In the dynamic world of technology, questions arise and solutions are sought. Stack Overflow stands as a beacon, guiding individuals through their technical difficulties with insights from experts around the globe.

In this blog, we dive into the world of Varnish, a pivotal tool for caching, web & API acceleration and content delivery, through the lens of the most asked and intriguing questions on Stack Overflow.

When talking about caching, nearly all the attention goes to ensuring that content is properly stored in the cache. While that makes total sense from a performance perspective, people tend to forget that removing objects from the cache is equally as important.

In this week's 2-Minute Tech Tuesday, we'll be discussing banning, which is a mechanism in Varnish to remove outdated content from the cache so that new content can be presented immediately, rather than waiting for the cache to expire.

It's cargo-cult fighting time! Today, we are going to look at a ban expression that you probably have used, and maybe even have recommended (gasp!) to your fellow Varnish users:

req.url ~ /

We'll discuss why we use it, why it's good but mostly bad, and how to fix it. Hopefully, along the way, we'll shed some light on some Varnish internals that you can use in other situations.