ArkDNS_

The challenge

One of our clients provides connectivity at serious scale — including to one of the largest music festivals in the UK. To protect their infrastructure and their customers they relied on a commercial DNS filtering service, and as usage grew, so did the bills. Licensing threatened to become one of their biggest running costs.

They asked us a straightforward question: could we build them their own?

The solution

ArkDNS is a cloud-based DNS service that filters domains and traffic by category, automatically detects malicious websites and bots, and enforces SafeSearch across Google, Bing and YouTube.

Administrators build rulesets from dozens of content categories, add their own whitelists and blacklists, and apply them per client. It can even block automatic system updates on Android, iOS and Windows devices — invaluable when you need to protect limited bandwidth on a busy festival site.

The technology

A DNS resolver sits in the critical path of everything its users do online, so the service had to be bullet-proof and scalable. ArkDNS runs on a global anycast network with regional load balancers and auto-scaling groups of servers. It is not tied to any single datacentre — if a region has connectivity problems, users are re-routed automatically to their next closest server.

The resolvers are written in Python and C for raw performance, with our usual web stack behind the management and configuration site. To prove the platform’s resilience we built our own version of Netflix’s Chaos Monkey, randomly killing production servers to make sure the service shrugs it off.

The outcome

ArkDNS now handles more than a billion DNS requests every day. It was built for less than the cost of a two-year licence with the market-leading alternative, carries no ongoing licence fees, and our client owns the product outright.

“Silverark were a joy to work with. Alex, the lead developer, was extremely helpful and had a holistic approach to implementing our solution, foreseeing potential issues that we hadn’t even considered.”

— Triston, client