REST service with a long response time?

Question

Django

There are two services (first and second). The second service is an interface to the photo analyzer. The photo analyzer can work for a very long time.
The purpose of the second service is to process the photo and return the result.
The first sends a photo to the second, the second confirms receipt.
The first service will not receive the results yet, it will gouge to the second with readiness requests.
How on the second to organize processing in the background, from which it will be possible to find out the status?
Is it possible to do this: a separate thread is created in which the analysis takes place. Accordingly, this stream will have two states:
1. Processing in
progress 2. Free and ready to receive.
If you can do this, then what to read about?
If it's so bad, then why?
How to connect to a stream from Django + django-rest and get its status. If the topic with processes is bad, then what are the options? Preferably under django. The term is very limited, I know best I know django.
It is advisable not to use DB. If not, then you can PostgreSQL.

Answer 1

Google it: celery
1. You get a photo. You send to be executed in the background. You give job-id.
2. If you are asked how the job-id is doing, you answer.