Part of the beauty of Varnish Cache is its flexibility. Most Varnish users are familiar with Varnish Configuration Language (VCL) and how it can be wielded like a weapon or deftly handled like a pen to create custom configurations.

While most Varnish users are aware of VCL, not all are able to use it to its full advantage. They do, often, have many ideas about how they would like to be able to use Varnish and with the help of Varnish Professional Services, companies have been able to reap the benefits of custom enhancements by tapping into Varnish engineering expertise.

Real-world implementation

MaxCDN (later acquired by StackPath), a major global CDN provider, needed specific VMOD (Varnish module) development. Turning directly to Varnish Software to create these custom modules allowed MaxCDN to unlock its maximum potential while saving time and expense.

Managing large volumes of traffic and thousands of websites, MaxCDN was already a Varnish Cache user, using it for its power and flexibility. When they needed to expand on Varnish Cache to be able to use it the way they needed to - again, for the power of Varnish Cache and the flexibility and extensible platform of VCL, they partnered up with Varnish Software and started using Varnish Plus and collaborating with Varnish Software’s internal engineers.

To maximize the benefit of Varnish Plus and its features, the project included custom development to the core products, which was done in the form of a few advanced VMODs as well as new feature development:

  • VMODs for managing large amounts of structured data inside of Varnish Cache Plus. This data would be frequently updated from an external source and it would need to scale to millions of rows of data.
  • AdvancedTLS/SSL support in Hitch. Varnish Software did custom work to support hundreds of thousands of concurrent SSL certificates in Hitch so it could support a large amount and ever-changing number SSL enabled websites, with no downtime.

The development project was fairly straightforward: MaxCDN provided a specification of their needs, Varnish engineers worked on the solution and delivered it. MaxCDN received the custom modifications they needed to make the most of Varnish Plus within their setup.