Preload FastCGI Cache

FastCGI Cache is fast and efficient, but it has one limitation: cached content is only generated after an actual user requests a page — and entries expire after about an hour. That means the first visitor to a fresh page never benefits from the cache.

A cache warm-up process solves this by periodically requesting your website's URLs in advance, so cached content is always ready before real visitors arrive.

Step 1 — Create the preload script

1. In the File Manager, navigate to public_html/ and create a new file called preload.php.
2. Paste the code below into the file.
3. Update the $sitemapUrl to match your website's actual sitemap URL.

<?php
$sitemapUrl = 'https://yourdomain.com/sitemap.xml';

// Fetch the sitemap with cURL (bypasses allow_url_fopen restrictions)
$ch = curl_init($sitemapUrl);
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_FOLLOWLOCATION => true,
    CURLOPT_USERAGENT      => 'Sitemap-Warmer-Bot'
]);
$xmlContent = curl_exec($ch);
$httpCode   = curl_getinfo($ch, CURLINFO_HTTP_CODE);

if ($httpCode !== 200) {
    die("Error: Could not fetch sitemap. HTTP Code: $httpCode");
}

// Parse the XML
$xml = simplexml_load_string($xmlContent);
if (!$xml) {
    die("Error: Failed to parse XML. Is the sitemap valid?");
}

// Handle namespaces (the "white screen" fix)
$ns = $xml->getDocNamespaces();
$xml->registerXPathNamespace('s', $ns[''] ?? 'http://www.sitemaps.org/schemas/sitemap/0.9');
$urls = $xml->xpath('//s:url');

if (empty($urls)) {
    die("Error: No URLs found in sitemap. Check the XML structure.");
}

// Warm the cache
foreach ($urls as $url) {
    $loc = (string) $url->loc;
    $chWarmer = curl_init($loc);
    curl_setopt_array($chWarmer, [
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_FOLLOWLOCATION => true,
        CURLOPT_TIMEOUT        => 10,
        CURLOPT_USERAGENT      => 'Nginx-FastCGI-Cache-Warmer',
    ]);
    curl_exec($chWarmer);
    $status = curl_getinfo($chWarmer, CURLINFO_HTTP_CODE);
    echo date('H:i:s') . " [$status] Processing: $loc<br>";
    usleep(100000);
}

echo "Done!";

Step 2 — Schedule the script as a cron job

In Developer Tools, create a new cron job using the command below. Replace the UUID with your website's directory name (the example below uses 5e43c690-1937-47aa-9ff5-e1c2d7daebb7):

/usr/bin/php /var/www/5e43c690-1937-47aa-9ff5-e1c2d7daebb7/public_html/preload.php > /dev/null 2>&1

Because cached files expire after one hour, set the execution interval to 1 hour. Running the cron more frequently has no effect, and longer intervals leave gaps where visitors hit uncached pages.

Find your website's UUID

If you're not sure what your site's UUID is:

1. Go to the File Manager.
2. Right-click any file and select Get Info.
3. Copy the UUID from the file's location path.

Step 3 — Verify it works

Visit the script directly in your browser at https://yourdomain.com/preload.php. If the output runs through your sitemap URLs and ends with Done!, cache warming is working correctly.