Debian Apache如何優化緩存

在Debian系統上優化Apache緩存可以通過多種方式實現，以提高網站性能和減少服務器負載。以下是一些常見的優化方法：

1. 啟用和配置Apache緩存模塊

Apache提供了幾個模塊來幫助緩存內容，例如mod_cache和mod_cache_disk。

啟用模塊

首先，確保你已經安裝了這些模塊。你可以使用以下命令來啟用它們：

sudo a2enmod cache
sudo a2enmod cache_disk
sudo systemctl restart apache2

配置緩存

編輯Apache配置文件（通常是/etc/apache2/apache2.conf或/etc/apache2/sites-available/your-site.conf），添加或修改以下配置：

<IfModule mod_cache.c>
    <IfModule mod_cache_disk.c>
        CacheEnable disk /your-cache-path
        CacheRoot /var/cache/apache2/mod_cache_disk
        CacheDirLevels 2
        CacheDirLength 1
        CacheDefaultExpire 3600
    </IfModule>
</IfModule>

<IfModule mod_expires.c>
    ExpiresActive On
    ExpiresByType text/html "access plus 1 hour"
    ExpiresByType text/css "access plus 1 week"
    ExpiresByType application/javascript "access plus 1 week"
    ExpiresByType image/jpeg "access plus 1 month"
    ExpiresByType image/png "access plus 1 month"
    ExpiresByType image/gif "access plus 1 month"
</IfModule>

2. 使用Varnish作為反向代理緩存

Varnish是一個高性能的反向代理緩存服務器，可以顯著提高網站性能。

安裝Varnish

sudo apt update
sudo apt install varnish

配置Varnish

編輯Varnish配置文件（通常是/etc/varnish/default.vcl），添加或修改以下配置：

backend default {
    .host = "127.0.0.1";
    .port = "80";
}

sub vcl_recv {
    if (req.http.Cookie ~ "PHPSESSID") {
        return (pass);
    }
    if (req.http.Authorization) {
        return (pass);
    }
    return (hash);
}

sub vcl_backend_response {
    if (bereq.http.Cache-Control ~ "no-cache") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Pragma ~ "no-cache") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "private") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-store") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "must-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "proxy-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "max-age=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "s-maxage=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-cache") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-store") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "private") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "must-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "proxy-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "max-age=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "s-maxage=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-cache") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-store") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "private") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "must-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "proxy-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "max-age=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "s-maxage=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-cache") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-store") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "private") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "must-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "proxy-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "max-age=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "s-maxage=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-cache") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-store") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "private") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "must-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "proxy-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "max-age=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "s-maxage=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-cache") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-store") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "private") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "must-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "proxy-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "max-age=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "s-maxage=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-cache") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-store") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "private") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "must-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "proxy-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "max-age=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "s-maxage=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-cache") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-store") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "private") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "must-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "proxy-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "max-age=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "s-maxage=0") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-cache") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "no-store") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "private") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "must-revalidate") {
        set beresp.uncacheable = true;
        return (deliver);
    }
    if (bereq.http.Cache-Control ~ "proxy-revalidate") {
        set beresp.uncacheable =