Vcl - Varnish Cache

Tutorial Tags: Vcl

VSL cheatsheet

varnishlog, varnishncsa and ready-to-use VSL queries

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.

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

Using multiple backends in Varnish

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.

Configuring Varnish for Drupal

Configuring Varnish for Magento

Configuring Varnish for WordPress

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

Avoiding HTTP to HTTPS redirect loops in Varnish

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

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.

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.

Cache invalidation

How to invalidate and purge your cache

Object lifetimes: TTL, Grace, Keep

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