Hasan CALISIR

NPP lets WordPress users manage Nginx Cache Purge and Preload (FastCGI, Proxy, SCGI, UWSGI) operations directly from the WordPress admin dashboard — actively warming the cache via site crawl, so your Nginx cache is always preloaded and ready.
➡️ Resources:
• Visit the <a href="https://github.com/psaux-it/nginx-fastcgi-cache-purge-and-preload" rel="nofollow ugc">NPP Main Development Repository</a> – Docs, issues & contributions and more. 
• Visit the <a href="https://github.com/psaux-it/nginx-fastcgi-cache-purge-and-preload/tree/main/safexec" rel="nofollow ugc">safexec Main Development Repository</a> – NPP’s privilege-dropping C wrapper. 
• Explore <a href="https://github.com/psaux-it/wordpress-nginx-cache-docker" rel="nofollow ugc">NPP Containerized</a> – Ready to run full stack Nginx Docker setup. 
• Refer to the plugin’s Help tab for additional guidance.
<h3>Features</h3>
🧹 Purge All Nginx Cache: Completely clear all cached data stored by Nginx.
🔄 Preload All Nginx Cache: Warm the Nginx cache with the most recent data for the entire website.
🎯 HTTP Purge (ngx_cache_purge): When the Nginx cache module is available, NPP uses it as the fastest purge path. Falls back gracefully to index and filesystem purge when the module is not present.
🚀 Auto Preload Nginx Cache: Automatically preloads the cache when Auto Purge is enabled for a POST/PAGE or after the Purge All action.
🧼 Auto Purge Nginx Cache: Purge cache on Post/Page content changes, comment status updates, theme/plugin updates, or when compatible Cache Plugins trigger a purge. Nginx cache is preloaded automatically if Auto Preload is enabled (for the entire site or individual page).
🔗 Purge Scope (Related Pages): Automatically purge related pages such as the Homepage, WooCommerce Shop page, and Category/Tag archives when a single URL is purged. Optionally preload those pages to keep the cache warm.
⏰ Schedule Nginx Cache Purge & Preload via WP Cron: Automate the purge and preload process using WordPress Cron jobs.
🧭 Proxy Support for Preload: Route preload requests through a proxy server for edge-case environments and containerized deployments.
⏱️ Live Preload Progress Monitoring: Watch the Nginx cache preload process in real time — complete with a dynamic progress bar, currently processed URL, 404 tracking, server load, and total completion time.
🌐 Remote Nginx Cache Purge & Preload via REST API: Remotely trigger cache purging and preloading through REST API endpoints.
⚙️ Manual Nginx Cache Purge & Preload: Allow manual purging and preloading of cache through the table view in the Advanced Tab.
📚 Nginx Cache Analyzer: Full HIT/MISS cache analyzer dashboard, from the last preload crawl with what is currently stored in the Nginx cache. Instantly spot uncached pages and Purge or Preload them directly in the Advanced Tab.
🔍 On-Page Nginx Cache Purge & Preload: Manually purge and preload Nginx cache for the currently visited page directly from the frontend.
🗝️ Custom Cache Key Support: Define a regex pattern to parse URLs based on your custom <code>_cache_key</code> format.
📊 Monitor Plugin and Nginx Cache Status: Monitor plugin status, cache status, and Nginx status from the Status tab.
📈 Cache Coverage Ratio: Live gauge in the WordPress dashboard widget showing the cache coverage ratio, based on the last preload snapshot. Refreshable on demand without a page reload.
☁️ Cloudflare APO Sync: Automatically mirrors NPP purge actions to Cloudflare APO to keep edge cache synchronized with your Nginx cache.
🔴 Redis Object Cache Sync: Bidirectional sync between NPP and Redis Object Cache. NPP Purge All flushes the Redis object cache, and a Redis flush triggers a full Nginx cache purge via NPP (when auto-purge is enabled).
🛒 WooCommerce Auto-Purge: Automatically purges Nginx cache when WooCommerce product stock quantity changes, stock status changes (in stock / out of stock / on backorder), or when an order is cancelled and stock is restored.
🔒 Concurrent Purge Serialization: Atomic lock mechanism prevents simultaneous purge operations from colliding, ensuring cache integrity during concurrent admin actions or background events.
🧩 Modular by Design: Easily integrate with external scripts and automation tools.
🖥️ User-Friendly Interface: Easy-to-use AJAX-powered settings, integrated into the WordPress admin bar and dashboard for quick access.
📋 Admin Notices and Logs: Receive notifications and view logs for plugin status and all cache-related actions within the WordPress admin area.
📧 Email Notifications: Receive email alerts upon completion of preload actions, with customizable templates to suit your needs.
<h3>Credits</h3>
This plugin is developed and maintained by Hasan CALISIR.
<h3>Privacy Policy</h3>
Prior to version 2.1.5, NPP optionally collected basic anonymous usage data when users explicitly opted in. As of version 2.1.5, all data collection and the opt-in mechanism have been completely removed. NPP collects no data whatsoever.
<h3>Support</h3>
For support and assistance, please contact Hasan CALISIR at hasan.calisir@psauxit.com.
<h3>License</h3>
This plugin is licensed under the GPLv2 or later.For more information, visit the plugin development page: <a href="https://github.com/psaux-it/nginx-fastcgi-cache-purge-and-preload" rel="nofollow ugc">Nginx Cache Purge Preload</a>

