Varnish

Varnish, explained and applied: VCL configs, cache invalidation, debugging with varnishlog, and squeezing speed out of a reverse proxy.

41 posts on Varnish.

2026-06

2026-06-08 Configuring Varnish on systemd in 2026: drop-in overrides, not varnish.params
2026-06-07 Debugging cookie stripping in Varnish: client vs backend request in 2026
2026-06-06 Reading the Varnish log in 2026: varnishlog -q, -g grouping and the VSL query language
2026-06-05 Varnish in 2026: it's called Vinyl Cache now, and the mental model still holds

2019-04

2019-04-06 Using Oh Dear! to keep your Varnish cache warm

2018-04

2018-04-30 Chalk Talk #3: how to optimise your content for Varnish
2018-04-16 Upcoming presentation at LOADays: Varnish Internals – Speeding up a site x100
2018-04-06 Chalk Talk #2: how does Varnish work?
2018-04-03 Varnish: same hash, different results? Check the Vary header!
2018-04-03 Varnishlog: show the hash() data in output

2018-03

2018-03-25 Chalk Talk #1: An introduction to Varnish
2018-03-15 Varnish 6.0 released

2017-07

2017-07-04 Podcast: Caching using Varnish

2016-10

2016-10-28 Varnish 5.x VCL configuration templates
2016-10-20 Varnish Explained

2016-09

2016-09-15 Varnish Cache 5.0 Released

2016-08

2016-08-11 Mark a varnish backend as healthy, sick or automatic via CLI

2016-07

2016-07-28 Varnish Agent: an HTML frontend to manage & monitor your varnish installation

2016-03

2016-03-14 Drupal’s itok parameters explained and a Varnish workaround for different backends

2015-10

2015-10-26 Varnish VCL Syntax Highlighting in Sublime Text

2015-04

2015-04-27 Varnish VCL: Case Insensitive Regex
2015-04-14 Varnish Cache 3.0 Is End Of Life

2015-03

2015-03-15 Running Varnish 4.x on systemd
2015-03-15 Debug Varnish 4.x on systemd That Fails to Start

2015-01

2015-01-06 Architecting Websites For The HTTP/2 Era

2014-12

2014-12-21 Explicitly Approving (Whitelisting) Cookies in Varnish With Libvmod-Cookie
2014-12-15 Varnish FetchError http first read error: -1 11 (Resource temporarily unavailable)
2014-12-14 Reload Varnish VCL without losing cache data
2014-12-14 Combine Apache’s HTTP authentication with X-Forwarded-For IP whitelisting in Varnish
2014-12-13 Varnish tip: see which cookies are being stripped in your VCL
2014-12-08 Varnish FetchError: straight insufficient bytes

2014-11

2014-11-30 The Next-Generation PHP Server Stack For 2015
2014-11-26 Varnish FetchError: Gunzip+ESI Failed at the very end

2014-04

2014-04-10 Varnish 4.0.0 released together with configuration templates

2012-11

2012-11-27 Stop. Caching. Static. Files. In. Varnish.

2011-11

2011-07

2011-07-03 Finished a draft Varnish 3.0 VCL for Fork CMS

2011-06

2011-06-29 Posting my Varnish 3.0 configs to Github
2011-06-29 Useful Varnish 3.0 Commands: one-liners with varnishtop and varnishlog