2017/04/19 08:21:08 [error] 31740#0: *4973 upstream prematurely closed connection while reading response header from upstream, client: 31.131.106.200, server: stream.dev.softformance.com, request: "POST /facebook_app/sync_by_app HTTP/1.1", upstream: "http://unix:/webapps/django-social-project/run/gunicorn.sock:/facebook_app/sync_by_app", host: "stream.dev.softformance.com", referrer: "http://stream.dev.softformance.com/admin/django_facebook_photo_api/post/"