[RSSAC Caucus] Research Paper - Optimal Selection of DNS Root Instance

[Joe Abley]

Op 8 sep. 2023 om 18:41 heeft Warren Kumari <warren at kumari.net> het volgende geschreven:

> Clearly this is wildly sub-optimal, but the failure here is not because of geography, the failure is that there are multiple networks in Fiji that **do not peer in Fiji**. 

Whether this is sub-optimal or a failure at all depends also on what you are optimising for.

In the case of a particular root server in a system when there are many, a system that is providing a service that most resolvers query only occasionally and usually not in the hot path for anything an end user is trying to do, it is reasonable to optimise for availability of the system as a whole rather than transaction latency for queries to any particular instance. 

As an extreme but not uncommon example, a resolver that keeps a local copy of the root zone and maintains its currency within the published SOA timers has very modest requirements of the root server system at all and probably doesn't consider a long trombone to get a response any kind of failure. 

In other examples where proximity is a clear advantage (like CDNs) the pressure from both supplier and consumer of services tends to mean that both ends have reasons to reduce transaction latency, and in those cases it's common to see the mismatch between topology and geography addressed in some way (at least when geography has a clear bearing on performance, as it does in your South Pacific example). The root server system is just not one of those examples. 


Joe