开源 Ubuntu nginx Windows linux命令 linux php Firefox 程序员 shell google centos mysql apache 微软 java Android Python wordpress HTML5

CentOS5.8下varnish-2.1.5的安装配置

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

一、安装CentOS5.8系统环境下的依耐关系

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:

./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.yuhongchun027.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 ~"^(.*).yuhongchun027.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.yuhongchun027.net";
 } else {
   set resp.http.X-Cache= "MISS FROM www.yuhongchun027.net";
 }
return (deliver);
}

五、启动varnish的命令很长,如下所示:

/usr/local/varnish/sbin/varnishd -n /data/varnish/cache -f
/usr/local/varnish/etc/varnish/better.vcl -a 0.0.0.0:80 -s
file,/data/varnish/varnish_cache.data,8G  -p user=varnish -p group=varnish
-p default_ttl=14400 -p thread_pool_max=8000 -p send_timeout=20 -w
5,51200,30 -T 127.0.0.1:3500  -p /usr/local/varnish/var/varnish.pid

验证其是否生效可以用curl –I命令,如下所示:

[root@localhost cache]# curl -I http://www.yuhongchun027.net/

以下结果显示varnish缓存已经起作用了:

HTTP/1.1 200 OK
Server: Apache/2.2.3 (CentOS)
last-Modified: Wed, 28 Aug 2013 16:27:33 GMT
ETag: "10d242-e-776b6740"
Content-type: text/html; charset=UTF-8
Content-Length: 14
date: Wed, 21 Aug 2013 17:47:48 GMT
X-Varnish: 1584727079 1584726982
Age: 10101
Via: 1.1 varnish
Connection: keep-alive
X-Cache: HIT  FROM www.yuhongchun027.net

六、如果vcl配置文件发生改动,想要不重启而直接reload,可以用如下操作,可以在本机上进行telnet操作,连接3500管理端口:

telnet 127.0.0.1 3500
vcl.load newconfig /usr/local/varnish/etc/varnish/better.vcl
200 13 
VCL compiled.
vcl.use newconfig
200 0

如果显示有200字样,则表示已经正常reload了,newconfig这个名字是自己定义的,熟悉varnish操作的朋友应该也清楚,通过telnet连接本机还可以进行清理缓存。

七、用varnishadm命令来清理缓存,例子如下所示:

清除所有缓存

/usr/local/varnish/bin/varnishadm -T 192.168.1.103:3500 url.purge *$

清除image目录下所有缓存

/usr/local/varnish/bin/varnishadm -T 192.168.1.103:3500 url.purge /image/

查看最近清除的详细url列表,可执行如下命令:

/usr/local/varnish/bin/varnishadm –T 192.168.1.103:3500 purge.list

另外,缓存命中率的高低直接说明了varnish的运行状态和效果,如果缓存率命中率过低,我们应该对varnish配置进行检查调整来进行提高,查看其命中率命令如下所示:

/usr/local/varnish/bin/varnishstat -n /data/varnish/cache

八、内核优化如下所示:

编辑/etc/sysctl.conf,添加如下选项:

net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.ip_local_port_range = 1024 65000
net.ipv4.tcp_max_syn_backlog = 8192
net.ipv4.tcp_max_tw_buckets = 5000
net.ipv4.tcp_max_syn_backlog = 65536
net.core.netdev_max_backlog =  32768
net.core.somaxconn = 32768
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_synack_retries = 2
net.ipv4.tcp_syn_retries = 2
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_max_orphans = 3276800

执行如下命令,让改动配置立即生效:

/sbin/sysctl –p

注意:老生常谈的ulimit的问题,这个话题说得太多了,这里实在不想再提了,记得将在/etc/rc.local添加如下内容:

ulimit –SHn 65535

注意:记得在启动varnish之前将此命令手动执行一遍(最方便的做法是放进经常运行的监控脚本或服务启动脚本),另外,在工作中发现,CentOS6.X x86_64下更改ulimit跟CentOS5.X x86_64是不同的,这点也请大家注意。以上即为varnish-2.1.5在CentOS5.8 x86_64下的安装配置过程,记录下作为工作笔记,方便以后在新机器上部署,年纪大了,起个备忘作用而矣。

延伸阅读

评论