Nginx Cache Purge Preload

The most comprehensive solution for managing Nginx (FastCGI, Proxy, SCGI, UWSGI) cache operations directly from your WordPress dashboard.

Daniel Bachhuber

Ipstenu (Mika Epstein)

Danila Vershinin

Mike Schroder

Kira Schroder

techpriester

This plugin does not install nor configure a cache proxy. It acts as an interface with such services.
One common method of caching content for websites is via the use of reverse proxy caching. Common examples of this are <a href="https://www.varnish-cache.org/" rel="nofollow ugc">Varnish</a> and <a href="https://www.nginx.org/" rel="nofollow ugc">NGINX</a>. These systems allow a website to update content and have the visitor’s experience cached without the need for complex plugins storing the files locally and using up a user’s disk space.
A reverse proxy cache is installed in front of a server and reviews requests. If the page being requested is already cached, it delivers the cached content. Otherwise it generates the page and the cache on demand.
The Proxy Cache Purge plugin sends a request to delete (aka flush) the cached data of a page or post every time it’s modified.
<h4>How It Works</h4>
When content on a site is updated by WordPress, the plugin reaches out to the proxy cache service with the URL of the page, requesting the cache be deleted.
Not all pages are deleted from the cache on every change. For example, when a post, page, or custom post type is edited, or a new comment is added, only the following pages will purge:
<ul>
<li>The front page</li>
<li>The post/page edited</li>
<li>Any categories, tags, and/or custom taxonomies associated with the page</li>
<li>Related feeds</li>
<li>Associated JSON API pages</li>
</ul>
In addition, your entire cache will be deleted on the following actions:
<ul>
<li>Changing themes</li>
<li>Pressing the Empty Cache button on the toolbar</li>
</ul>
Plugins can hook into the purge actions as well, to filter their own events to trigger a purge.
On a multisite network using subfolders, only network admins can purge the main site.
<h4>Development Mode</h4>
If you’re working on a site and need to turn off caching in one of two ways:
<ol>
<li>Add <code>define( 'VHP_DEVMODE', true );</code> to your <code>wp-config.php</code> file</li>
<li>Go to Proxy Cache -> Settings and enable Debug Mode for 24 hours at a time</li>
</ol>
That will break cache on page loads. It is not recommended for production!
<h4>Cache Tags (BETA)</h4>
As of version 5.4.0, Proxy Cache Purge includes an optional Cache Tags / Surrogate Keys purge mode. This feature is marked as BETA and is disabled by default.
When enabled, the plugin:
<ul>
<li>Adds cache-tag headers to WordPress responses (for example, tagging pages by post ID, post type, taxonomy terms, author, and archives).</li>
<li>Uses tag-based purges instead of individual URL purges when content is updated, which can reduce purge traffic and improve consistency on complex sites.</li>
</ul>
Requirements:
<ul>
<li>A proxy cache that supports Cache Tags / Surrogate Keys and advertises this via standard <code>Surrogate-Capability</code> headers (for example, <code>Surrogate-Capability: vhp="Surrogate/1.0 tags/1"</code>).</li>
</ul>
How to enable:
<ul>
<li>Go to Proxy Cache → Settings → Purge Method and check “Use Cache Tags (Surrogate Keys)”. The checkbox is only enabled when your cache tells WordPress it supports tags (or when you explicitly enable it via a define).</li>
<li>
Alternatively, you can force-enable or force-disable detection via <code>wp-config.php</code>:
define( ‘VHP_VARNISH_TAGS’, true ); // Force treat cache as tag-capable 
