What is Varnish? Wait a minute, what is HTTP while we’re at it? If you, like most of the world, are in the dark about HTTP, then let’s back up and explain. This is Hypertext Transfer Protocol, the basis for communication on the web. You are using it all the time without knowing it, but it could go faster; much faster. That’s where Varnish comes in, but not for technophobes or end users. This is developer technology.
You know what an accelerator is; there is a pedal in your car that makes the vehicle move faster if you press it. That’s what Varnish does. If you install this into any system using HTTP, it will cache information faster than normal by anything from 300 to 1,000 times.
By its very nature, this system only works with HTTP, but this is the major method of transferring data around the web. Varnish works with reverse proxy servers, meaning servers which capture information from a server or multiple servers but redirect them as if from the original source. A typical application of Varnish is before a Drupal Open Source site as a way to defend it from unauthorized readers.
What Is Drupal?
Drupal is considered the top content management system among companies around the world as well as universities and government agencies. This agile system is easy to scale, shares information in many languages, and is open to the developer community for ongoing improvement. Subscribers create websites using free tools then look for web hosting services to get their Drupal sites online.
Varnish: How Fast?
That’s right, you could be exchanging information as fast as 1,000 times your usual speed, but that’s bound by certain things. One of them is network speed. If your web host is relatively slow, Varnish will still make HTTP better, but not by 1,000 times. Another would be the size of information and what sort of info is being passed around.
Varnish is also really agile with the different sorts of programs it encounters. Special language called VCL lets the developer write protocol about content to deliver and accept. Modules extend Varnish too, so it will do more; much more.
Where Does Varnish Come from?
This is another of those free items created and disseminated to make the web more accessible to more people. It came out in 2005 and was named for something the creator of Varnish saw on a poster: a word which refers to a visual and textural smoothing of something to the point of appearing nicer than it is. A coat of varnish will create a shine on old furniture and suggests the exterior is smooth even when it’s rough. Varnish is not deceptive in the internet world, however. It really makes performance smoother.
More About Varnish
The system provides an invisible fastball that users confirm will really speed up even a slow system. While a site like Drupal is notoriously slow, with Varnish users will experience unbelievable speed. Varnish reads Drupal and accepts its commands automatically, but it does not have to be used exclusively with Drupal. That’s just a common application.
Alternatives to Varnish
There are other ways to speed up caching, but Varnish is user-friendly; easy to set up; and it’s free. Certain programs work with Varnish to fill in certain gaps, so it doesn’t have to be your exclusive Drupal accelerator.