CDN and caching can get confused for one another. Learn the differences between CDN and caching to help decide what you should use for optimal web performance.

At our second annual customer summit, Andrew Betts of the Financial Times discussed using VCL to “solve anything” — pushing his team’s problems to the CDN layer.

This month's tip is more a theoretical exercise than anything else, just to show the power of VCL, and to explain a few regular expressions. I'm going to discuss VCL that deletes cookies.

Reusing connections between your Varnish instance and your backends (origins) is a good idea for multiple reasons. If your Varnish is on the same network as your backends and you're doing…

The cache hit ratio (or hit ratio for short) is the ratio of hits to cacheable requests (hits and misses combined). There's also cache coverage, the ratio of cacheable requests to all…

If you want to increase the efficiency of your Varnish (or Fastly) cache, you need to figure out what traffic is not cached. By definition, any traffic that reaches your origin is not cached…

In the continued quest to increase cache hit ratios, the chant is: "Normalize, normalize, normalize." Less variation in your requests means you have a higher chance of getting hits. This…

A long time ago, I was helping out at a gaming conference where there was an intranet CMS using a Twitter search plugin. Unfortunately, the rather saturated Internet connection was slowing…

If you're caching URLs that include user input, such as a search box, and the search is case insensitive, there's a really easy way to increase your hit ratio: convert the URL to lowercase.