So it seems that @Addshore set up this job to pull and process dumps access logs. This was set up as part of T118739, puts logs on stat1007 at /srv/log/webrequest/archive/dumps.wikimedia.org, and is processed here.
We found this because @WDoranWMF would like some basic stats on dumps downloads. He will detail this here so we can know how to crunch the existing data.
After said crunching, we should set up a job to delete old logs in accordance with our retention policy. Thanks to @ArielGlenn for the data archeology.