Varnish Cache 4.0.0

Release date:

10 April, 2014


Varnish is distributed as both source and binary packages. Please choose the appropriate version for your platform.

Summary of changes

We've just released Varnish Cache 4.0.0.

New features include:

  • Full support for streaming objects through from the backend on a cache miss. Bytes will be sent to 1..n requesting clients as they come in from the backend server.
  • Background (re)fetch of expired objects. On a cache miss where a stale copy is available, serve the client the stale copy while fetching an updated copy from the backend in the background.
  • New varnishlog query language, allowing automatic grouping of requests when debugging ESI or a failed backend request. (among much more)
  • Comprehensive request timestamp and byte counters.
  • Security improvements, including disabling of run-time changes to security sensitive parameters. 

Source version of the software can be downloaded from:

For the full detailed list of changes, see the changes.rst file.

Debian and Redhat packages will be available shortly.

Existing users will need to adapt their VCL files before running Varnish 4. The changes needed are outlined in the upgrade documentation.

The development team would like to thank Amedia AS and Redpill Linpro AS for their help in testing Varnish Cache 4.0 on production traffic. We couldn't have made this release without it.

We're celebrating this release by having Varnish 4 release parties around the world. See our web site to find the one nearest you!

Varnish Cache is developed under the Varnish Moral License and is currently looking for funding to continue the development. If you or your business can help out, see Poul-Henning's VML pages.