Nginx Cache Purge Preload vs SQLite Object Cache

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. NPP is the only Nginx cache plugin that doesn’t just clear the table — it sets the whole banquet. No other Nginx cache plugin comes close to its feature list, purge architecture, preload intelligence on WordPress. 🖥️ Quick WP-CLI Manage your Nginx cache entirely from the command line. Perfect for automation, cron jobs, panels, and headless workflows. Purge: wp npp purge | wp npp purge --page-url= Preload: wp npp preload | wp npp preload --page-url= | wp npp preload --stop Get Full command list: wp help npp | wp help npp ➡️ Resources: • Visit the NPP Main Development Repository – Docs, issues & contributions and more. • Visit the safexec Main Development Repository – NPP’s privilege-dropping C wrapper. • Explore NPP Containerized – Ready to run full stack Nginx Docker setup. • Read the NPP Main Architecture – Technical deep dive article. • Refer to the plugin’s Help tab for more deeper additional guidance. Features 🧹 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 (ngx_cache_purge) is available, NPP uses it as the fastest purge path. Falls back gracefully to index and filesystem purge when the module is not present. 🗂️ INDEX Purge: Leverages the preload-generated URL → Filepath index to directly resolve and purge cache without filesystem traversal. If the cache exists and is valid, purge is executed immediately for near-instant performance. ⚡ RG Purge: ripgrep-powered cache file lookup that replaces slow PHP directory scanning for single-URL purges, enabling near-instant deletes on large or FUSE-mounted caches. Automatically falls back to standard scan if unavailable. 🚀 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. 📡 Preload Feeds: Take full control of RSS/Atom feed caching. Decide site‑wide or per‑URL whether the main feed, per‑post comment feeds, and taxonomy RSS feeds are included in the preload process. ⏰ 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. 🪫 Preload All MISS: A targeted replacement for the expensive Preload All. Instead of purging and re‑caching everything (Preload All), it targets and populates only the cache entries that are not yet warmed. Perfect for sites with high cache coverage (>50%) where a full Preload All be wasteful. 🔍 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 _cache_key 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: Coordinates cache invalidation between NPP and Redis Object Cache during NPP-driven operations. NPP Purge All and Preload workflows handle Redis flushing at the appropriate stage to ensure both cache layers stay aligned. 🛒 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. 🖲️ WP-CLI Support: Manage Nginx cache directly from the command line. Purge and preload cache, view status reports, inspect logs, update settings, flush cache, and manage scheduled tasks without accessing the WordPress admin dashboard. 🔒 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. Credits This plugin is developed and maintained by Hasan CALISIR. Privacy Policy 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. Support For support and assistance, please contact Hasan CALISIR at [email protected]. License This plugin is licensed under the GPLv2 or later.For more information, visit the plugin development page: Nginx Cache Purge Preload

A persistent object cache helps your site perform well. This one uses the widely available SQLite3 extension, and optionally the igbinary and APCu extensions to php. Many hosting services offer those extensions, and they are easy to install on a server you control. What is this about? It’s about making your site’s web server perform better. An object cache does that by reducing the workload on your MariaDB or MySQL database. This is not a page cache; these persistent objects go into a different kind of cache. These objects aren’t chunks of web pages ready for people to view in their browsers, they are data objects for use by the WordPress software. Caches are ubiquitous in computing, and WordPress has its own caching subsystem. Caches contain short-term copies of the results of expensive database lookups or computations, and allow software to use the copy rather than repeating the expensive operation. This plugin (like other object-caching plugins) extends WordPress’s caching subsystem to save those short-term copies from page view to page view. WordPress’s cache happens to be a memoization cache. Without a persistent object cache, every WordPress page view must use your MariaDB or MySQL database server to retrieve everything about your site. When a user requests a page, WordPress starts from scratch and loads everything it needs from your database server. Only then can it deliver content to your user. With a persistent object cache, WordPress immediately loads much of the information it needs. This lightens the load on your database server and delivers content to your users faster. Who should use this? If your site runs on a single web server machine, and that server provides the SQLite3 and igbinary extensions to php, this plugin will almost certainly make your site work faster. And if that server provides the APCu extension, this plugin uses it too. Some hosting providers offer redis cache servers. If your provider offers redis, it may be a good choice. You can use it via the Redis Object Cache plugin. Sites using redis have one SQL database and another non-SQL storage server: redis. Other hosting providers offer memcached, which has the Memcached Object Cache plugin. And some large multipurpose cache plugins, such as the LiteSpeed Cache, also offer object caching based on one of those cache server software packages. The cache-server approach to object caching comes into its own when you have multiple load-balanced web server machines handling your site. SQLite doesn’t work correctly in a multiple-web-server environment. But, for single-server site configurations, SQLite, possibly assisted by APCu, performs well. And the vast majority of sites are single-server. APCu APCu is an in-memory storage medium. It lets php programs, like WordPress, store data in shared memory so it’s very fast to retrieve when needed. If APCu is available on your host server, you can configure this plugin to use it. It reduces the typical cache lookup time to one-fifth or less of the SQLite lookup time, which is itself a few tens of microseconds. Performance counts, especially on busy web sites. Please look at Installation to learn how to configure this plugin to use APCu. The plugin works fast without it, and faster with it. WP-CLI: Even if APCu is in use, caching with SQLite is necessary when your web site uses WP-CLI, because WP-CLI programs do not have access to the APCu cache. This plugin writes all cached data both to APCu and to SQLite and makes sure the two are synchronized. WP-CLI You can control this plugin via WP-CLI once you activate it. Please type this command into your shell for details. wp help sqlite-object-cache Credits Thanks to Till Krüss. His Redis Object Cache plugin serves as a model for this one. And thanks to Ari Stathopoulos and Jonny Harris for reviewing this. Props to Matt Jones for finding and fixing a bug that appeared on a heavily loaded system. Thanks to Massimo Villa for testing help, and to nickchomey for a comprehensive code review. All defects are, of course, entirely the author’s responsibility. And thanks to Jetbrains for the use of their software development tools, especially PhpStorm. It’s hard to imagine how a plugin like this one could be developed without PhpStorm’s tools for exploring epic code bases like WordPress’s. How can I learn more about making my WordPress site more efficient? We offer several plugins to help with your site’s database efficiency. You can read about them here.