nginx 配置

cache.conf

// 反代优化 https://www.maxcdn.com/blog/nginx-application-performance-optimization/

worker_processes 4;  // params int auto
worker_connections 1024; 每个worker建立连接数,server+client

// 默认值
thread_pool default threads=32 max_queue=65536;

thread_pool pool_1 threads=16;
thread_pool pool_2 threads=16;

events {
    // 默认监听一个端口, 通知给所有worker, 所有竞争accept新的连接
    accept_mutex on;       // 关闭 新请求过来时,多个worker串行获取连接
    accept_mutex reuseport; // 新系统特性SO_REUSEPORT, 能加速通知到worker,减少延迟
}

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

    access_log off;

    // 多块磁盘加速
    proxy_cache_path /mnt/disk1 levels=1:2 keys_zone=cache_1:10m max_size=1024G inactive=60m
                     use_temp_path=off;
    proxy_cache_path /mnt/disk2 levels=1:2 keys_zone=cache_2:10m max_size=1024G 
                     use_temp_path=off;
    
    // cache参数
    // - levels: 目录层级
    // - keys_zone: 内存中存 缓存key及metadata(计数什么的) 1MB大约存8000个key
    // - max_size: 设置空间上限
    // - inactive: 多长时间未使用从缓存删除, 不同于cache-control里的expired, expired时回触发refreshes
    // - use_temp_path: 禁用temp,nginx默认回先存tmp目录,在复制到具体的缓存目录

    proxy_cache_revalidate on;      // cache-control expired 时, 发起请求带If-Modified-Since 
    proxy_cache_min_uses 3;         // 至少访问几次后才缓存, 防止异常刷磁盘
    proxy_cache_background_update on;
    proxy_cache_lock on;            // 只有MISS时第一个连接回源
    proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504;
    // 回源异常时使用过期的缓存,对应inactive

    add_header X-Cache-Status $upstream_cache_status;

    // 覆盖默认 cache-control
    proxy_ignore_headers Cache-Control;
    proxy_ignore_headers Set-Cookie;    // 忽略Set-Cookie头
    proxy_cache_methods GET HEAD POST;  // cache哪些请求
    proxy_cache_valid any 30m;

    // 哪些是不需要缓存的，cookies带nocache, 或query带nocache
    proxy_cache_bypass $cookie_nocache $arg_nocache;
    // key规则, 可以cookie按人缓存
    proxy_cache_key $proxy_host$request_uri$cookie_jessionid;


    // A/B测试分组
    split_clients $request_uri $disk {
        80%     1;
        *       2;      // 默认
    }

    server {
        listen 8000;

        location / {
            root /storage;
            aio threads=default;
            sendfile on;
            sendfile_max_chunk 512k;
        }

        location /cache/ {
            proxy_pass http://backend;
            proxy_cache_key $request_uri;
            proxy_cache cache_$disk;
            aio threads=pool_$disk;
            sendfile on;
        }
        
        location /skip_cache/ {
            set $skip_cache 0;
            if ($request_method = POST) {
                set $skip_cache 1;
            }

            if ($query_string != "") {
                set $skip_cache 1;
            }

            # Don't cache uris containing the following segments
            if ($request_uri ~* "/wp-admin/|/wp-json/|/xmlrpc.php|wp-.*.php|/feed/|index.php|sitemap(_index)?.xml") {
                set $skip_cache 1;
            }

            # Don't use the cache for logged in users or recent commenters
            if ($http_cookie ~* "comment_author|wordpress_[a-f0-9]+|wp-postpass|wordpress_no_cache|wordpress_logged_in") {
                set $skip_cache 1;
            }

            fastcgi_cache_bypass $skip_cache;
            fastcgi_no_cache $skip_cache;
            proxy_cache_bypass $skip_cache;
            proxy_cache_bypass $cookie_nocache $arg_nocache$arg_comment;
            proxy_cache_bypass $http_pragma    $http_authorization;
        }
    }
}