I want a sink operator to be the downstream for multiple upstream process function operators, however, I want the sink operator to be conscious of which upstream operator the data is coming from so it can add a special tag.
I don't want to include an extra field to indicate operator name in the upstream operators since that would incur a lot of extra repeated IO which doesn't seem optimal. Is there a way where the downstream sink can more directly access to check which upstream operator a certain event was flowing from?