Nginx系列（十四 nginx缓存）

一.代理模块缓存

1.配置文件

<code><span>#注：proxy_temp_path和proxy_cache_path指定的路径必须在同一分区</span>
proxy_temp_path /web/tmp/nginx;
<span>#设置Web缓存区名称为cache_one，内存缓存空间大小为100MB，1天没有被访问的内容自动清除，硬盘缓存空间大小为1GB。</span>
proxy_cache_path /web/cache/nginx levels=<span>1</span>:<span>2</span> keys_z>100m inactive=<span>1</span>d max_size=<span>1</span>g;
</code>

<code>location / {
            <span>#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。</span>
            proxy_next_upstream http_502 http_504 error timeout invalid_header;
            proxy_cache cache_one;
            <span>#对不同的HTTP状态码设置不同的缓存时间</span>
            proxy_cache_valid <span>200</span><span>304</span><span>1</span>h;
            <span>#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</span>
            proxy_cache_key <span>$host</span><span>$uri</span><span>$is_args</span><span>$args</span>;
            proxy_pass http://webserver;
            proxy_redirect off;
            proxy_<span>set</span>_header Host <span>$host</span>;
            proxy_<span>set</span>_header X-Real-IP <span>$remote_addr</span>;
            proxy_<span>set</span>_header X-Forwarded-For <span>$proxy_add_x_forwarded_for</span>;
        }</code>

反向代理的缓存功能是一个重定向，不是根据url生成缓存静态文件的功能

二.fastcgi模块缓存

1.配置文件

<code>fastcgi_temp_path /web/tmp/fastcgi;
<span>#设置fastcgi缓存路径 levels代表目录层级,1:2会生成16*256,2:2会生成256*256 keys_zone代表缓冲区名称 inactive代表过期时间 max_size代表最多用多少磁盘空间</span>
fastcgi_cache_path /web/cache/fastcgi levels=<span>1</span>:<span>2</span> keys_z>100m inactive=<span>1</span>d max_size=<span>1</span>g;
</code>

<code><span>location</span><span>~ [^/]\.php(/|$)</span> {
            <span>fastcgi_cache</span> cache_two;
            <span>fastcgi_cache_valid</span><span>200</span><span>10m</span>;
            <span>fastcgi_cache_methods</span> GET HEAD;
            <span>#忽视以下头信息</span><span>fastcgi_ignore_headers</span><span>"Cache-Control"</span><span>"Expires"</span><span>"Set-Cookie"</span>;
            <span>fastcgi_cache_key</span><span>"<span>$scheme</span><span>$request_method</span><span>$host</span><span>$request_uri</span>"</span>;
            <span>#添加状态头信息</span><span>add_header</span> X-Cache-CFC <span>"<span>$upstream_cache_status</span> - <span>$upstream_response_time</span>"</span>;

            <span>fastcgi_index</span> index.php;
            <span>fastcgi_pass</span><span>127.0.0.1:9000</span>;
            <span>include</span>      fastcgi_params;

            <span>fastcgi_split_path_info</span><span> ^(.+?\.php)(/.*)$</span>;
            <span>fastcgi_param</span> SCRIPT_FILENAME <span>$document_root</span><span>$fastcgi_script_name</span>;
            <span>fastcgi_param</span> SCRIPT_NAME <span>$fastcgi_script_name</span>;
            <span>fastcgi_param</span> PATH_INFO <span>$fastcgi_path_info</span>;
            <span>fastcgi_param</span> PATH_TRANSLATED <span>$document_root</span><span>$fastcgi_path_info</span>;
        }   </code>

注意：
1.如果fastcgi响应的头信息里有Expires Cache-Control Set-Cookie的时候，fastcgi_cache是不起作用的，所以需要把fastcgi_ignore_headers这个配置项加上。

2.添加头信息X-Cache-CFC 是为了测试缓存是否起作用，$upstream_cache_status包含以下几个状态：
MISS 未命中，请求被传送到后端
HIT 缓存命中
EXPIRED 缓存已经过期请求被传送到后端
UPDATING 正在更新缓存，将使用旧的应答
STALE 后端将得到过期的应答
BYPASS 缓存被绕过了

三.参考

http://www.qttc.net/201307355.html
https://serversforhackers.com/nginx-caching/
http://www.ha97.com/5194.html
http://www.cnxct.com/several-reminder-in-nginx-fastcgi_cache-and-php-session_cache_limiter/

以上就介绍了Nginx系列（十四 nginx缓存），包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。