My solution, for the record: https://gist.github.com/qm2k/ea5f67fcf4e3dd2208ab3bc4ee233560

I'd like to check worldwide connectivity to my site. I create a new measurement via web-interface and add, say, 300 probes, expecting them to cover most world countries. However, looking at the map I notice that most are selected from Europe: there're two dozens in Netherlands (many with same ASNs), but only two in Australia, one in Japan and nothing in Brazil. Obviously, most ATLAS probes are from Europe, and selection algorithm does not take probe density into account.

Wouldn't it be nice to have the following features in web-interface and API:
* even distribution of probes by country or continent based on population, area, and other user-defined weight numbers;
* avoiding probes with same ASNs
?

I don't know how current algorithm works, but easiest modification would be two-step process: (1) randomly select country based on specified weights; (2) randomly select probe within country, avoiding earlier selected probes or ASNs and failing if none are left available; repeat from step 1 until necessary number of probes is selected.

P.S. I tried to manually request 1 probe from each country, but stumbled on unrecognised country codes, countries with no probes etc. before even trying population-weighted distribution. Without direct access to probes database nice solution can be difficult to achieve via current API, although crude one looks possible.

P.P.S. I understand this option will create more load on probes in less-covered countries, but since it's possible to limit selection to specific countries anyway this is hardly a strong argument against adding this feature.

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With Best Regards,
Marat Khalili