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, 8 regions were selected for data collection: Ireland, Zaragoza, London, Paris, Frankfurt, Zurich, Milan, and Stockholm.
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: 16 of 16 endpoint-region datasets available from 8 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.