define( ‘VHP_VARNISH_TAGS’, false ); // Force treat cache as not tag-capable
</li>
</ul>
Because this feature depends on your cache configuration, it is recommended that you test it carefully in staging before enabling it on production.
<h4>Background Purging with WP-Cron</h4>
On busy sites, sending many PURGE requests directly from admin requests can slow things down. When you define <code>DISABLE_WP_CRON</code> as <code>true</code> in <code>wp-config.php</code> (because you are running a real system cron that calls <code>wp-cron.php</code>), Proxy Cache Purge automatically switches to an asynchronous mode:
<ul>
<li>Purge requests (both URL-based and tag-based, when Cache Tags are enabled) are collected into a small per-site queue.</li>
<li>The queue is processed by WP-Cron in the background, keeping your admin and content-editing actions responsive even when many URLs or tags must be invalidated.</li>
</ul>
Object-cache purges (the “Purge Database Cache” option) remain synchronous and are not affected by this behaviour. The Proxy Cache settings page and Site Health integration expose basic queue status so you can verify that background purging is healthy; if the queue appears large or very old, check that your system cron is correctly invoking WordPress cron.
Important: Cron Frequency and Cache Freshness
When using background purging, the frequency of your system cron determines how quickly cache invalidations are processed. The longer the interval between cron runs, the longer visitors may see stale content after updates.
For minimal stale content, run your system cron every minute:
<pre><code>* * * * * /usr/bin/php /var/www/html/wp-cron.php
</code></pre>
If you can tolerate slightly longer delays, every 2-5 minutes is also acceptable. However, running cron less frequently (e.g., every 15 minutes) means cache purges may be delayed by that amount after content changes.
Note: Scheduled posts are handled specially. When a scheduled post is published via WP-Cron, the cache is purged synchronously within the same cron run, ensuring immediate cache invalidation without waiting for the next cron execution.
For detailed instructions on setting up a proper Linux-based WordPress cron, see: <a href="https://www.getpagespeed.com/web-apps/wordpress/wordpress-cron-optimization" rel="nofollow ugc">WordPress Cron Optimization</a>.
Disabling Background Purging
If you have <code>DISABLE_WP_CRON</code> defined but do not want background purging (for example, on low-traffic sites where immediate purges are preferred), you can force-disable cron-based purging by adding this to your <code>wp-config.php</code>:
<pre><code>define( 'VHP_DISABLE_CRON_PURGING', true );
</code></pre>
With this constant set, all cache purges will execute immediately during the request, regardless of the <code>DISABLE_WP_CRON</code> setting.
<h3>WP-CLI</h3>
Purge
Purge commands let you empty the cache.
<ul>
<li><code>wp varnish purge</code> – Flush the entire site cache (equivalent to clicking “Empty Cache” in admin)</li>
<li><code>wp varnish purge --all</code> – Explicitly flush the entire site cache</li>
<li><code>wp varnish purge <url></code> – Flush cache for a specific URL and all content below it (wildcard)</li>
<li><code>wp varnish purge <url> --url-only</code> – Flush cache for only the exact URL specified (no wildcard)</li>
<li><code>wp varnish purge --tag=<tag></code> – Flush cache by tag (requires Cache Tags mode to be enabled)</li>
</ul>
Examples:
<ul>
<li><code>wp varnish purge</code> – Purge entire site</li>
<li><code>wp varnish purge --all</code> – Same as above, more explicit</li>
