Caching

HTTP caching is a technique used to speed up the delivery of web content by storing previously requested resources, such as images, scripts, and stylesheets, in a cache.

A web accelerator, such as Varnish, may be used to implement HTTP caching. The usual set up will place the web accelerator between Plone and the Internet. When a request is made to the site, the web accelerator will intercept the request. It then checks to see if it has a cached copy of the requested resource. If a cached copy is found, the accelerator will serve the cached copy directly to the client, else it will make a request to the backend Plone server and then store a copy on the content in its local cache.

HTTP caching and the speed of delivering web content can be improved using a Content Delivery Network (CDN). A CDN is a network of servers located in various geographic regions that work together to deliver web content to users quickly and efficiently. When a user requests a resource from a website that uses a CDN, the request is directed to the closest server in the CDN, rather than having to travel all the way to the website's origin server.

Cache support in Plone

Plone ships with powerful and extensible HTTP and In-Memory cache support, implemented by the package plone.app.caching.