器接
收、处理,所以不缓存;
if (req.request !="GET" && req.request != "HEAD")
{
return (pipe);
}
if (req.http.Expect)
{
return (pipe);
}
if (req.http.Authenticate|| req.http.Cookie)
{
return (pass);
}
if (req.http.Cache-Control~ "no-cache")
{
return (pass);
}
#对JSP或者PHP文件不缓存
if(req.url ~"\.jsp" || req.url ~ "\.php" )
{
return (pass);
}
else
{
return (lookup);
}
}sub vcl_pipe
{
return (pipe);
}sub vcl_pass
{
return (pass);
}sub vcl_hash
{
set req.hash += req.url;
if (req.http.host)
{
set req.hash +=req.http.host;
}
else
{
set req.hash +=server.ip;
}
return (hash);
}sub vcl_hit
{
if (req.request =="PURGE")
{
set obj.ttl = 0s;
error 200"Purged.";
}
if (!obj.cacheable)
{
return (pass);
}
return (deliver);
}sub vcl_miss
{
if (req.request =="PURGE")
{
error 404 "Not incache.";
}
if (req.http.user-agent ~"spider")
{
error 503 "Notpresently in cache";
}
return (fetch);
}
sub vcl_fetch
{
if (req.request =="GET" && req.url ~ "\.(txt|js)$")
{
set beresp.ttl = 3600s;
}
else
{
set beresp.ttl = 30d;
}
if (!beresp.cacheable)
{
return (pass);
}
if (beresp.http.Set-Cookie)
{
return (pass);
}
return (deliver);
}
sub vcl_deliver {
if (obj.hits > 0) {
set resp.http.X-Cache= "HIT FROM www.linuxidc.net";
} else {
set resp.http.X-Cache= "MISS FROM www.linuxidc.net";
}
return (deliver);
}