It is not really true that DNS is for people only: it is used as an aliasing system, for load balancing, and for caching (with no cache invalidation mechanism other than ahead-of-time TTL setting). It is used to make entire protocols work (MX records for email, but SRV records are used for much more). Now, if we do look at the most basic of basic DNS roles — mapping a human readable name to arbitrary set of numbers i…
- note I was talking about internal infrastructure, not public services - DNS load balancing is not that important for internal services in most Cases? Would only use it if alternatives won’t work. - the virtual host issue is really adressed by /etc/hosts, I thought that was obvious, I now regret not explicitly adressing it.
In the other example (Amazon DynamoDB issue), the problem is with dynamically choosing from a large dynamic pool of IP addresses for a service — DNS is but one mechanism to do it. If it wasn't DNS, it could have been something else that did that job that was broken. Even /etc/hosts if it was updated with an empty record.
What I am saying is that your analysis is not defining the problem you want solved exactly, your examples are not backing up your proposal or analysis, and you are ignoring all the things DNS does both for public and private infrastructure. You seem to have some intuition about this adding complexity and thus being a risk (which is true), but you need to do a better job of connecting and analysing real risks and proposed solutions (and their comparative performance).