研究了2天的nginx缓存 出现各种报错
我把配置文件修改过后还是报错
location ~ /purge(/.*) 
                { 
                allow          127.0.0.1; 
                allow          192.168.0.0/24; 
                deny            all; 
                proxy_cache_purge      cache_one  $host$1$is_args$args; 
                }

nginx: [emerg] unknown directive "proxy_cache_purge" in /home/data/websrv/nginx/conf/nginx.conf:75

nginx: [emerg] unknown directive "proxy_cache_purge

报错提示
发现模块没有安装，有的重新安装模块
安装 ngx_cache_purge-1.3.tar
wget http://labs.frickle.com/files/ngx_cache_purge-2.0.tar.gz 
tar -zxvf ngx_cache_purge-2.0.tar.gz 
cd /home/data/install/lnmp/nginx-1.0.15/ 
查看版本 
nginx -V

[root@ceshi nginx-1.0.15]# /home/data/websrv/nginx/sbin/nginx -V 
nginx version: nginx/1.0.15 
configure arguments: --prefix=/home/data/websrv/nginx --with-http_stub_status_module

啥配置都没 所以只能重新编译
./configure --user=nginx --group=nginx --add-module=/home/data/install/ngx_cache_purge-2.0 \ 
 --prefix=/home/data/websrv/nginx --with-http_stub_status_module --with-http_ssl_module 
加模块 
onfiguration summary 
  + using system PCRE library 
  + using system OpenSSL library 
  + md5: using OpenSSL library 
  + sha1: using OpenSSL library 
  + using system zlib library 
  nginx path prefix: "/home/data/websrv/nginx"
  nginx binary file: "/home/data/websrv/nginx/sbin/nginx"
  nginx configuration prefix: "/home/data/websrv/nginx/conf"
  nginx configuration file: "/home/data/websrv/nginx/conf/nginx.conf"
  nginx pid file: "/home/data/websrv/nginx/logs/nginx.pid"
  nginx error log file: "/home/data/websrv/nginx/logs/error.log"
  nginx http access log file: "/home/data/websrv/nginx/logs/access.log"
  nginx http client request body temporary files: "client_body_temp"
  nginx http proxy temporary files: "proxy_temp"
  nginx http fastcgi temporary files: "fastcgi_temp"
  nginx http uwsgi temporary files: "uwsgi_temp"
  nginx http scgi temporary files: "scgi_temp"

注意这里只要make 而不要make install
make，不要make install会覆盖

    -o objs/src/http/ngx_http_postpone_filter_module.o \ 
                src/http/ngx_http_postpone_filter_module.c 
gcc -c  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs -I src/http -I src/http/modules \ 
                -o objs/src/http/modules/ngx_http_ssi_filter_module.o \ 
                src/http/modules/ngx_http_ssi_filter_module.c 
gcc -c  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs -I src/http -I src/http/modules \ 
                -o objs/src/http/modules/ngx_http_charset_filter_module.o \ 
                src/http/modules/ngx_http_charset_filter_module.c 
gcc -c  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs -I src/http -I src/http/modules \ 
                -o objs/src/http/modules/ngx_http_userid_filter_module.o \ 
                src/http/modules/ngx_http_userid_filter_module.c 
gcc -c  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs -I src/http -I src/http/modules \ 
                -o objs/src/http/modules/ngx_http_autoindex_module.o \ 
                src/http/modules/ngx_http_autoindex_module.c 
gcc -c  -I src/core -I src/event -I src/event/modules -I src/os/unix -I objs -I src/http -I src/http/modules \ 
                -o objs/src/http/modules/ngx_http_auth_basic_module.o \ 
                src/http/modules/ngx_http_auth_basic_module.c 
make[1]: Leaving directory `/home/data/install/lnmp/nginx-1.0.15' 
make -f objs/Makefile manpage 
make[1]: Entering directory `/home/data/install/lnmp/nginx-1.0.15' 
sed -e "s|%%PREFIX%%|/home/data/websrv/nginx|" \ 
                -e "s|%%PID_PATH%%|/home/data/websrv/nginx/logs/nginx.pid|" \ 
                -e "s|%%CONF_PATH%%|/home/data/websrv/nginx/conf/nginx.conf|" \ 
                -e "s|%%ERROR_LOG_PATH%%|/home/data/websrv/nginx/logs/error.log|" \ 
                < man/nginx.8 > objs/nginx.8 
make[1]: Leaving directory `/home/data/install/lnmp/nginx-1.0.15'

替换nginx二进制文件
[root@ceshi nginx-1.0.15]# killall nginx 
[root@ceshi nginx-1.0.15]# cp ./objs/nginx /home/data/websrv/nginx/sbin/ 
cp：是否覆盖"/home/data/websrv/nginx/sbin/nginx"？ y 
service nginx start 
这次就没报错了 
    location ~ /purge(/.*) 
                { 
                allow          127.0.0.1; 
                allow          192.168.0.0/24; 
                deny            all; 
                proxy_cache_purge  cache_one  $host$1$is_args$args; 
                } 
                access_log      off; 
        } 
Starting nginx daemon: nginx 
started.

正常启动nginx了
当是发现 nginx 页面是500

500 Internal Server Error

[root@ceshi nginx-1.0.15]#  ulimit -n 
655360 
[root@ceshi nginx-1.0.15]#  ulimit -n 65535 
[root@ceshi nginx-1.0.15]# cat /proc/sys/fs/file-max 
65535

解决，也可以直接改配置文件
vi /etc/security/limits.conf 
在文件末加上： 
 *                soft  nofile        65535 
 *                hard  nofile        65535

127.0.0.1 - - [06/Nov/2013:01:52:05 +0800] "GET /static_gmd/images/shadow_bg.jpg HTTP/1.0" 500 0 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.66 Safari/537.36"

服务器端会判断上次的 config 时间是否比 If-Modified-Since 晚。如果自上次 request 之后又更新了 config，那么服务器就会返回完整的内容；如果期间没有更新 config，那么服务器就没必要返回完整的内容，只需要向客户端发送一个 304 Not Modified 状态码就可以了。