Why LSCache Plugins are Better Than Rewrite Rules

Rewrite rules can be used to configure LSCache, but if there is a plugin available for your web application, we strongly recommend you use the plugin.

With rewrite rules, there is no ability to purge the cache, and so you can only cache items for a very short time, otherwise you run a great risk of serving stale content. Plugins have more cache-management controls, including the ability to purge the cache at will.

This is the most compelling reason to choose a plugin over rewrite rules: Smart Purge technology.

When content in your web application changes, an LSCache plugin is able to analyze dependencies and trigger a cache purge not only for the content that has changed, but for all other content that is related to it. In WordPress, that means that a new blog post triggers a cache purge for the relevant category and tag archive pages. In PrestaShop, that means that a change in a product's stock level triggers a purge of that product's detail page as well as the product's category pages.

With rewrite rules, the cache is only emptied when the TTL (Time to Live) is expired.

Let’s say that we were to cache a page with a TTL of one week. No matter the level of traffic - one request per hour or 500 requests in a 10-second period - a single hit to the back-end during that entire week is all that would be necessary. We can set such a long TTL confidently with an LSCache plugin, because we know if content changes, Smart Purge will kick in and trigger any necessary purges.

We have no such assurances with rewrite rules, and so, we must keep the TTL relatively short in order to avoid the possibility of serving stale content.

Because of these short TTLs, rewrite-rule-based caches must re-cache frequently, even if content is relatively stable. Blindly re-caching content in this way leads to wasted CPU resources.

A plugin can distinguish between private content and public content, whereas rewrite rules cannot.Additionally, LSCache plugins have the ability to use ESI to serve private blocks of data within public pages, which means we can easily serve cached pages to logged-in users.