insta_posts with user_id=0 in elasticsearch

[Urhengulas]

Description

At the moment we have 583652 insta_posts in our elasticsearch indexed, which have an user_id of 0.

You can see that in aggregations.user.buckets of the return of the request in kibana of this:

GET /insta_posts/_search
{"aggregations":{"user":{"terms":{"field":"user_id"}}}}

Some statistics regarding our postgres:

instascraper=> SELECT COUNT(*) FROM posts WHERE user_id is NULL;
 count  
--------
 724473
(1 row)

instascraper=> SELECT max(id) FROM posts WHERE user_id is NULL;
   max    
----------
 49919470
(1 row)

instascraper=> SELECT min(id) FROM posts WHERE user_id is NULL;
 min  
------
 9641
(1 row)

We guess that in some messages in kafka/postgres.public.posts have no user_id and thereby the indexer is using the zero value for that field which is 0.