One of the most important things any business needs is to understand how its service is performing. If you already use Varnish, you’ve probably enjoyed real-time performance monitoring with Varnish Custom Statistics (VCS). But you might have wondered why it hasn't been available to you on the go.

If you don’t use Varnish already, but you do require real-time insight into your web and app performance, you’ll appreciate that Varnish gives you all the information you need - now instantly available to you in app form.

Anders Nordby, Web Operations Specialist with the Møller Group in Norway, wanted to integrate Varnish Custom Statistics (VCS) with the DataDog IT monitoring and data visualization solution and wrote a blog to share how easy and useful it has been to identifying trouble spots and issues in real time.

I quite like the Varnish Custom Statistics, the idea behind it is super simple (aggregate data about classes of requests) and yet, its use cases are extremely diverse: people use it to monitor most requested URLs, to watch for brewing backend issues, to do A/B testing, or to create image walls to show the most read articles (here's the article about how it's done).

A couple of years ago we introduced the real-time statistics API with VAC. Varnish Cache provides a lot of statistics on website activity; however, in order to obtain this information it must be pulled from each server manually. Additionally, they are not available in real time. Meanwhile, Varnish Administration Console provides valuable real-time analytics across multiple instances.