VCL – The Language that Powers Varnish Cache and Other Varnish Features

Load balancing allows Varnish to distribute backend requests to multiple backend servers. This video shows how to leverage the "directors" VMOD to distribute the load using various distribution algorithms.

We'll use Varnish as an authentication gateway to handle basic authentication.

We'll talk about varnishncsa, a tool that produces Varnish logs in the NCSA-style log format.

Varnish is the world's most powerful and flexible HTTP cache that is used to accelerate more than 10 million websites globally. A big part of its attraction, besides its industry leading performance, is the Varnish Configuration Language (VCL).

VCL is a domain-specific programming language that powers Varnish. It is used to configure the caching policies and to control the way Varnish interacts with both the client and the origin web server.

Having a full-blown programming language to describe the configuration of your cache gives you unparalleled flexibility to tune the behavior of the cache to your exact needs.

In this webinar you will learn the basic syntax of VCL, the way VCL controls the behavior of Varnish and some common use cases.

We'll teach you how to inspect and modify incoming requests, create policies to bypass the cache, control the time to live of cached objects, modify responses, manage cache variations, make decisions on the edge and many other tips and tricks that allow you to go beyond the capabilities of HTTP's built-in caching mechanisms.

Thanks to VCL and the rich ecosystem of Varnish modules (VMODs) you can go from caching on the edge with Varnish to full-blown edge compute.