Otodom Price Stats: runs ended with "the sample is too thin" and delivered nothing

What happened

The same site change as the one above: Otodom.pl moved city and province out of the address block the search pages carry. This actor samples listings and groups them by city to compute a price per square metre per city. With the city empty on every listing, no city reached the minimum of five listings and the run stopped with "No city reached 5 listings with a price per m2 - the sample is too thin".

Our scheduled run on 5 October already returned 11 city rows where the days before had returned 28 to 37, the change being under way; on 6 October it returned nothing and failed.

Impact

Runs on 6 October failed and delivered nothing; a failed run bills only the actor start. Runs on 5 October delivered fewer city rows than the sample held. We do not see our customers' runs. If one of yours in that window came back short, open an issue on the actor's Issues tab with the run.

Root cause

As above: the grouping key came from a field the site stopped filling. Sampling itself kept working, so the run reached the grouping step with a full sample and no city to put it under.

Fix

Shipped 6 October (build 0.1.16), the same afternoon. The city comes from the geocoded list, matched by level. The scheduled run that followed returned 14 city rows from a smaller verification sample, and the next day's 38 city rows from 1,218 listings.

What changed so it cannot recur this way

The failure reached our failure channel and was escalated automatically within minutes of the scheduled run; the fix landed the same day. The fixture captured from the live page fails the build if the field goes empty again.

Questions about this incident? contact@lowlanddata.com - reports get read the same day.