The swh backend API clients (swh.storage.api.client and swh.obstorage.api.client) often fail with a BadStatusLine exception from deep in the bowels of urllib3.
This is especially significant under high loads (e.g. when rehashing millions of objects through the objstorage api).
Basically, there is a race condition between the client, which eagerly pipelines requests, and the server, which reaps children every few hundred thousand requests because of a memory leak (T757).
The HTTP implementation of the WSGI runners (gunicorn, uwsgi) is not supposed to be exposed to external clients; We should probably bite the bullet and front them with an actual reverse proxy such as nginx or apache (ugh).