Varnish tutorials

Using multiple backends in Varnish

Using multiple backends in Varnish

Defining backend servers in VCL

How to define and configure backend servers in Varnish

Using basic authentication in VCL backend probes

When your backend requires authorized access via basic authentication, you need to configure the health probe for your backend in VCL to support basic authentication.

Banning content from Varnish

Use Varnish's ban mechanism to remove cached objects from the cache.

Purging content from Varnish

Use the purge return action in VCL to remove cached objects from the Varnish cache.

Cache invalidation

How to invalidate and purge your cache

HTTP caching basics

Learn the basics of HTTP caching and learn how to control the behavior of a web cache by using conventional HTTP headers

Avoiding HTTP to HTTPS redirect loops in Varnish

How to avoid HTTP to HTTPS redirect loops in Varnish by creating protocol-based cached variations.

Mixed content and ERR_TOO_MANY_REDIRECTS errors in WordPress when using Varnish

Fixing mixed content issues and avoiding the ERR_TOO_MANY_REDIRECTS error in WordPress when using Varnish.

Configuring Varnish for Drupal

Configuring Varnish for Drupal

Configuring Varnish for Magento

Configuring Varnish for Magento

Configuring Varnish for WordPress

Configuring Varnish for WordPress

VSL cheatsheet

varnishlog, varnishncsa and ready-to-use VSL queries

How to configure TLS in Varnish

Learn how to configure TLS in Varnish for both client TLS and backend TLS

Put Varnish on ports 80 and 443

Learn how to reconfigure the Varnish listening ports to 80 and 443

Change your web server port to run Varnish on the same server

Learn how to reconfigure the port of your Apache or Nginx web server to run Varnish on the same machine as your web server.

Starting Varnish

Learn how to start Varnish after installing it

Generating Varnish access logs with varnishncsa

How to generate NCSA compatible access logs for Varnish with varnishncsa.

Configuring Varnish systemd services

Learn how to configure systemd services to manage Varnish.

Varnishlog: measure your Varnish cache performance

How to measure your Varnish cache performance with varnishlog.

Troubleshooting Varnish

How to troubleshoot Varnish when problems occur.

Varnish monitoring

Monitoring your Varnish installation

Hands-on varnishtest

Learn varnishtest by examples

Testing Varnish with varnishtest

The Varnish Configuration Language (VCL) is a domain-specific programming language used by Varnish to control request handling, routing, caching, and several other aspects.

Bypassing the cache for specific URL patterns

How to bypass the cache for specific URLs and URL patterns in Varnish

Performing HTTP redirections in Varnish

Trigger vcl_synth and use a synthetic HTTP response to perform a HTTP redirections in Varnish

Example VCL template

An example VCL template for Varnish

Caching POST requests in Varnish

Learn how to cache POST requests with Varnish

Logging cache hits and misses

Logging cache hits and misses by tracking the request type (hit, miss, pass, pipe, synth, or hitmiss) in a custom x-cache request header

Varnish Configuration Language (VCL)

The Varnish Configuration Language (VCL) is a domain-specific programming language used by Varnish to control request handling, routing, caching, and several other aspects.

Load a synthetic output template from a file

Load the VCL output template for vcl_synth and vcl_backend_error from a file.

Varnish built-in VCL

Learn about Varnish's default behavior by looking at the various subroutines that are part of the built-in VCL.

Object lifetimes: TTL, Grace, Keep

Learn how object lifetimes work in Varnish: from TTL, to Grace and Keep.

Introduction: how does Varnish work?

Now what?

Peculiarities