varnish 项目实战

1、工作原理

在当前主流的Web服务架构体系中，Cache担任着越来越重要的作用。常见的基于浏览器的C/S架构，Web Cache更是节约服务器资源的关键。而最近几年由FreeBSD创始人之一Kamp开发的varnish更是一个不可多得的Web Cache Server。严格意义上说，Varnish是一个高性能的反向代理软件，只不过与其出色的缓存功能相比，企业更愿意使用其搭建缓存服务器。同时，由于其工作在Web Server的前端，有一部分企业已经在生产环境中使用其作为旧版本的squid的替代方案，以在相同的服务器成本下提供更好的缓存效果，Varnish更是作为CDN缓存服务器的可选服务之一。

Varnish主要有以下几点特性：

1.缓存位置：可以使用内存也可以使用磁盘。如果要使用磁盘的话推荐SSD做RAID1

2.日志存储：日志也存储在内存中。存储策略：固定大小，循环使用

3.支持虚拟内存的使用。

4.有精确的时间管理机制，即缓存的时间属性控制。

5.状态引擎架构：在不同的引擎上完成对不同的缓存和代理数据进行处理。可以通过特定的配置语言设计不同的控制语句，以决定数据在不同位置以不同方式缓存。类似于netfilter中的钩子，在特定的地方对经过的报文进行特定规则的处理。

6.缓存管理：以二叉堆格式管理缓存数据，做到数据的及时清理。

摘自:  http://blog.51cto.com/12205781/2049222

2、Keepalived + Haproxy + Varnish + LNMP 实战

2.1、架构拓扑

2.2、设备列表

Name	IP	Role	remark
Node01	192.168.1.233, vip:192.168.1.100	Haproxy master	Keepalived
Node02	192.168.1.111, vip:192.168.1.100	Haproxy backup	Keepalived
Node03	192.168.1.178	Varnish	agency
Node04	192.168.1.242	Web	Lnmp
Node05	192.168.1.128	Web	Lnmp

2.3、服务安装

2.3.1、Node4,Node5 上安装LNMP服务

rpm –ivh  http://nginx.org/packages/centos/7/noarch/RPMS/nginx-release-centos-7-0.el7.ngx.noarch.rpm
yum -y install nginx mariadb-server php-fpm php-mysql

优化nginx配置

vim /etc/nginx/nginx.conf

user nginx;
worker_processes 1;

error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;

events {
   worker_connections 65535;             
}

http {
   include /etc/nginx/mime.types;
   default_type application/octet-stream;

log_format main '$remote_addr - $remote_user [$time_local] "$request" '
   '$status $body_bytes_sent "$http_referer" '
   '"$http_user_agent" "$http_x_forwarded_for"';

access_log /var/log/nginx/access.log main;

sendfile on;           #启动高效传输文件的模式
   tcp_nopush on;         #包累计到一定大小后发送
   tcp_nodelay on;        #开启 关闭延迟发送

keepalive_timeout 60;      #设定保持长连接超时时长
   client_header_timeout 10;    #设置请求头的超时时间
   client_body_timeout 10;        #设置请求体的超时时间
   reset_timedout_connection on;   #告诉nginx关闭不响应的客户端连接
   send_timeout 10;           #响应客户端超时时间，这个超时时间仅限于两个活动之间的时间，如果超过这个时间，客户端没有任何活动，nginx关闭连接

#limit_conn_zone $binary_remote_addr zone=addr:5m;    
   #limit_conn addr 100;

gzip on;

include /etc/nginx/conf.d/*.conf;
}

vim /etc/nginx/conf.d/default.conf

server {
   listen 80;
   server_name website.com;

location / {
   root /usr/share/nginx/html;
   index index.php index.html index.htm;

location ~ \.php$ {
   root html;
   fastcgi_pass 127.0.0.1:9000;
   fastcgi_index index.php;
   fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
   include fastcgi_params;
}

检查语法配置与启动服务

ngint -t
systemctl restart nginx

查看系统文件描述符数量
ulimit -n
修改
ulimit -n 65535

修改php-fpm

vim /etc/php.ini
date.timezone = Asia/Shanghai
short_open_tag = On        #允许短标签, php语法中可用短标签

启动服务

systemctl start nginx
systemctl start mariadb
systemctl start php-fpm

systemctl enable nginx
systemctl enable mariadb
systemctl enable php-fpm

2.3.2、node01,node02 haproxy & keepalived服务安装

yum install haproxy -y
yum install keepalived -y

配置haproxy, (frontend , backend , listen)

vim /etc/haproxy/haproxy.cfg

frontend web
bind *:80

default_backend varnish-server

backend varnish-server
balance roundrobin
server varnishserver 192.168.1.178:6081 check inter 3000 rise 3 fall 5

listen admin
bind :9527
stats enable
stats uri /haproxyadmin
stats auth admin:admin
stats refresh 20s
stats admin if TRUE

