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为什么要做web cache,我想大家最主要的是解决流量的压力。随着网站流量的提升,如果只是单台机器既处理静态文件,又处理动态脚本,显然效率很难上升,不能处理日益上涨的流量压力。与此同时某些网站的页面内容并不是经常变化,因此我们可以分两层架构来组织网站。前端web缓存+后端web服务器,可以参看这里配置nginx反向代理配置
前端web缓存有多重方式实现,原理就是队请求结果页面静态化并设置一个超时期限,缓存页面过期后,新请求到达时重新到后端web服务器获取内容更新;没有nginx前比较流行的方法是squid,但squid不能充分利用处理器的多核特性,越来越多的网站选用nginx来做前端的web缓存。
要想使用nginx的缓存功能要保证nginx添加了proxy模块。我们可以使用-V选项(大写的V,小写的v是看版本号的)来查看nginx的编译参数。我使用的是默认的参数编译的,如下所示:
[root@bogon ~]# /usr/local/nginx/sbin/nginx -V
nginx version: nginx/1.7.6
built by gcc 4.4.7 20120313 (Red Hat 4.4.7-4) (GCC)
configure arguments: --prefix=/usr/local/nginx --without-http_memcached_module --user=www --group=www --with-http_stub_status_module --with-openssl=/usr/ --with-pcre=/root/tools/pcre-8.36
nginx的所有模块必须在编译的时候添加,不能再运行的时候动态加载,默认的编译选项下包含的模块,如果你不是显示的用参数关闭它。
nginx默认安装的模块如下
模块名称 | 描述 | 版本 | 如何禁用 |
---|---|---|---|
Core | Control ports, locations, error pages, aliases, and other essentials. | --without-http | |
Access | Allow/deny based on IP address. | --without-http_access_module | |
Auth Basic | Basic HTTP authentication. | --without-http_auth_basic_module | |
Auto Index | Generates automatic directory listings. | --without-http_autoindex_module | |
Browser | Interpret "User-Agent" string. | 0.4.3 | --without-http_browser_module |
Charset | Recode web pages. | --without-http_charset_module | |
Empty GIF | Serve a 1x1 image from memory. | 0.3.10 | --without-http_empty_gif_module |
FastCGI | FastCGI Support. | --without-http_fastcgi_module | |
Geo | Set config variables using key/value pairs of IP addresses. | 0.1.17 | --without-http_geo_module |
Gzip | Gzip responses. | --without-http_gzip_module | |
Headers | Set arbitrary HTTP response headers. | ||
Index | Controls which files are to be used as index. | ||
Limit Requests | Limit frequency of connections from a client. | 0.7.20 | --without-http_limit_req_module |
Limit Zone | Limit simultaneous connections from a client. Deprecated in 1.1.8, use Limit Conn Instead. | 0.5.6 | --without-http_limit_zone_module |
Limit Conn | Limit concurrent connections based on a variable. | --without-http_limit_conn_module | |
Log | Customize access logs. | ||
Map | Set config variables using arbitrary key/value pairs. | 0.3.16 | --without-http_map_module |
Memcached | Memcached support. | --without-http_memcached_module | |
Proxy | Proxy to upstream servers. | --without-http_proxy_module | |
Referer | Filter requests based on Referer header. |
--without-http_referer_module | |
Rewrite | Request rewriting using regular expressions. | --without-http_rewrite_module | |
SCGI | SCGI protocol support. | 0.8.42 | --without-http_scgi_module |
Split Clients | Splits clients based on some conditions | 0.8.37 | --without-http_split_clients_module |
SSI | Server-side includes. | --without-http_ssi_module | |
Upstream | For load-balancing. | --without-http_upstream_ip_hash_module (ip_hash directive only) | |
User ID | Issue identifying cookies. | --without-http_userid_module | |
uWSGI | uWSGI protocol support. | 0.8.40 | --without-http_uwsgi_module |
X-Accel | X-Sendfile-like module. |
proxy模块中常用的指令时proxy_pass和proxy_cache.
nginx的web缓存功能的主要是由proxy_cache、fastcgi_cache指令集和相关指令集完成,proxy_cache指令负责反向代理缓存后端服务器的静态内容,fastcgi_cache主要用来处理FastCGI动态进程缓存(这里我不是很清楚这两个指令的区别,好像功能上都差不多,尤其后面这句话的意思,是我翻译过来的)。
确认proxy模块安装好后,下面对nginx的配置文件进行设置,重点部分如标红字体所示。
这是我的nginx.conf配置文件。
user www-data;
worker_processes 1;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid logs/nginx.pid;
events {
worker_connections 1024;
}
http {
include 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" "$host"‘;
#access_log logs/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#Compression Settings
gzip on;
gzip_http_version 1.0;
gzip_comp_level 2;
gzip_proxied any;
gzip_min_length 1100;
gzip_buffers 16 8k;
gzip_types text/plain text/css application/x-javascript text/xml application/xml application/xml+rss text/javascript;
# Some version of IE 6 don‘t handle compression well on some mime-types,
# so just disable for them
gzip_disable "MSIE [1-6].(?!.*SV1)";
# Set a vary header so downstream proxies don‘t send cached gzipped
# content to IE6
gzip_vary on;
#end gzip
#cache begin
proxy_buffering on;
proxy_cache_valid any 10m;
proxy_cache_path /data/cache levels=1:2 keys_zone=my-cache:8m max_size=1000m inactive=600m;
proxy_temp_path /data/temp;
proxy_buffer_size 4k;
proxy_buffers 100 8k;
#cache end
## Basic reverse proxy server ##
## Apache (vm02) backend for www.example.com ##
upstream apachephp {
server www.quancha.cn:8080; #Apache1
}
## Start www.quancha.cn ##
server {
listen 80;
server_name *.quancha.cn;
access_log logs/quancha.access.log main;
error_log logs/quancha.error.log;
root html;
index index.html index.htm index.php;
## send request back to apache1 ##
location / {
proxy_pass http://apachephp;
proxy_cache my-cache;
proxy_cache_valid 200;
#Proxy Settings
proxy_redirect off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
proxy_max_temp_file_size 0;
proxy_connect_timeout 90;
proxy_send_timeout 90;
proxy_read_timeout 90;
proxy_buffer_size 4k;
proxy_buffers 4 32k;
proxy_busy_buffers_size 64k;
proxy_temp_file_write_size 64k;
##End Proxy Settings
}
}
## End www.quancha.cn ##
}
配置文件中以proxy_开头的指令我们大都可以字面意思得到理解。请务必注意一点proxy_cache_path和proxy_temp_path设置的目录需要在同一分区,因为它们之间是硬链接的关系。
最后启动nginx,来迎接着激动人心的时刻吧。我已经迫不及待了。如果文章哪里有问题或者你遇到了什么麻烦,可以留言让我知道。
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原文地址:http://www.cnblogs.com/jenqz/p/4635164.html