... and readers benefit from improved response times On behalf of VG Multimedia, the publisher of Norway’s biggest online newspaper, we have worked with Danish developer Poul-Henning Kamp to produce a new web accelerator. A web accelerator is a system which relieves a web server in order to give users a better, faster browsing experience.
The accelerator caches the pages produced by the web server, so that they do not need to be reproduced for every reader. Instead, the pages are only updated when the content is changed, saving both processing power and time.
The idea behind Varnish was the brainchild of system administrator Anders Berg from VG Multimedia. With over 45 million page views every week – around half of these being for the front page – he saw the enormous potential for how a better web accelerator could both reduce the amount of hardware needed and provide readers with information more quickly.
“The software we were using for caching was designed for a different era and different technology,” says Anders. “VG has been using Open Source code since 1995.”
Approval in a matter of minutes
The next step was to find skilled partners to develop the idea into a solution.
“Two names quickly made their way to the top of the list: Redpill Linpro and Danish developer Poul-Henning Kamp.“ Both of them were excited by the idea. The anticipated savings in terms of hardware presented such strong arguments that the director of VG Multimedia approved the project in under 15 minutes.
He also allowed the completed solution to be made available free of charge to the international Open Source community, which VG Multimedia itself had benefited from on a number of occasions.
VG Multimedia was not tied to using support from a professional supplier, and we acted as a sparring partner during the concept and development process.
One computer instead of twelve
“Our aim was to run the VG network on a single computer instead of twelve.
“Varnish offers a huge potential saving in terms of hardware for many websites, particularly larger sites. Varnish also gives a dramatically improved response time for the site. This avoids the risk of the site being perceived as slower than its competitors.”
“Varnish caches the requested pages from the server, so the server avoids having to reproduce multiple impressions of the same page. This means that the next user can view the page without experiencing a delay.”
Varnish also features user-friendly functionality to determine which pages no longer need to be cached or shown. This is particularly important for online newspapers, which need to react quickly to breaking news.
A user-friendly rescue package
Essentially, Varnish could be positioned in front of a website with serious problems without having to configure anything, giving an immediate positive effect and resolving the crisis. The solution fits like a glove for such situations – like a mini rescue package.
“The code for Varnish can be downloaded, installed, amended and adapted on as many servers as you want – free of charge. The threshold for adapting Varnish to suit your own needs is relatively low.
“Those who run websites will have no problems doing so. And if you need professional services in connection with Varnish, Redpill Linpro can offer development, adaptation, operation and support,” adds Redpill Linpro senior consultant Stein Halvorsen, who has been involved in the project ever since Anders first contacted him with the idea back in 2005.
More about Varnish
Varnish was launched by us in September 2006, and is now used by hundreds of satisfied internet service providers and websites worldwide.
Varnish is particularly effective for dynamic websites with large volumes of content and traffic. In contrast to other web accelerators which were originally created as client proxies, Varnish was developed from scratch as a web accelerator.
Most websites display dynamic pages which consist of multiple elements. This takes time, and the CPU has to construct each page for every single user, even when the content is exactly the same. Varnish boosts efficiency by caching the most-read pages, thus improving the reader’s experience and reducing server load by up to 90 percent. Varnish was primarily developed for FreeBSD 6 and Linux 2.6, and optimises the use of these operating systems’ virtual memory and advanced I/O functions.
Varnish is based on Open Source code, is distributed under a BSD licence, and is relatively easy to install and adapt. We and others offer adaptation and development for requirements which are not covered by the existing version.