[root@localhost ~]# vim /usr/local/nginx/conf/nginx.conf

user  www www;
worker_processes  8;error_log  logs/error.log crit;
pid        logs/nginx.pid;
worker_rlimit_nofile 65535;events {worker_connections  65535;
}http {include       mime.types;default_type  application/octet-stream;server_names_hash_bucket_size 128;client_header_buffer_size 32k;large_client_header_buffers 4 32k;client_max_body_size 300m;sendfile        on;tcp_nopush     on;tcp_nodelay on;keepalive_timeout  65;client_body_buffer_size 512k;proxy_connect_timeout 5;proxy_read_timeout 60;proxy_send_timeout 5;proxy_buffer_size 16k;proxy_buffers 4 64k;proxy_busy_buffers_size 128k;proxy_temp_file_write_size 128k;gzip  on;gzip_min_length 1k;gzip_buffers 4 16k;gzip_http_version 1.1;gzip_comp_level 2;gzip_types text/plain application/x-javascript text/css application/xml;gzip_vary on;#注：proxy_temp_path和proxy_cache_path指定的路径必须在同一分区proxy_temp_path /data/proxy_temp_dir;proxy_cache_path /data/proxy_cache_dir levels=1:2 keys_zone=cache_one:200m inactive=1d max_size=30g;
#设置Web缓存区名称为cache_one，内存缓存空间大小为200MB，1天清理一次缓存，硬盘缓存空间大小为30Gupstream web_proxy_cache {server 192.168.56.113:80 weight=1 max_fails=2 fail_timeout=30s;server 192.168.56.114:80 weight=1 max_fails=2 fail_timeout=30s;}server {listen       80;server {listen       80;server_name  192.168.56.120;root   /data/web/www;index  index.html index.htm;location / {proxy_next_upstream http_502 http_504 error timeout invalid_header;
# 如果后端的服务器返回502、504、执行超时等错误，自动将请求转发到upstream负载均衡池中的另一台服务器，实现故障转移proxy_cache cache_one;proxy_cache_valid 200 304 12h;   #对不同的HTTP状态码设置不同的缓存时间# 以域名、URI、参数组合成Web缓存的Key值，Nginx根据Key值哈希，存储缓存内容到二级缓存目录内proxy_cache_key $host$uri$is_args$args;proxy_set_header Host $host;proxy_set_header X-Forwarded-For $remote_addr;proxy_pass http://web_proxy_cache;expires 1d;}# 用于清除缓存，假设一个URL为http://192.168.56.120/test.txt，通过访问http://192.168.56.120/purge/test.txt就可以清除该URL的缓存。location ~ /purge(/.*) {  # 设置只允许指定的IP或IP段才可以清除URL缓存allow 127.0.0.1;allow 192.168.56.0/24;deny all;proxy_cache_purge cache_one $host$1$is_args$args;}location ~ .*\.(php|jsp|cgii)?$ {  # 扩展名以.php、.jsp、.cgi结尾的动态应用程序不缓存proxy_set_header Host $host;proxy_set_header X-Forwarded-For $remote_addr;proxy_pass http://web_proxy_cache;}access_log off;}
}

清除123.jpg的缓存，访问http://192.168.56.120/purge/123.jpg 即可看到下面的页面

四、通过日志查看HIT 情况

1、开启日志

log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for" '
'"$upstream_cache_status"';
access_log logs/access.log main;

4、计算HIT命中概率