启动服务

systemctl start haproxy
systemctl enable haproxy

配置keepalived

node01

 vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   notification_email {
      root@localhost
   }
   notification_email_from root@localhost
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id keepalived_haproxy
}

vrrp_script chk_haproxy {
   script "killall -0 haproxy"
   interval 2
   fall 2
   rise 2
   weight -4
}

vrrp_instance VI_1 {
   state MASTER
   interface enp0s8
   virtual_router_id 170
   priority 100
   advert_int 1
   authentication {
      auth_type PASS
      auth_pass keer
   }
virtual_ipaddress {
   192.168.1.100
}
track_script {
   chk_haproxy
}

node02 修改对应 state,priority,

启动服务

systemctl start keepalived
systemctl enable keepalived

2.3.3 node03 varnish配置

yum install epel-release
yum install varnish –y

修改配置文件

vim /etc/varnish/varnish.params    #进程配置文件

VARNISH_ADMIN_LISTEN_PORT=6082  
VARNISH_STORAGE="file,/data/cache,1G"    # 缓存在本地磁盘

vim /etc/varnish/default.vcl  #总配置文件

①定义一个健康监测：

vcl 4.0; #指定版本 import directors; #加载后端的轮询模块
probe backend_healthcheck { #设置名为backend_healthcheck的健康监测
 .url = "/index.html";
 .window = 5;
 .threshold = 2; 
 .interval = 3s;
 .timeout = 1s;
}

② 设置后端server：
backend web1 {
 .host = "192.168.1.242";   #node04 ip
 .port = "80";
 .probe = backend_healthcheck;
}
backend web2 {
 .host = "192.168.1.128";     #node05 ip
 .port = "80";
 .probe = backend_healthcheck;
}

③ 配置后端集群事件:
sub vcl_init {
 new img_cluster = directors.round_robin();
 img_cluster.add_backend(web1);
 img_cluster.add_backend(web2);
}
acl purgers { # 定义可访问来源IP,权限控制
 "127.0.0.1";
 "192.168.0.0"/16;
}

sub vcl_recv {
# Happens before we check if we have this in cache already.
#
# Typically you clean up the request here, removing cookies you don't need,
# rewriting the request, etc.
   if (req.method == "GET" && req.http.cookie) {
      return(hash); //处理完recv 引擎，给下一个hash引擎处理
   }
   if (req.method != "GET" &&
   req.method != "HEAD" &&
   req.method != "PUT" &&
   req.method != "POST" &&
   req.method != "TRACE" &&
   req.method != "OPTIONS" &&
   req.method != "PURGE" &&
   req.method != "DELETE") {
   return (pipe); #除了上边的请求头部，通过通道直接扔后端的pass
   }

   if (req.url ~ "index.php") {
      return(pass);
   }

   if (req.method == "PURGE") { #PURGE请求的处理的头部，清缓存
      if (client.ip ~ purgers) {
         return(purge);
      }
   }

   if (req.http.X-Forward-For) { #为发往后端主机的请求添加X-Forward-For首部
      set req.http.X-Forward-For = req.http.X-Forward-For + "," + client.ip;
   } 
   else {
      set req.http.X-Forward-For = client.ip;
   }
   return(hash);
}

sub vcl_backend_response {
# Happens after we have read the response headers from the backend.
#
# Here you clean the response headers, removing silly Set-Cookie headers
# and other mistakes your backend does.
   if (bereq.url ~ "\.(jpg|jpeg|gif|png)$") {
      set beresp.ttl = 30d;
   }
   if (bereq.url ~ "\.(html|css|js)$") {
   set beresp.ttl = 7d;
   }
   if (beresp.http.Set-Cookie) { #定义带Set-Cookie首部的后端响应不缓存，直接返回给客户端
   set beresp.grace = 30m;
   return(deliver);
   }
}

sub vcl_deliver {
# Happens when we have all the pieces we need, and are about to send the
# response to the client.
#
# You can do accounting or modifying the final object here.

   if (obj.hits > ) { #为响应添加X-Cache首部，显示缓存是否命中
      set resp.http.X-Cache = "HIT from " + server.ip;
   } 
   else {
      set resp.http.X-Cache = "MISS";
   }
   unset resp.http.X-Powered-By; #取消显示php框架版本的header头
   unset resp.http.Via; #取消显示varnish的header头
   unset resp.http.Server;
   unset resp.http.X-Drupal-Cache;
   unset resp.http.Link;
   unset resp.http.X-Varnish;
}

sub vcl_hash {
   hash_data(req.url);
}

启动服务

service varnish start
service enable start

测试

Varnish服务器上查看

varnishstat