This week’s episode is about Grace mode, Varnish’s interpretation of stale-while-revalidate.

How to configure saint mode and grace in Varnish 4.1
A very important feature of Varnish is the ability to deal with misbehaving servers. In this blog I will explain how to properly configure saint mode and grace.

Saint mode and grace have been present since Varnish 2.1, but to make this blog post easier I will cover the differences between Varnish 3 (EOL for real!)  and the current stable Varnish 4.1.