Fast DNS resolvers are a crucial component in delivering a snappy internet experience for end-customers. If the resolvers are down or under heavy load, even the best internet connection is useless for most customers.
In this talk I'll cover how to design and set up a scalable, highly available DNS resolver infrastructure for internet service providers.
- Anycast IPs using BGP for horizontal scaling and high-availability
- Health checks
- Scaling nodes vertically to optimize cache ratios
- Automation is key