Varnish Cache is a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast. It typically speeds up delivery with a factor of 300 - 1000x, depending on your architecture.
To get started with Varnish-Cache we recommend that you read the installation guide Varnish Installation. Once you have Varnish up and running we recommend that you go through our tutorial - The Varnish Tutorial, and finally the The Varnish Users Guide.
If you need to find out how to use a specific Varnish tool, the The Varnish Reference Manual contains detailed documentation over the tools. Changes from previous versions are located in the What’s new / Upgrading chapter. In closing, we have Poul-Hennings random outbursts, a collection of blog posts from Poul-Henning Kamp related to Varnish and HTTP.
Conventions used in this manual include:
service varnish restart
A command you can run, or a shortkey you can press. Used either in the terminal or after starting one of the tools.
- /usr/local/, varnishadm, sess_timeout
A utility, Varnish configurable parameter or path.
Longer listings like example command output and VCL look like this:
$ /opt/varnish/sbin/varnishd -V
varnishd (varnish-trunk revision 1234567)
Copyright (c) 2006 Verdens Gang AS
Copyright (c) 2006-2023 Varnish Software