[atlas] More even earth distribution of measurement probes

Cool, will try it! I almost wrote my own tool already, but I didn't try 
to make even spatial distribution, it is obviously more difficult than 
by-country one.


--

With Best Regards,
Marat Khalili

On 10/03/17 14:56, Vesna Manojlovic wrote:
> Dear Marat,
>
> On 10/03/17 09:47, Marat Khalili wrote:
>> 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.
>
> There was a hackathon project that made this possible in some way, 
> called "Spatial Bucketing of RIPE Atlas Probes on Map Projection", by 
> Julian Hammer:
>
> "[he] wanted to solve the following problem: when scheduling 
> measurements from lots of probes, requesting a "random worldwide 
> selection" currently results in a choice that is very biased towards 
> Western/Northern Europe and the USA (see image without Sbucket on the 
> left).
>
> Julian's solution makes a more equal selection, by using the grid to 
> divide the globe and choose probes based on that division (see image 
> on the right after applying Sbucket)."
>
> Images: https://labs.ripe.net/Members/becha/ripe-atlas-hackathon-results
>
> Code: https://github.com/cod3monk/RIPE-Atlas-sbucket
>
> I hope you find this useful!
>
> Cheers,
> Vesna
>
>> However, looking at the map
>> <https://atlas.ripe.net/measurements/7861872/?filter=#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.
>>
>> -- 
>>
>> With Best Regards,
>> Marat Khalili