The point of this exercise was not to get a global view of the pool system. It was to prove the point that if using the global pool name pool.ntp.org, a client still only gets allocated servers from the local country zone, maybe a bit beyond. But not really from the overall global pool. Precisely due to “how the pool DNS service accounts for the locale of the query source, as seen by the pool.ntp.org authoritative nameservers”, modulated by how/whether intermediate nameservers pass through a client’s locale to the authoritative nameservers.
I.e., if a country zone is under-served, using the global zone does not help/make much of a difference as compared to using the country zone. I.e., the load is not spread across servers beyond the country zone (at least not to the degree that has been claimed, e.g., earlier in this thread).
I.e., clients in a country may still get bad service due to too few servers in the zone, and if those are overloaded. And servers in a country may still get overloaded, even if all clients were using the global zone, because clients from the country still only get assigned to servers from the country zone, rather than servers being drawn from all servers available in the global zone. The latter is the target that Ask aims for with the changes he is mulling over, it is not yet reality.
Please note that the original finding was done as part of the paper and associated blog post referred to earlier. I was just giving my results as a practical hands-on example of the effect reported in the paper, encouraging people to try it for themselves if they don’t believe the finding, there is a simple, very illustrative Python script contained in the blog post. And/or read the full paper.
Only difference is, if I recall correctly, that for the paper, the nameservers for the pool were asked directly, while I was going through intermediaries. But the effect is essentially the same, except in the latter case, due to how some intermediaries operate, one may get slightly more servers. Or, if the intermediaries pass the source information through to the GeoDNS servers, one gets exactly the same servers as from the GeoDNS servers themselves.
My original point with this thread was to propose a mechanism that could help servers in under-served zones. And I was mentioning the limitation of the global zone only because the claim was made earlier in this thread that there were no such thing as an under-served zone, if only every client were to use the global zone.