Scenario
Block propagation and regional arrival lag.
The probe(s) subscribe with eth_subscribe(newHeads) and capture each block header arrival. Datasets from all regions are merged by number + hash to detect the leader and followers for each block.
Of the available 31 regions, 31 regions were selected for data collection: Oregon, N. California, Mexico, Columbus, OH, N. Virginia, Montreal, São Paulo, Ireland, Zaragoza, London, Paris, Frankfurt, Zurich, Milan, Stockholm, Cape Town, Tel Aviv, Dubai, Mumbai, Hyderabad, Bangkok, Kuala Lumpur, Singapore, Jakarta, Hong Kong, Taipei, Seoul, Osaka, Tokyo, Melbourne, and Sydney.
Each location probe breaks its processing loop if / when the endpoint response is too-many-requests, a.k.a. HTTP code 429 etc. Also, codes 401 and 403.
Coverage at render time: 62 of 62 endpoint-region datasets available from 31 selected regions x 2 endpoints.
Findings
Summary
Stats are aggregated from the dataset in the details table for blocks that were seen by every region.
Details
Block leading region-endpoint vs. every other arrival for the same block hash. Regional "wall clocks" are treated as globally synchronized.