Doing the right thing: Magento + Varnish Cache

Update January 13th, 2017: You can find an up-to-date article about how to use Magento 2 and Varnish 4.1 in the Varnish Software Web Developer Wiki: Step-by-step guide to making your Magento2 site fly. The wiki contains VCL snippet examples, tips and tricks for web developers using Magento and guides for other e-commerce and CMS systems as well.

Here is a series of posts highlighting Varnish Cache and its usage in the real world, solving real problems.

HTTP is the universal transport protocol and the only universally deployed API accross devices, clients, servers running all kind of operating systems. Varnish Cache being the HTTP "Swiss Army Knife" or the HTTP "Husqvarna Extreme Logging Chainsaw" if you will, can potentially be used to solve lots of different problems. At Varnish Software I am in contact on a daily basis with people using Varnish to do things we had not even thought of after all these years of making and providing services for the software. With Varnish you can compress, cut&paste, upgrade, secure, add performance and speed up your website's content delivery, and a whole lot of other things that I will blog about the coming months.

Today i will have a take on Magento, a fast growing Open Source E-commerce platform which is known for being flexible, but not so much for being fast. Enter:

Since my last post on this subject, many things have happened in the Magento world, with the main highlight being that Magento Inc was bought by Ebay, which was not really surprising as they made an investment in the company already in early 2010. Still, this means that the Magento Platform has a rather interesting future as a crucial piece for eBay's success (as are PayPal and X.Commerce). So without any further ado:

A 250x Faster Magento is possible!

This is what is up in the interwebs regarding Varnish and Magento! And I see two main trends:

• A lot of people doing great work with the Magento and Varnish Cache combo
• Lots of PHP code and VCL sauce lying around in blogs, presentations and different websites

As I will focus on the people doing great work in this post, I want first to give a piece of advice to those relying on random code and configuration files:

It is better to stand on the shoulders of giants, right?

Your (or your customer's) e-commerce site is the last possible place on the web where you should be testing random VCL snippets and unknown PHP code on. It is easy to write a how-to but it is hard to maintain it, specially as software develops and things change. People create and maintain software for a reason, so when doing performance related changes to your website, think twice! Be careful not to burn your revenue stream.

If you still want to go this road I have two choices for you:

Re-invent the wheel: Do-It-Yourself®

If you have time and no deadlines: DIY Magento+Varnish is the solution for you. Learning how to use Magento, understand HTTP Headers and get a hold of reverse proxy caching and Varnish Cache specifically will take you some time. For you I have one piece of advice: “There are only two hard things in Computer Science: cache invalidation and naming things.” quote originally from Philip Lewis Karlton. Good luck!

Use the interwebs and blogs

As I stated above: Unmaintained and outdated information applied wrongly is self-harming. Once that is said, there are lots of nice written blogs on how to architect and deploy a website running Magento and accelerate it with Varnish Cache. As usual, google is your friend here. Good luck to you too!

Let's stand on each other's shoulders!

Some people take pride in their job and take it serious. People that do so often achieve what is described as success. Putting your eggs in the right basket is what you have to do. Doing the right thing means choosing the right plugin for you! So, instead of doing things all by yourself, try and use someone else's software and help them make it better if you want. To the table I bring to you (in chronological order of development):

• Pagecache powered by Varnish - Phoenix Media
  • Description:
    This plug-in was made in the beginning of 2011. It is architecturally approved by Varnish Software as all Varnish related configurations and settings have been reviewed by the core team in close cooperation with Phoenix Media. The bundled VCL allows it to run in one or multi server environments with Magento and to purge Varnish’s cache either on demand or event based (e.g. when a product gets out of stock or a CMS page is changed) right from the Magento backend, which is pretty cool. Also, the PageCache module supports Magento design exceptions to cache different versions of the same shop page per device (think browser and iphone). Support for ESI coming in Q1 2012. Supports Varnish 2.1.x and 3.0.x
  • Pricing and Availability:
    Two editions: Free Community Edition & Enterprise edition for €1,000.- with additional advanced features and support. Works with Magento CE > 1.4 & PE, EE > 1.7
    Developed and supported by our Integration Partner and Magento Gold Partner Phoenix Media with a proven track record of making Magento extensions. Available on Magento Connect.
• Magneto-Varnish - Madalin Oprea
  • Description:
    Started in May 2011. It features a basic administration interface to add your server IP but no caching granularity or any additional control. Supports Varnish 2.1.x and additional 3.0.x support was added recently.
  • Pricing and Availability:
    Free. Not sure about which Magento editions and versions it supports.
    Maintained by Madalin Oprea and lives on Github.
• AOE Static - Fabrizio Branca
  • Description:
    Started in May 2011. It has some nice features as it makes caching just work. It is more like like a proof-of-concept but handles also session-users through nifty tricks (javascript and such). For real sites it has some drawbacks as no management interface is provided and thus no caching granularity to speak of here either, but it is a good start.
  • Pricing and Availability:
    Free. Works under Magento CE 1.5 & 1.6 and Magento EE 1.10 & 1.11. Might work in newer versions as well.
    Maintained by Fabrizio Branca and lives on Github.
• Cache Extension powered by Varnish - creativeStyle
  • Description:
    As far as I could see this module contains code from blog posts around the web. Although it aims high, it is not very sophisticated and lacks documentation. VCL editing in your browser without checking the configuration first could harm your installation badly. It has a forum of users where you can ask and probably get help.
  • Pricing and Availability:
    Free. Works on Magento Community edition only, not sure which versions it supports.
    Maintained by creativeStyle, company that as far as I could see has no record on any Magento extensions. Available on Magento Connect.

As you see there are many solutions you can use, have a look and decide for yourself. My pick: