Varnish Goes Upstack with Varnish Modules and Varnish Configuration Language

This is a guest post by Denis Brækhus and Espen Braastad, developers on the Varnish API Engine from Varnish Software. Varnish has long been used in discriminating backends, so it's interesting to see what they are up to.

Varnish Software has just released Varnish API Engine, a high performance HTTP API Gateway which handles authentication, authorization and throttling all built on top of Varnish Cache. The Varnish API Engine can easily extend your current set of APIs with a uniform access control layer that has built in caching abilities for high volume read operations, and it provides real-time metrics.

Varnish API Engine is built using well known components like memcached, SQLite and most importantly Varnish Cache. The management API is written in Python. A core part of the product is written as an application on top of Varnish using VCL (Varnish Configuration Language) and VMODs (Varnish Modules) for extended functionality.

We would like to use this as an opportunity to show how you can create your own flexible yet still high performance applications in VCL with the help of VMODs.

VMODs (Varnish Modules)

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A Practical Guide to Varnish - Why Varnish Matters

This is a guest post by Jeff Su from Factual.

What is Varnish?

Varnish is an open source, high performance http accelerator that sits in front of a web stack and caches pages.  This caching layer is very configurable and can be used for both static and dynamic content.

One great thing about Varnish is that it can improve the performance of your website without requiring any code changes.  If you haven’t heard of Varnish (or have heard of it, but haven’t used it), please read on.  Adding Varnish to your stack can be completely noninvasive, but if you tweak your stack to play along with some of varnish’s more advanced features, you’ll be able to increase performance by orders of magnitude.

Some of the high profile companies using Varnish include: Twitter, Facebook, Heroku and LinkedIn.

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How Gravatar scales on WordPress.com hardware

Automattic recently purchase Gravatar and have switched the server onto their hosting platform. WordPress.com host over 1.7 million blogs with well over 60'000 new posts submitted each day generating 10 - 12 million page views per day. Barry on WordPress.com has a great post on the changes they've introduced to help Gravatar scale.

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