<li><code>wp varnish purge https://example.com/hello-world/</code> – Purge this URL and everything below it</li>
<li><code>wp varnish purge https://example.com/hello-world/ --url-only</code> – Purge only this exact URL</li>
<li><code>wp varnish purge https://example.com/wp-content/themes/ --wildcard</code> – Purge all theme files</li>
<li><code>wp varnish purge --tag=p-123</code> – Purge all pages tagged with post ID 123</li>
<li><code>wp varnish purge --tag=pt-post</code> – Purge all cached pages of post type “post”</li>
</ul>
Debug
Debugging can help you figure out why your cache isn’t working as well as it could. The default is for your home page, but you can pass any URL on your domain.
<ul>
<li><code>wp varnish debug [<url>]</code></li>
</ul>
Available parameters:
<ul>
<li><code>[--include-headers]</code> — Include headers in debug check output</li>
<li><code>[--include-grep]</code> — Grep active theme and plugin directories for common issues</li>
</ul>
DevMode
Development mode allows you to disable the cache, temporarily.
<ul>
<li><code>wp varnish devmode [<activate|deactivate|toggle>]</code> – Change development mode state</li>
</ul>
Async purge queue (cron-mode)
When you define <code>DISABLE_WP_CRON</code> as <code>true</code> and run a real system cron for WordPress, Proxy Cache Purge can move heavy purge work into a small background queue that is processed by WP‑Cron.
You can inspect and manage that queue via WP‑CLI:
<ul>
<li><code>wp varnish queue status</code> – show whether cron-mode is active, if a full purge is queued, counts of queued URLs/tags, and the last queue run time.</li>
<li><code>wp varnish queue process</code> – process any items currently in the queue (useful to run after deploys or cache‑sensitive operations).</li>
<li><code>wp varnish queue clear</code> – clear the queue without sending any PURGE requests.</li>
</ul>
These commands do not replace your normal WordPress cron (you still need a cron entry that calls <code>wp cron event run --due-now</code> or hits <code>wp-cron.php</code>), but they give you a simple operational handle when using cron‑mode.
<h4>Understanding Purge Behavior</h4>
There are different types of cache purges, and they behave differently:
Manual Purges (Admin Bar)
<ul>
<li>“Purge Cache (All Pages)” – Sends a single regex purge request to invalidate the entire cache. Always executes immediately.</li>
<li>“Purge Cache (this page)” – Purges only the exact URL you’re viewing. Always executes immediately.</li>
</ul>
Manual purges are always immediate, even when background cron-mode is enabled. This is intentional: when you click a button, you expect immediate results.
Automatic Purges (Post Save/Update)
When you save or update a post, the plugin automatically purges:
<ul>
<li>The post’s URL</li>
<li>The homepage</li>
<li>Category archive pages</li>
<li>Tag archive pages</li>
<li>Author archive page</li>
<li>Date-based archives</li>
<li>RSS feeds</li>
<li>Related REST API endpoints</li>
</ul>
This can be 20-50+ URLs depending on your site structure. When cron-mode is enabled, these automatic purges are queued and processed in the background to avoid slowing down the post editor.
Key Difference
 Action 
 URLs Purged 
 Uses Cron Queue?
 “Purge Cache (All Pages)” 
 1 (regex) 
 No – always immediate
 “Purge Cache (this page)” 
 1 
 No – always immediate
 Post save/update 
 20-50+ 
 Yes (if cron-mode enabled)
If you need to immediately purge all URLs related to a specific post (not just the post URL), save the post – the automatic purge will handle all related URLs.

Proxy Cache Purge

Automatically empty proxy cached content when your site is modified.

Nginx Cache Purge Preload vs Proxy Cache Purge