Getting the occasional 503 on GETting big files

[calpaterson]

Description

When requesting big files I get the occasional 503

Steps to reproduce

1. curl https://csvbase.com/ubieratlupa/monuments (with or without etags

Expected result

200s or 304s

Actual result

Sometimes, 503

Additional details

The suggestion here is that something is being loaded into memory that should not be, and perhaps that this is even happening on etag hits.